6131 lines
184 KiB
C
6131 lines
184 KiB
C
/* Expands front end tree to back end RTL for GNU C-Compiler
|
||
Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc.
|
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|
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This file is part of GNU CC.
|
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|
||
GNU CC is free software; you can redistribute it and/or modify
|
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it under the terms of the GNU General Public License as published by
|
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the Free Software Foundation; either version 2, or (at your option)
|
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any later version.
|
||
|
||
GNU CC is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with GNU CC; see the file COPYING. If not, write to
|
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the Free Software Foundation, 59 Temple Place - Suite 330,
|
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Boston, MA 02111-1307, USA. */
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|
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|
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/* This file handles the generation of rtl code from tree structure
|
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above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
|
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It also creates the rtl expressions for parameters and auto variables
|
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and has full responsibility for allocating stack slots.
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|
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The functions whose names start with `expand_' are called by the
|
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parser to generate RTL instructions for various kinds of constructs.
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Some control and binding constructs require calling several such
|
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functions at different times. For example, a simple if-then
|
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is expanded by calling `expand_start_cond' (with the condition-expression
|
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as argument) before parsing the then-clause and calling `expand_end_cond'
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after parsing the then-clause. */
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#include "config.h"
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#include "system.h"
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#include "rtl.h"
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#include "tree.h"
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#include "flags.h"
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#include "except.h"
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#include "function.h"
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#include "insn-flags.h"
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#include "insn-config.h"
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#include "insn-codes.h"
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#include "expr.h"
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#include "hard-reg-set.h"
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#include "obstack.h"
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#include "loop.h"
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#include "recog.h"
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#include "machmode.h"
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#include "toplev.h"
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#include "output.h"
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#define obstack_chunk_alloc xmalloc
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#define obstack_chunk_free free
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struct obstack stmt_obstack;
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|
||
/* Assume that case vectors are not pc-relative. */
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#ifndef CASE_VECTOR_PC_RELATIVE
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#define CASE_VECTOR_PC_RELATIVE 0
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#endif
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/* Filename and line number of last line-number note,
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whether we actually emitted it or not. */
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char *emit_filename;
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int emit_lineno;
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||
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/* Nonzero if within a ({...}) grouping, in which case we must
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always compute a value for each expr-stmt in case it is the last one. */
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int expr_stmts_for_value;
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||
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/* Each time we expand an expression-statement,
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record the expr's type and its RTL value here. */
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static tree last_expr_type;
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static rtx last_expr_value;
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/* Each time we expand the end of a binding contour (in `expand_end_bindings')
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||
and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
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This is used by the `remember_end_note' function to record the endpoint
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||
of each generated block in its associated BLOCK node. */
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static rtx last_block_end_note;
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/* Number of binding contours started so far in this function. */
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int block_start_count;
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/* Functions and data structures for expanding case statements. */
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|
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/* Case label structure, used to hold info on labels within case
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statements. We handle "range" labels; for a single-value label
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as in C, the high and low limits are the same.
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An AVL tree of case nodes is initially created, and later transformed
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to a list linked via the RIGHT fields in the nodes. Nodes with
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higher case values are later in the list.
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Switch statements can be output in one of two forms. A branch table
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is used if there are more than a few labels and the labels are dense
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within the range between the smallest and largest case value. If a
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branch table is used, no further manipulations are done with the case
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node chain.
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The alternative to the use of a branch table is to generate a series
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of compare and jump insns. When that is done, we use the LEFT, RIGHT,
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and PARENT fields to hold a binary tree. Initially the tree is
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totally unbalanced, with everything on the right. We balance the tree
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with nodes on the left having lower case values than the parent
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and nodes on the right having higher values. We then output the tree
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in order. */
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struct case_node
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{
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struct case_node *left; /* Left son in binary tree */
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struct case_node *right; /* Right son in binary tree; also node chain */
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struct case_node *parent; /* Parent of node in binary tree */
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tree low; /* Lowest index value for this label */
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tree high; /* Highest index value for this label */
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tree code_label; /* Label to jump to when node matches */
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int balance;
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||
};
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typedef struct case_node case_node;
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typedef struct case_node *case_node_ptr;
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/* These are used by estimate_case_costs and balance_case_nodes. */
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/* This must be a signed type, and non-ANSI compilers lack signed char. */
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static short *cost_table;
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||
static int use_cost_table;
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||
|
||
/* Stack of control and binding constructs we are currently inside.
|
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|
||
These constructs begin when you call `expand_start_WHATEVER'
|
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and end when you call `expand_end_WHATEVER'. This stack records
|
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info about how the construct began that tells the end-function
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||
what to do. It also may provide information about the construct
|
||
to alter the behavior of other constructs within the body.
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||
For example, they may affect the behavior of C `break' and `continue'.
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||
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||
Each construct gets one `struct nesting' object.
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All of these objects are chained through the `all' field.
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`nesting_stack' points to the first object (innermost construct).
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||
The position of an entry on `nesting_stack' is in its `depth' field.
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||
|
||
Each type of construct has its own individual stack.
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||
For example, loops have `loop_stack'. Each object points to the
|
||
next object of the same type through the `next' field.
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||
|
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Some constructs are visible to `break' exit-statements and others
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are not. Which constructs are visible depends on the language.
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||
Therefore, the data structure allows each construct to be visible
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or not, according to the args given when the construct is started.
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The construct is visible if the `exit_label' field is non-null.
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In that case, the value should be a CODE_LABEL rtx. */
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struct nesting
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{
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struct nesting *all;
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struct nesting *next;
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int depth;
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rtx exit_label;
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union
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{
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/* For conds (if-then and if-then-else statements). */
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struct
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{
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/* Label for the end of the if construct.
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There is none if EXITFLAG was not set
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and no `else' has been seen yet. */
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rtx endif_label;
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/* Label for the end of this alternative.
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This may be the end of the if or the next else/elseif. */
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rtx next_label;
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} cond;
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/* For loops. */
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struct
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{
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/* Label at the top of the loop; place to loop back to. */
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rtx start_label;
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/* Label at the end of the whole construct. */
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rtx end_label;
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/* Label before a jump that branches to the end of the whole
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construct. This is where destructors go if any. */
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rtx alt_end_label;
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/* Label for `continue' statement to jump to;
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this is in front of the stepper of the loop. */
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rtx continue_label;
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} loop;
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/* For variable binding contours. */
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struct
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{
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/* Sequence number of this binding contour within the function,
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in order of entry. */
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int block_start_count;
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/* Nonzero => value to restore stack to on exit. */
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rtx stack_level;
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/* The NOTE that starts this contour.
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Used by expand_goto to check whether the destination
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is within each contour or not. */
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rtx first_insn;
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/* Innermost containing binding contour that has a stack level. */
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struct nesting *innermost_stack_block;
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/* List of cleanups to be run on exit from this contour.
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This is a list of expressions to be evaluated.
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The TREE_PURPOSE of each link is the ..._DECL node
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which the cleanup pertains to. */
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tree cleanups;
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/* List of cleanup-lists of blocks containing this block,
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as they were at the locus where this block appears.
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There is an element for each containing block,
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ordered innermost containing block first.
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The tail of this list can be 0,
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if all remaining elements would be empty lists.
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The element's TREE_VALUE is the cleanup-list of that block,
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which may be null. */
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tree outer_cleanups;
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/* Chain of labels defined inside this binding contour.
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For contours that have stack levels or cleanups. */
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struct label_chain *label_chain;
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/* Number of function calls seen, as of start of this block. */
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int function_call_count;
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/* Nonzero if this is associated with a EH region. */
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int exception_region;
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/* The saved target_temp_slot_level from our outer block.
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We may reset target_temp_slot_level to be the level of
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this block, if that is done, target_temp_slot_level
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reverts to the saved target_temp_slot_level at the very
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end of the block. */
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int target_temp_slot_level;
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/* True if we are currently emitting insns in an area of
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output code that is controlled by a conditional
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expression. This is used by the cleanup handling code to
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generate conditional cleanup actions. */
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int conditional_code;
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/* A place to move the start of the exception region for any
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of the conditional cleanups, must be at the end or after
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the start of the last unconditional cleanup, and before any
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conditional branch points. */
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rtx last_unconditional_cleanup;
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/* When in a conditional context, this is the specific
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cleanup list associated with last_unconditional_cleanup,
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where we place the conditionalized cleanups. */
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tree *cleanup_ptr;
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} block;
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/* For switch (C) or case (Pascal) statements,
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and also for dummies (see `expand_start_case_dummy'). */
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struct
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{
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/* The insn after which the case dispatch should finally
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be emitted. Zero for a dummy. */
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rtx start;
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/* A list of case labels; it is first built as an AVL tree.
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During expand_end_case, this is converted to a list, and may be
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rearranged into a nearly balanced binary tree. */
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struct case_node *case_list;
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/* Label to jump to if no case matches. */
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tree default_label;
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/* The expression to be dispatched on. */
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tree index_expr;
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/* Type that INDEX_EXPR should be converted to. */
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tree nominal_type;
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/* Number of range exprs in case statement. */
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int num_ranges;
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/* Name of this kind of statement, for warnings. */
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const char *printname;
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/* Used to save no_line_numbers till we see the first case label.
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We set this to -1 when we see the first case label in this
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case statement. */
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int line_number_status;
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||
} case_stmt;
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} data;
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};
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/* Chain of all pending binding contours. */
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struct nesting *block_stack;
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/* If any new stacks are added here, add them to POPSTACKS too. */
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/* Chain of all pending binding contours that restore stack levels
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or have cleanups. */
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struct nesting *stack_block_stack;
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/* Chain of all pending conditional statements. */
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struct nesting *cond_stack;
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/* Chain of all pending loops. */
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struct nesting *loop_stack;
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/* Chain of all pending case or switch statements. */
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struct nesting *case_stack;
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|
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/* Separate chain including all of the above,
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chained through the `all' field. */
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struct nesting *nesting_stack;
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||
/* Number of entries on nesting_stack now. */
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int nesting_depth;
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/* Allocate and return a new `struct nesting'. */
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#define ALLOC_NESTING() \
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(struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
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|
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/* Pop the nesting stack element by element until we pop off
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the element which is at the top of STACK.
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Update all the other stacks, popping off elements from them
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as we pop them from nesting_stack. */
|
||
|
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#define POPSTACK(STACK) \
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do { struct nesting *target = STACK; \
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struct nesting *this; \
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do { this = nesting_stack; \
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if (loop_stack == this) \
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loop_stack = loop_stack->next; \
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||
if (cond_stack == this) \
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cond_stack = cond_stack->next; \
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if (block_stack == this) \
|
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block_stack = block_stack->next; \
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if (stack_block_stack == this) \
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stack_block_stack = stack_block_stack->next; \
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if (case_stack == this) \
|
||
case_stack = case_stack->next; \
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||
nesting_depth = nesting_stack->depth - 1; \
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nesting_stack = this->all; \
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||
obstack_free (&stmt_obstack, this); } \
|
||
while (this != target); } while (0)
|
||
|
||
/* In some cases it is impossible to generate code for a forward goto
|
||
until the label definition is seen. This happens when it may be necessary
|
||
for the goto to reset the stack pointer: we don't yet know how to do that.
|
||
So expand_goto puts an entry on this fixup list.
|
||
Each time a binding contour that resets the stack is exited,
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||
we check each fixup.
|
||
If the target label has now been defined, we can insert the proper code. */
|
||
|
||
struct goto_fixup
|
||
{
|
||
/* Points to following fixup. */
|
||
struct goto_fixup *next;
|
||
/* Points to the insn before the jump insn.
|
||
If more code must be inserted, it goes after this insn. */
|
||
rtx before_jump;
|
||
/* The LABEL_DECL that this jump is jumping to, or 0
|
||
for break, continue or return. */
|
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tree target;
|
||
/* The BLOCK for the place where this goto was found. */
|
||
tree context;
|
||
/* The CODE_LABEL rtx that this is jumping to. */
|
||
rtx target_rtl;
|
||
/* Number of binding contours started in current function
|
||
before the label reference. */
|
||
int block_start_count;
|
||
/* The outermost stack level that should be restored for this jump.
|
||
Each time a binding contour that resets the stack is exited,
|
||
if the target label is *not* yet defined, this slot is updated. */
|
||
rtx stack_level;
|
||
/* List of lists of cleanup expressions to be run by this goto.
|
||
There is one element for each block that this goto is within.
|
||
The tail of this list can be 0,
|
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if all remaining elements would be empty.
|
||
The TREE_VALUE contains the cleanup list of that block as of the
|
||
time this goto was seen.
|
||
The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
|
||
tree cleanup_list_list;
|
||
};
|
||
|
||
static struct goto_fixup *goto_fixup_chain;
|
||
|
||
/* Within any binding contour that must restore a stack level,
|
||
all labels are recorded with a chain of these structures. */
|
||
|
||
struct label_chain
|
||
{
|
||
/* Points to following fixup. */
|
||
struct label_chain *next;
|
||
tree label;
|
||
};
|
||
|
||
|
||
/* Non-zero if we are using EH to handle cleanus. */
|
||
static int using_eh_for_cleanups_p = 0;
|
||
|
||
|
||
static int n_occurrences PROTO((int, const char *));
|
||
static void expand_goto_internal PROTO((tree, rtx, rtx));
|
||
static int expand_fixup PROTO((tree, rtx, rtx));
|
||
static rtx expand_nl_handler_label PROTO((rtx, rtx));
|
||
static void expand_nl_goto_receiver PROTO((void));
|
||
static void expand_nl_goto_receivers PROTO((struct nesting *));
|
||
static void fixup_gotos PROTO((struct nesting *, rtx, tree,
|
||
rtx, int));
|
||
static void expand_null_return_1 PROTO((rtx, int));
|
||
static void expand_value_return PROTO((rtx));
|
||
static int tail_recursion_args PROTO((tree, tree));
|
||
static void expand_cleanups PROTO((tree, tree, int, int));
|
||
static void check_seenlabel PROTO((void));
|
||
static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
|
||
static int estimate_case_costs PROTO((case_node_ptr));
|
||
static void group_case_nodes PROTO((case_node_ptr));
|
||
static void balance_case_nodes PROTO((case_node_ptr *,
|
||
case_node_ptr));
|
||
static int node_has_low_bound PROTO((case_node_ptr, tree));
|
||
static int node_has_high_bound PROTO((case_node_ptr, tree));
|
||
static int node_is_bounded PROTO((case_node_ptr, tree));
|
||
static void emit_jump_if_reachable PROTO((rtx));
|
||
static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
|
||
static int add_case_node PROTO((tree, tree, tree, tree *));
|
||
static struct case_node *case_tree2list PROTO((case_node *, case_node *));
|
||
|
||
void
|
||
using_eh_for_cleanups ()
|
||
{
|
||
using_eh_for_cleanups_p = 1;
|
||
}
|
||
|
||
void
|
||
init_stmt ()
|
||
{
|
||
gcc_obstack_init (&stmt_obstack);
|
||
init_eh ();
|
||
}
|
||
|
||
void
|
||
init_stmt_for_function ()
|
||
{
|
||
/* We are not currently within any block, conditional, loop or case. */
|
||
block_stack = 0;
|
||
stack_block_stack = 0;
|
||
loop_stack = 0;
|
||
case_stack = 0;
|
||
cond_stack = 0;
|
||
nesting_stack = 0;
|
||
nesting_depth = 0;
|
||
|
||
block_start_count = 0;
|
||
|
||
/* No gotos have been expanded yet. */
|
||
goto_fixup_chain = 0;
|
||
|
||
/* We are not processing a ({...}) grouping. */
|
||
expr_stmts_for_value = 0;
|
||
last_expr_type = 0;
|
||
|
||
init_eh_for_function ();
|
||
}
|
||
|
||
void
|
||
save_stmt_status (p)
|
||
struct function *p;
|
||
{
|
||
p->block_stack = block_stack;
|
||
p->stack_block_stack = stack_block_stack;
|
||
p->cond_stack = cond_stack;
|
||
p->loop_stack = loop_stack;
|
||
p->case_stack = case_stack;
|
||
p->nesting_stack = nesting_stack;
|
||
p->nesting_depth = nesting_depth;
|
||
p->block_start_count = block_start_count;
|
||
p->last_expr_type = last_expr_type;
|
||
p->last_expr_value = last_expr_value;
|
||
p->expr_stmts_for_value = expr_stmts_for_value;
|
||
p->emit_filename = emit_filename;
|
||
p->emit_lineno = emit_lineno;
|
||
p->goto_fixup_chain = goto_fixup_chain;
|
||
save_eh_status (p);
|
||
}
|
||
|
||
void
|
||
restore_stmt_status (p)
|
||
struct function *p;
|
||
{
|
||
block_stack = p->block_stack;
|
||
stack_block_stack = p->stack_block_stack;
|
||
cond_stack = p->cond_stack;
|
||
loop_stack = p->loop_stack;
|
||
case_stack = p->case_stack;
|
||
nesting_stack = p->nesting_stack;
|
||
nesting_depth = p->nesting_depth;
|
||
block_start_count = p->block_start_count;
|
||
last_expr_type = p->last_expr_type;
|
||
last_expr_value = p->last_expr_value;
|
||
expr_stmts_for_value = p->expr_stmts_for_value;
|
||
emit_filename = p->emit_filename;
|
||
emit_lineno = p->emit_lineno;
|
||
goto_fixup_chain = p->goto_fixup_chain;
|
||
restore_eh_status (p);
|
||
}
|
||
|
||
/* Emit a no-op instruction. */
|
||
|
||
void
|
||
emit_nop ()
|
||
{
|
||
rtx last_insn;
|
||
|
||
last_insn = get_last_insn ();
|
||
if (!optimize
|
||
&& (GET_CODE (last_insn) == CODE_LABEL
|
||
|| (GET_CODE (last_insn) == NOTE
|
||
&& prev_real_insn (last_insn) == 0)))
|
||
emit_insn (gen_nop ());
|
||
}
|
||
|
||
/* Return the rtx-label that corresponds to a LABEL_DECL,
|
||
creating it if necessary. */
|
||
|
||
rtx
|
||
label_rtx (label)
|
||
tree label;
|
||
{
|
||
if (TREE_CODE (label) != LABEL_DECL)
|
||
abort ();
|
||
|
||
if (DECL_RTL (label))
|
||
return DECL_RTL (label);
|
||
|
||
return DECL_RTL (label) = gen_label_rtx ();
|
||
}
|
||
|
||
/* Add an unconditional jump to LABEL as the next sequential instruction. */
|
||
|
||
void
|
||
emit_jump (label)
|
||
rtx label;
|
||
{
|
||
do_pending_stack_adjust ();
|
||
emit_jump_insn (gen_jump (label));
|
||
emit_barrier ();
|
||
}
|
||
|
||
/* Emit code to jump to the address
|
||
specified by the pointer expression EXP. */
|
||
|
||
void
|
||
expand_computed_goto (exp)
|
||
tree exp;
|
||
{
|
||
rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
|
||
|
||
#ifdef POINTERS_EXTEND_UNSIGNED
|
||
x = convert_memory_address (Pmode, x);
|
||
#endif
|
||
|
||
emit_queue ();
|
||
/* Be sure the function is executable. */
|
||
if (current_function_check_memory_usage)
|
||
emit_library_call (chkr_check_exec_libfunc, 1,
|
||
VOIDmode, 1, x, ptr_mode);
|
||
|
||
do_pending_stack_adjust ();
|
||
emit_indirect_jump (x);
|
||
|
||
current_function_has_computed_jump = 1;
|
||
}
|
||
|
||
/* Handle goto statements and the labels that they can go to. */
|
||
|
||
/* Specify the location in the RTL code of a label LABEL,
|
||
which is a LABEL_DECL tree node.
|
||
|
||
This is used for the kind of label that the user can jump to with a
|
||
goto statement, and for alternatives of a switch or case statement.
|
||
RTL labels generated for loops and conditionals don't go through here;
|
||
they are generated directly at the RTL level, by other functions below.
|
||
|
||
Note that this has nothing to do with defining label *names*.
|
||
Languages vary in how they do that and what that even means. */
|
||
|
||
void
|
||
expand_label (label)
|
||
tree label;
|
||
{
|
||
struct label_chain *p;
|
||
|
||
do_pending_stack_adjust ();
|
||
emit_label (label_rtx (label));
|
||
if (DECL_NAME (label))
|
||
LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
|
||
|
||
if (stack_block_stack != 0)
|
||
{
|
||
p = (struct label_chain *) oballoc (sizeof (struct label_chain));
|
||
p->next = stack_block_stack->data.block.label_chain;
|
||
stack_block_stack->data.block.label_chain = p;
|
||
p->label = label;
|
||
}
|
||
}
|
||
|
||
/* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
|
||
from nested functions. */
|
||
|
||
void
|
||
declare_nonlocal_label (label)
|
||
tree label;
|
||
{
|
||
rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
|
||
|
||
nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
|
||
LABEL_PRESERVE_P (label_rtx (label)) = 1;
|
||
if (nonlocal_goto_handler_slots == 0)
|
||
{
|
||
emit_stack_save (SAVE_NONLOCAL,
|
||
&nonlocal_goto_stack_level,
|
||
PREV_INSN (tail_recursion_reentry));
|
||
}
|
||
nonlocal_goto_handler_slots
|
||
= gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
|
||
}
|
||
|
||
/* Generate RTL code for a `goto' statement with target label LABEL.
|
||
LABEL should be a LABEL_DECL tree node that was or will later be
|
||
defined with `expand_label'. */
|
||
|
||
void
|
||
expand_goto (label)
|
||
tree label;
|
||
{
|
||
tree context;
|
||
|
||
/* Check for a nonlocal goto to a containing function. */
|
||
context = decl_function_context (label);
|
||
if (context != 0 && context != current_function_decl)
|
||
{
|
||
struct function *p = find_function_data (context);
|
||
rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
|
||
rtx temp, handler_slot;
|
||
tree link;
|
||
|
||
/* Find the corresponding handler slot for this label. */
|
||
handler_slot = p->nonlocal_goto_handler_slots;
|
||
for (link = p->nonlocal_labels; TREE_VALUE (link) != label;
|
||
link = TREE_CHAIN (link))
|
||
handler_slot = XEXP (handler_slot, 1);
|
||
handler_slot = XEXP (handler_slot, 0);
|
||
|
||
p->has_nonlocal_label = 1;
|
||
current_function_has_nonlocal_goto = 1;
|
||
LABEL_REF_NONLOCAL_P (label_ref) = 1;
|
||
|
||
/* Copy the rtl for the slots so that they won't be shared in
|
||
case the virtual stack vars register gets instantiated differently
|
||
in the parent than in the child. */
|
||
|
||
#if HAVE_nonlocal_goto
|
||
if (HAVE_nonlocal_goto)
|
||
emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
|
||
copy_rtx (handler_slot),
|
||
copy_rtx (p->nonlocal_goto_stack_level),
|
||
label_ref));
|
||
else
|
||
#endif
|
||
{
|
||
rtx addr;
|
||
|
||
/* Restore frame pointer for containing function.
|
||
This sets the actual hard register used for the frame pointer
|
||
to the location of the function's incoming static chain info.
|
||
The non-local goto handler will then adjust it to contain the
|
||
proper value and reload the argument pointer, if needed. */
|
||
emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
|
||
|
||
/* We have now loaded the frame pointer hardware register with
|
||
the address of that corresponds to the start of the virtual
|
||
stack vars. So replace virtual_stack_vars_rtx in all
|
||
addresses we use with stack_pointer_rtx. */
|
||
|
||
/* Get addr of containing function's current nonlocal goto handler,
|
||
which will do any cleanups and then jump to the label. */
|
||
addr = copy_rtx (handler_slot);
|
||
temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
|
||
hard_frame_pointer_rtx));
|
||
|
||
/* Restore the stack pointer. Note this uses fp just restored. */
|
||
addr = p->nonlocal_goto_stack_level;
|
||
if (addr)
|
||
addr = replace_rtx (copy_rtx (addr),
|
||
virtual_stack_vars_rtx,
|
||
hard_frame_pointer_rtx);
|
||
|
||
emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
|
||
|
||
/* USE of hard_frame_pointer_rtx added for consistency; not clear if
|
||
really needed. */
|
||
emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
|
||
emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
|
||
emit_indirect_jump (temp);
|
||
}
|
||
}
|
||
else
|
||
expand_goto_internal (label, label_rtx (label), NULL_RTX);
|
||
}
|
||
|
||
/* Generate RTL code for a `goto' statement with target label BODY.
|
||
LABEL should be a LABEL_REF.
|
||
LAST_INSN, if non-0, is the rtx we should consider as the last
|
||
insn emitted (for the purposes of cleaning up a return). */
|
||
|
||
static void
|
||
expand_goto_internal (body, label, last_insn)
|
||
tree body;
|
||
rtx label;
|
||
rtx last_insn;
|
||
{
|
||
struct nesting *block;
|
||
rtx stack_level = 0;
|
||
|
||
if (GET_CODE (label) != CODE_LABEL)
|
||
abort ();
|
||
|
||
/* If label has already been defined, we can tell now
|
||
whether and how we must alter the stack level. */
|
||
|
||
if (PREV_INSN (label) != 0)
|
||
{
|
||
/* Find the innermost pending block that contains the label.
|
||
(Check containment by comparing insn-uids.)
|
||
Then restore the outermost stack level within that block,
|
||
and do cleanups of all blocks contained in it. */
|
||
for (block = block_stack; block; block = block->next)
|
||
{
|
||
if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
|
||
break;
|
||
if (block->data.block.stack_level != 0)
|
||
stack_level = block->data.block.stack_level;
|
||
/* Execute the cleanups for blocks we are exiting. */
|
||
if (block->data.block.cleanups != 0)
|
||
{
|
||
expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
|
||
do_pending_stack_adjust ();
|
||
}
|
||
}
|
||
|
||
if (stack_level)
|
||
{
|
||
/* Ensure stack adjust isn't done by emit_jump, as this
|
||
would clobber the stack pointer. This one should be
|
||
deleted as dead by flow. */
|
||
clear_pending_stack_adjust ();
|
||
do_pending_stack_adjust ();
|
||
emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
|
||
}
|
||
|
||
if (body != 0 && DECL_TOO_LATE (body))
|
||
error ("jump to `%s' invalidly jumps into binding contour",
|
||
IDENTIFIER_POINTER (DECL_NAME (body)));
|
||
}
|
||
/* Label not yet defined: may need to put this goto
|
||
on the fixup list. */
|
||
else if (! expand_fixup (body, label, last_insn))
|
||
{
|
||
/* No fixup needed. Record that the label is the target
|
||
of at least one goto that has no fixup. */
|
||
if (body != 0)
|
||
TREE_ADDRESSABLE (body) = 1;
|
||
}
|
||
|
||
emit_jump (label);
|
||
}
|
||
|
||
/* Generate if necessary a fixup for a goto
|
||
whose target label in tree structure (if any) is TREE_LABEL
|
||
and whose target in rtl is RTL_LABEL.
|
||
|
||
If LAST_INSN is nonzero, we pretend that the jump appears
|
||
after insn LAST_INSN instead of at the current point in the insn stream.
|
||
|
||
The fixup will be used later to insert insns just before the goto.
|
||
Those insns will restore the stack level as appropriate for the
|
||
target label, and will (in the case of C++) also invoke any object
|
||
destructors which have to be invoked when we exit the scopes which
|
||
are exited by the goto.
|
||
|
||
Value is nonzero if a fixup is made. */
|
||
|
||
static int
|
||
expand_fixup (tree_label, rtl_label, last_insn)
|
||
tree tree_label;
|
||
rtx rtl_label;
|
||
rtx last_insn;
|
||
{
|
||
struct nesting *block, *end_block;
|
||
|
||
/* See if we can recognize which block the label will be output in.
|
||
This is possible in some very common cases.
|
||
If we succeed, set END_BLOCK to that block.
|
||
Otherwise, set it to 0. */
|
||
|
||
if (cond_stack
|
||
&& (rtl_label == cond_stack->data.cond.endif_label
|
||
|| rtl_label == cond_stack->data.cond.next_label))
|
||
end_block = cond_stack;
|
||
/* If we are in a loop, recognize certain labels which
|
||
are likely targets. This reduces the number of fixups
|
||
we need to create. */
|
||
else if (loop_stack
|
||
&& (rtl_label == loop_stack->data.loop.start_label
|
||
|| rtl_label == loop_stack->data.loop.end_label
|
||
|| rtl_label == loop_stack->data.loop.continue_label))
|
||
end_block = loop_stack;
|
||
else
|
||
end_block = 0;
|
||
|
||
/* Now set END_BLOCK to the binding level to which we will return. */
|
||
|
||
if (end_block)
|
||
{
|
||
struct nesting *next_block = end_block->all;
|
||
block = block_stack;
|
||
|
||
/* First see if the END_BLOCK is inside the innermost binding level.
|
||
If so, then no cleanups or stack levels are relevant. */
|
||
while (next_block && next_block != block)
|
||
next_block = next_block->all;
|
||
|
||
if (next_block)
|
||
return 0;
|
||
|
||
/* Otherwise, set END_BLOCK to the innermost binding level
|
||
which is outside the relevant control-structure nesting. */
|
||
next_block = block_stack->next;
|
||
for (block = block_stack; block != end_block; block = block->all)
|
||
if (block == next_block)
|
||
next_block = next_block->next;
|
||
end_block = next_block;
|
||
}
|
||
|
||
/* Does any containing block have a stack level or cleanups?
|
||
If not, no fixup is needed, and that is the normal case
|
||
(the only case, for standard C). */
|
||
for (block = block_stack; block != end_block; block = block->next)
|
||
if (block->data.block.stack_level != 0
|
||
|| block->data.block.cleanups != 0)
|
||
break;
|
||
|
||
if (block != end_block)
|
||
{
|
||
/* Ok, a fixup is needed. Add a fixup to the list of such. */
|
||
struct goto_fixup *fixup
|
||
= (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
|
||
/* In case an old stack level is restored, make sure that comes
|
||
after any pending stack adjust. */
|
||
/* ?? If the fixup isn't to come at the present position,
|
||
doing the stack adjust here isn't useful. Doing it with our
|
||
settings at that location isn't useful either. Let's hope
|
||
someone does it! */
|
||
if (last_insn == 0)
|
||
do_pending_stack_adjust ();
|
||
fixup->target = tree_label;
|
||
fixup->target_rtl = rtl_label;
|
||
|
||
/* Create a BLOCK node and a corresponding matched set of
|
||
NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
|
||
this point. The notes will encapsulate any and all fixup
|
||
code which we might later insert at this point in the insn
|
||
stream. Also, the BLOCK node will be the parent (i.e. the
|
||
`SUPERBLOCK') of any other BLOCK nodes which we might create
|
||
later on when we are expanding the fixup code.
|
||
|
||
Note that optimization passes (including expand_end_loop)
|
||
might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
|
||
as a placeholder. */
|
||
|
||
{
|
||
register rtx original_before_jump
|
||
= last_insn ? last_insn : get_last_insn ();
|
||
rtx start;
|
||
|
||
start_sequence ();
|
||
pushlevel (0);
|
||
start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
|
||
fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
|
||
last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
|
||
fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
|
||
end_sequence ();
|
||
emit_insns_after (start, original_before_jump);
|
||
}
|
||
|
||
fixup->block_start_count = block_start_count;
|
||
fixup->stack_level = 0;
|
||
fixup->cleanup_list_list
|
||
= ((block->data.block.outer_cleanups
|
||
|| block->data.block.cleanups)
|
||
? tree_cons (NULL_TREE, block->data.block.cleanups,
|
||
block->data.block.outer_cleanups)
|
||
: 0);
|
||
fixup->next = goto_fixup_chain;
|
||
goto_fixup_chain = fixup;
|
||
}
|
||
|
||
return block != 0;
|
||
}
|
||
|
||
|
||
|
||
/* Expand any needed fixups in the outputmost binding level of the
|
||
function. FIRST_INSN is the first insn in the function. */
|
||
|
||
void
|
||
expand_fixups (first_insn)
|
||
rtx first_insn;
|
||
{
|
||
fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
|
||
}
|
||
|
||
/* When exiting a binding contour, process all pending gotos requiring fixups.
|
||
THISBLOCK is the structure that describes the block being exited.
|
||
STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
|
||
CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
|
||
FIRST_INSN is the insn that began this contour.
|
||
|
||
Gotos that jump out of this contour must restore the
|
||
stack level and do the cleanups before actually jumping.
|
||
|
||
DONT_JUMP_IN nonzero means report error there is a jump into this
|
||
contour from before the beginning of the contour.
|
||
This is also done if STACK_LEVEL is nonzero. */
|
||
|
||
static void
|
||
fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
|
||
struct nesting *thisblock;
|
||
rtx stack_level;
|
||
tree cleanup_list;
|
||
rtx first_insn;
|
||
int dont_jump_in;
|
||
{
|
||
register struct goto_fixup *f, *prev;
|
||
|
||
/* F is the fixup we are considering; PREV is the previous one. */
|
||
/* We run this loop in two passes so that cleanups of exited blocks
|
||
are run first, and blocks that are exited are marked so
|
||
afterwards. */
|
||
|
||
for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
|
||
{
|
||
/* Test for a fixup that is inactive because it is already handled. */
|
||
if (f->before_jump == 0)
|
||
{
|
||
/* Delete inactive fixup from the chain, if that is easy to do. */
|
||
if (prev != 0)
|
||
prev->next = f->next;
|
||
}
|
||
/* Has this fixup's target label been defined?
|
||
If so, we can finalize it. */
|
||
else if (PREV_INSN (f->target_rtl) != 0)
|
||
{
|
||
register rtx cleanup_insns;
|
||
|
||
/* Get the first non-label after the label
|
||
this goto jumps to. If that's before this scope begins,
|
||
we don't have a jump into the scope. */
|
||
rtx after_label = f->target_rtl;
|
||
while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
|
||
after_label = NEXT_INSN (after_label);
|
||
|
||
/* If this fixup jumped into this contour from before the beginning
|
||
of this contour, report an error. */
|
||
/* ??? Bug: this does not detect jumping in through intermediate
|
||
blocks that have stack levels or cleanups.
|
||
It detects only a problem with the innermost block
|
||
around the label. */
|
||
if (f->target != 0
|
||
&& (dont_jump_in || stack_level || cleanup_list)
|
||
/* If AFTER_LABEL is 0, it means the jump goes to the end
|
||
of the rtl, which means it jumps into this scope. */
|
||
&& (after_label == 0
|
||
|| INSN_UID (first_insn) < INSN_UID (after_label))
|
||
&& INSN_UID (first_insn) > INSN_UID (f->before_jump)
|
||
&& ! DECL_ERROR_ISSUED (f->target))
|
||
{
|
||
error_with_decl (f->target,
|
||
"label `%s' used before containing binding contour");
|
||
/* Prevent multiple errors for one label. */
|
||
DECL_ERROR_ISSUED (f->target) = 1;
|
||
}
|
||
|
||
/* We will expand the cleanups into a sequence of their own and
|
||
then later on we will attach this new sequence to the insn
|
||
stream just ahead of the actual jump insn. */
|
||
|
||
start_sequence ();
|
||
|
||
/* Temporarily restore the lexical context where we will
|
||
logically be inserting the fixup code. We do this for the
|
||
sake of getting the debugging information right. */
|
||
|
||
pushlevel (0);
|
||
set_block (f->context);
|
||
|
||
/* Expand the cleanups for blocks this jump exits. */
|
||
if (f->cleanup_list_list)
|
||
{
|
||
tree lists;
|
||
for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
|
||
/* Marked elements correspond to blocks that have been closed.
|
||
Do their cleanups. */
|
||
if (TREE_ADDRESSABLE (lists)
|
||
&& TREE_VALUE (lists) != 0)
|
||
{
|
||
expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
|
||
/* Pop any pushes done in the cleanups,
|
||
in case function is about to return. */
|
||
do_pending_stack_adjust ();
|
||
}
|
||
}
|
||
|
||
/* Restore stack level for the biggest contour that this
|
||
jump jumps out of. */
|
||
if (f->stack_level)
|
||
emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
|
||
|
||
/* Finish up the sequence containing the insns which implement the
|
||
necessary cleanups, and then attach that whole sequence to the
|
||
insn stream just ahead of the actual jump insn. Attaching it
|
||
at that point insures that any cleanups which are in fact
|
||
implicit C++ object destructions (which must be executed upon
|
||
leaving the block) appear (to the debugger) to be taking place
|
||
in an area of the generated code where the object(s) being
|
||
destructed are still "in scope". */
|
||
|
||
cleanup_insns = get_insns ();
|
||
poplevel (1, 0, 0);
|
||
|
||
end_sequence ();
|
||
emit_insns_after (cleanup_insns, f->before_jump);
|
||
|
||
|
||
f->before_jump = 0;
|
||
}
|
||
}
|
||
|
||
/* For any still-undefined labels, do the cleanups for this block now.
|
||
We must do this now since items in the cleanup list may go out
|
||
of scope when the block ends. */
|
||
for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
|
||
if (f->before_jump != 0
|
||
&& PREV_INSN (f->target_rtl) == 0
|
||
/* Label has still not appeared. If we are exiting a block with
|
||
a stack level to restore, that started before the fixup,
|
||
mark this stack level as needing restoration
|
||
when the fixup is later finalized. */
|
||
&& thisblock != 0
|
||
/* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
|
||
means the label is undefined. That's erroneous, but possible. */
|
||
&& (thisblock->data.block.block_start_count
|
||
<= f->block_start_count))
|
||
{
|
||
tree lists = f->cleanup_list_list;
|
||
rtx cleanup_insns;
|
||
|
||
for (; lists; lists = TREE_CHAIN (lists))
|
||
/* If the following elt. corresponds to our containing block
|
||
then the elt. must be for this block. */
|
||
if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
|
||
{
|
||
start_sequence ();
|
||
pushlevel (0);
|
||
set_block (f->context);
|
||
expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
|
||
do_pending_stack_adjust ();
|
||
cleanup_insns = get_insns ();
|
||
poplevel (1, 0, 0);
|
||
end_sequence ();
|
||
if (cleanup_insns != 0)
|
||
f->before_jump
|
||
= emit_insns_after (cleanup_insns, f->before_jump);
|
||
|
||
f->cleanup_list_list = TREE_CHAIN (lists);
|
||
}
|
||
|
||
if (stack_level)
|
||
f->stack_level = stack_level;
|
||
}
|
||
}
|
||
|
||
/* Return the number of times character C occurs in string S. */
|
||
static int
|
||
n_occurrences (c, s)
|
||
int c;
|
||
const char *s;
|
||
{
|
||
int n = 0;
|
||
while (*s)
|
||
n += (*s++ == c);
|
||
return n;
|
||
}
|
||
|
||
/* Generate RTL for an asm statement (explicit assembler code).
|
||
BODY is a STRING_CST node containing the assembler code text,
|
||
or an ADDR_EXPR containing a STRING_CST. */
|
||
|
||
void
|
||
expand_asm (body)
|
||
tree body;
|
||
{
|
||
if (current_function_check_memory_usage)
|
||
{
|
||
error ("`asm' cannot be used with `-fcheck-memory-usage'");
|
||
return;
|
||
}
|
||
|
||
if (TREE_CODE (body) == ADDR_EXPR)
|
||
body = TREE_OPERAND (body, 0);
|
||
|
||
emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
|
||
TREE_STRING_POINTER (body)));
|
||
last_expr_type = 0;
|
||
}
|
||
|
||
/* Generate RTL for an asm statement with arguments.
|
||
STRING is the instruction template.
|
||
OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
|
||
Each output or input has an expression in the TREE_VALUE and
|
||
a constraint-string in the TREE_PURPOSE.
|
||
CLOBBERS is a list of STRING_CST nodes each naming a hard register
|
||
that is clobbered by this insn.
|
||
|
||
Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
|
||
Some elements of OUTPUTS may be replaced with trees representing temporary
|
||
values. The caller should copy those temporary values to the originally
|
||
specified lvalues.
|
||
|
||
VOL nonzero means the insn is volatile; don't optimize it. */
|
||
|
||
void
|
||
expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
|
||
tree string, outputs, inputs, clobbers;
|
||
int vol;
|
||
char *filename;
|
||
int line;
|
||
{
|
||
rtvec argvec, constraints;
|
||
rtx body;
|
||
int ninputs = list_length (inputs);
|
||
int noutputs = list_length (outputs);
|
||
int ninout = 0;
|
||
int nclobbers;
|
||
tree tail;
|
||
register int i;
|
||
/* Vector of RTX's of evaluated output operands. */
|
||
rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
|
||
int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
|
||
rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
|
||
enum machine_mode *inout_mode
|
||
= (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
|
||
/* The insn we have emitted. */
|
||
rtx insn;
|
||
|
||
/* An ASM with no outputs needs to be treated as volatile, for now. */
|
||
if (noutputs == 0)
|
||
vol = 1;
|
||
|
||
if (current_function_check_memory_usage)
|
||
{
|
||
error ("`asm' cannot be used with `-fcheck-memory-usage'");
|
||
return;
|
||
}
|
||
|
||
/* Count the number of meaningful clobbered registers, ignoring what
|
||
we would ignore later. */
|
||
nclobbers = 0;
|
||
for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
|
||
{
|
||
char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
|
||
i = decode_reg_name (regname);
|
||
if (i >= 0 || i == -4)
|
||
++nclobbers;
|
||
else if (i == -2)
|
||
error ("unknown register name `%s' in `asm'", regname);
|
||
}
|
||
|
||
last_expr_type = 0;
|
||
|
||
/* Check that the number of alternatives is constant across all
|
||
operands. */
|
||
if (outputs || inputs)
|
||
{
|
||
tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
|
||
int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
|
||
tree next = inputs;
|
||
|
||
if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
|
||
{
|
||
error ("too many alternatives in `asm'");
|
||
return;
|
||
}
|
||
|
||
tmp = outputs;
|
||
while (tmp)
|
||
{
|
||
char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
|
||
if (n_occurrences (',', constraint) != nalternatives)
|
||
{
|
||
error ("operand constraints for `asm' differ in number of alternatives");
|
||
return;
|
||
}
|
||
if (TREE_CHAIN (tmp))
|
||
tmp = TREE_CHAIN (tmp);
|
||
else
|
||
tmp = next, next = 0;
|
||
}
|
||
}
|
||
|
||
for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
|
||
{
|
||
tree val = TREE_VALUE (tail);
|
||
tree type = TREE_TYPE (val);
|
||
char *constraint;
|
||
char *p;
|
||
int c_len;
|
||
int j;
|
||
int is_inout = 0;
|
||
int allows_reg = 0;
|
||
int allows_mem = 0;
|
||
|
||
/* If there's an erroneous arg, emit no insn. */
|
||
if (TREE_TYPE (val) == error_mark_node)
|
||
return;
|
||
|
||
/* Make sure constraint has `=' and does not have `+'. Also, see
|
||
if it allows any register. Be liberal on the latter test, since
|
||
the worst that happens if we get it wrong is we issue an error
|
||
message. */
|
||
|
||
c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
|
||
constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
|
||
|
||
/* Allow the `=' or `+' to not be at the beginning of the string,
|
||
since it wasn't explicitly documented that way, and there is a
|
||
large body of code that puts it last. Swap the character to
|
||
the front, so as not to uglify any place else. */
|
||
switch (c_len)
|
||
{
|
||
default:
|
||
if ((p = strchr (constraint, '=')) != NULL)
|
||
break;
|
||
if ((p = strchr (constraint, '+')) != NULL)
|
||
break;
|
||
case 0:
|
||
error ("output operand constraint lacks `='");
|
||
return;
|
||
}
|
||
|
||
if (p != constraint)
|
||
{
|
||
j = *p;
|
||
bcopy (constraint, constraint+1, p-constraint);
|
||
*constraint = j;
|
||
|
||
warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
|
||
}
|
||
|
||
is_inout = constraint[0] == '+';
|
||
/* Replace '+' with '='. */
|
||
constraint[0] = '=';
|
||
/* Make sure we can specify the matching operand. */
|
||
if (is_inout && i > 9)
|
||
{
|
||
error ("output operand constraint %d contains `+'", i);
|
||
return;
|
||
}
|
||
|
||
for (j = 1; j < c_len; j++)
|
||
switch (constraint[j])
|
||
{
|
||
case '+':
|
||
case '=':
|
||
error ("operand constraint contains '+' or '=' at illegal position.");
|
||
return;
|
||
|
||
case '%':
|
||
if (i + 1 == ninputs + noutputs)
|
||
{
|
||
error ("`%%' constraint used with last operand");
|
||
return;
|
||
}
|
||
break;
|
||
|
||
case '?': case '!': case '*': case '&':
|
||
case 'E': case 'F': case 'G': case 'H':
|
||
case 's': case 'i': case 'n':
|
||
case 'I': case 'J': case 'K': case 'L': case 'M':
|
||
case 'N': case 'O': case 'P': case ',':
|
||
#ifdef EXTRA_CONSTRAINT
|
||
case 'Q': case 'R': case 'S': case 'T': case 'U':
|
||
#endif
|
||
break;
|
||
|
||
case '0': case '1': case '2': case '3': case '4':
|
||
case '5': case '6': case '7': case '8': case '9':
|
||
error ("matching constraint not valid in output operand");
|
||
break;
|
||
|
||
case 'V': case 'm': case 'o':
|
||
allows_mem = 1;
|
||
break;
|
||
|
||
case '<': case '>':
|
||
/* ??? Before flow, auto inc/dec insns are not supposed to exist,
|
||
excepting those that expand_call created. So match memory
|
||
and hope. */
|
||
allows_mem = 1;
|
||
break;
|
||
|
||
case 'g': case 'X':
|
||
allows_reg = 1;
|
||
allows_mem = 1;
|
||
break;
|
||
|
||
case 'p': case 'r':
|
||
default:
|
||
allows_reg = 1;
|
||
break;
|
||
}
|
||
|
||
/* If an output operand is not a decl or indirect ref and our constraint
|
||
allows a register, make a temporary to act as an intermediate.
|
||
Make the asm insn write into that, then our caller will copy it to
|
||
the real output operand. Likewise for promoted variables. */
|
||
|
||
real_output_rtx[i] = NULL_RTX;
|
||
if ((TREE_CODE (val) == INDIRECT_REF
|
||
&& allows_mem)
|
||
|| (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
|
||
&& (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
|
||
&& ! (GET_CODE (DECL_RTL (val)) == REG
|
||
&& GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
|
||
|| ! allows_reg
|
||
|| is_inout)
|
||
{
|
||
if (! allows_reg)
|
||
mark_addressable (TREE_VALUE (tail));
|
||
|
||
output_rtx[i]
|
||
= expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
|
||
EXPAND_MEMORY_USE_WO);
|
||
|
||
if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
|
||
error ("output number %d not directly addressable", i);
|
||
if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
|
||
{
|
||
real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
|
||
output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
|
||
if (is_inout)
|
||
emit_move_insn (output_rtx[i], real_output_rtx[i]);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
output_rtx[i] = assign_temp (type, 0, 0, 0);
|
||
TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
|
||
}
|
||
|
||
if (is_inout)
|
||
{
|
||
inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
|
||
inout_opnum[ninout++] = i;
|
||
}
|
||
}
|
||
|
||
ninputs += ninout;
|
||
if (ninputs + noutputs > MAX_RECOG_OPERANDS)
|
||
{
|
||
error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
|
||
return;
|
||
}
|
||
|
||
/* Make vectors for the expression-rtx and constraint strings. */
|
||
|
||
argvec = rtvec_alloc (ninputs);
|
||
constraints = rtvec_alloc (ninputs);
|
||
|
||
body = gen_rtx_ASM_OPERANDS (VOIDmode,
|
||
TREE_STRING_POINTER (string), "", 0, argvec,
|
||
constraints, filename, line);
|
||
|
||
MEM_VOLATILE_P (body) = vol;
|
||
|
||
/* Eval the inputs and put them into ARGVEC.
|
||
Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
|
||
|
||
i = 0;
|
||
for (tail = inputs; tail; tail = TREE_CHAIN (tail))
|
||
{
|
||
int j;
|
||
int allows_reg = 0, allows_mem = 0;
|
||
char *constraint, *orig_constraint;
|
||
int c_len;
|
||
rtx op;
|
||
|
||
/* If there's an erroneous arg, emit no insn,
|
||
because the ASM_INPUT would get VOIDmode
|
||
and that could cause a crash in reload. */
|
||
if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
|
||
return;
|
||
|
||
/* ??? Can this happen, and does the error message make any sense? */
|
||
if (TREE_PURPOSE (tail) == NULL_TREE)
|
||
{
|
||
error ("hard register `%s' listed as input operand to `asm'",
|
||
TREE_STRING_POINTER (TREE_VALUE (tail)) );
|
||
return;
|
||
}
|
||
|
||
c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
|
||
constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
|
||
orig_constraint = constraint;
|
||
|
||
/* Make sure constraint has neither `=', `+', nor '&'. */
|
||
|
||
for (j = 0; j < c_len; j++)
|
||
switch (constraint[j])
|
||
{
|
||
case '+': case '=': case '&':
|
||
if (constraint == orig_constraint)
|
||
{
|
||
error ("input operand constraint contains `%c'", constraint[j]);
|
||
return;
|
||
}
|
||
break;
|
||
|
||
case '%':
|
||
if (constraint == orig_constraint
|
||
&& i + 1 == ninputs - ninout)
|
||
{
|
||
error ("`%%' constraint used with last operand");
|
||
return;
|
||
}
|
||
break;
|
||
|
||
case 'V': case 'm': case 'o':
|
||
allows_mem = 1;
|
||
break;
|
||
|
||
case '<': case '>':
|
||
case '?': case '!': case '*':
|
||
case 'E': case 'F': case 'G': case 'H': case 'X':
|
||
case 's': case 'i': case 'n':
|
||
case 'I': case 'J': case 'K': case 'L': case 'M':
|
||
case 'N': case 'O': case 'P': case ',':
|
||
#ifdef EXTRA_CONSTRAINT
|
||
case 'Q': case 'R': case 'S': case 'T': case 'U':
|
||
#endif
|
||
break;
|
||
|
||
/* Whether or not a numeric constraint allows a register is
|
||
decided by the matching constraint, and so there is no need
|
||
to do anything special with them. We must handle them in
|
||
the default case, so that we don't unnecessarily force
|
||
operands to memory. */
|
||
case '0': case '1': case '2': case '3': case '4':
|
||
case '5': case '6': case '7': case '8': case '9':
|
||
if (constraint[j] >= '0' + noutputs)
|
||
{
|
||
error
|
||
("matching constraint references invalid operand number");
|
||
return;
|
||
}
|
||
|
||
/* Try and find the real constraint for this dup. */
|
||
if ((j == 0 && c_len == 1)
|
||
|| (j == 1 && c_len == 2 && constraint[0] == '%'))
|
||
{
|
||
tree o = outputs;
|
||
for (j = constraint[j] - '0'; j > 0; --j)
|
||
o = TREE_CHAIN (o);
|
||
|
||
c_len = TREE_STRING_LENGTH (TREE_PURPOSE (o)) - 1;
|
||
constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
|
||
j = 0;
|
||
break;
|
||
}
|
||
|
||
/* ... fall through ... */
|
||
|
||
case 'p': case 'r':
|
||
default:
|
||
allows_reg = 1;
|
||
break;
|
||
|
||
case 'g':
|
||
allows_reg = 1;
|
||
allows_mem = 1;
|
||
break;
|
||
}
|
||
|
||
if (! allows_reg && allows_mem)
|
||
mark_addressable (TREE_VALUE (tail));
|
||
|
||
op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
|
||
|
||
if (asm_operand_ok (op, constraint) <= 0)
|
||
{
|
||
if (allows_reg)
|
||
op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
|
||
else if (!allows_mem)
|
||
warning ("asm operand %d probably doesn't match constraints", i);
|
||
else if (CONSTANT_P (op))
|
||
op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
|
||
op);
|
||
else if (GET_CODE (op) == REG
|
||
|| GET_CODE (op) == SUBREG
|
||
|| GET_CODE (op) == CONCAT)
|
||
{
|
||
tree type = TREE_TYPE (TREE_VALUE (tail));
|
||
rtx memloc = assign_temp (type, 1, 1, 1);
|
||
|
||
emit_move_insn (memloc, op);
|
||
op = memloc;
|
||
}
|
||
else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
|
||
/* We won't recognize volatile memory as available a
|
||
memory_operand at this point. Ignore it. */
|
||
;
|
||
else if (queued_subexp_p (op))
|
||
;
|
||
else
|
||
/* ??? Leave this only until we have experience with what
|
||
happens in combine and elsewhere when constraints are
|
||
not satisfied. */
|
||
warning ("asm operand %d probably doesn't match constraints", i);
|
||
}
|
||
XVECEXP (body, 3, i) = op;
|
||
|
||
XVECEXP (body, 4, i) /* constraints */
|
||
= gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
|
||
orig_constraint);
|
||
i++;
|
||
}
|
||
|
||
/* Protect all the operands from the queue,
|
||
now that they have all been evaluated. */
|
||
|
||
for (i = 0; i < ninputs - ninout; i++)
|
||
XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
|
||
|
||
for (i = 0; i < noutputs; i++)
|
||
output_rtx[i] = protect_from_queue (output_rtx[i], 1);
|
||
|
||
/* For in-out operands, copy output rtx to input rtx. */
|
||
for (i = 0; i < ninout; i++)
|
||
{
|
||
static char match[9+1][2]
|
||
= {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
|
||
int j = inout_opnum[i];
|
||
|
||
XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
|
||
= output_rtx[j];
|
||
XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
|
||
= gen_rtx_ASM_INPUT (inout_mode[j], match[j]);
|
||
}
|
||
|
||
/* Now, for each output, construct an rtx
|
||
(set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
|
||
ARGVEC CONSTRAINTS))
|
||
If there is more than one, put them inside a PARALLEL. */
|
||
|
||
if (noutputs == 1 && nclobbers == 0)
|
||
{
|
||
XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
|
||
insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
|
||
}
|
||
else if (noutputs == 0 && nclobbers == 0)
|
||
{
|
||
/* No output operands: put in a raw ASM_OPERANDS rtx. */
|
||
insn = emit_insn (body);
|
||
}
|
||
else
|
||
{
|
||
rtx obody = body;
|
||
int num = noutputs;
|
||
if (num == 0) num = 1;
|
||
body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
|
||
|
||
/* For each output operand, store a SET. */
|
||
|
||
for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
|
||
{
|
||
XVECEXP (body, 0, i)
|
||
= gen_rtx_SET (VOIDmode,
|
||
output_rtx[i],
|
||
gen_rtx_ASM_OPERANDS (VOIDmode,
|
||
TREE_STRING_POINTER (string),
|
||
TREE_STRING_POINTER (TREE_PURPOSE (tail)),
|
||
i, argvec, constraints,
|
||
filename, line));
|
||
MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
|
||
}
|
||
|
||
/* If there are no outputs (but there are some clobbers)
|
||
store the bare ASM_OPERANDS into the PARALLEL. */
|
||
|
||
if (i == 0)
|
||
XVECEXP (body, 0, i++) = obody;
|
||
|
||
/* Store (clobber REG) for each clobbered register specified. */
|
||
|
||
for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
|
||
{
|
||
char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
|
||
int j = decode_reg_name (regname);
|
||
|
||
if (j < 0)
|
||
{
|
||
if (j == -3) /* `cc', which is not a register */
|
||
continue;
|
||
|
||
if (j == -4) /* `memory', don't cache memory across asm */
|
||
{
|
||
XVECEXP (body, 0, i++)
|
||
= gen_rtx_CLOBBER (VOIDmode,
|
||
gen_rtx_MEM (BLKmode,
|
||
gen_rtx_SCRATCH (VOIDmode)));
|
||
continue;
|
||
}
|
||
|
||
/* Ignore unknown register, error already signaled. */
|
||
continue;
|
||
}
|
||
|
||
/* Use QImode since that's guaranteed to clobber just one reg. */
|
||
XVECEXP (body, 0, i++)
|
||
= gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
|
||
}
|
||
|
||
insn = emit_insn (body);
|
||
}
|
||
|
||
/* For any outputs that needed reloading into registers, spill them
|
||
back to where they belong. */
|
||
for (i = 0; i < noutputs; ++i)
|
||
if (real_output_rtx[i])
|
||
emit_move_insn (real_output_rtx[i], output_rtx[i]);
|
||
|
||
free_temp_slots ();
|
||
}
|
||
|
||
/* Generate RTL to evaluate the expression EXP
|
||
and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
|
||
|
||
void
|
||
expand_expr_stmt (exp)
|
||
tree exp;
|
||
{
|
||
/* If -W, warn about statements with no side effects,
|
||
except for an explicit cast to void (e.g. for assert()), and
|
||
except inside a ({...}) where they may be useful. */
|
||
if (expr_stmts_for_value == 0 && exp != error_mark_node)
|
||
{
|
||
if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
|
||
&& !(TREE_CODE (exp) == CONVERT_EXPR
|
||
&& TREE_TYPE (exp) == void_type_node))
|
||
warning_with_file_and_line (emit_filename, emit_lineno,
|
||
"statement with no effect");
|
||
else if (warn_unused)
|
||
warn_if_unused_value (exp);
|
||
}
|
||
|
||
/* If EXP is of function type and we are expanding statements for
|
||
value, convert it to pointer-to-function. */
|
||
if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
|
||
exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
|
||
|
||
last_expr_type = TREE_TYPE (exp);
|
||
last_expr_value = expand_expr (exp,
|
||
(expr_stmts_for_value
|
||
? NULL_RTX : const0_rtx),
|
||
VOIDmode, 0);
|
||
|
||
/* If all we do is reference a volatile value in memory,
|
||
copy it to a register to be sure it is actually touched. */
|
||
if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
|
||
&& TREE_THIS_VOLATILE (exp))
|
||
{
|
||
if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
|
||
;
|
||
else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
|
||
copy_to_reg (last_expr_value);
|
||
else
|
||
{
|
||
rtx lab = gen_label_rtx ();
|
||
|
||
/* Compare the value with itself to reference it. */
|
||
emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
|
||
expand_expr (TYPE_SIZE (last_expr_type),
|
||
NULL_RTX, VOIDmode, 0),
|
||
BLKmode, 0,
|
||
TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
|
||
lab);
|
||
emit_label (lab);
|
||
}
|
||
}
|
||
|
||
/* If this expression is part of a ({...}) and is in memory, we may have
|
||
to preserve temporaries. */
|
||
preserve_temp_slots (last_expr_value);
|
||
|
||
/* Free any temporaries used to evaluate this expression. Any temporary
|
||
used as a result of this expression will already have been preserved
|
||
above. */
|
||
free_temp_slots ();
|
||
|
||
emit_queue ();
|
||
}
|
||
|
||
/* Warn if EXP contains any computations whose results are not used.
|
||
Return 1 if a warning is printed; 0 otherwise. */
|
||
|
||
int
|
||
warn_if_unused_value (exp)
|
||
tree exp;
|
||
{
|
||
if (TREE_USED (exp))
|
||
return 0;
|
||
|
||
switch (TREE_CODE (exp))
|
||
{
|
||
case PREINCREMENT_EXPR:
|
||
case POSTINCREMENT_EXPR:
|
||
case PREDECREMENT_EXPR:
|
||
case POSTDECREMENT_EXPR:
|
||
case MODIFY_EXPR:
|
||
case INIT_EXPR:
|
||
case TARGET_EXPR:
|
||
case CALL_EXPR:
|
||
case METHOD_CALL_EXPR:
|
||
case RTL_EXPR:
|
||
case TRY_CATCH_EXPR:
|
||
case WITH_CLEANUP_EXPR:
|
||
case EXIT_EXPR:
|
||
/* We don't warn about COND_EXPR because it may be a useful
|
||
construct if either arm contains a side effect. */
|
||
case COND_EXPR:
|
||
return 0;
|
||
|
||
case BIND_EXPR:
|
||
/* For a binding, warn if no side effect within it. */
|
||
return warn_if_unused_value (TREE_OPERAND (exp, 1));
|
||
|
||
case SAVE_EXPR:
|
||
return warn_if_unused_value (TREE_OPERAND (exp, 1));
|
||
|
||
case TRUTH_ORIF_EXPR:
|
||
case TRUTH_ANDIF_EXPR:
|
||
/* In && or ||, warn if 2nd operand has no side effect. */
|
||
return warn_if_unused_value (TREE_OPERAND (exp, 1));
|
||
|
||
case COMPOUND_EXPR:
|
||
if (TREE_NO_UNUSED_WARNING (exp))
|
||
return 0;
|
||
if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
|
||
return 1;
|
||
/* Let people do `(foo (), 0)' without a warning. */
|
||
if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
|
||
return 0;
|
||
return warn_if_unused_value (TREE_OPERAND (exp, 1));
|
||
|
||
case NOP_EXPR:
|
||
case CONVERT_EXPR:
|
||
case NON_LVALUE_EXPR:
|
||
/* Don't warn about values cast to void. */
|
||
if (TREE_TYPE (exp) == void_type_node)
|
||
return 0;
|
||
/* Don't warn about conversions not explicit in the user's program. */
|
||
if (TREE_NO_UNUSED_WARNING (exp))
|
||
return 0;
|
||
/* Assignment to a cast usually results in a cast of a modify.
|
||
Don't complain about that. There can be an arbitrary number of
|
||
casts before the modify, so we must loop until we find the first
|
||
non-cast expression and then test to see if that is a modify. */
|
||
{
|
||
tree tem = TREE_OPERAND (exp, 0);
|
||
|
||
while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
|
||
tem = TREE_OPERAND (tem, 0);
|
||
|
||
if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
|
||
|| TREE_CODE (tem) == CALL_EXPR)
|
||
return 0;
|
||
}
|
||
goto warn;
|
||
|
||
case INDIRECT_REF:
|
||
/* Don't warn about automatic dereferencing of references, since
|
||
the user cannot control it. */
|
||
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
|
||
return warn_if_unused_value (TREE_OPERAND (exp, 0));
|
||
/* ... fall through ... */
|
||
|
||
default:
|
||
/* Referencing a volatile value is a side effect, so don't warn. */
|
||
if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
|
||
|| TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
|
||
&& TREE_THIS_VOLATILE (exp))
|
||
return 0;
|
||
warn:
|
||
warning_with_file_and_line (emit_filename, emit_lineno,
|
||
"value computed is not used");
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
/* Clear out the memory of the last expression evaluated. */
|
||
|
||
void
|
||
clear_last_expr ()
|
||
{
|
||
last_expr_type = 0;
|
||
}
|
||
|
||
/* Begin a statement which will return a value.
|
||
Return the RTL_EXPR for this statement expr.
|
||
The caller must save that value and pass it to expand_end_stmt_expr. */
|
||
|
||
tree
|
||
expand_start_stmt_expr ()
|
||
{
|
||
int momentary;
|
||
tree t;
|
||
|
||
/* Make the RTL_EXPR node temporary, not momentary,
|
||
so that rtl_expr_chain doesn't become garbage. */
|
||
momentary = suspend_momentary ();
|
||
t = make_node (RTL_EXPR);
|
||
resume_momentary (momentary);
|
||
do_pending_stack_adjust ();
|
||
start_sequence_for_rtl_expr (t);
|
||
NO_DEFER_POP;
|
||
expr_stmts_for_value++;
|
||
return t;
|
||
}
|
||
|
||
/* Restore the previous state at the end of a statement that returns a value.
|
||
Returns a tree node representing the statement's value and the
|
||
insns to compute the value.
|
||
|
||
The nodes of that expression have been freed by now, so we cannot use them.
|
||
But we don't want to do that anyway; the expression has already been
|
||
evaluated and now we just want to use the value. So generate a RTL_EXPR
|
||
with the proper type and RTL value.
|
||
|
||
If the last substatement was not an expression,
|
||
return something with type `void'. */
|
||
|
||
tree
|
||
expand_end_stmt_expr (t)
|
||
tree t;
|
||
{
|
||
OK_DEFER_POP;
|
||
|
||
if (last_expr_type == 0)
|
||
{
|
||
last_expr_type = void_type_node;
|
||
last_expr_value = const0_rtx;
|
||
}
|
||
else if (last_expr_value == 0)
|
||
/* There are some cases where this can happen, such as when the
|
||
statement is void type. */
|
||
last_expr_value = const0_rtx;
|
||
else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
|
||
/* Remove any possible QUEUED. */
|
||
last_expr_value = protect_from_queue (last_expr_value, 0);
|
||
|
||
emit_queue ();
|
||
|
||
TREE_TYPE (t) = last_expr_type;
|
||
RTL_EXPR_RTL (t) = last_expr_value;
|
||
RTL_EXPR_SEQUENCE (t) = get_insns ();
|
||
|
||
rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
|
||
|
||
end_sequence ();
|
||
|
||
/* Don't consider deleting this expr or containing exprs at tree level. */
|
||
TREE_SIDE_EFFECTS (t) = 1;
|
||
/* Propagate volatility of the actual RTL expr. */
|
||
TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
|
||
|
||
last_expr_type = 0;
|
||
expr_stmts_for_value--;
|
||
|
||
return t;
|
||
}
|
||
|
||
/* Generate RTL for the start of an if-then. COND is the expression
|
||
whose truth should be tested.
|
||
|
||
If EXITFLAG is nonzero, this conditional is visible to
|
||
`exit_something'. */
|
||
|
||
void
|
||
expand_start_cond (cond, exitflag)
|
||
tree cond;
|
||
int exitflag;
|
||
{
|
||
struct nesting *thiscond = ALLOC_NESTING ();
|
||
|
||
/* Make an entry on cond_stack for the cond we are entering. */
|
||
|
||
thiscond->next = cond_stack;
|
||
thiscond->all = nesting_stack;
|
||
thiscond->depth = ++nesting_depth;
|
||
thiscond->data.cond.next_label = gen_label_rtx ();
|
||
/* Before we encounter an `else', we don't need a separate exit label
|
||
unless there are supposed to be exit statements
|
||
to exit this conditional. */
|
||
thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
|
||
thiscond->data.cond.endif_label = thiscond->exit_label;
|
||
cond_stack = thiscond;
|
||
nesting_stack = thiscond;
|
||
|
||
do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
|
||
}
|
||
|
||
/* Generate RTL between then-clause and the elseif-clause
|
||
of an if-then-elseif-.... */
|
||
|
||
void
|
||
expand_start_elseif (cond)
|
||
tree cond;
|
||
{
|
||
if (cond_stack->data.cond.endif_label == 0)
|
||
cond_stack->data.cond.endif_label = gen_label_rtx ();
|
||
emit_jump (cond_stack->data.cond.endif_label);
|
||
emit_label (cond_stack->data.cond.next_label);
|
||
cond_stack->data.cond.next_label = gen_label_rtx ();
|
||
do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
|
||
}
|
||
|
||
/* Generate RTL between the then-clause and the else-clause
|
||
of an if-then-else. */
|
||
|
||
void
|
||
expand_start_else ()
|
||
{
|
||
if (cond_stack->data.cond.endif_label == 0)
|
||
cond_stack->data.cond.endif_label = gen_label_rtx ();
|
||
|
||
emit_jump (cond_stack->data.cond.endif_label);
|
||
emit_label (cond_stack->data.cond.next_label);
|
||
cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
|
||
}
|
||
|
||
/* After calling expand_start_else, turn this "else" into an "else if"
|
||
by providing another condition. */
|
||
|
||
void
|
||
expand_elseif (cond)
|
||
tree cond;
|
||
{
|
||
cond_stack->data.cond.next_label = gen_label_rtx ();
|
||
do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
|
||
}
|
||
|
||
/* Generate RTL for the end of an if-then.
|
||
Pop the record for it off of cond_stack. */
|
||
|
||
void
|
||
expand_end_cond ()
|
||
{
|
||
struct nesting *thiscond = cond_stack;
|
||
|
||
do_pending_stack_adjust ();
|
||
if (thiscond->data.cond.next_label)
|
||
emit_label (thiscond->data.cond.next_label);
|
||
if (thiscond->data.cond.endif_label)
|
||
emit_label (thiscond->data.cond.endif_label);
|
||
|
||
POPSTACK (cond_stack);
|
||
last_expr_type = 0;
|
||
}
|
||
|
||
|
||
|
||
/* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
|
||
loop should be exited by `exit_something'. This is a loop for which
|
||
`expand_continue' will jump to the top of the loop.
|
||
|
||
Make an entry on loop_stack to record the labels associated with
|
||
this loop. */
|
||
|
||
struct nesting *
|
||
expand_start_loop (exit_flag)
|
||
int exit_flag;
|
||
{
|
||
register struct nesting *thisloop = ALLOC_NESTING ();
|
||
|
||
/* Make an entry on loop_stack for the loop we are entering. */
|
||
|
||
thisloop->next = loop_stack;
|
||
thisloop->all = nesting_stack;
|
||
thisloop->depth = ++nesting_depth;
|
||
thisloop->data.loop.start_label = gen_label_rtx ();
|
||
thisloop->data.loop.end_label = gen_label_rtx ();
|
||
thisloop->data.loop.alt_end_label = 0;
|
||
thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
|
||
thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
|
||
loop_stack = thisloop;
|
||
nesting_stack = thisloop;
|
||
|
||
do_pending_stack_adjust ();
|
||
emit_queue ();
|
||
emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
|
||
emit_label (thisloop->data.loop.start_label);
|
||
|
||
return thisloop;
|
||
}
|
||
|
||
/* Like expand_start_loop but for a loop where the continuation point
|
||
(for expand_continue_loop) will be specified explicitly. */
|
||
|
||
struct nesting *
|
||
expand_start_loop_continue_elsewhere (exit_flag)
|
||
int exit_flag;
|
||
{
|
||
struct nesting *thisloop = expand_start_loop (exit_flag);
|
||
loop_stack->data.loop.continue_label = gen_label_rtx ();
|
||
return thisloop;
|
||
}
|
||
|
||
/* Specify the continuation point for a loop started with
|
||
expand_start_loop_continue_elsewhere.
|
||
Use this at the point in the code to which a continue statement
|
||
should jump. */
|
||
|
||
void
|
||
expand_loop_continue_here ()
|
||
{
|
||
do_pending_stack_adjust ();
|
||
emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
|
||
emit_label (loop_stack->data.loop.continue_label);
|
||
}
|
||
|
||
/* Finish a loop. Generate a jump back to the top and the loop-exit label.
|
||
Pop the block off of loop_stack. */
|
||
|
||
void
|
||
expand_end_loop ()
|
||
{
|
||
rtx start_label = loop_stack->data.loop.start_label;
|
||
rtx insn = get_last_insn ();
|
||
int needs_end_jump = 1;
|
||
|
||
/* Mark the continue-point at the top of the loop if none elsewhere. */
|
||
if (start_label == loop_stack->data.loop.continue_label)
|
||
emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
|
||
|
||
do_pending_stack_adjust ();
|
||
|
||
/* If optimizing, perhaps reorder the loop.
|
||
First, try to use a condjump near the end.
|
||
expand_exit_loop_if_false ends loops with unconditional jumps,
|
||
like this:
|
||
|
||
if (test) goto label;
|
||
optional: cleanup
|
||
goto loop_stack->data.loop.end_label
|
||
barrier
|
||
label:
|
||
|
||
If we find such a pattern, we can end the loop earlier. */
|
||
|
||
if (optimize
|
||
&& GET_CODE (insn) == CODE_LABEL
|
||
&& LABEL_NAME (insn) == NULL
|
||
&& GET_CODE (PREV_INSN (insn)) == BARRIER)
|
||
{
|
||
rtx label = insn;
|
||
rtx jump = PREV_INSN (PREV_INSN (label));
|
||
|
||
if (GET_CODE (jump) == JUMP_INSN
|
||
&& GET_CODE (PATTERN (jump)) == SET
|
||
&& SET_DEST (PATTERN (jump)) == pc_rtx
|
||
&& GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
|
||
&& (XEXP (SET_SRC (PATTERN (jump)), 0)
|
||
== loop_stack->data.loop.end_label))
|
||
{
|
||
rtx prev;
|
||
|
||
/* The test might be complex and reference LABEL multiple times,
|
||
like the loop in loop_iterations to set vtop. To handle this,
|
||
we move LABEL. */
|
||
insn = PREV_INSN (label);
|
||
reorder_insns (label, label, start_label);
|
||
|
||
for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
|
||
{
|
||
/* We ignore line number notes, but if we see any other note,
|
||
in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
|
||
NOTE_INSN_LOOP_*, we disable this optimization. */
|
||
if (GET_CODE (prev) == NOTE)
|
||
{
|
||
if (NOTE_LINE_NUMBER (prev) < 0)
|
||
break;
|
||
continue;
|
||
}
|
||
if (GET_CODE (prev) == CODE_LABEL)
|
||
break;
|
||
if (GET_CODE (prev) == JUMP_INSN)
|
||
{
|
||
if (GET_CODE (PATTERN (prev)) == SET
|
||
&& SET_DEST (PATTERN (prev)) == pc_rtx
|
||
&& GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
|
||
&& (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
|
||
== LABEL_REF)
|
||
&& XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
|
||
{
|
||
XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
|
||
= start_label;
|
||
emit_note_after (NOTE_INSN_LOOP_END, prev);
|
||
needs_end_jump = 0;
|
||
}
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* If the loop starts with a loop exit, roll that to the end where
|
||
it will optimize together with the jump back.
|
||
|
||
We look for the conditional branch to the exit, except that once
|
||
we find such a branch, we don't look past 30 instructions.
|
||
|
||
In more detail, if the loop presently looks like this (in pseudo-C):
|
||
|
||
start_label:
|
||
if (test) goto end_label;
|
||
body;
|
||
goto start_label;
|
||
end_label:
|
||
|
||
transform it to look like:
|
||
|
||
goto start_label;
|
||
newstart_label:
|
||
body;
|
||
start_label:
|
||
if (test) goto end_label;
|
||
goto newstart_label;
|
||
end_label:
|
||
|
||
Here, the `test' may actually consist of some reasonably complex
|
||
code, terminating in a test. */
|
||
|
||
if (optimize
|
||
&& needs_end_jump
|
||
&&
|
||
! (GET_CODE (insn) == JUMP_INSN
|
||
&& GET_CODE (PATTERN (insn)) == SET
|
||
&& SET_DEST (PATTERN (insn)) == pc_rtx
|
||
&& GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
|
||
{
|
||
int eh_regions = 0;
|
||
int num_insns = 0;
|
||
rtx last_test_insn = NULL_RTX;
|
||
|
||
/* Scan insns from the top of the loop looking for a qualified
|
||
conditional exit. */
|
||
for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
|
||
insn = NEXT_INSN (insn))
|
||
{
|
||
if (GET_CODE (insn) == NOTE)
|
||
{
|
||
if (optimize < 2
|
||
&& (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
|
||
|| NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
|
||
/* The code that actually moves the exit test will
|
||
carefully leave BLOCK notes in their original
|
||
location. That means, however, that we can't debug
|
||
the exit test itself. So, we refuse to move code
|
||
containing BLOCK notes at low optimization levels. */
|
||
break;
|
||
|
||
if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
|
||
++eh_regions;
|
||
else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
|
||
{
|
||
--eh_regions;
|
||
if (eh_regions < 0)
|
||
/* We've come to the end of an EH region, but
|
||
never saw the beginning of that region. That
|
||
means that an EH region begins before the top
|
||
of the loop, and ends in the middle of it. The
|
||
existence of such a situation violates a basic
|
||
assumption in this code, since that would imply
|
||
that even when EH_REGIONS is zero, we might
|
||
move code out of an exception region. */
|
||
abort ();
|
||
}
|
||
|
||
/* We must not walk into a nested loop. */
|
||
if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
|
||
break;
|
||
|
||
/* We already know this INSN is a NOTE, so there's no
|
||
point in looking at it to see if it's a JUMP. */
|
||
continue;
|
||
}
|
||
|
||
if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
|
||
num_insns++;
|
||
|
||
if (last_test_insn && num_insns > 30)
|
||
break;
|
||
|
||
if (eh_regions > 0)
|
||
/* We don't want to move a partial EH region. Consider:
|
||
|
||
while ( ( { try {
|
||
if (cond ()) 0;
|
||
else {
|
||
bar();
|
||
1;
|
||
}
|
||
} catch (...) {
|
||
1;
|
||
} )) {
|
||
body;
|
||
}
|
||
|
||
This isn't legal C++, but here's what it's supposed to
|
||
mean: if cond() is true, stop looping. Otherwise,
|
||
call bar, and keep looping. In addition, if cond
|
||
throws an exception, catch it and keep looping. Such
|
||
constructs are certainy legal in LISP.
|
||
|
||
We should not move the `if (cond()) 0' test since then
|
||
the EH-region for the try-block would be broken up.
|
||
(In this case we would the EH_BEG note for the `try'
|
||
and `if cond()' but not the call to bar() or the
|
||
EH_END note.)
|
||
|
||
So we don't look for tests within an EH region. */
|
||
continue;
|
||
|
||
if (GET_CODE (insn) == JUMP_INSN
|
||
&& GET_CODE (PATTERN (insn)) == SET
|
||
&& SET_DEST (PATTERN (insn)) == pc_rtx)
|
||
{
|
||
/* This is indeed a jump. */
|
||
rtx dest1 = NULL_RTX;
|
||
rtx dest2 = NULL_RTX;
|
||
rtx potential_last_test;
|
||
if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
|
||
{
|
||
/* A conditional jump. */
|
||
dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
|
||
dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
|
||
potential_last_test = insn;
|
||
}
|
||
else
|
||
{
|
||
/* An unconditional jump. */
|
||
dest1 = SET_SRC (PATTERN (insn));
|
||
/* Include the BARRIER after the JUMP. */
|
||
potential_last_test = NEXT_INSN (insn);
|
||
}
|
||
|
||
do {
|
||
if (dest1 && GET_CODE (dest1) == LABEL_REF
|
||
&& ((XEXP (dest1, 0)
|
||
== loop_stack->data.loop.alt_end_label)
|
||
|| (XEXP (dest1, 0)
|
||
== loop_stack->data.loop.end_label)))
|
||
{
|
||
last_test_insn = potential_last_test;
|
||
break;
|
||
}
|
||
|
||
/* If this was a conditional jump, there may be
|
||
another label at which we should look. */
|
||
dest1 = dest2;
|
||
dest2 = NULL_RTX;
|
||
} while (dest1);
|
||
}
|
||
}
|
||
|
||
if (last_test_insn != 0 && last_test_insn != get_last_insn ())
|
||
{
|
||
/* We found one. Move everything from there up
|
||
to the end of the loop, and add a jump into the loop
|
||
to jump to there. */
|
||
register rtx newstart_label = gen_label_rtx ();
|
||
register rtx start_move = start_label;
|
||
rtx next_insn;
|
||
|
||
/* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
|
||
then we want to move this note also. */
|
||
if (GET_CODE (PREV_INSN (start_move)) == NOTE
|
||
&& (NOTE_LINE_NUMBER (PREV_INSN (start_move))
|
||
== NOTE_INSN_LOOP_CONT))
|
||
start_move = PREV_INSN (start_move);
|
||
|
||
emit_label_after (newstart_label, PREV_INSN (start_move));
|
||
|
||
/* Actually move the insns. Start at the beginning, and
|
||
keep copying insns until we've copied the
|
||
last_test_insn. */
|
||
for (insn = start_move; insn; insn = next_insn)
|
||
{
|
||
/* Figure out which insn comes after this one. We have
|
||
to do this before we move INSN. */
|
||
if (insn == last_test_insn)
|
||
/* We've moved all the insns. */
|
||
next_insn = NULL_RTX;
|
||
else
|
||
next_insn = NEXT_INSN (insn);
|
||
|
||
if (GET_CODE (insn) == NOTE
|
||
&& (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
|
||
|| NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
|
||
/* We don't want to move NOTE_INSN_BLOCK_BEGs or
|
||
NOTE_INSN_BLOCK_ENDs because the correct generation
|
||
of debugging information depends on these appearing
|
||
in the same order in the RTL and in the tree
|
||
structure, where they are represented as BLOCKs.
|
||
So, we don't move block notes. Of course, moving
|
||
the code inside the block is likely to make it
|
||
impossible to debug the instructions in the exit
|
||
test, but such is the price of optimization. */
|
||
continue;
|
||
|
||
/* Move the INSN. */
|
||
reorder_insns (insn, insn, get_last_insn ());
|
||
}
|
||
|
||
emit_jump_insn_after (gen_jump (start_label),
|
||
PREV_INSN (newstart_label));
|
||
emit_barrier_after (PREV_INSN (newstart_label));
|
||
start_label = newstart_label;
|
||
}
|
||
}
|
||
|
||
if (needs_end_jump)
|
||
{
|
||
emit_jump (start_label);
|
||
emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
|
||
}
|
||
emit_label (loop_stack->data.loop.end_label);
|
||
|
||
POPSTACK (loop_stack);
|
||
|
||
last_expr_type = 0;
|
||
}
|
||
|
||
/* Generate a jump to the current loop's continue-point.
|
||
This is usually the top of the loop, but may be specified
|
||
explicitly elsewhere. If not currently inside a loop,
|
||
return 0 and do nothing; caller will print an error message. */
|
||
|
||
int
|
||
expand_continue_loop (whichloop)
|
||
struct nesting *whichloop;
|
||
{
|
||
last_expr_type = 0;
|
||
if (whichloop == 0)
|
||
whichloop = loop_stack;
|
||
if (whichloop == 0)
|
||
return 0;
|
||
expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
|
||
NULL_RTX);
|
||
return 1;
|
||
}
|
||
|
||
/* Generate a jump to exit the current loop. If not currently inside a loop,
|
||
return 0 and do nothing; caller will print an error message. */
|
||
|
||
int
|
||
expand_exit_loop (whichloop)
|
||
struct nesting *whichloop;
|
||
{
|
||
last_expr_type = 0;
|
||
if (whichloop == 0)
|
||
whichloop = loop_stack;
|
||
if (whichloop == 0)
|
||
return 0;
|
||
expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
|
||
return 1;
|
||
}
|
||
|
||
/* Generate a conditional jump to exit the current loop if COND
|
||
evaluates to zero. If not currently inside a loop,
|
||
return 0 and do nothing; caller will print an error message. */
|
||
|
||
int
|
||
expand_exit_loop_if_false (whichloop, cond)
|
||
struct nesting *whichloop;
|
||
tree cond;
|
||
{
|
||
rtx label = gen_label_rtx ();
|
||
rtx last_insn;
|
||
last_expr_type = 0;
|
||
|
||
if (whichloop == 0)
|
||
whichloop = loop_stack;
|
||
if (whichloop == 0)
|
||
return 0;
|
||
/* In order to handle fixups, we actually create a conditional jump
|
||
around a unconditional branch to exit the loop. If fixups are
|
||
necessary, they go before the unconditional branch. */
|
||
|
||
|
||
do_jump (cond, NULL_RTX, label);
|
||
last_insn = get_last_insn ();
|
||
if (GET_CODE (last_insn) == CODE_LABEL)
|
||
whichloop->data.loop.alt_end_label = last_insn;
|
||
expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
|
||
NULL_RTX);
|
||
emit_label (label);
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Return nonzero if the loop nest is empty. Else return zero. */
|
||
|
||
int
|
||
stmt_loop_nest_empty ()
|
||
{
|
||
return (loop_stack == NULL);
|
||
}
|
||
|
||
/* Return non-zero if we should preserve sub-expressions as separate
|
||
pseudos. We never do so if we aren't optimizing. We always do so
|
||
if -fexpensive-optimizations.
|
||
|
||
Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
|
||
the loop may still be a small one. */
|
||
|
||
int
|
||
preserve_subexpressions_p ()
|
||
{
|
||
rtx insn;
|
||
|
||
if (flag_expensive_optimizations)
|
||
return 1;
|
||
|
||
if (optimize == 0 || loop_stack == 0)
|
||
return 0;
|
||
|
||
insn = get_last_insn_anywhere ();
|
||
|
||
return (insn
|
||
&& (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
|
||
< n_non_fixed_regs * 3));
|
||
|
||
}
|
||
|
||
/* Generate a jump to exit the current loop, conditional, binding contour
|
||
or case statement. Not all such constructs are visible to this function,
|
||
only those started with EXIT_FLAG nonzero. Individual languages use
|
||
the EXIT_FLAG parameter to control which kinds of constructs you can
|
||
exit this way.
|
||
|
||
If not currently inside anything that can be exited,
|
||
return 0 and do nothing; caller will print an error message. */
|
||
|
||
int
|
||
expand_exit_something ()
|
||
{
|
||
struct nesting *n;
|
||
last_expr_type = 0;
|
||
for (n = nesting_stack; n; n = n->all)
|
||
if (n->exit_label != 0)
|
||
{
|
||
expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Generate RTL to return from the current function, with no value.
|
||
(That is, we do not do anything about returning any value.) */
|
||
|
||
void
|
||
expand_null_return ()
|
||
{
|
||
struct nesting *block = block_stack;
|
||
rtx last_insn = 0;
|
||
|
||
/* Does any pending block have cleanups? */
|
||
|
||
while (block && block->data.block.cleanups == 0)
|
||
block = block->next;
|
||
|
||
/* If yes, use a goto to return, since that runs cleanups. */
|
||
|
||
expand_null_return_1 (last_insn, block != 0);
|
||
}
|
||
|
||
/* Generate RTL to return from the current function, with value VAL. */
|
||
|
||
static void
|
||
expand_value_return (val)
|
||
rtx val;
|
||
{
|
||
struct nesting *block = block_stack;
|
||
rtx last_insn = get_last_insn ();
|
||
rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
|
||
|
||
/* Copy the value to the return location
|
||
unless it's already there. */
|
||
|
||
if (return_reg != val)
|
||
{
|
||
#ifdef PROMOTE_FUNCTION_RETURN
|
||
tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
|
||
int unsignedp = TREE_UNSIGNED (type);
|
||
enum machine_mode mode
|
||
= promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
|
||
&unsignedp, 1);
|
||
|
||
if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
|
||
convert_move (return_reg, val, unsignedp);
|
||
else
|
||
#endif
|
||
emit_move_insn (return_reg, val);
|
||
}
|
||
if (GET_CODE (return_reg) == REG
|
||
&& REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
|
||
emit_insn (gen_rtx_USE (VOIDmode, return_reg));
|
||
/* Handle calls that return values in multiple non-contiguous locations.
|
||
The Irix 6 ABI has examples of this. */
|
||
else if (GET_CODE (return_reg) == PARALLEL)
|
||
{
|
||
int i;
|
||
|
||
for (i = 0; i < XVECLEN (return_reg, 0); i++)
|
||
{
|
||
rtx x = XEXP (XVECEXP (return_reg, 0, i), 0);
|
||
|
||
if (GET_CODE (x) == REG
|
||
&& REGNO (x) < FIRST_PSEUDO_REGISTER)
|
||
emit_insn (gen_rtx_USE (VOIDmode, x));
|
||
}
|
||
}
|
||
|
||
/* Does any pending block have cleanups? */
|
||
|
||
while (block && block->data.block.cleanups == 0)
|
||
block = block->next;
|
||
|
||
/* If yes, use a goto to return, since that runs cleanups.
|
||
Use LAST_INSN to put cleanups *before* the move insn emitted above. */
|
||
|
||
expand_null_return_1 (last_insn, block != 0);
|
||
}
|
||
|
||
/* Output a return with no value. If LAST_INSN is nonzero,
|
||
pretend that the return takes place after LAST_INSN.
|
||
If USE_GOTO is nonzero then don't use a return instruction;
|
||
go to the return label instead. This causes any cleanups
|
||
of pending blocks to be executed normally. */
|
||
|
||
static void
|
||
expand_null_return_1 (last_insn, use_goto)
|
||
rtx last_insn;
|
||
int use_goto;
|
||
{
|
||
rtx end_label = cleanup_label ? cleanup_label : return_label;
|
||
|
||
clear_pending_stack_adjust ();
|
||
do_pending_stack_adjust ();
|
||
last_expr_type = 0;
|
||
|
||
/* PCC-struct return always uses an epilogue. */
|
||
if (current_function_returns_pcc_struct || use_goto)
|
||
{
|
||
if (end_label == 0)
|
||
end_label = return_label = gen_label_rtx ();
|
||
expand_goto_internal (NULL_TREE, end_label, last_insn);
|
||
return;
|
||
}
|
||
|
||
/* Otherwise output a simple return-insn if one is available,
|
||
unless it won't do the job. */
|
||
#ifdef HAVE_return
|
||
if (HAVE_return && use_goto == 0 && cleanup_label == 0)
|
||
{
|
||
emit_jump_insn (gen_return ());
|
||
emit_barrier ();
|
||
return;
|
||
}
|
||
#endif
|
||
|
||
/* Otherwise jump to the epilogue. */
|
||
expand_goto_internal (NULL_TREE, end_label, last_insn);
|
||
}
|
||
|
||
/* Generate RTL to evaluate the expression RETVAL and return it
|
||
from the current function. */
|
||
|
||
void
|
||
expand_return (retval)
|
||
tree retval;
|
||
{
|
||
/* If there are any cleanups to be performed, then they will
|
||
be inserted following LAST_INSN. It is desirable
|
||
that the last_insn, for such purposes, should be the
|
||
last insn before computing the return value. Otherwise, cleanups
|
||
which call functions can clobber the return value. */
|
||
/* ??? rms: I think that is erroneous, because in C++ it would
|
||
run destructors on variables that might be used in the subsequent
|
||
computation of the return value. */
|
||
rtx last_insn = 0;
|
||
register rtx val = 0;
|
||
register rtx op0;
|
||
tree retval_rhs;
|
||
int cleanups;
|
||
|
||
/* If function wants no value, give it none. */
|
||
if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
|
||
{
|
||
expand_expr (retval, NULL_RTX, VOIDmode, 0);
|
||
emit_queue ();
|
||
expand_null_return ();
|
||
return;
|
||
}
|
||
|
||
/* Are any cleanups needed? E.g. C++ destructors to be run? */
|
||
/* This is not sufficient. We also need to watch for cleanups of the
|
||
expression we are about to expand. Unfortunately, we cannot know
|
||
if it has cleanups until we expand it, and we want to change how we
|
||
expand it depending upon if we need cleanups. We can't win. */
|
||
#if 0
|
||
cleanups = any_pending_cleanups (1);
|
||
#else
|
||
cleanups = 1;
|
||
#endif
|
||
|
||
if (TREE_CODE (retval) == RESULT_DECL)
|
||
retval_rhs = retval;
|
||
else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
|
||
&& TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
|
||
retval_rhs = TREE_OPERAND (retval, 1);
|
||
else if (TREE_TYPE (retval) == void_type_node)
|
||
/* Recognize tail-recursive call to void function. */
|
||
retval_rhs = retval;
|
||
else
|
||
retval_rhs = NULL_TREE;
|
||
|
||
/* Only use `last_insn' if there are cleanups which must be run. */
|
||
if (cleanups || cleanup_label != 0)
|
||
last_insn = get_last_insn ();
|
||
|
||
/* Distribute return down conditional expr if either of the sides
|
||
may involve tail recursion (see test below). This enhances the number
|
||
of tail recursions we see. Don't do this always since it can produce
|
||
sub-optimal code in some cases and we distribute assignments into
|
||
conditional expressions when it would help. */
|
||
|
||
if (optimize && retval_rhs != 0
|
||
&& frame_offset == 0
|
||
&& TREE_CODE (retval_rhs) == COND_EXPR
|
||
&& (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
|
||
|| TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
|
||
{
|
||
rtx label = gen_label_rtx ();
|
||
tree expr;
|
||
|
||
do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
|
||
start_cleanup_deferral ();
|
||
expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
|
||
DECL_RESULT (current_function_decl),
|
||
TREE_OPERAND (retval_rhs, 1));
|
||
TREE_SIDE_EFFECTS (expr) = 1;
|
||
expand_return (expr);
|
||
emit_label (label);
|
||
|
||
expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
|
||
DECL_RESULT (current_function_decl),
|
||
TREE_OPERAND (retval_rhs, 2));
|
||
TREE_SIDE_EFFECTS (expr) = 1;
|
||
expand_return (expr);
|
||
end_cleanup_deferral ();
|
||
return;
|
||
}
|
||
|
||
/* Attempt to optimize the call if it is tail recursive. */
|
||
if (optimize_tail_recursion (retval_rhs, last_insn))
|
||
return;
|
||
|
||
#ifdef HAVE_return
|
||
/* This optimization is safe if there are local cleanups
|
||
because expand_null_return takes care of them.
|
||
??? I think it should also be safe when there is a cleanup label,
|
||
because expand_null_return takes care of them, too.
|
||
Any reason why not? */
|
||
if (HAVE_return && cleanup_label == 0
|
||
&& ! current_function_returns_pcc_struct
|
||
&& BRANCH_COST <= 1)
|
||
{
|
||
/* If this is return x == y; then generate
|
||
if (x == y) return 1; else return 0;
|
||
if we can do it with explicit return insns and branches are cheap,
|
||
but not if we have the corresponding scc insn. */
|
||
int has_scc = 0;
|
||
if (retval_rhs)
|
||
switch (TREE_CODE (retval_rhs))
|
||
{
|
||
case EQ_EXPR:
|
||
#ifdef HAVE_seq
|
||
has_scc = HAVE_seq;
|
||
#endif
|
||
case NE_EXPR:
|
||
#ifdef HAVE_sne
|
||
has_scc = HAVE_sne;
|
||
#endif
|
||
case GT_EXPR:
|
||
#ifdef HAVE_sgt
|
||
has_scc = HAVE_sgt;
|
||
#endif
|
||
case GE_EXPR:
|
||
#ifdef HAVE_sge
|
||
has_scc = HAVE_sge;
|
||
#endif
|
||
case LT_EXPR:
|
||
#ifdef HAVE_slt
|
||
has_scc = HAVE_slt;
|
||
#endif
|
||
case LE_EXPR:
|
||
#ifdef HAVE_sle
|
||
has_scc = HAVE_sle;
|
||
#endif
|
||
case TRUTH_ANDIF_EXPR:
|
||
case TRUTH_ORIF_EXPR:
|
||
case TRUTH_AND_EXPR:
|
||
case TRUTH_OR_EXPR:
|
||
case TRUTH_NOT_EXPR:
|
||
case TRUTH_XOR_EXPR:
|
||
if (! has_scc)
|
||
{
|
||
op0 = gen_label_rtx ();
|
||
jumpifnot (retval_rhs, op0);
|
||
expand_value_return (const1_rtx);
|
||
emit_label (op0);
|
||
expand_value_return (const0_rtx);
|
||
return;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
}
|
||
#endif /* HAVE_return */
|
||
|
||
/* If the result is an aggregate that is being returned in one (or more)
|
||
registers, load the registers here. The compiler currently can't handle
|
||
copying a BLKmode value into registers. We could put this code in a
|
||
more general area (for use by everyone instead of just function
|
||
call/return), but until this feature is generally usable it is kept here
|
||
(and in expand_call). The value must go into a pseudo in case there
|
||
are cleanups that will clobber the real return register. */
|
||
|
||
if (retval_rhs != 0
|
||
&& TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
|
||
&& GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
|
||
{
|
||
int i, bitpos, xbitpos;
|
||
int big_endian_correction = 0;
|
||
int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
|
||
int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
|
||
int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),
|
||
(unsigned int)BITS_PER_WORD);
|
||
rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
|
||
rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
|
||
rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
|
||
enum machine_mode tmpmode, result_reg_mode;
|
||
|
||
/* Structures whose size is not a multiple of a word are aligned
|
||
to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
|
||
machine, this means we must skip the empty high order bytes when
|
||
calculating the bit offset. */
|
||
if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
|
||
big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
|
||
* BITS_PER_UNIT));
|
||
|
||
/* Copy the structure BITSIZE bits at a time. */
|
||
for (bitpos = 0, xbitpos = big_endian_correction;
|
||
bitpos < bytes * BITS_PER_UNIT;
|
||
bitpos += bitsize, xbitpos += bitsize)
|
||
{
|
||
/* We need a new destination pseudo each time xbitpos is
|
||
on a word boundary and when xbitpos == big_endian_correction
|
||
(the first time through). */
|
||
if (xbitpos % BITS_PER_WORD == 0
|
||
|| xbitpos == big_endian_correction)
|
||
{
|
||
/* Generate an appropriate register. */
|
||
dst = gen_reg_rtx (word_mode);
|
||
result_pseudos[xbitpos / BITS_PER_WORD] = dst;
|
||
|
||
/* Clobber the destination before we move anything into it. */
|
||
emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
|
||
}
|
||
|
||
/* We need a new source operand each time bitpos is on a word
|
||
boundary. */
|
||
if (bitpos % BITS_PER_WORD == 0)
|
||
src = operand_subword_force (result_val,
|
||
bitpos / BITS_PER_WORD,
|
||
BLKmode);
|
||
|
||
/* Use bitpos for the source extraction (left justified) and
|
||
xbitpos for the destination store (right justified). */
|
||
store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
|
||
extract_bit_field (src, bitsize,
|
||
bitpos % BITS_PER_WORD, 1,
|
||
NULL_RTX, word_mode,
|
||
word_mode,
|
||
bitsize / BITS_PER_UNIT,
|
||
BITS_PER_WORD),
|
||
bitsize / BITS_PER_UNIT, BITS_PER_WORD);
|
||
}
|
||
|
||
/* Find the smallest integer mode large enough to hold the
|
||
entire structure and use that mode instead of BLKmode
|
||
on the USE insn for the return register. */
|
||
bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
|
||
for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
|
||
tmpmode != MAX_MACHINE_MODE;
|
||
tmpmode = GET_MODE_WIDER_MODE (tmpmode))
|
||
{
|
||
/* Have we found a large enough mode? */
|
||
if (GET_MODE_SIZE (tmpmode) >= bytes)
|
||
break;
|
||
}
|
||
|
||
/* No suitable mode found. */
|
||
if (tmpmode == MAX_MACHINE_MODE)
|
||
abort ();
|
||
|
||
PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
|
||
|
||
if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
|
||
result_reg_mode = word_mode;
|
||
else
|
||
result_reg_mode = tmpmode;
|
||
result_reg = gen_reg_rtx (result_reg_mode);
|
||
|
||
emit_queue ();
|
||
for (i = 0; i < n_regs; i++)
|
||
emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
|
||
result_pseudos[i]);
|
||
|
||
if (tmpmode != result_reg_mode)
|
||
result_reg = gen_lowpart (tmpmode, result_reg);
|
||
|
||
expand_value_return (result_reg);
|
||
}
|
||
else if (cleanups
|
||
&& retval_rhs != 0
|
||
&& TREE_TYPE (retval_rhs) != void_type_node
|
||
&& GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
|
||
{
|
||
/* Calculate the return value into a pseudo reg. */
|
||
val = gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl)));
|
||
val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
|
||
val = force_not_mem (val);
|
||
emit_queue ();
|
||
/* Return the calculated value, doing cleanups first. */
|
||
expand_value_return (val);
|
||
}
|
||
else
|
||
{
|
||
/* No cleanups or no hard reg used;
|
||
calculate value into hard return reg. */
|
||
expand_expr (retval, const0_rtx, VOIDmode, 0);
|
||
emit_queue ();
|
||
expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
|
||
}
|
||
}
|
||
|
||
/* Return 1 if the end of the generated RTX is not a barrier.
|
||
This means code already compiled can drop through. */
|
||
|
||
int
|
||
drop_through_at_end_p ()
|
||
{
|
||
rtx insn = get_last_insn ();
|
||
while (insn && GET_CODE (insn) == NOTE)
|
||
insn = PREV_INSN (insn);
|
||
return insn && GET_CODE (insn) != BARRIER;
|
||
}
|
||
|
||
/* Test CALL_EXPR to determine if it is a potential tail recursion call
|
||
and emit code to optimize the tail recursion. LAST_INSN indicates where
|
||
to place the jump to the tail recursion label. Return TRUE if the
|
||
call was optimized into a goto.
|
||
|
||
This is only used by expand_return, but expand_call is expected to
|
||
use it soon. */
|
||
|
||
int
|
||
optimize_tail_recursion (call_expr, last_insn)
|
||
tree call_expr;
|
||
rtx last_insn;
|
||
{
|
||
/* For tail-recursive call to current function,
|
||
just jump back to the beginning.
|
||
It's unsafe if any auto variable in this function
|
||
has its address taken; for simplicity,
|
||
require stack frame to be empty. */
|
||
if (optimize && call_expr != 0
|
||
&& frame_offset == 0
|
||
&& TREE_CODE (call_expr) == CALL_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR
|
||
&& TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl
|
||
/* Finish checking validity, and if valid emit code
|
||
to set the argument variables for the new call. */
|
||
&& tail_recursion_args (TREE_OPERAND (call_expr, 1),
|
||
DECL_ARGUMENTS (current_function_decl)))
|
||
{
|
||
if (tail_recursion_label == 0)
|
||
{
|
||
tail_recursion_label = gen_label_rtx ();
|
||
emit_label_after (tail_recursion_label,
|
||
tail_recursion_reentry);
|
||
}
|
||
emit_queue ();
|
||
expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
|
||
emit_barrier ();
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Emit code to alter this function's formal parms for a tail-recursive call.
|
||
ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
|
||
FORMALS is the chain of decls of formals.
|
||
Return 1 if this can be done;
|
||
otherwise return 0 and do not emit any code. */
|
||
|
||
static int
|
||
tail_recursion_args (actuals, formals)
|
||
tree actuals, formals;
|
||
{
|
||
register tree a = actuals, f = formals;
|
||
register int i;
|
||
register rtx *argvec;
|
||
|
||
/* Check that number and types of actuals are compatible
|
||
with the formals. This is not always true in valid C code.
|
||
Also check that no formal needs to be addressable
|
||
and that all formals are scalars. */
|
||
|
||
/* Also count the args. */
|
||
|
||
for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
|
||
{
|
||
if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
|
||
!= TYPE_MAIN_VARIANT (TREE_TYPE (f)))
|
||
return 0;
|
||
if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
|
||
return 0;
|
||
}
|
||
if (a != 0 || f != 0)
|
||
return 0;
|
||
|
||
/* Compute all the actuals. */
|
||
|
||
argvec = (rtx *) alloca (i * sizeof (rtx));
|
||
|
||
for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
|
||
argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
|
||
|
||
/* Find which actual values refer to current values of previous formals.
|
||
Copy each of them now, before any formal is changed. */
|
||
|
||
for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
|
||
{
|
||
int copy = 0;
|
||
register int j;
|
||
for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
|
||
if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
|
||
{ copy = 1; break; }
|
||
if (copy)
|
||
argvec[i] = copy_to_reg (argvec[i]);
|
||
}
|
||
|
||
/* Store the values of the actuals into the formals. */
|
||
|
||
for (f = formals, a = actuals, i = 0; f;
|
||
f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
|
||
{
|
||
if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
|
||
emit_move_insn (DECL_RTL (f), argvec[i]);
|
||
else
|
||
convert_move (DECL_RTL (f), argvec[i],
|
||
TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
|
||
}
|
||
|
||
free_temp_slots ();
|
||
return 1;
|
||
}
|
||
|
||
/* Generate the RTL code for entering a binding contour.
|
||
The variables are declared one by one, by calls to `expand_decl'.
|
||
|
||
EXIT_FLAG is nonzero if this construct should be visible to
|
||
`exit_something'. */
|
||
|
||
void
|
||
expand_start_bindings (exit_flag)
|
||
int exit_flag;
|
||
{
|
||
struct nesting *thisblock = ALLOC_NESTING ();
|
||
rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
|
||
|
||
/* Make an entry on block_stack for the block we are entering. */
|
||
|
||
thisblock->next = block_stack;
|
||
thisblock->all = nesting_stack;
|
||
thisblock->depth = ++nesting_depth;
|
||
thisblock->data.block.stack_level = 0;
|
||
thisblock->data.block.cleanups = 0;
|
||
thisblock->data.block.function_call_count = 0;
|
||
thisblock->data.block.exception_region = 0;
|
||
thisblock->data.block.target_temp_slot_level = target_temp_slot_level;
|
||
|
||
thisblock->data.block.conditional_code = 0;
|
||
thisblock->data.block.last_unconditional_cleanup = note;
|
||
thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
|
||
|
||
if (block_stack
|
||
&& !(block_stack->data.block.cleanups == NULL_TREE
|
||
&& block_stack->data.block.outer_cleanups == NULL_TREE))
|
||
thisblock->data.block.outer_cleanups
|
||
= tree_cons (NULL_TREE, block_stack->data.block.cleanups,
|
||
block_stack->data.block.outer_cleanups);
|
||
else
|
||
thisblock->data.block.outer_cleanups = 0;
|
||
thisblock->data.block.label_chain = 0;
|
||
thisblock->data.block.innermost_stack_block = stack_block_stack;
|
||
thisblock->data.block.first_insn = note;
|
||
thisblock->data.block.block_start_count = ++block_start_count;
|
||
thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
|
||
block_stack = thisblock;
|
||
nesting_stack = thisblock;
|
||
|
||
/* Make a new level for allocating stack slots. */
|
||
push_temp_slots ();
|
||
}
|
||
|
||
/* Specify the scope of temporaries created by TARGET_EXPRs. Similar
|
||
to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
|
||
expand_expr are made. After we end the region, we know that all
|
||
space for all temporaries that were created by TARGET_EXPRs will be
|
||
destroyed and their space freed for reuse. */
|
||
|
||
void
|
||
expand_start_target_temps ()
|
||
{
|
||
/* This is so that even if the result is preserved, the space
|
||
allocated will be freed, as we know that it is no longer in use. */
|
||
push_temp_slots ();
|
||
|
||
/* Start a new binding layer that will keep track of all cleanup
|
||
actions to be performed. */
|
||
expand_start_bindings (0);
|
||
|
||
target_temp_slot_level = temp_slot_level;
|
||
}
|
||
|
||
void
|
||
expand_end_target_temps ()
|
||
{
|
||
expand_end_bindings (NULL_TREE, 0, 0);
|
||
|
||
/* This is so that even if the result is preserved, the space
|
||
allocated will be freed, as we know that it is no longer in use. */
|
||
pop_temp_slots ();
|
||
}
|
||
|
||
/* Mark top block of block_stack as an implicit binding for an
|
||
exception region. This is used to prevent infinite recursion when
|
||
ending a binding with expand_end_bindings. It is only ever called
|
||
by expand_eh_region_start, as that it the only way to create a
|
||
block stack for a exception region. */
|
||
|
||
void
|
||
mark_block_as_eh_region ()
|
||
{
|
||
block_stack->data.block.exception_region = 1;
|
||
if (block_stack->next
|
||
&& block_stack->next->data.block.conditional_code)
|
||
{
|
||
block_stack->data.block.conditional_code
|
||
= block_stack->next->data.block.conditional_code;
|
||
block_stack->data.block.last_unconditional_cleanup
|
||
= block_stack->next->data.block.last_unconditional_cleanup;
|
||
block_stack->data.block.cleanup_ptr
|
||
= block_stack->next->data.block.cleanup_ptr;
|
||
}
|
||
}
|
||
|
||
/* True if we are currently emitting insns in an area of output code
|
||
that is controlled by a conditional expression. This is used by
|
||
the cleanup handling code to generate conditional cleanup actions. */
|
||
|
||
int
|
||
conditional_context ()
|
||
{
|
||
return block_stack && block_stack->data.block.conditional_code;
|
||
}
|
||
|
||
/* Mark top block of block_stack as not for an implicit binding for an
|
||
exception region. This is only ever done by expand_eh_region_end
|
||
to let expand_end_bindings know that it is being called explicitly
|
||
to end the binding layer for just the binding layer associated with
|
||
the exception region, otherwise expand_end_bindings would try and
|
||
end all implicit binding layers for exceptions regions, and then
|
||
one normal binding layer. */
|
||
|
||
void
|
||
mark_block_as_not_eh_region ()
|
||
{
|
||
block_stack->data.block.exception_region = 0;
|
||
}
|
||
|
||
/* True if the top block of block_stack was marked as for an exception
|
||
region by mark_block_as_eh_region. */
|
||
|
||
int
|
||
is_eh_region ()
|
||
{
|
||
return block_stack && block_stack->data.block.exception_region;
|
||
}
|
||
|
||
/* Given a pointer to a BLOCK node, save a pointer to the most recently
|
||
generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
|
||
BLOCK node. */
|
||
|
||
void
|
||
remember_end_note (block)
|
||
register tree block;
|
||
{
|
||
BLOCK_END_NOTE (block) = last_block_end_note;
|
||
last_block_end_note = NULL_RTX;
|
||
}
|
||
|
||
/* Emit a handler label for a nonlocal goto handler.
|
||
Also emit code to store the handler label in SLOT before BEFORE_INSN. */
|
||
|
||
static rtx
|
||
expand_nl_handler_label (slot, before_insn)
|
||
rtx slot, before_insn;
|
||
{
|
||
rtx insns;
|
||
rtx handler_label = gen_label_rtx ();
|
||
|
||
/* Don't let jump_optimize delete the handler. */
|
||
LABEL_PRESERVE_P (handler_label) = 1;
|
||
|
||
start_sequence ();
|
||
emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
|
||
insns = get_insns ();
|
||
end_sequence ();
|
||
emit_insns_before (insns, before_insn);
|
||
|
||
emit_label (handler_label);
|
||
|
||
return handler_label;
|
||
}
|
||
|
||
/* Emit code to restore vital registers at the beginning of a nonlocal goto
|
||
handler. */
|
||
static void
|
||
expand_nl_goto_receiver ()
|
||
{
|
||
#ifdef HAVE_nonlocal_goto
|
||
if (! HAVE_nonlocal_goto)
|
||
#endif
|
||
/* First adjust our frame pointer to its actual value. It was
|
||
previously set to the start of the virtual area corresponding to
|
||
the stacked variables when we branched here and now needs to be
|
||
adjusted to the actual hardware fp value.
|
||
|
||
Assignments are to virtual registers are converted by
|
||
instantiate_virtual_regs into the corresponding assignment
|
||
to the underlying register (fp in this case) that makes
|
||
the original assignment true.
|
||
So the following insn will actually be
|
||
decrementing fp by STARTING_FRAME_OFFSET. */
|
||
emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
|
||
|
||
#if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
|
||
if (fixed_regs[ARG_POINTER_REGNUM])
|
||
{
|
||
#ifdef ELIMINABLE_REGS
|
||
/* If the argument pointer can be eliminated in favor of the
|
||
frame pointer, we don't need to restore it. We assume here
|
||
that if such an elimination is present, it can always be used.
|
||
This is the case on all known machines; if we don't make this
|
||
assumption, we do unnecessary saving on many machines. */
|
||
static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
|
||
size_t i;
|
||
|
||
for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
|
||
if (elim_regs[i].from == ARG_POINTER_REGNUM
|
||
&& elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
|
||
break;
|
||
|
||
if (i == sizeof elim_regs / sizeof elim_regs [0])
|
||
#endif
|
||
{
|
||
/* Now restore our arg pointer from the address at which it
|
||
was saved in our stack frame.
|
||
If there hasn't be space allocated for it yet, make
|
||
some now. */
|
||
if (arg_pointer_save_area == 0)
|
||
arg_pointer_save_area
|
||
= assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
|
||
emit_move_insn (virtual_incoming_args_rtx,
|
||
/* We need a pseudo here, or else
|
||
instantiate_virtual_regs_1 complains. */
|
||
copy_to_reg (arg_pointer_save_area));
|
||
}
|
||
}
|
||
#endif
|
||
|
||
#ifdef HAVE_nonlocal_goto_receiver
|
||
if (HAVE_nonlocal_goto_receiver)
|
||
emit_insn (gen_nonlocal_goto_receiver ());
|
||
#endif
|
||
}
|
||
|
||
/* Make handlers for nonlocal gotos taking place in the function calls in
|
||
block THISBLOCK. */
|
||
|
||
static void
|
||
expand_nl_goto_receivers (thisblock)
|
||
struct nesting *thisblock;
|
||
{
|
||
tree link;
|
||
rtx afterward = gen_label_rtx ();
|
||
rtx insns, slot;
|
||
rtx label_list;
|
||
int any_invalid;
|
||
|
||
/* Record the handler address in the stack slot for that purpose,
|
||
during this block, saving and restoring the outer value. */
|
||
if (thisblock->next != 0)
|
||
for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
|
||
{
|
||
rtx save_receiver = gen_reg_rtx (Pmode);
|
||
emit_move_insn (XEXP (slot, 0), save_receiver);
|
||
|
||
start_sequence ();
|
||
emit_move_insn (save_receiver, XEXP (slot, 0));
|
||
insns = get_insns ();
|
||
end_sequence ();
|
||
emit_insns_before (insns, thisblock->data.block.first_insn);
|
||
}
|
||
|
||
/* Jump around the handlers; they run only when specially invoked. */
|
||
emit_jump (afterward);
|
||
|
||
/* Make a separate handler for each label. */
|
||
link = nonlocal_labels;
|
||
slot = nonlocal_goto_handler_slots;
|
||
label_list = NULL_RTX;
|
||
for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
|
||
/* Skip any labels we shouldn't be able to jump to from here,
|
||
we generate one special handler for all of them below which just calls
|
||
abort. */
|
||
if (! DECL_TOO_LATE (TREE_VALUE (link)))
|
||
{
|
||
rtx lab;
|
||
lab = expand_nl_handler_label (XEXP (slot, 0),
|
||
thisblock->data.block.first_insn);
|
||
label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
|
||
|
||
expand_nl_goto_receiver ();
|
||
|
||
/* Jump to the "real" nonlocal label. */
|
||
expand_goto (TREE_VALUE (link));
|
||
}
|
||
|
||
/* A second pass over all nonlocal labels; this time we handle those
|
||
we should not be able to jump to at this point. */
|
||
link = nonlocal_labels;
|
||
slot = nonlocal_goto_handler_slots;
|
||
any_invalid = 0;
|
||
for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
|
||
if (DECL_TOO_LATE (TREE_VALUE (link)))
|
||
{
|
||
rtx lab;
|
||
lab = expand_nl_handler_label (XEXP (slot, 0),
|
||
thisblock->data.block.first_insn);
|
||
label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
|
||
any_invalid = 1;
|
||
}
|
||
|
||
if (any_invalid)
|
||
{
|
||
expand_nl_goto_receiver ();
|
||
emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
|
||
VOIDmode, 0);
|
||
emit_barrier ();
|
||
}
|
||
|
||
nonlocal_goto_handler_labels = label_list;
|
||
emit_label (afterward);
|
||
}
|
||
|
||
/* Generate RTL code to terminate a binding contour.
|
||
|
||
VARS is the chain of VAR_DECL nodes for the variables bound in this
|
||
contour. There may actually be other nodes in this chain, but any
|
||
nodes other than VAR_DECLS are ignored.
|
||
|
||
MARK_ENDS is nonzero if we should put a note at the beginning
|
||
and end of this binding contour.
|
||
|
||
DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
|
||
(That is true automatically if the contour has a saved stack level.) */
|
||
|
||
void
|
||
expand_end_bindings (vars, mark_ends, dont_jump_in)
|
||
tree vars;
|
||
int mark_ends;
|
||
int dont_jump_in;
|
||
{
|
||
register struct nesting *thisblock;
|
||
register tree decl;
|
||
|
||
while (block_stack->data.block.exception_region)
|
||
{
|
||
/* Because we don't need or want a new temporary level and
|
||
because we didn't create one in expand_eh_region_start,
|
||
create a fake one now to avoid removing one in
|
||
expand_end_bindings. */
|
||
push_temp_slots ();
|
||
|
||
block_stack->data.block.exception_region = 0;
|
||
|
||
expand_end_bindings (NULL_TREE, 0, 0);
|
||
}
|
||
|
||
/* Since expand_eh_region_start does an expand_start_bindings, we
|
||
have to first end all the bindings that were created by
|
||
expand_eh_region_start. */
|
||
|
||
thisblock = block_stack;
|
||
|
||
if (warn_unused)
|
||
for (decl = vars; decl; decl = TREE_CHAIN (decl))
|
||
if (TREE_CODE (decl) == VAR_DECL
|
||
&& ! TREE_USED (decl)
|
||
&& ! DECL_IN_SYSTEM_HEADER (decl)
|
||
&& DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
|
||
warning_with_decl (decl, "unused variable `%s'");
|
||
|
||
if (thisblock->exit_label)
|
||
{
|
||
do_pending_stack_adjust ();
|
||
emit_label (thisblock->exit_label);
|
||
}
|
||
|
||
/* If necessary, make handlers for nonlocal gotos taking
|
||
place in the function calls in this block. */
|
||
if (function_call_count != thisblock->data.block.function_call_count
|
||
&& nonlocal_labels
|
||
/* Make handler for outermost block
|
||
if there were any nonlocal gotos to this function. */
|
||
&& (thisblock->next == 0 ? current_function_has_nonlocal_label
|
||
/* Make handler for inner block if it has something
|
||
special to do when you jump out of it. */
|
||
: (thisblock->data.block.cleanups != 0
|
||
|| thisblock->data.block.stack_level != 0)))
|
||
expand_nl_goto_receivers (thisblock);
|
||
|
||
/* Don't allow jumping into a block that has a stack level.
|
||
Cleanups are allowed, though. */
|
||
if (dont_jump_in
|
||
|| thisblock->data.block.stack_level != 0)
|
||
{
|
||
struct label_chain *chain;
|
||
|
||
/* Any labels in this block are no longer valid to go to.
|
||
Mark them to cause an error message. */
|
||
for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
|
||
{
|
||
DECL_TOO_LATE (chain->label) = 1;
|
||
/* If any goto without a fixup came to this label,
|
||
that must be an error, because gotos without fixups
|
||
come from outside all saved stack-levels. */
|
||
if (TREE_ADDRESSABLE (chain->label))
|
||
error_with_decl (chain->label,
|
||
"label `%s' used before containing binding contour");
|
||
}
|
||
}
|
||
|
||
/* Restore stack level in effect before the block
|
||
(only if variable-size objects allocated). */
|
||
/* Perform any cleanups associated with the block. */
|
||
|
||
if (thisblock->data.block.stack_level != 0
|
||
|| thisblock->data.block.cleanups != 0)
|
||
{
|
||
/* Only clean up here if this point can actually be reached. */
|
||
int reachable = GET_CODE (get_last_insn ()) != BARRIER;
|
||
|
||
/* Don't let cleanups affect ({...}) constructs. */
|
||
int old_expr_stmts_for_value = expr_stmts_for_value;
|
||
rtx old_last_expr_value = last_expr_value;
|
||
tree old_last_expr_type = last_expr_type;
|
||
expr_stmts_for_value = 0;
|
||
|
||
/* Do the cleanups. */
|
||
expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
|
||
if (reachable)
|
||
do_pending_stack_adjust ();
|
||
|
||
expr_stmts_for_value = old_expr_stmts_for_value;
|
||
last_expr_value = old_last_expr_value;
|
||
last_expr_type = old_last_expr_type;
|
||
|
||
/* Restore the stack level. */
|
||
|
||
if (reachable && thisblock->data.block.stack_level != 0)
|
||
{
|
||
emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
|
||
thisblock->data.block.stack_level, NULL_RTX);
|
||
if (nonlocal_goto_handler_slots != 0)
|
||
emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
|
||
NULL_RTX);
|
||
}
|
||
|
||
/* Any gotos out of this block must also do these things.
|
||
Also report any gotos with fixups that came to labels in this
|
||
level. */
|
||
fixup_gotos (thisblock,
|
||
thisblock->data.block.stack_level,
|
||
thisblock->data.block.cleanups,
|
||
thisblock->data.block.first_insn,
|
||
dont_jump_in);
|
||
}
|
||
|
||
/* Mark the beginning and end of the scope if requested.
|
||
We do this now, after running cleanups on the variables
|
||
just going out of scope, so they are in scope for their cleanups. */
|
||
|
||
if (mark_ends)
|
||
last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
|
||
else
|
||
/* Get rid of the beginning-mark if we don't make an end-mark. */
|
||
NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
|
||
|
||
/* If doing stupid register allocation, make sure lives of all
|
||
register variables declared here extend thru end of scope. */
|
||
|
||
if (obey_regdecls)
|
||
for (decl = vars; decl; decl = TREE_CHAIN (decl))
|
||
if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl))
|
||
use_variable (DECL_RTL (decl));
|
||
|
||
/* Restore the temporary level of TARGET_EXPRs. */
|
||
target_temp_slot_level = thisblock->data.block.target_temp_slot_level;
|
||
|
||
/* Restore block_stack level for containing block. */
|
||
|
||
stack_block_stack = thisblock->data.block.innermost_stack_block;
|
||
POPSTACK (block_stack);
|
||
|
||
/* Pop the stack slot nesting and free any slots at this level. */
|
||
pop_temp_slots ();
|
||
}
|
||
|
||
/* Generate RTL for the automatic variable declaration DECL.
|
||
(Other kinds of declarations are simply ignored if seen here.) */
|
||
|
||
void
|
||
expand_decl (decl)
|
||
register tree decl;
|
||
{
|
||
struct nesting *thisblock = block_stack;
|
||
tree type;
|
||
|
||
type = TREE_TYPE (decl);
|
||
|
||
/* Only automatic variables need any expansion done.
|
||
Static and external variables, and external functions,
|
||
will be handled by `assemble_variable' (called from finish_decl).
|
||
TYPE_DECL and CONST_DECL require nothing.
|
||
PARM_DECLs are handled in `assign_parms'. */
|
||
|
||
if (TREE_CODE (decl) != VAR_DECL)
|
||
return;
|
||
if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
|
||
return;
|
||
|
||
/* Create the RTL representation for the variable. */
|
||
|
||
if (type == error_mark_node)
|
||
DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
|
||
else if (DECL_SIZE (decl) == 0)
|
||
/* Variable with incomplete type. */
|
||
{
|
||
if (DECL_INITIAL (decl) == 0)
|
||
/* Error message was already done; now avoid a crash. */
|
||
DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
|
||
else
|
||
/* An initializer is going to decide the size of this array.
|
||
Until we know the size, represent its address with a reg. */
|
||
DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
|
||
MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
|
||
}
|
||
else if (DECL_MODE (decl) != BLKmode
|
||
/* If -ffloat-store, don't put explicit float vars
|
||
into regs. */
|
||
&& !(flag_float_store
|
||
&& TREE_CODE (type) == REAL_TYPE)
|
||
&& ! TREE_THIS_VOLATILE (decl)
|
||
&& ! TREE_ADDRESSABLE (decl)
|
||
&& (DECL_REGISTER (decl) || ! obey_regdecls)
|
||
/* if -fcheck-memory-usage, check all variables. */
|
||
&& ! current_function_check_memory_usage)
|
||
{
|
||
/* Automatic variable that can go in a register. */
|
||
int unsignedp = TREE_UNSIGNED (type);
|
||
enum machine_mode reg_mode
|
||
= promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
|
||
|
||
DECL_RTL (decl) = gen_reg_rtx (reg_mode);
|
||
mark_user_reg (DECL_RTL (decl));
|
||
|
||
if (POINTER_TYPE_P (type))
|
||
mark_reg_pointer (DECL_RTL (decl),
|
||
(TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
|
||
/ BITS_PER_UNIT));
|
||
}
|
||
|
||
else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST
|
||
&& ! (flag_stack_check && ! STACK_CHECK_BUILTIN
|
||
&& (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0
|
||
|| (TREE_INT_CST_LOW (DECL_SIZE (decl))
|
||
> STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT))))
|
||
{
|
||
/* Variable of fixed size that goes on the stack. */
|
||
rtx oldaddr = 0;
|
||
rtx addr;
|
||
|
||
/* If we previously made RTL for this decl, it must be an array
|
||
whose size was determined by the initializer.
|
||
The old address was a register; set that register now
|
||
to the proper address. */
|
||
if (DECL_RTL (decl) != 0)
|
||
{
|
||
if (GET_CODE (DECL_RTL (decl)) != MEM
|
||
|| GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
|
||
abort ();
|
||
oldaddr = XEXP (DECL_RTL (decl), 0);
|
||
}
|
||
|
||
DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
|
||
MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
|
||
AGGREGATE_TYPE_P (TREE_TYPE (decl)));
|
||
|
||
/* Set alignment we actually gave this decl. */
|
||
DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
|
||
: GET_MODE_BITSIZE (DECL_MODE (decl)));
|
||
|
||
if (oldaddr)
|
||
{
|
||
addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
|
||
if (addr != oldaddr)
|
||
emit_move_insn (oldaddr, addr);
|
||
}
|
||
|
||
/* If this is a memory ref that contains aggregate components,
|
||
mark it as such for cse and loop optimize. */
|
||
MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
|
||
AGGREGATE_TYPE_P (TREE_TYPE (decl)));
|
||
#if 0
|
||
/* If this is in memory because of -ffloat-store,
|
||
set the volatile bit, to prevent optimizations from
|
||
undoing the effects. */
|
||
if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
|
||
MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
|
||
#endif
|
||
|
||
MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
|
||
}
|
||
else
|
||
/* Dynamic-size object: must push space on the stack. */
|
||
{
|
||
rtx address, size;
|
||
|
||
/* Record the stack pointer on entry to block, if have
|
||
not already done so. */
|
||
if (thisblock->data.block.stack_level == 0)
|
||
{
|
||
do_pending_stack_adjust ();
|
||
emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
|
||
&thisblock->data.block.stack_level,
|
||
thisblock->data.block.first_insn);
|
||
stack_block_stack = thisblock;
|
||
}
|
||
|
||
/* Compute the variable's size, in bytes. */
|
||
size = expand_expr (size_binop (CEIL_DIV_EXPR,
|
||
DECL_SIZE (decl),
|
||
size_int (BITS_PER_UNIT)),
|
||
NULL_RTX, VOIDmode, 0);
|
||
free_temp_slots ();
|
||
|
||
/* Allocate space on the stack for the variable. Note that
|
||
DECL_ALIGN says how the variable is to be aligned and we
|
||
cannot use it to conclude anything about the alignment of
|
||
the size. */
|
||
address = allocate_dynamic_stack_space (size, NULL_RTX,
|
||
TYPE_ALIGN (TREE_TYPE (decl)));
|
||
|
||
/* Reference the variable indirect through that rtx. */
|
||
DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
|
||
|
||
/* If this is a memory ref that contains aggregate components,
|
||
mark it as such for cse and loop optimize. */
|
||
MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
|
||
AGGREGATE_TYPE_P (TREE_TYPE (decl)));
|
||
|
||
/* Indicate the alignment we actually gave this variable. */
|
||
#ifdef STACK_BOUNDARY
|
||
DECL_ALIGN (decl) = STACK_BOUNDARY;
|
||
#else
|
||
DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
|
||
#endif
|
||
}
|
||
|
||
if (TREE_THIS_VOLATILE (decl))
|
||
MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
|
||
#if 0 /* A variable is not necessarily unchanging
|
||
just because it is const. RTX_UNCHANGING_P
|
||
means no change in the function,
|
||
not merely no change in the variable's scope.
|
||
It is correct to set RTX_UNCHANGING_P if the variable's scope
|
||
is the whole function. There's no convenient way to test that. */
|
||
if (TREE_READONLY (decl))
|
||
RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
|
||
#endif
|
||
|
||
/* If doing stupid register allocation, make sure life of any
|
||
register variable starts here, at the start of its scope. */
|
||
|
||
if (obey_regdecls)
|
||
use_variable (DECL_RTL (decl));
|
||
}
|
||
|
||
|
||
|
||
/* Emit code to perform the initialization of a declaration DECL. */
|
||
|
||
void
|
||
expand_decl_init (decl)
|
||
tree decl;
|
||
{
|
||
int was_used = TREE_USED (decl);
|
||
|
||
/* If this is a CONST_DECL, we don't have to generate any code, but
|
||
if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
|
||
to be set while in the obstack containing the constant. If we don't
|
||
do this, we can lose if we have functions nested three deep and the middle
|
||
function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
|
||
the innermost function is the first to expand that STRING_CST. */
|
||
if (TREE_CODE (decl) == CONST_DECL)
|
||
{
|
||
if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
|
||
expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
|
||
EXPAND_INITIALIZER);
|
||
return;
|
||
}
|
||
|
||
if (TREE_STATIC (decl))
|
||
return;
|
||
|
||
/* Compute and store the initial value now. */
|
||
|
||
if (DECL_INITIAL (decl) == error_mark_node)
|
||
{
|
||
enum tree_code code = TREE_CODE (TREE_TYPE (decl));
|
||
|
||
if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
|
||
|| code == POINTER_TYPE || code == REFERENCE_TYPE)
|
||
expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
|
||
0, 0);
|
||
emit_queue ();
|
||
}
|
||
else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
|
||
{
|
||
emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
|
||
expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
|
||
emit_queue ();
|
||
}
|
||
|
||
/* Don't let the initialization count as "using" the variable. */
|
||
TREE_USED (decl) = was_used;
|
||
|
||
/* Free any temporaries we made while initializing the decl. */
|
||
preserve_temp_slots (NULL_RTX);
|
||
free_temp_slots ();
|
||
}
|
||
|
||
/* CLEANUP is an expression to be executed at exit from this binding contour;
|
||
for example, in C++, it might call the destructor for this variable.
|
||
|
||
We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
|
||
CLEANUP multiple times, and have the correct semantics. This
|
||
happens in exception handling, for gotos, returns, breaks that
|
||
leave the current scope.
|
||
|
||
If CLEANUP is nonzero and DECL is zero, we record a cleanup
|
||
that is not associated with any particular variable. */
|
||
|
||
int
|
||
expand_decl_cleanup (decl, cleanup)
|
||
tree decl, cleanup;
|
||
{
|
||
struct nesting *thisblock = block_stack;
|
||
|
||
/* Error if we are not in any block. */
|
||
if (thisblock == 0)
|
||
return 0;
|
||
|
||
/* Record the cleanup if there is one. */
|
||
|
||
if (cleanup != 0)
|
||
{
|
||
tree t;
|
||
rtx seq;
|
||
tree *cleanups = &thisblock->data.block.cleanups;
|
||
int cond_context = conditional_context ();
|
||
|
||
if (cond_context)
|
||
{
|
||
rtx flag = gen_reg_rtx (word_mode);
|
||
rtx set_flag_0;
|
||
tree cond;
|
||
|
||
start_sequence ();
|
||
emit_move_insn (flag, const0_rtx);
|
||
set_flag_0 = get_insns ();
|
||
end_sequence ();
|
||
|
||
thisblock->data.block.last_unconditional_cleanup
|
||
= emit_insns_after (set_flag_0,
|
||
thisblock->data.block.last_unconditional_cleanup);
|
||
|
||
emit_move_insn (flag, const1_rtx);
|
||
|
||
/* All cleanups must be on the function_obstack. */
|
||
push_obstacks_nochange ();
|
||
resume_temporary_allocation ();
|
||
|
||
cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
|
||
DECL_RTL (cond) = flag;
|
||
|
||
/* Conditionalize the cleanup. */
|
||
cleanup = build (COND_EXPR, void_type_node,
|
||
truthvalue_conversion (cond),
|
||
cleanup, integer_zero_node);
|
||
cleanup = fold (cleanup);
|
||
|
||
pop_obstacks ();
|
||
|
||
cleanups = thisblock->data.block.cleanup_ptr;
|
||
}
|
||
|
||
/* All cleanups must be on the function_obstack. */
|
||
push_obstacks_nochange ();
|
||
resume_temporary_allocation ();
|
||
cleanup = unsave_expr (cleanup);
|
||
pop_obstacks ();
|
||
|
||
t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
|
||
|
||
if (! cond_context)
|
||
/* If this block has a cleanup, it belongs in stack_block_stack. */
|
||
stack_block_stack = thisblock;
|
||
|
||
if (cond_context)
|
||
{
|
||
start_sequence ();
|
||
}
|
||
|
||
/* If this was optimized so that there is no exception region for the
|
||
cleanup, then mark the TREE_LIST node, so that we can later tell
|
||
if we need to call expand_eh_region_end. */
|
||
if (! using_eh_for_cleanups_p
|
||
|| expand_eh_region_start_tree (decl, cleanup))
|
||
TREE_ADDRESSABLE (t) = 1;
|
||
/* If that started a new EH region, we're in a new block. */
|
||
thisblock = block_stack;
|
||
|
||
if (cond_context)
|
||
{
|
||
seq = get_insns ();
|
||
end_sequence ();
|
||
if (seq)
|
||
thisblock->data.block.last_unconditional_cleanup
|
||
= emit_insns_after (seq,
|
||
thisblock->data.block.last_unconditional_cleanup);
|
||
}
|
||
else
|
||
{
|
||
thisblock->data.block.last_unconditional_cleanup
|
||
= get_last_insn ();
|
||
thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
|
||
}
|
||
}
|
||
return 1;
|
||
}
|
||
|
||
/* Like expand_decl_cleanup, but suppress generating an exception handler
|
||
to perform the cleanup. */
|
||
|
||
int
|
||
expand_decl_cleanup_no_eh (decl, cleanup)
|
||
tree decl, cleanup;
|
||
{
|
||
int save_eh = using_eh_for_cleanups_p;
|
||
int result;
|
||
|
||
using_eh_for_cleanups_p = 0;
|
||
result = expand_decl_cleanup (decl, cleanup);
|
||
using_eh_for_cleanups_p = save_eh;
|
||
|
||
return result;
|
||
}
|
||
|
||
/* Arrange for the top element of the dynamic cleanup chain to be
|
||
popped if we exit the current binding contour. DECL is the
|
||
associated declaration, if any, otherwise NULL_TREE. If the
|
||
current contour is left via an exception, then __sjthrow will pop
|
||
the top element off the dynamic cleanup chain. The code that
|
||
avoids doing the action we push into the cleanup chain in the
|
||
exceptional case is contained in expand_cleanups.
|
||
|
||
This routine is only used by expand_eh_region_start, and that is
|
||
the only way in which an exception region should be started. This
|
||
routine is only used when using the setjmp/longjmp codegen method
|
||
for exception handling. */
|
||
|
||
int
|
||
expand_dcc_cleanup (decl)
|
||
tree decl;
|
||
{
|
||
struct nesting *thisblock = block_stack;
|
||
tree cleanup;
|
||
|
||
/* Error if we are not in any block. */
|
||
if (thisblock == 0)
|
||
return 0;
|
||
|
||
/* Record the cleanup for the dynamic handler chain. */
|
||
|
||
/* All cleanups must be on the function_obstack. */
|
||
push_obstacks_nochange ();
|
||
resume_temporary_allocation ();
|
||
cleanup = make_node (POPDCC_EXPR);
|
||
pop_obstacks ();
|
||
|
||
/* Add the cleanup in a manner similar to expand_decl_cleanup. */
|
||
thisblock->data.block.cleanups
|
||
= temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
|
||
|
||
/* If this block has a cleanup, it belongs in stack_block_stack. */
|
||
stack_block_stack = thisblock;
|
||
return 1;
|
||
}
|
||
|
||
/* Arrange for the top element of the dynamic handler chain to be
|
||
popped if we exit the current binding contour. DECL is the
|
||
associated declaration, if any, otherwise NULL_TREE. If the current
|
||
contour is left via an exception, then __sjthrow will pop the top
|
||
element off the dynamic handler chain. The code that avoids doing
|
||
the action we push into the handler chain in the exceptional case
|
||
is contained in expand_cleanups.
|
||
|
||
This routine is only used by expand_eh_region_start, and that is
|
||
the only way in which an exception region should be started. This
|
||
routine is only used when using the setjmp/longjmp codegen method
|
||
for exception handling. */
|
||
|
||
int
|
||
expand_dhc_cleanup (decl)
|
||
tree decl;
|
||
{
|
||
struct nesting *thisblock = block_stack;
|
||
tree cleanup;
|
||
|
||
/* Error if we are not in any block. */
|
||
if (thisblock == 0)
|
||
return 0;
|
||
|
||
/* Record the cleanup for the dynamic handler chain. */
|
||
|
||
/* All cleanups must be on the function_obstack. */
|
||
push_obstacks_nochange ();
|
||
resume_temporary_allocation ();
|
||
cleanup = make_node (POPDHC_EXPR);
|
||
pop_obstacks ();
|
||
|
||
/* Add the cleanup in a manner similar to expand_decl_cleanup. */
|
||
thisblock->data.block.cleanups
|
||
= temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
|
||
|
||
/* If this block has a cleanup, it belongs in stack_block_stack. */
|
||
stack_block_stack = thisblock;
|
||
return 1;
|
||
}
|
||
|
||
/* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
|
||
DECL_ELTS is the list of elements that belong to DECL's type.
|
||
In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
|
||
|
||
void
|
||
expand_anon_union_decl (decl, cleanup, decl_elts)
|
||
tree decl, cleanup, decl_elts;
|
||
{
|
||
struct nesting *thisblock = block_stack;
|
||
rtx x;
|
||
|
||
expand_decl (decl);
|
||
expand_decl_cleanup (decl, cleanup);
|
||
x = DECL_RTL (decl);
|
||
|
||
while (decl_elts)
|
||
{
|
||
tree decl_elt = TREE_VALUE (decl_elts);
|
||
tree cleanup_elt = TREE_PURPOSE (decl_elts);
|
||
enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
|
||
|
||
/* Propagate the union's alignment to the elements. */
|
||
DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
|
||
|
||
/* If the element has BLKmode and the union doesn't, the union is
|
||
aligned such that the element doesn't need to have BLKmode, so
|
||
change the element's mode to the appropriate one for its size. */
|
||
if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
|
||
DECL_MODE (decl_elt) = mode
|
||
= mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
|
||
MODE_INT, 1);
|
||
|
||
/* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
|
||
instead create a new MEM rtx with the proper mode. */
|
||
if (GET_CODE (x) == MEM)
|
||
{
|
||
if (mode == GET_MODE (x))
|
||
DECL_RTL (decl_elt) = x;
|
||
else
|
||
{
|
||
DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
|
||
MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
|
||
RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
|
||
}
|
||
}
|
||
else if (GET_CODE (x) == REG)
|
||
{
|
||
if (mode == GET_MODE (x))
|
||
DECL_RTL (decl_elt) = x;
|
||
else
|
||
DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
|
||
}
|
||
else
|
||
abort ();
|
||
|
||
/* Record the cleanup if there is one. */
|
||
|
||
if (cleanup != 0)
|
||
thisblock->data.block.cleanups
|
||
= temp_tree_cons (decl_elt, cleanup_elt,
|
||
thisblock->data.block.cleanups);
|
||
|
||
decl_elts = TREE_CHAIN (decl_elts);
|
||
}
|
||
}
|
||
|
||
/* Expand a list of cleanups LIST.
|
||
Elements may be expressions or may be nested lists.
|
||
|
||
If DONT_DO is nonnull, then any list-element
|
||
whose TREE_PURPOSE matches DONT_DO is omitted.
|
||
This is sometimes used to avoid a cleanup associated with
|
||
a value that is being returned out of the scope.
|
||
|
||
If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
|
||
goto and handle protection regions specially in that case.
|
||
|
||
If REACHABLE, we emit code, otherwise just inform the exception handling
|
||
code about this finalization. */
|
||
|
||
static void
|
||
expand_cleanups (list, dont_do, in_fixup, reachable)
|
||
tree list;
|
||
tree dont_do;
|
||
int in_fixup;
|
||
int reachable;
|
||
{
|
||
tree tail;
|
||
for (tail = list; tail; tail = TREE_CHAIN (tail))
|
||
if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
|
||
{
|
||
if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
|
||
expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
|
||
else
|
||
{
|
||
if (! in_fixup)
|
||
{
|
||
tree cleanup = TREE_VALUE (tail);
|
||
|
||
/* See expand_d{h,c}c_cleanup for why we avoid this. */
|
||
if (TREE_CODE (cleanup) != POPDHC_EXPR
|
||
&& TREE_CODE (cleanup) != POPDCC_EXPR
|
||
/* See expand_eh_region_start_tree for this case. */
|
||
&& ! TREE_ADDRESSABLE (tail))
|
||
{
|
||
cleanup = protect_with_terminate (cleanup);
|
||
expand_eh_region_end (cleanup);
|
||
}
|
||
}
|
||
|
||
if (reachable)
|
||
{
|
||
/* Cleanups may be run multiple times. For example,
|
||
when exiting a binding contour, we expand the
|
||
cleanups associated with that contour. When a goto
|
||
within that binding contour has a target outside that
|
||
contour, it will expand all cleanups from its scope to
|
||
the target. Though the cleanups are expanded multiple
|
||
times, the control paths are non-overlapping so the
|
||
cleanups will not be executed twice. */
|
||
|
||
/* We may need to protect fixups with rethrow regions. */
|
||
int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
|
||
|
||
if (protect)
|
||
expand_fixup_region_start ();
|
||
|
||
expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
|
||
if (protect)
|
||
expand_fixup_region_end (TREE_VALUE (tail));
|
||
free_temp_slots ();
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Mark when the context we are emitting RTL for as a conditional
|
||
context, so that any cleanup actions we register with
|
||
expand_decl_init will be properly conditionalized when those
|
||
cleanup actions are later performed. Must be called before any
|
||
expression (tree) is expanded that is within a conditional context. */
|
||
|
||
void
|
||
start_cleanup_deferral ()
|
||
{
|
||
/* block_stack can be NULL if we are inside the parameter list. It is
|
||
OK to do nothing, because cleanups aren't possible here. */
|
||
if (block_stack)
|
||
++block_stack->data.block.conditional_code;
|
||
}
|
||
|
||
/* Mark the end of a conditional region of code. Because cleanup
|
||
deferrals may be nested, we may still be in a conditional region
|
||
after we end the currently deferred cleanups, only after we end all
|
||
deferred cleanups, are we back in unconditional code. */
|
||
|
||
void
|
||
end_cleanup_deferral ()
|
||
{
|
||
/* block_stack can be NULL if we are inside the parameter list. It is
|
||
OK to do nothing, because cleanups aren't possible here. */
|
||
if (block_stack)
|
||
--block_stack->data.block.conditional_code;
|
||
}
|
||
|
||
/* Move all cleanups from the current block_stack
|
||
to the containing block_stack, where they are assumed to
|
||
have been created. If anything can cause a temporary to
|
||
be created, but not expanded for more than one level of
|
||
block_stacks, then this code will have to change. */
|
||
|
||
void
|
||
move_cleanups_up ()
|
||
{
|
||
struct nesting *block = block_stack;
|
||
struct nesting *outer = block->next;
|
||
|
||
outer->data.block.cleanups
|
||
= chainon (block->data.block.cleanups,
|
||
outer->data.block.cleanups);
|
||
block->data.block.cleanups = 0;
|
||
}
|
||
|
||
tree
|
||
last_cleanup_this_contour ()
|
||
{
|
||
if (block_stack == 0)
|
||
return 0;
|
||
|
||
return block_stack->data.block.cleanups;
|
||
}
|
||
|
||
/* Return 1 if there are any pending cleanups at this point.
|
||
If THIS_CONTOUR is nonzero, check the current contour as well.
|
||
Otherwise, look only at the contours that enclose this one. */
|
||
|
||
int
|
||
any_pending_cleanups (this_contour)
|
||
int this_contour;
|
||
{
|
||
struct nesting *block;
|
||
|
||
if (block_stack == 0)
|
||
return 0;
|
||
|
||
if (this_contour && block_stack->data.block.cleanups != NULL)
|
||
return 1;
|
||
if (block_stack->data.block.cleanups == 0
|
||
&& block_stack->data.block.outer_cleanups == 0)
|
||
return 0;
|
||
|
||
for (block = block_stack->next; block; block = block->next)
|
||
if (block->data.block.cleanups != 0)
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Enter a case (Pascal) or switch (C) statement.
|
||
Push a block onto case_stack and nesting_stack
|
||
to accumulate the case-labels that are seen
|
||
and to record the labels generated for the statement.
|
||
|
||
EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
|
||
Otherwise, this construct is transparent for `exit_something'.
|
||
|
||
EXPR is the index-expression to be dispatched on.
|
||
TYPE is its nominal type. We could simply convert EXPR to this type,
|
||
but instead we take short cuts. */
|
||
|
||
void
|
||
expand_start_case (exit_flag, expr, type, printname)
|
||
int exit_flag;
|
||
tree expr;
|
||
tree type;
|
||
const char *printname;
|
||
{
|
||
register struct nesting *thiscase = ALLOC_NESTING ();
|
||
|
||
/* Make an entry on case_stack for the case we are entering. */
|
||
|
||
thiscase->next = case_stack;
|
||
thiscase->all = nesting_stack;
|
||
thiscase->depth = ++nesting_depth;
|
||
thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
|
||
thiscase->data.case_stmt.case_list = 0;
|
||
thiscase->data.case_stmt.index_expr = expr;
|
||
thiscase->data.case_stmt.nominal_type = type;
|
||
thiscase->data.case_stmt.default_label = 0;
|
||
thiscase->data.case_stmt.num_ranges = 0;
|
||
thiscase->data.case_stmt.printname = printname;
|
||
thiscase->data.case_stmt.line_number_status = force_line_numbers ();
|
||
case_stack = thiscase;
|
||
nesting_stack = thiscase;
|
||
|
||
do_pending_stack_adjust ();
|
||
|
||
/* Make sure case_stmt.start points to something that won't
|
||
need any transformation before expand_end_case. */
|
||
if (GET_CODE (get_last_insn ()) != NOTE)
|
||
emit_note (NULL_PTR, NOTE_INSN_DELETED);
|
||
|
||
thiscase->data.case_stmt.start = get_last_insn ();
|
||
|
||
start_cleanup_deferral ();
|
||
}
|
||
|
||
|
||
/* Start a "dummy case statement" within which case labels are invalid
|
||
and are not connected to any larger real case statement.
|
||
This can be used if you don't want to let a case statement jump
|
||
into the middle of certain kinds of constructs. */
|
||
|
||
void
|
||
expand_start_case_dummy ()
|
||
{
|
||
register struct nesting *thiscase = ALLOC_NESTING ();
|
||
|
||
/* Make an entry on case_stack for the dummy. */
|
||
|
||
thiscase->next = case_stack;
|
||
thiscase->all = nesting_stack;
|
||
thiscase->depth = ++nesting_depth;
|
||
thiscase->exit_label = 0;
|
||
thiscase->data.case_stmt.case_list = 0;
|
||
thiscase->data.case_stmt.start = 0;
|
||
thiscase->data.case_stmt.nominal_type = 0;
|
||
thiscase->data.case_stmt.default_label = 0;
|
||
thiscase->data.case_stmt.num_ranges = 0;
|
||
case_stack = thiscase;
|
||
nesting_stack = thiscase;
|
||
start_cleanup_deferral ();
|
||
}
|
||
|
||
/* End a dummy case statement. */
|
||
|
||
void
|
||
expand_end_case_dummy ()
|
||
{
|
||
end_cleanup_deferral ();
|
||
POPSTACK (case_stack);
|
||
}
|
||
|
||
/* Return the data type of the index-expression
|
||
of the innermost case statement, or null if none. */
|
||
|
||
tree
|
||
case_index_expr_type ()
|
||
{
|
||
if (case_stack)
|
||
return TREE_TYPE (case_stack->data.case_stmt.index_expr);
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
check_seenlabel ()
|
||
{
|
||
/* If this is the first label, warn if any insns have been emitted. */
|
||
if (case_stack->data.case_stmt.line_number_status >= 0)
|
||
{
|
||
rtx insn;
|
||
|
||
restore_line_number_status
|
||
(case_stack->data.case_stmt.line_number_status);
|
||
case_stack->data.case_stmt.line_number_status = -1;
|
||
|
||
for (insn = case_stack->data.case_stmt.start;
|
||
insn;
|
||
insn = NEXT_INSN (insn))
|
||
{
|
||
if (GET_CODE (insn) == CODE_LABEL)
|
||
break;
|
||
if (GET_CODE (insn) != NOTE
|
||
&& (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
|
||
{
|
||
do
|
||
insn = PREV_INSN (insn);
|
||
while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
|
||
|
||
/* If insn is zero, then there must have been a syntax error. */
|
||
if (insn)
|
||
warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
|
||
NOTE_LINE_NUMBER(insn),
|
||
"unreachable code at beginning of %s",
|
||
case_stack->data.case_stmt.printname);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Accumulate one case or default label inside a case or switch statement.
|
||
VALUE is the value of the case (a null pointer, for a default label).
|
||
The function CONVERTER, when applied to arguments T and V,
|
||
converts the value V to the type T.
|
||
|
||
If not currently inside a case or switch statement, return 1 and do
|
||
nothing. The caller will print a language-specific error message.
|
||
If VALUE is a duplicate or overlaps, return 2 and do nothing
|
||
except store the (first) duplicate node in *DUPLICATE.
|
||
If VALUE is out of range, return 3 and do nothing.
|
||
If we are jumping into the scope of a cleanup or var-sized array, return 5.
|
||
Return 0 on success.
|
||
|
||
Extended to handle range statements. */
|
||
|
||
int
|
||
pushcase (value, converter, label, duplicate)
|
||
register tree value;
|
||
tree (*converter) PROTO((tree, tree));
|
||
register tree label;
|
||
tree *duplicate;
|
||
{
|
||
tree index_type;
|
||
tree nominal_type;
|
||
|
||
/* Fail if not inside a real case statement. */
|
||
if (! (case_stack && case_stack->data.case_stmt.start))
|
||
return 1;
|
||
|
||
if (stack_block_stack
|
||
&& stack_block_stack->depth > case_stack->depth)
|
||
return 5;
|
||
|
||
index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
|
||
nominal_type = case_stack->data.case_stmt.nominal_type;
|
||
|
||
/* If the index is erroneous, avoid more problems: pretend to succeed. */
|
||
if (index_type == error_mark_node)
|
||
return 0;
|
||
|
||
/* Convert VALUE to the type in which the comparisons are nominally done. */
|
||
if (value != 0)
|
||
value = (*converter) (nominal_type, value);
|
||
|
||
check_seenlabel ();
|
||
|
||
/* Fail if this value is out of range for the actual type of the index
|
||
(which may be narrower than NOMINAL_TYPE). */
|
||
if (value != 0 && ! int_fits_type_p (value, index_type))
|
||
return 3;
|
||
|
||
/* Fail if this is a duplicate or overlaps another entry. */
|
||
if (value == 0)
|
||
{
|
||
if (case_stack->data.case_stmt.default_label != 0)
|
||
{
|
||
*duplicate = case_stack->data.case_stmt.default_label;
|
||
return 2;
|
||
}
|
||
case_stack->data.case_stmt.default_label = label;
|
||
}
|
||
else
|
||
return add_case_node (value, value, label, duplicate);
|
||
|
||
expand_label (label);
|
||
return 0;
|
||
}
|
||
|
||
/* Like pushcase but this case applies to all values between VALUE1 and
|
||
VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
|
||
value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
|
||
starts at VALUE1 and ends at the highest value of the index type.
|
||
If both are NULL, this case applies to all values.
|
||
|
||
The return value is the same as that of pushcase but there is one
|
||
additional error code: 4 means the specified range was empty. */
|
||
|
||
int
|
||
pushcase_range (value1, value2, converter, label, duplicate)
|
||
register tree value1, value2;
|
||
tree (*converter) PROTO((tree, tree));
|
||
register tree label;
|
||
tree *duplicate;
|
||
{
|
||
tree index_type;
|
||
tree nominal_type;
|
||
|
||
/* Fail if not inside a real case statement. */
|
||
if (! (case_stack && case_stack->data.case_stmt.start))
|
||
return 1;
|
||
|
||
if (stack_block_stack
|
||
&& stack_block_stack->depth > case_stack->depth)
|
||
return 5;
|
||
|
||
index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
|
||
nominal_type = case_stack->data.case_stmt.nominal_type;
|
||
|
||
/* If the index is erroneous, avoid more problems: pretend to succeed. */
|
||
if (index_type == error_mark_node)
|
||
return 0;
|
||
|
||
check_seenlabel ();
|
||
|
||
/* Convert VALUEs to type in which the comparisons are nominally done
|
||
and replace any unspecified value with the corresponding bound. */
|
||
if (value1 == 0)
|
||
value1 = TYPE_MIN_VALUE (index_type);
|
||
if (value2 == 0)
|
||
value2 = TYPE_MAX_VALUE (index_type);
|
||
|
||
/* Fail if the range is empty. Do this before any conversion since
|
||
we want to allow out-of-range empty ranges. */
|
||
if (value2 && tree_int_cst_lt (value2, value1))
|
||
return 4;
|
||
|
||
value1 = (*converter) (nominal_type, value1);
|
||
|
||
/* If the max was unbounded, use the max of the nominal_type we are
|
||
converting to. Do this after the < check above to suppress false
|
||
positives. */
|
||
if (!value2)
|
||
value2 = TYPE_MAX_VALUE (nominal_type);
|
||
value2 = (*converter) (nominal_type, value2);
|
||
|
||
/* Fail if these values are out of range. */
|
||
if (TREE_CONSTANT_OVERFLOW (value1)
|
||
|| ! int_fits_type_p (value1, index_type))
|
||
return 3;
|
||
|
||
if (TREE_CONSTANT_OVERFLOW (value2)
|
||
|| ! int_fits_type_p (value2, index_type))
|
||
return 3;
|
||
|
||
return add_case_node (value1, value2, label, duplicate);
|
||
}
|
||
|
||
/* Do the actual insertion of a case label for pushcase and pushcase_range
|
||
into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
|
||
slowdown for large switch statements. */
|
||
|
||
static int
|
||
add_case_node (low, high, label, duplicate)
|
||
tree low, high;
|
||
tree label;
|
||
tree *duplicate;
|
||
{
|
||
struct case_node *p, **q, *r;
|
||
|
||
q = &case_stack->data.case_stmt.case_list;
|
||
p = *q;
|
||
|
||
while ((r = *q))
|
||
{
|
||
p = r;
|
||
|
||
/* Keep going past elements distinctly greater than HIGH. */
|
||
if (tree_int_cst_lt (high, p->low))
|
||
q = &p->left;
|
||
|
||
/* or distinctly less than LOW. */
|
||
else if (tree_int_cst_lt (p->high, low))
|
||
q = &p->right;
|
||
|
||
else
|
||
{
|
||
/* We have an overlap; this is an error. */
|
||
*duplicate = p->code_label;
|
||
return 2;
|
||
}
|
||
}
|
||
|
||
/* Add this label to the chain, and succeed.
|
||
Copy LOW, HIGH so they are on temporary rather than momentary
|
||
obstack and will thus survive till the end of the case statement. */
|
||
|
||
r = (struct case_node *) oballoc (sizeof (struct case_node));
|
||
r->low = copy_node (low);
|
||
|
||
/* If the bounds are equal, turn this into the one-value case. */
|
||
|
||
if (tree_int_cst_equal (low, high))
|
||
r->high = r->low;
|
||
else
|
||
{
|
||
r->high = copy_node (high);
|
||
case_stack->data.case_stmt.num_ranges++;
|
||
}
|
||
|
||
r->code_label = label;
|
||
expand_label (label);
|
||
|
||
*q = r;
|
||
r->parent = p;
|
||
r->left = 0;
|
||
r->right = 0;
|
||
r->balance = 0;
|
||
|
||
while (p)
|
||
{
|
||
struct case_node *s;
|
||
|
||
if (r == p->left)
|
||
{
|
||
int b;
|
||
|
||
if (! (b = p->balance))
|
||
/* Growth propagation from left side. */
|
||
p->balance = -1;
|
||
else if (b < 0)
|
||
{
|
||
if (r->balance < 0)
|
||
{
|
||
/* R-Rotation */
|
||
if ((p->left = s = r->right))
|
||
s->parent = p;
|
||
|
||
r->right = p;
|
||
p->balance = 0;
|
||
r->balance = 0;
|
||
s = p->parent;
|
||
p->parent = r;
|
||
|
||
if ((r->parent = s))
|
||
{
|
||
if (s->left == p)
|
||
s->left = r;
|
||
else
|
||
s->right = r;
|
||
}
|
||
else
|
||
case_stack->data.case_stmt.case_list = r;
|
||
}
|
||
else
|
||
/* r->balance == +1 */
|
||
{
|
||
/* LR-Rotation */
|
||
|
||
int b2;
|
||
struct case_node *t = r->right;
|
||
|
||
if ((p->left = s = t->right))
|
||
s->parent = p;
|
||
|
||
t->right = p;
|
||
if ((r->right = s = t->left))
|
||
s->parent = r;
|
||
|
||
t->left = r;
|
||
b = t->balance;
|
||
b2 = b < 0;
|
||
p->balance = b2;
|
||
b2 = -b2 - b;
|
||
r->balance = b2;
|
||
t->balance = 0;
|
||
s = p->parent;
|
||
p->parent = t;
|
||
r->parent = t;
|
||
|
||
if ((t->parent = s))
|
||
{
|
||
if (s->left == p)
|
||
s->left = t;
|
||
else
|
||
s->right = t;
|
||
}
|
||
else
|
||
case_stack->data.case_stmt.case_list = t;
|
||
}
|
||
break;
|
||
}
|
||
|
||
else
|
||
{
|
||
/* p->balance == +1; growth of left side balances the node. */
|
||
p->balance = 0;
|
||
break;
|
||
}
|
||
}
|
||
else
|
||
/* r == p->right */
|
||
{
|
||
int b;
|
||
|
||
if (! (b = p->balance))
|
||
/* Growth propagation from right side. */
|
||
p->balance++;
|
||
else if (b > 0)
|
||
{
|
||
if (r->balance > 0)
|
||
{
|
||
/* L-Rotation */
|
||
|
||
if ((p->right = s = r->left))
|
||
s->parent = p;
|
||
|
||
r->left = p;
|
||
p->balance = 0;
|
||
r->balance = 0;
|
||
s = p->parent;
|
||
p->parent = r;
|
||
if ((r->parent = s))
|
||
{
|
||
if (s->left == p)
|
||
s->left = r;
|
||
else
|
||
s->right = r;
|
||
}
|
||
|
||
else
|
||
case_stack->data.case_stmt.case_list = r;
|
||
}
|
||
|
||
else
|
||
/* r->balance == -1 */
|
||
{
|
||
/* RL-Rotation */
|
||
int b2;
|
||
struct case_node *t = r->left;
|
||
|
||
if ((p->right = s = t->left))
|
||
s->parent = p;
|
||
|
||
t->left = p;
|
||
|
||
if ((r->left = s = t->right))
|
||
s->parent = r;
|
||
|
||
t->right = r;
|
||
b = t->balance;
|
||
b2 = b < 0;
|
||
r->balance = b2;
|
||
b2 = -b2 - b;
|
||
p->balance = b2;
|
||
t->balance = 0;
|
||
s = p->parent;
|
||
p->parent = t;
|
||
r->parent = t;
|
||
|
||
if ((t->parent = s))
|
||
{
|
||
if (s->left == p)
|
||
s->left = t;
|
||
else
|
||
s->right = t;
|
||
}
|
||
|
||
else
|
||
case_stack->data.case_stmt.case_list = t;
|
||
}
|
||
break;
|
||
}
|
||
else
|
||
{
|
||
/* p->balance == -1; growth of right side balances the node. */
|
||
p->balance = 0;
|
||
break;
|
||
}
|
||
}
|
||
|
||
r = p;
|
||
p = p->parent;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* Returns the number of possible values of TYPE.
|
||
Returns -1 if the number is unknown or variable.
|
||
Returns -2 if the number does not fit in a HOST_WIDE_INT.
|
||
Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
|
||
do not increase monotonically (there may be duplicates);
|
||
to 1 if the values increase monotonically, but not always by 1;
|
||
otherwise sets it to 0. */
|
||
|
||
HOST_WIDE_INT
|
||
all_cases_count (type, spareness)
|
||
tree type;
|
||
int *spareness;
|
||
{
|
||
HOST_WIDE_INT count;
|
||
*spareness = 0;
|
||
|
||
switch (TREE_CODE (type))
|
||
{
|
||
tree t;
|
||
case BOOLEAN_TYPE:
|
||
count = 2;
|
||
break;
|
||
case CHAR_TYPE:
|
||
count = 1 << BITS_PER_UNIT;
|
||
break;
|
||
default:
|
||
case INTEGER_TYPE:
|
||
if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
|
||
|| TYPE_MAX_VALUE (type) == NULL
|
||
|| TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
|
||
return -1;
|
||
else
|
||
{
|
||
/* count
|
||
= TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
|
||
- TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
|
||
but with overflow checking. */
|
||
tree mint = TYPE_MIN_VALUE (type);
|
||
tree maxt = TYPE_MAX_VALUE (type);
|
||
HOST_WIDE_INT lo, hi;
|
||
neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
|
||
&lo, &hi);
|
||
add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
|
||
lo, hi, &lo, &hi);
|
||
add_double (lo, hi, 1, 0, &lo, &hi);
|
||
if (hi != 0 || lo < 0)
|
||
return -2;
|
||
count = lo;
|
||
}
|
||
break;
|
||
case ENUMERAL_TYPE:
|
||
count = 0;
|
||
for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
|
||
{
|
||
if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
|
||
|| TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
|
||
|| TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
|
||
!= TREE_INT_CST_LOW (TREE_VALUE (t)))
|
||
*spareness = 1;
|
||
count++;
|
||
}
|
||
if (*spareness == 1)
|
||
{
|
||
tree prev = TREE_VALUE (TYPE_VALUES (type));
|
||
for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
|
||
{
|
||
if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
|
||
{
|
||
*spareness = 2;
|
||
break;
|
||
}
|
||
prev = TREE_VALUE (t);
|
||
}
|
||
|
||
}
|
||
}
|
||
return count;
|
||
}
|
||
|
||
|
||
#define BITARRAY_TEST(ARRAY, INDEX) \
|
||
((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
|
||
& (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
|
||
#define BITARRAY_SET(ARRAY, INDEX) \
|
||
((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
|
||
|= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
|
||
|
||
/* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
|
||
with the case values we have seen, assuming the case expression
|
||
has the given TYPE.
|
||
SPARSENESS is as determined by all_cases_count.
|
||
|
||
The time needed is proportional to COUNT, unless
|
||
SPARSENESS is 2, in which case quadratic time is needed. */
|
||
|
||
void
|
||
mark_seen_cases (type, cases_seen, count, sparseness)
|
||
tree type;
|
||
unsigned char *cases_seen;
|
||
long count;
|
||
int sparseness;
|
||
{
|
||
tree next_node_to_try = NULL_TREE;
|
||
long next_node_offset = 0;
|
||
|
||
register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
|
||
tree val = make_node (INTEGER_CST);
|
||
TREE_TYPE (val) = type;
|
||
if (! root)
|
||
; /* Do nothing */
|
||
else if (sparseness == 2)
|
||
{
|
||
tree t;
|
||
HOST_WIDE_INT xlo;
|
||
|
||
/* This less efficient loop is only needed to handle
|
||
duplicate case values (multiple enum constants
|
||
with the same value). */
|
||
TREE_TYPE (val) = TREE_TYPE (root->low);
|
||
for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
|
||
t = TREE_CHAIN (t), xlo++)
|
||
{
|
||
TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
|
||
TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
|
||
n = root;
|
||
do
|
||
{
|
||
/* Keep going past elements distinctly greater than VAL. */
|
||
if (tree_int_cst_lt (val, n->low))
|
||
n = n->left;
|
||
|
||
/* or distinctly less than VAL. */
|
||
else if (tree_int_cst_lt (n->high, val))
|
||
n = n->right;
|
||
|
||
else
|
||
{
|
||
/* We have found a matching range. */
|
||
BITARRAY_SET (cases_seen, xlo);
|
||
break;
|
||
}
|
||
}
|
||
while (n);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (root->left)
|
||
case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
|
||
for (n = root; n; n = n->right)
|
||
{
|
||
TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
|
||
TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
|
||
while ( ! tree_int_cst_lt (n->high, val))
|
||
{
|
||
/* Calculate (into xlo) the "offset" of the integer (val).
|
||
The element with lowest value has offset 0, the next smallest
|
||
element has offset 1, etc. */
|
||
|
||
HOST_WIDE_INT xlo, xhi;
|
||
tree t;
|
||
if (sparseness && TYPE_VALUES (type) != NULL_TREE)
|
||
{
|
||
/* The TYPE_VALUES will be in increasing order, so
|
||
starting searching where we last ended. */
|
||
t = next_node_to_try;
|
||
xlo = next_node_offset;
|
||
xhi = 0;
|
||
for (;;)
|
||
{
|
||
if (t == NULL_TREE)
|
||
{
|
||
t = TYPE_VALUES (type);
|
||
xlo = 0;
|
||
}
|
||
if (tree_int_cst_equal (val, TREE_VALUE (t)))
|
||
{
|
||
next_node_to_try = TREE_CHAIN (t);
|
||
next_node_offset = xlo + 1;
|
||
break;
|
||
}
|
||
xlo++;
|
||
t = TREE_CHAIN (t);
|
||
if (t == next_node_to_try)
|
||
{
|
||
xlo = -1;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
t = TYPE_MIN_VALUE (type);
|
||
if (t)
|
||
neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
|
||
&xlo, &xhi);
|
||
else
|
||
xlo = xhi = 0;
|
||
add_double (xlo, xhi,
|
||
TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
|
||
&xlo, &xhi);
|
||
}
|
||
|
||
if (xhi == 0 && xlo >= 0 && xlo < count)
|
||
BITARRAY_SET (cases_seen, xlo);
|
||
add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
|
||
1, 0,
|
||
&TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Called when the index of a switch statement is an enumerated type
|
||
and there is no default label.
|
||
|
||
Checks that all enumeration literals are covered by the case
|
||
expressions of a switch. Also, warn if there are any extra
|
||
switch cases that are *not* elements of the enumerated type.
|
||
|
||
If all enumeration literals were covered by the case expressions,
|
||
turn one of the expressions into the default expression since it should
|
||
not be possible to fall through such a switch. */
|
||
|
||
void
|
||
check_for_full_enumeration_handling (type)
|
||
tree type;
|
||
{
|
||
register struct case_node *n;
|
||
register tree chain;
|
||
#if 0 /* variable used by 'if 0'ed code below. */
|
||
register struct case_node **l;
|
||
int all_values = 1;
|
||
#endif
|
||
|
||
/* True iff the selector type is a numbered set mode. */
|
||
int sparseness = 0;
|
||
|
||
/* The number of possible selector values. */
|
||
HOST_WIDE_INT size;
|
||
|
||
/* For each possible selector value. a one iff it has been matched
|
||
by a case value alternative. */
|
||
unsigned char *cases_seen;
|
||
|
||
/* The allocated size of cases_seen, in chars. */
|
||
long bytes_needed;
|
||
|
||
if (! warn_switch)
|
||
return;
|
||
|
||
size = all_cases_count (type, &sparseness);
|
||
bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
|
||
|
||
if (size > 0 && size < 600000
|
||
/* We deliberately use malloc here - not xmalloc. */
|
||
&& (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
|
||
{
|
||
long i;
|
||
tree v = TYPE_VALUES (type);
|
||
bzero (cases_seen, bytes_needed);
|
||
|
||
/* The time complexity of this code is normally O(N), where
|
||
N being the number of members in the enumerated type.
|
||
However, if type is a ENUMERAL_TYPE whose values do not
|
||
increase monotonically, O(N*log(N)) time may be needed. */
|
||
|
||
mark_seen_cases (type, cases_seen, size, sparseness);
|
||
|
||
for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
|
||
{
|
||
if (BITARRAY_TEST(cases_seen, i) == 0)
|
||
warning ("enumeration value `%s' not handled in switch",
|
||
IDENTIFIER_POINTER (TREE_PURPOSE (v)));
|
||
}
|
||
|
||
free (cases_seen);
|
||
}
|
||
|
||
/* Now we go the other way around; we warn if there are case
|
||
expressions that don't correspond to enumerators. This can
|
||
occur since C and C++ don't enforce type-checking of
|
||
assignments to enumeration variables. */
|
||
|
||
if (case_stack->data.case_stmt.case_list
|
||
&& case_stack->data.case_stmt.case_list->left)
|
||
case_stack->data.case_stmt.case_list
|
||
= case_tree2list (case_stack->data.case_stmt.case_list, 0);
|
||
if (warn_switch)
|
||
for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
|
||
{
|
||
for (chain = TYPE_VALUES (type);
|
||
chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
|
||
chain = TREE_CHAIN (chain))
|
||
;
|
||
|
||
if (!chain)
|
||
{
|
||
if (TYPE_NAME (type) == 0)
|
||
warning ("case value `%ld' not in enumerated type",
|
||
(long) TREE_INT_CST_LOW (n->low));
|
||
else
|
||
warning ("case value `%ld' not in enumerated type `%s'",
|
||
(long) TREE_INT_CST_LOW (n->low),
|
||
IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
|
||
== IDENTIFIER_NODE)
|
||
? TYPE_NAME (type)
|
||
: DECL_NAME (TYPE_NAME (type))));
|
||
}
|
||
if (!tree_int_cst_equal (n->low, n->high))
|
||
{
|
||
for (chain = TYPE_VALUES (type);
|
||
chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
|
||
chain = TREE_CHAIN (chain))
|
||
;
|
||
|
||
if (!chain)
|
||
{
|
||
if (TYPE_NAME (type) == 0)
|
||
warning ("case value `%ld' not in enumerated type",
|
||
(long) TREE_INT_CST_LOW (n->high));
|
||
else
|
||
warning ("case value `%ld' not in enumerated type `%s'",
|
||
(long) TREE_INT_CST_LOW (n->high),
|
||
IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
|
||
== IDENTIFIER_NODE)
|
||
? TYPE_NAME (type)
|
||
: DECL_NAME (TYPE_NAME (type))));
|
||
}
|
||
}
|
||
}
|
||
|
||
#if 0
|
||
/* ??? This optimization is disabled because it causes valid programs to
|
||
fail. ANSI C does not guarantee that an expression with enum type
|
||
will have a value that is the same as one of the enumeration literals. */
|
||
|
||
/* If all values were found as case labels, make one of them the default
|
||
label. Thus, this switch will never fall through. We arbitrarily pick
|
||
the last one to make the default since this is likely the most
|
||
efficient choice. */
|
||
|
||
if (all_values)
|
||
{
|
||
for (l = &case_stack->data.case_stmt.case_list;
|
||
(*l)->right != 0;
|
||
l = &(*l)->right)
|
||
;
|
||
|
||
case_stack->data.case_stmt.default_label = (*l)->code_label;
|
||
*l = 0;
|
||
}
|
||
#endif /* 0 */
|
||
}
|
||
|
||
|
||
/* Terminate a case (Pascal) or switch (C) statement
|
||
in which ORIG_INDEX is the expression to be tested.
|
||
Generate the code to test it and jump to the right place. */
|
||
|
||
void
|
||
expand_end_case (orig_index)
|
||
tree orig_index;
|
||
{
|
||
tree minval = NULL_TREE, maxval = NULL_TREE, range, orig_minval;
|
||
rtx default_label = 0;
|
||
register struct case_node *n;
|
||
unsigned int count;
|
||
rtx index;
|
||
rtx table_label;
|
||
int ncases;
|
||
rtx *labelvec;
|
||
register int i;
|
||
rtx before_case;
|
||
register struct nesting *thiscase = case_stack;
|
||
tree index_expr, index_type;
|
||
int unsignedp;
|
||
|
||
table_label = gen_label_rtx ();
|
||
index_expr = thiscase->data.case_stmt.index_expr;
|
||
index_type = TREE_TYPE (index_expr);
|
||
unsignedp = TREE_UNSIGNED (index_type);
|
||
|
||
do_pending_stack_adjust ();
|
||
|
||
/* This might get an spurious warning in the presence of a syntax error;
|
||
it could be fixed by moving the call to check_seenlabel after the
|
||
check for error_mark_node, and copying the code of check_seenlabel that
|
||
deals with case_stack->data.case_stmt.line_number_status /
|
||
restore_line_number_status in front of the call to end_cleanup_deferral;
|
||
However, this might miss some useful warnings in the presence of
|
||
non-syntax errors. */
|
||
check_seenlabel ();
|
||
|
||
/* An ERROR_MARK occurs for various reasons including invalid data type. */
|
||
if (index_type != error_mark_node)
|
||
{
|
||
/* If switch expression was an enumerated type, check that all
|
||
enumeration literals are covered by the cases.
|
||
No sense trying this if there's a default case, however. */
|
||
|
||
if (!thiscase->data.case_stmt.default_label
|
||
&& TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
|
||
&& TREE_CODE (index_expr) != INTEGER_CST)
|
||
check_for_full_enumeration_handling (TREE_TYPE (orig_index));
|
||
|
||
/* If we don't have a default-label, create one here,
|
||
after the body of the switch. */
|
||
if (thiscase->data.case_stmt.default_label == 0)
|
||
{
|
||
thiscase->data.case_stmt.default_label
|
||
= build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
|
||
expand_label (thiscase->data.case_stmt.default_label);
|
||
}
|
||
default_label = label_rtx (thiscase->data.case_stmt.default_label);
|
||
|
||
before_case = get_last_insn ();
|
||
|
||
if (thiscase->data.case_stmt.case_list
|
||
&& thiscase->data.case_stmt.case_list->left)
|
||
thiscase->data.case_stmt.case_list
|
||
= case_tree2list(thiscase->data.case_stmt.case_list, 0);
|
||
|
||
/* Simplify the case-list before we count it. */
|
||
group_case_nodes (thiscase->data.case_stmt.case_list);
|
||
|
||
/* Get upper and lower bounds of case values.
|
||
Also convert all the case values to the index expr's data type. */
|
||
|
||
count = 0;
|
||
for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
|
||
{
|
||
/* Check low and high label values are integers. */
|
||
if (TREE_CODE (n->low) != INTEGER_CST)
|
||
abort ();
|
||
if (TREE_CODE (n->high) != INTEGER_CST)
|
||
abort ();
|
||
|
||
n->low = convert (index_type, n->low);
|
||
n->high = convert (index_type, n->high);
|
||
|
||
/* Count the elements and track the largest and smallest
|
||
of them (treating them as signed even if they are not). */
|
||
if (count++ == 0)
|
||
{
|
||
minval = n->low;
|
||
maxval = n->high;
|
||
}
|
||
else
|
||
{
|
||
if (INT_CST_LT (n->low, minval))
|
||
minval = n->low;
|
||
if (INT_CST_LT (maxval, n->high))
|
||
maxval = n->high;
|
||
}
|
||
/* A range counts double, since it requires two compares. */
|
||
if (! tree_int_cst_equal (n->low, n->high))
|
||
count++;
|
||
}
|
||
|
||
orig_minval = minval;
|
||
|
||
/* Compute span of values. */
|
||
if (count != 0)
|
||
range = fold (build (MINUS_EXPR, index_type, maxval, minval));
|
||
|
||
end_cleanup_deferral ();
|
||
|
||
if (count == 0)
|
||
{
|
||
expand_expr (index_expr, const0_rtx, VOIDmode, 0);
|
||
emit_queue ();
|
||
emit_jump (default_label);
|
||
}
|
||
|
||
/* If range of values is much bigger than number of values,
|
||
make a sequence of conditional branches instead of a dispatch.
|
||
If the switch-index is a constant, do it this way
|
||
because we can optimize it. */
|
||
|
||
#ifndef CASE_VALUES_THRESHOLD
|
||
#ifdef HAVE_casesi
|
||
#define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
|
||
#else
|
||
/* If machine does not have a case insn that compares the
|
||
bounds, this means extra overhead for dispatch tables
|
||
which raises the threshold for using them. */
|
||
#define CASE_VALUES_THRESHOLD 5
|
||
#endif /* HAVE_casesi */
|
||
#endif /* CASE_VALUES_THRESHOLD */
|
||
|
||
else if (TREE_INT_CST_HIGH (range) != 0
|
||
|| count < (unsigned int) CASE_VALUES_THRESHOLD
|
||
|| ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
|
||
> 10 * count)
|
||
#ifndef ASM_OUTPUT_ADDR_DIFF_ELT
|
||
|| flag_pic
|
||
#endif
|
||
|| TREE_CODE (index_expr) == INTEGER_CST
|
||
/* These will reduce to a constant. */
|
||
|| (TREE_CODE (index_expr) == CALL_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
|
||
&& DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
|
||
|| (TREE_CODE (index_expr) == COMPOUND_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
|
||
{
|
||
index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
|
||
|
||
/* If the index is a short or char that we do not have
|
||
an insn to handle comparisons directly, convert it to
|
||
a full integer now, rather than letting each comparison
|
||
generate the conversion. */
|
||
|
||
if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
|
||
&& (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
|
||
== CODE_FOR_nothing))
|
||
{
|
||
enum machine_mode wider_mode;
|
||
for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
|
||
wider_mode = GET_MODE_WIDER_MODE (wider_mode))
|
||
if (cmp_optab->handlers[(int) wider_mode].insn_code
|
||
!= CODE_FOR_nothing)
|
||
{
|
||
index = convert_to_mode (wider_mode, index, unsignedp);
|
||
break;
|
||
}
|
||
}
|
||
|
||
emit_queue ();
|
||
do_pending_stack_adjust ();
|
||
|
||
index = protect_from_queue (index, 0);
|
||
if (GET_CODE (index) == MEM)
|
||
index = copy_to_reg (index);
|
||
if (GET_CODE (index) == CONST_INT
|
||
|| TREE_CODE (index_expr) == INTEGER_CST)
|
||
{
|
||
/* Make a tree node with the proper constant value
|
||
if we don't already have one. */
|
||
if (TREE_CODE (index_expr) != INTEGER_CST)
|
||
{
|
||
index_expr
|
||
= build_int_2 (INTVAL (index),
|
||
unsignedp || INTVAL (index) >= 0 ? 0 : -1);
|
||
index_expr = convert (index_type, index_expr);
|
||
}
|
||
|
||
/* For constant index expressions we need only
|
||
issue a unconditional branch to the appropriate
|
||
target code. The job of removing any unreachable
|
||
code is left to the optimisation phase if the
|
||
"-O" option is specified. */
|
||
for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
|
||
if (! tree_int_cst_lt (index_expr, n->low)
|
||
&& ! tree_int_cst_lt (n->high, index_expr))
|
||
break;
|
||
|
||
if (n)
|
||
emit_jump (label_rtx (n->code_label));
|
||
else
|
||
emit_jump (default_label);
|
||
}
|
||
else
|
||
{
|
||
/* If the index expression is not constant we generate
|
||
a binary decision tree to select the appropriate
|
||
target code. This is done as follows:
|
||
|
||
The list of cases is rearranged into a binary tree,
|
||
nearly optimal assuming equal probability for each case.
|
||
|
||
The tree is transformed into RTL, eliminating
|
||
redundant test conditions at the same time.
|
||
|
||
If program flow could reach the end of the
|
||
decision tree an unconditional jump to the
|
||
default code is emitted. */
|
||
|
||
use_cost_table
|
||
= (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
|
||
&& estimate_case_costs (thiscase->data.case_stmt.case_list));
|
||
balance_case_nodes (&thiscase->data.case_stmt.case_list,
|
||
NULL_PTR);
|
||
emit_case_nodes (index, thiscase->data.case_stmt.case_list,
|
||
default_label, index_type);
|
||
emit_jump_if_reachable (default_label);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
int win = 0;
|
||
#ifdef HAVE_casesi
|
||
if (HAVE_casesi)
|
||
{
|
||
enum machine_mode index_mode = SImode;
|
||
int index_bits = GET_MODE_BITSIZE (index_mode);
|
||
rtx op1, op2;
|
||
enum machine_mode op_mode;
|
||
|
||
/* Convert the index to SImode. */
|
||
if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
|
||
> GET_MODE_BITSIZE (index_mode))
|
||
{
|
||
enum machine_mode omode = TYPE_MODE (index_type);
|
||
rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
|
||
|
||
/* We must handle the endpoints in the original mode. */
|
||
index_expr = build (MINUS_EXPR, index_type,
|
||
index_expr, minval);
|
||
minval = integer_zero_node;
|
||
index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
|
||
emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
|
||
omode, 1, 0, default_label);
|
||
/* Now we can safely truncate. */
|
||
index = convert_to_mode (index_mode, index, 0);
|
||
}
|
||
else
|
||
{
|
||
if (TYPE_MODE (index_type) != index_mode)
|
||
{
|
||
index_expr = convert (type_for_size (index_bits, 0),
|
||
index_expr);
|
||
index_type = TREE_TYPE (index_expr);
|
||
}
|
||
|
||
index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
|
||
}
|
||
emit_queue ();
|
||
index = protect_from_queue (index, 0);
|
||
do_pending_stack_adjust ();
|
||
|
||
op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
|
||
if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
|
||
(index, op_mode))
|
||
index = copy_to_mode_reg (op_mode, index);
|
||
|
||
op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
|
||
|
||
op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
|
||
if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
|
||
(op1, op_mode))
|
||
op1 = copy_to_mode_reg (op_mode, op1);
|
||
|
||
op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
|
||
|
||
op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
|
||
if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
|
||
(op2, op_mode))
|
||
op2 = copy_to_mode_reg (op_mode, op2);
|
||
|
||
emit_jump_insn (gen_casesi (index, op1, op2,
|
||
table_label, default_label));
|
||
win = 1;
|
||
}
|
||
#endif
|
||
#ifdef HAVE_tablejump
|
||
if (! win && HAVE_tablejump)
|
||
{
|
||
index_expr = convert (thiscase->data.case_stmt.nominal_type,
|
||
fold (build (MINUS_EXPR, index_type,
|
||
index_expr, minval)));
|
||
index_type = TREE_TYPE (index_expr);
|
||
index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
|
||
emit_queue ();
|
||
index = protect_from_queue (index, 0);
|
||
do_pending_stack_adjust ();
|
||
|
||
do_tablejump (index, TYPE_MODE (index_type),
|
||
expand_expr (range, NULL_RTX, VOIDmode, 0),
|
||
table_label, default_label);
|
||
win = 1;
|
||
}
|
||
#endif
|
||
if (! win)
|
||
abort ();
|
||
|
||
/* Get table of labels to jump to, in order of case index. */
|
||
|
||
ncases = TREE_INT_CST_LOW (range) + 1;
|
||
labelvec = (rtx *) alloca (ncases * sizeof (rtx));
|
||
bzero ((char *) labelvec, ncases * sizeof (rtx));
|
||
|
||
for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
|
||
{
|
||
register HOST_WIDE_INT i
|
||
= TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
|
||
|
||
while (1)
|
||
{
|
||
labelvec[i]
|
||
= gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
|
||
if (i + TREE_INT_CST_LOW (orig_minval)
|
||
== TREE_INT_CST_LOW (n->high))
|
||
break;
|
||
i++;
|
||
}
|
||
}
|
||
|
||
/* Fill in the gaps with the default. */
|
||
for (i = 0; i < ncases; i++)
|
||
if (labelvec[i] == 0)
|
||
labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
|
||
|
||
/* Output the table */
|
||
emit_label (table_label);
|
||
|
||
if (CASE_VECTOR_PC_RELATIVE || flag_pic)
|
||
emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
|
||
gen_rtx_LABEL_REF (Pmode, table_label),
|
||
gen_rtvec_v (ncases, labelvec),
|
||
const0_rtx, const0_rtx, 0));
|
||
else
|
||
emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
|
||
gen_rtvec_v (ncases, labelvec)));
|
||
|
||
/* If the case insn drops through the table,
|
||
after the table we must jump to the default-label.
|
||
Otherwise record no drop-through after the table. */
|
||
#ifdef CASE_DROPS_THROUGH
|
||
emit_jump (default_label);
|
||
#else
|
||
emit_barrier ();
|
||
#endif
|
||
}
|
||
|
||
before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
|
||
reorder_insns (before_case, get_last_insn (),
|
||
thiscase->data.case_stmt.start);
|
||
}
|
||
else
|
||
end_cleanup_deferral ();
|
||
|
||
if (thiscase->exit_label)
|
||
emit_label (thiscase->exit_label);
|
||
|
||
POPSTACK (case_stack);
|
||
|
||
free_temp_slots ();
|
||
}
|
||
|
||
/* Convert the tree NODE into a list linked by the right field, with the left
|
||
field zeroed. RIGHT is used for recursion; it is a list to be placed
|
||
rightmost in the resulting list. */
|
||
|
||
static struct case_node *
|
||
case_tree2list (node, right)
|
||
struct case_node *node, *right;
|
||
{
|
||
struct case_node *left;
|
||
|
||
if (node->right)
|
||
right = case_tree2list (node->right, right);
|
||
|
||
node->right = right;
|
||
if ((left = node->left))
|
||
{
|
||
node->left = 0;
|
||
return case_tree2list (left, node);
|
||
}
|
||
|
||
return node;
|
||
}
|
||
|
||
/* Generate code to jump to LABEL if OP1 and OP2 are equal. */
|
||
|
||
static void
|
||
do_jump_if_equal (op1, op2, label, unsignedp)
|
||
rtx op1, op2, label;
|
||
int unsignedp;
|
||
{
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& GET_CODE (op2) == CONST_INT)
|
||
{
|
||
if (INTVAL (op1) == INTVAL (op2))
|
||
emit_jump (label);
|
||
}
|
||
else
|
||
{
|
||
enum machine_mode mode = GET_MODE (op1);
|
||
if (mode == VOIDmode)
|
||
mode = GET_MODE (op2);
|
||
emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
|
||
0, label);
|
||
}
|
||
}
|
||
|
||
/* Not all case values are encountered equally. This function
|
||
uses a heuristic to weight case labels, in cases where that
|
||
looks like a reasonable thing to do.
|
||
|
||
Right now, all we try to guess is text, and we establish the
|
||
following weights:
|
||
|
||
chars above space: 16
|
||
digits: 16
|
||
default: 12
|
||
space, punct: 8
|
||
tab: 4
|
||
newline: 2
|
||
other "\" chars: 1
|
||
remaining chars: 0
|
||
|
||
If we find any cases in the switch that are not either -1 or in the range
|
||
of valid ASCII characters, or are control characters other than those
|
||
commonly used with "\", don't treat this switch scanning text.
|
||
|
||
Return 1 if these nodes are suitable for cost estimation, otherwise
|
||
return 0. */
|
||
|
||
static int
|
||
estimate_case_costs (node)
|
||
case_node_ptr node;
|
||
{
|
||
tree min_ascii = build_int_2 (-1, -1);
|
||
tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
|
||
case_node_ptr n;
|
||
int i;
|
||
|
||
/* If we haven't already made the cost table, make it now. Note that the
|
||
lower bound of the table is -1, not zero. */
|
||
|
||
if (cost_table == NULL)
|
||
{
|
||
cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
|
||
bzero ((char *) (cost_table - 1), 129 * sizeof (short));
|
||
|
||
for (i = 0; i < 128; i++)
|
||
{
|
||
if (ISALNUM (i))
|
||
cost_table[i] = 16;
|
||
else if (ISPUNCT (i))
|
||
cost_table[i] = 8;
|
||
else if (ISCNTRL (i))
|
||
cost_table[i] = -1;
|
||
}
|
||
|
||
cost_table[' '] = 8;
|
||
cost_table['\t'] = 4;
|
||
cost_table['\0'] = 4;
|
||
cost_table['\n'] = 2;
|
||
cost_table['\f'] = 1;
|
||
cost_table['\v'] = 1;
|
||
cost_table['\b'] = 1;
|
||
}
|
||
|
||
/* See if all the case expressions look like text. It is text if the
|
||
constant is >= -1 and the highest constant is <= 127. Do all comparisons
|
||
as signed arithmetic since we don't want to ever access cost_table with a
|
||
value less than -1. Also check that none of the constants in a range
|
||
are strange control characters. */
|
||
|
||
for (n = node; n; n = n->right)
|
||
{
|
||
if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
|
||
return 0;
|
||
|
||
for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
|
||
if (cost_table[i] < 0)
|
||
return 0;
|
||
}
|
||
|
||
/* All interesting values are within the range of interesting
|
||
ASCII characters. */
|
||
return 1;
|
||
}
|
||
|
||
/* Scan an ordered list of case nodes
|
||
combining those with consecutive values or ranges.
|
||
|
||
Eg. three separate entries 1: 2: 3: become one entry 1..3: */
|
||
|
||
static void
|
||
group_case_nodes (head)
|
||
case_node_ptr head;
|
||
{
|
||
case_node_ptr node = head;
|
||
|
||
while (node)
|
||
{
|
||
rtx lb = next_real_insn (label_rtx (node->code_label));
|
||
rtx lb2;
|
||
case_node_ptr np = node;
|
||
|
||
/* Try to group the successors of NODE with NODE. */
|
||
while (((np = np->right) != 0)
|
||
/* Do they jump to the same place? */
|
||
&& ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
|
||
|| (lb != 0 && lb2 != 0
|
||
&& simplejump_p (lb)
|
||
&& simplejump_p (lb2)
|
||
&& rtx_equal_p (SET_SRC (PATTERN (lb)),
|
||
SET_SRC (PATTERN (lb2)))))
|
||
/* Are their ranges consecutive? */
|
||
&& tree_int_cst_equal (np->low,
|
||
fold (build (PLUS_EXPR,
|
||
TREE_TYPE (node->high),
|
||
node->high,
|
||
integer_one_node)))
|
||
/* An overflow is not consecutive. */
|
||
&& tree_int_cst_lt (node->high,
|
||
fold (build (PLUS_EXPR,
|
||
TREE_TYPE (node->high),
|
||
node->high,
|
||
integer_one_node))))
|
||
{
|
||
node->high = np->high;
|
||
}
|
||
/* NP is the first node after NODE which can't be grouped with it.
|
||
Delete the nodes in between, and move on to that node. */
|
||
node->right = np;
|
||
node = np;
|
||
}
|
||
}
|
||
|
||
/* Take an ordered list of case nodes
|
||
and transform them into a near optimal binary tree,
|
||
on the assumption that any target code selection value is as
|
||
likely as any other.
|
||
|
||
The transformation is performed by splitting the ordered
|
||
list into two equal sections plus a pivot. The parts are
|
||
then attached to the pivot as left and right branches. Each
|
||
branch is then transformed recursively. */
|
||
|
||
static void
|
||
balance_case_nodes (head, parent)
|
||
case_node_ptr *head;
|
||
case_node_ptr parent;
|
||
{
|
||
register case_node_ptr np;
|
||
|
||
np = *head;
|
||
if (np)
|
||
{
|
||
int cost = 0;
|
||
int i = 0;
|
||
int ranges = 0;
|
||
register case_node_ptr *npp;
|
||
case_node_ptr left;
|
||
|
||
/* Count the number of entries on branch. Also count the ranges. */
|
||
|
||
while (np)
|
||
{
|
||
if (!tree_int_cst_equal (np->low, np->high))
|
||
{
|
||
ranges++;
|
||
if (use_cost_table)
|
||
cost += cost_table[TREE_INT_CST_LOW (np->high)];
|
||
}
|
||
|
||
if (use_cost_table)
|
||
cost += cost_table[TREE_INT_CST_LOW (np->low)];
|
||
|
||
i++;
|
||
np = np->right;
|
||
}
|
||
|
||
if (i > 2)
|
||
{
|
||
/* Split this list if it is long enough for that to help. */
|
||
npp = head;
|
||
left = *npp;
|
||
if (use_cost_table)
|
||
{
|
||
/* Find the place in the list that bisects the list's total cost,
|
||
Here I gets half the total cost. */
|
||
int n_moved = 0;
|
||
i = (cost + 1) / 2;
|
||
while (1)
|
||
{
|
||
/* Skip nodes while their cost does not reach that amount. */
|
||
if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
|
||
i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
|
||
i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
|
||
if (i <= 0)
|
||
break;
|
||
npp = &(*npp)->right;
|
||
n_moved += 1;
|
||
}
|
||
if (n_moved == 0)
|
||
{
|
||
/* Leave this branch lopsided, but optimize left-hand
|
||
side and fill in `parent' fields for right-hand side. */
|
||
np = *head;
|
||
np->parent = parent;
|
||
balance_case_nodes (&np->left, np);
|
||
for (; np->right; np = np->right)
|
||
np->right->parent = np;
|
||
return;
|
||
}
|
||
}
|
||
/* If there are just three nodes, split at the middle one. */
|
||
else if (i == 3)
|
||
npp = &(*npp)->right;
|
||
else
|
||
{
|
||
/* Find the place in the list that bisects the list's total cost,
|
||
where ranges count as 2.
|
||
Here I gets half the total cost. */
|
||
i = (i + ranges + 1) / 2;
|
||
while (1)
|
||
{
|
||
/* Skip nodes while their cost does not reach that amount. */
|
||
if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
|
||
i--;
|
||
i--;
|
||
if (i <= 0)
|
||
break;
|
||
npp = &(*npp)->right;
|
||
}
|
||
}
|
||
*head = np = *npp;
|
||
*npp = 0;
|
||
np->parent = parent;
|
||
np->left = left;
|
||
|
||
/* Optimize each of the two split parts. */
|
||
balance_case_nodes (&np->left, np);
|
||
balance_case_nodes (&np->right, np);
|
||
}
|
||
else
|
||
{
|
||
/* Else leave this branch as one level,
|
||
but fill in `parent' fields. */
|
||
np = *head;
|
||
np->parent = parent;
|
||
for (; np->right; np = np->right)
|
||
np->right->parent = np;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Search the parent sections of the case node tree
|
||
to see if a test for the lower bound of NODE would be redundant.
|
||
INDEX_TYPE is the type of the index expression.
|
||
|
||
The instructions to generate the case decision tree are
|
||
output in the same order as nodes are processed so it is
|
||
known that if a parent node checks the range of the current
|
||
node minus one that the current node is bounded at its lower
|
||
span. Thus the test would be redundant. */
|
||
|
||
static int
|
||
node_has_low_bound (node, index_type)
|
||
case_node_ptr node;
|
||
tree index_type;
|
||
{
|
||
tree low_minus_one;
|
||
case_node_ptr pnode;
|
||
|
||
/* If the lower bound of this node is the lowest value in the index type,
|
||
we need not test it. */
|
||
|
||
if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
|
||
return 1;
|
||
|
||
/* If this node has a left branch, the value at the left must be less
|
||
than that at this node, so it cannot be bounded at the bottom and
|
||
we need not bother testing any further. */
|
||
|
||
if (node->left)
|
||
return 0;
|
||
|
||
low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
|
||
node->low, integer_one_node));
|
||
|
||
/* If the subtraction above overflowed, we can't verify anything.
|
||
Otherwise, look for a parent that tests our value - 1. */
|
||
|
||
if (! tree_int_cst_lt (low_minus_one, node->low))
|
||
return 0;
|
||
|
||
for (pnode = node->parent; pnode; pnode = pnode->parent)
|
||
if (tree_int_cst_equal (low_minus_one, pnode->high))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Search the parent sections of the case node tree
|
||
to see if a test for the upper bound of NODE would be redundant.
|
||
INDEX_TYPE is the type of the index expression.
|
||
|
||
The instructions to generate the case decision tree are
|
||
output in the same order as nodes are processed so it is
|
||
known that if a parent node checks the range of the current
|
||
node plus one that the current node is bounded at its upper
|
||
span. Thus the test would be redundant. */
|
||
|
||
static int
|
||
node_has_high_bound (node, index_type)
|
||
case_node_ptr node;
|
||
tree index_type;
|
||
{
|
||
tree high_plus_one;
|
||
case_node_ptr pnode;
|
||
|
||
/* If there is no upper bound, obviously no test is needed. */
|
||
|
||
if (TYPE_MAX_VALUE (index_type) == NULL)
|
||
return 1;
|
||
|
||
/* If the upper bound of this node is the highest value in the type
|
||
of the index expression, we need not test against it. */
|
||
|
||
if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
|
||
return 1;
|
||
|
||
/* If this node has a right branch, the value at the right must be greater
|
||
than that at this node, so it cannot be bounded at the top and
|
||
we need not bother testing any further. */
|
||
|
||
if (node->right)
|
||
return 0;
|
||
|
||
high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
|
||
node->high, integer_one_node));
|
||
|
||
/* If the addition above overflowed, we can't verify anything.
|
||
Otherwise, look for a parent that tests our value + 1. */
|
||
|
||
if (! tree_int_cst_lt (node->high, high_plus_one))
|
||
return 0;
|
||
|
||
for (pnode = node->parent; pnode; pnode = pnode->parent)
|
||
if (tree_int_cst_equal (high_plus_one, pnode->low))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Search the parent sections of the
|
||
case node tree to see if both tests for the upper and lower
|
||
bounds of NODE would be redundant. */
|
||
|
||
static int
|
||
node_is_bounded (node, index_type)
|
||
case_node_ptr node;
|
||
tree index_type;
|
||
{
|
||
return (node_has_low_bound (node, index_type)
|
||
&& node_has_high_bound (node, index_type));
|
||
}
|
||
|
||
/* Emit an unconditional jump to LABEL unless it would be dead code. */
|
||
|
||
static void
|
||
emit_jump_if_reachable (label)
|
||
rtx label;
|
||
{
|
||
if (GET_CODE (get_last_insn ()) != BARRIER)
|
||
emit_jump (label);
|
||
}
|
||
|
||
/* Emit step-by-step code to select a case for the value of INDEX.
|
||
The thus generated decision tree follows the form of the
|
||
case-node binary tree NODE, whose nodes represent test conditions.
|
||
INDEX_TYPE is the type of the index of the switch.
|
||
|
||
Care is taken to prune redundant tests from the decision tree
|
||
by detecting any boundary conditions already checked by
|
||
emitted rtx. (See node_has_high_bound, node_has_low_bound
|
||
and node_is_bounded, above.)
|
||
|
||
Where the test conditions can be shown to be redundant we emit
|
||
an unconditional jump to the target code. As a further
|
||
optimization, the subordinates of a tree node are examined to
|
||
check for bounded nodes. In this case conditional and/or
|
||
unconditional jumps as a result of the boundary check for the
|
||
current node are arranged to target the subordinates associated
|
||
code for out of bound conditions on the current node.
|
||
|
||
We can assume that when control reaches the code generated here,
|
||
the index value has already been compared with the parents
|
||
of this node, and determined to be on the same side of each parent
|
||
as this node is. Thus, if this node tests for the value 51,
|
||
and a parent tested for 52, we don't need to consider
|
||
the possibility of a value greater than 51. If another parent
|
||
tests for the value 50, then this node need not test anything. */
|
||
|
||
static void
|
||
emit_case_nodes (index, node, default_label, index_type)
|
||
rtx index;
|
||
case_node_ptr node;
|
||
rtx default_label;
|
||
tree index_type;
|
||
{
|
||
/* If INDEX has an unsigned type, we must make unsigned branches. */
|
||
int unsignedp = TREE_UNSIGNED (index_type);
|
||
typedef rtx rtx_fn ();
|
||
enum machine_mode mode = GET_MODE (index);
|
||
|
||
/* See if our parents have already tested everything for us.
|
||
If they have, emit an unconditional jump for this node. */
|
||
if (node_is_bounded (node, index_type))
|
||
emit_jump (label_rtx (node->code_label));
|
||
|
||
else if (tree_int_cst_equal (node->low, node->high))
|
||
{
|
||
/* Node is single valued. First see if the index expression matches
|
||
this node and then check our children, if any. */
|
||
|
||
do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
|
||
label_rtx (node->code_label), unsignedp);
|
||
|
||
if (node->right != 0 && node->left != 0)
|
||
{
|
||
/* This node has children on both sides.
|
||
Dispatch to one side or the other
|
||
by comparing the index value with this node's value.
|
||
If one subtree is bounded, check that one first,
|
||
so we can avoid real branches in the tree. */
|
||
|
||
if (node_is_bounded (node->right, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0,
|
||
label_rtx (node->right->code_label));
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
}
|
||
|
||
else if (node_is_bounded (node->left, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
LT, NULL_RTX, mode, unsignedp, 0,
|
||
label_rtx (node->left->code_label));
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
|
||
else
|
||
{
|
||
/* Neither node is bounded. First distinguish the two sides;
|
||
then emit the code for one side at a time. */
|
||
|
||
tree test_label
|
||
= build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
|
||
|
||
/* See if the value is on the right. */
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0,
|
||
label_rtx (test_label));
|
||
|
||
/* Value must be on the left.
|
||
Handle the left-hand subtree. */
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
/* If left-hand subtree does nothing,
|
||
go to default. */
|
||
emit_jump_if_reachable (default_label);
|
||
|
||
/* Code branches here for the right-hand subtree. */
|
||
expand_label (test_label);
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
}
|
||
|
||
else if (node->right != 0 && node->left == 0)
|
||
{
|
||
/* Here we have a right child but no left so we issue conditional
|
||
branch to default and process the right child.
|
||
|
||
Omit the conditional branch to default if we it avoid only one
|
||
right child; it costs too much space to save so little time. */
|
||
|
||
if (node->right->right || node->right->left
|
||
|| !tree_int_cst_equal (node->right->low, node->right->high))
|
||
{
|
||
if (!node_has_low_bound (node, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->high,
|
||
NULL_RTX,
|
||
VOIDmode, 0),
|
||
LT, NULL_RTX, mode, unsignedp, 0,
|
||
default_label);
|
||
}
|
||
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
else
|
||
/* We cannot process node->right normally
|
||
since we haven't ruled out the numbers less than
|
||
this node's value. So handle node->right explicitly. */
|
||
do_jump_if_equal (index,
|
||
expand_expr (node->right->low, NULL_RTX,
|
||
VOIDmode, 0),
|
||
label_rtx (node->right->code_label), unsignedp);
|
||
}
|
||
|
||
else if (node->right == 0 && node->left != 0)
|
||
{
|
||
/* Just one subtree, on the left. */
|
||
|
||
#if 0 /* The following code and comment were formerly part
|
||
of the condition here, but they didn't work
|
||
and I don't understand what the idea was. -- rms. */
|
||
/* If our "most probable entry" is less probable
|
||
than the default label, emit a jump to
|
||
the default label using condition codes
|
||
already lying around. With no right branch,
|
||
a branch-greater-than will get us to the default
|
||
label correctly. */
|
||
if (use_cost_table
|
||
&& cost_table[TREE_INT_CST_LOW (node->high)] < 12)
|
||
;
|
||
#endif /* 0 */
|
||
if (node->left->left || node->left->right
|
||
|| !tree_int_cst_equal (node->left->low, node->left->high))
|
||
{
|
||
if (!node_has_high_bound (node, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->high,
|
||
NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0,
|
||
default_label);
|
||
}
|
||
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
}
|
||
else
|
||
/* We cannot process node->left normally
|
||
since we haven't ruled out the numbers less than
|
||
this node's value. So handle node->left explicitly. */
|
||
do_jump_if_equal (index,
|
||
expand_expr (node->left->low, NULL_RTX,
|
||
VOIDmode, 0),
|
||
label_rtx (node->left->code_label), unsignedp);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Node is a range. These cases are very similar to those for a single
|
||
value, except that we do not start by testing whether this node
|
||
is the one to branch to. */
|
||
|
||
if (node->right != 0 && node->left != 0)
|
||
{
|
||
/* Node has subtrees on both sides.
|
||
If the right-hand subtree is bounded,
|
||
test for it first, since we can go straight there.
|
||
Otherwise, we need to make a branch in the control structure,
|
||
then handle the two subtrees. */
|
||
tree test_label = 0;
|
||
|
||
|
||
if (node_is_bounded (node->right, index_type))
|
||
/* Right hand node is fully bounded so we can eliminate any
|
||
testing and branch directly to the target code. */
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0,
|
||
label_rtx (node->right->code_label));
|
||
else
|
||
{
|
||
/* Right hand node requires testing.
|
||
Branch to a label where we will handle it later. */
|
||
|
||
test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0,
|
||
label_rtx (test_label));
|
||
}
|
||
|
||
/* Value belongs to this node or to the left-hand subtree. */
|
||
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GE, NULL_RTX, mode, unsignedp, 0,
|
||
label_rtx (node->code_label));
|
||
|
||
/* Handle the left-hand subtree. */
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
|
||
/* If right node had to be handled later, do that now. */
|
||
|
||
if (test_label)
|
||
{
|
||
/* If the left-hand subtree fell through,
|
||
don't let it fall into the right-hand subtree. */
|
||
emit_jump_if_reachable (default_label);
|
||
|
||
expand_label (test_label);
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
}
|
||
|
||
else if (node->right != 0 && node->left == 0)
|
||
{
|
||
/* Deal with values to the left of this node,
|
||
if they are possible. */
|
||
if (!node_has_low_bound (node, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
|
||
VOIDmode, 0),
|
||
LT, NULL_RTX, mode, unsignedp, 0,
|
||
default_label);
|
||
}
|
||
|
||
/* Value belongs to this node or to the right-hand subtree. */
|
||
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
LE, NULL_RTX, mode, unsignedp, 0,
|
||
label_rtx (node->code_label));
|
||
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
|
||
else if (node->right == 0 && node->left != 0)
|
||
{
|
||
/* Deal with values to the right of this node,
|
||
if they are possible. */
|
||
if (!node_has_high_bound (node, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0,
|
||
default_label);
|
||
}
|
||
|
||
/* Value belongs to this node or to the left-hand subtree. */
|
||
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GE, NULL_RTX, mode, unsignedp, 0,
|
||
label_rtx (node->code_label));
|
||
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
}
|
||
|
||
else
|
||
{
|
||
/* Node has no children so we check low and high bounds to remove
|
||
redundant tests. Only one of the bounds can exist,
|
||
since otherwise this node is bounded--a case tested already. */
|
||
|
||
if (!node_has_high_bound (node, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
|
||
VOIDmode, 0),
|
||
GT, NULL_RTX, mode, unsignedp, 0,
|
||
default_label);
|
||
}
|
||
|
||
if (!node_has_low_bound (node, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
|
||
VOIDmode, 0),
|
||
LT, NULL_RTX, mode, unsignedp, 0,
|
||
default_label);
|
||
}
|
||
|
||
emit_jump (label_rtx (node->code_label));
|
||
}
|
||
}
|
||
}
|
||
|
||
/* These routines are used by the loop unrolling code. They copy BLOCK trees
|
||
so that the debugging info will be correct for the unrolled loop. */
|
||
|
||
/* Indexed by block number, contains a pointer to the N'th block node.
|
||
|
||
Allocated by the call to identify_blocks, then released after the call
|
||
to reorder_blocks in the function unroll_block_trees. */
|
||
|
||
static tree *block_vector;
|
||
|
||
void
|
||
find_loop_tree_blocks ()
|
||
{
|
||
tree block = DECL_INITIAL (current_function_decl);
|
||
|
||
block_vector = identify_blocks (block, get_insns ());
|
||
}
|
||
|
||
void
|
||
unroll_block_trees ()
|
||
{
|
||
tree block = DECL_INITIAL (current_function_decl);
|
||
|
||
reorder_blocks (block_vector, block, get_insns ());
|
||
|
||
/* Release any memory allocated by identify_blocks. */
|
||
if (block_vector)
|
||
free (block_vector);
|
||
}
|