5907 lines
145 KiB
C
5907 lines
145 KiB
C
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/* Induction variable optimizations.
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Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 2, or (at your option) any
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later version.
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GCC is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING. If not, write to the Free
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Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301, USA. */
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/* This pass tries to find the optimal set of induction variables for the loop.
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It optimizes just the basic linear induction variables (although adding
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support for other types should not be too hard). It includes the
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optimizations commonly known as strength reduction, induction variable
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coalescing and induction variable elimination. It does it in the
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following steps:
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1) The interesting uses of induction variables are found. This includes
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-- uses of induction variables in non-linear expressions
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-- addresses of arrays
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-- comparisons of induction variables
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2) Candidates for the induction variables are found. This includes
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-- old induction variables
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-- the variables defined by expressions derived from the "interesting
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uses" above
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3) The optimal (w.r. to a cost function) set of variables is chosen. The
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cost function assigns a cost to sets of induction variables and consists
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of three parts:
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-- The use costs. Each of the interesting uses chooses the best induction
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variable in the set and adds its cost to the sum. The cost reflects
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the time spent on modifying the induction variables value to be usable
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for the given purpose (adding base and offset for arrays, etc.).
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-- The variable costs. Each of the variables has a cost assigned that
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reflects the costs associated with incrementing the value of the
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variable. The original variables are somewhat preferred.
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-- The set cost. Depending on the size of the set, extra cost may be
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added to reflect register pressure.
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All the costs are defined in a machine-specific way, using the target
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hooks and machine descriptions to determine them.
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4) The trees are transformed to use the new variables, the dead code is
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removed.
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All of this is done loop by loop. Doing it globally is theoretically
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possible, it might give a better performance and it might enable us
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to decide costs more precisely, but getting all the interactions right
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would be complicated. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "tree.h"
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#include "rtl.h"
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#include "tm_p.h"
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#include "hard-reg-set.h"
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#include "basic-block.h"
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#include "output.h"
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#include "diagnostic.h"
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#include "tree-flow.h"
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#include "tree-dump.h"
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#include "timevar.h"
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#include "cfgloop.h"
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#include "varray.h"
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#include "expr.h"
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#include "tree-pass.h"
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#include "ggc.h"
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#include "insn-config.h"
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#include "recog.h"
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#include "hashtab.h"
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#include "tree-chrec.h"
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#include "tree-scalar-evolution.h"
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#include "cfgloop.h"
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#include "params.h"
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#include "langhooks.h"
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/* The infinite cost. */
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#define INFTY 10000000
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/* The expected number of loop iterations. TODO -- use profiling instead of
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this. */
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#define AVG_LOOP_NITER(LOOP) 5
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/* Representation of the induction variable. */
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struct iv
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{
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tree base; /* Initial value of the iv. */
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tree base_object; /* A memory object to that the induction variable points. */
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tree step; /* Step of the iv (constant only). */
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tree ssa_name; /* The ssa name with the value. */
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bool biv_p; /* Is it a biv? */
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bool have_use_for; /* Do we already have a use for it? */
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unsigned use_id; /* The identifier in the use if it is the case. */
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};
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/* Per-ssa version information (induction variable descriptions, etc.). */
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struct version_info
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{
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tree name; /* The ssa name. */
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struct iv *iv; /* Induction variable description. */
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bool has_nonlin_use; /* For a loop-level invariant, whether it is used in
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an expression that is not an induction variable. */
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unsigned inv_id; /* Id of an invariant. */
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bool preserve_biv; /* For the original biv, whether to preserve it. */
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};
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/* Types of uses. */
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enum use_type
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{
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USE_NONLINEAR_EXPR, /* Use in a nonlinear expression. */
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USE_ADDRESS, /* Use in an address. */
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USE_COMPARE /* Use is a compare. */
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};
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/* The candidate - cost pair. */
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struct cost_pair
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{
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struct iv_cand *cand; /* The candidate. */
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unsigned cost; /* The cost. */
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bitmap depends_on; /* The list of invariants that have to be
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preserved. */
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tree value; /* For final value elimination, the expression for
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the final value of the iv. For iv elimination,
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the new bound to compare with. */
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};
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/* Use. */
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struct iv_use
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{
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unsigned id; /* The id of the use. */
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enum use_type type; /* Type of the use. */
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struct iv *iv; /* The induction variable it is based on. */
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tree stmt; /* Statement in that it occurs. */
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tree *op_p; /* The place where it occurs. */
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bitmap related_cands; /* The set of "related" iv candidates, plus the common
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important ones. */
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unsigned n_map_members; /* Number of candidates in the cost_map list. */
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struct cost_pair *cost_map;
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/* The costs wrto the iv candidates. */
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struct iv_cand *selected;
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/* The selected candidate. */
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};
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/* The position where the iv is computed. */
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enum iv_position
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{
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IP_NORMAL, /* At the end, just before the exit condition. */
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IP_END, /* At the end of the latch block. */
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IP_ORIGINAL /* The original biv. */
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};
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/* The induction variable candidate. */
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struct iv_cand
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{
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unsigned id; /* The number of the candidate. */
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bool important; /* Whether this is an "important" candidate, i.e. such
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that it should be considered by all uses. */
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enum iv_position pos; /* Where it is computed. */
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tree incremented_at; /* For original biv, the statement where it is
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incremented. */
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tree var_before; /* The variable used for it before increment. */
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tree var_after; /* The variable used for it after increment. */
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struct iv *iv; /* The value of the candidate. NULL for
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"pseudocandidate" used to indicate the possibility
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to replace the final value of an iv by direct
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computation of the value. */
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unsigned cost; /* Cost of the candidate. */
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bitmap depends_on; /* The list of invariants that are used in step of the
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biv. */
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};
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/* The data used by the induction variable optimizations. */
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typedef struct iv_use *iv_use_p;
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DEF_VEC_P(iv_use_p);
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DEF_VEC_ALLOC_P(iv_use_p,heap);
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typedef struct iv_cand *iv_cand_p;
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DEF_VEC_P(iv_cand_p);
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DEF_VEC_ALLOC_P(iv_cand_p,heap);
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struct ivopts_data
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{
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/* The currently optimized loop. */
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struct loop *current_loop;
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/* Number of registers used in it. */
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unsigned regs_used;
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/* Numbers of iterations for all exits of the current loop. */
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htab_t niters;
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/* The size of version_info array allocated. */
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unsigned version_info_size;
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/* The array of information for the ssa names. */
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struct version_info *version_info;
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/* The bitmap of indices in version_info whose value was changed. */
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bitmap relevant;
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/* The maximum invariant id. */
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unsigned max_inv_id;
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/* The uses of induction variables. */
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VEC(iv_use_p,heap) *iv_uses;
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/* The candidates. */
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VEC(iv_cand_p,heap) *iv_candidates;
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/* A bitmap of important candidates. */
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bitmap important_candidates;
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/* Whether to consider just related and important candidates when replacing a
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use. */
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bool consider_all_candidates;
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};
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/* An assignment of iv candidates to uses. */
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struct iv_ca
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{
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/* The number of uses covered by the assignment. */
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unsigned upto;
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/* Number of uses that cannot be expressed by the candidates in the set. */
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unsigned bad_uses;
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/* Candidate assigned to a use, together with the related costs. */
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struct cost_pair **cand_for_use;
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/* Number of times each candidate is used. */
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unsigned *n_cand_uses;
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/* The candidates used. */
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bitmap cands;
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/* The number of candidates in the set. */
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unsigned n_cands;
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/* Total number of registers needed. */
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unsigned n_regs;
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/* Total cost of expressing uses. */
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unsigned cand_use_cost;
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/* Total cost of candidates. */
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unsigned cand_cost;
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/* Number of times each invariant is used. */
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unsigned *n_invariant_uses;
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/* Total cost of the assignment. */
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unsigned cost;
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};
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/* Difference of two iv candidate assignments. */
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struct iv_ca_delta
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{
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/* Changed use. */
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struct iv_use *use;
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/* An old assignment (for rollback purposes). */
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struct cost_pair *old_cp;
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/* A new assignment. */
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struct cost_pair *new_cp;
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/* Next change in the list. */
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struct iv_ca_delta *next_change;
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};
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/* Bound on number of candidates below that all candidates are considered. */
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#define CONSIDER_ALL_CANDIDATES_BOUND \
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((unsigned) PARAM_VALUE (PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND))
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/* If there are more iv occurrences, we just give up (it is quite unlikely that
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optimizing such a loop would help, and it would take ages). */
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#define MAX_CONSIDERED_USES \
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((unsigned) PARAM_VALUE (PARAM_IV_MAX_CONSIDERED_USES))
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/* If there are at most this number of ivs in the set, try removing unnecessary
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ivs from the set always. */
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#define ALWAYS_PRUNE_CAND_SET_BOUND \
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((unsigned) PARAM_VALUE (PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND))
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/* The list of trees for that the decl_rtl field must be reset is stored
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here. */
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static VEC(tree,heap) *decl_rtl_to_reset;
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/* Number of uses recorded in DATA. */
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static inline unsigned
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n_iv_uses (struct ivopts_data *data)
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{
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return VEC_length (iv_use_p, data->iv_uses);
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}
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/* Ith use recorded in DATA. */
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static inline struct iv_use *
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iv_use (struct ivopts_data *data, unsigned i)
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{
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return VEC_index (iv_use_p, data->iv_uses, i);
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}
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/* Number of candidates recorded in DATA. */
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static inline unsigned
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n_iv_cands (struct ivopts_data *data)
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{
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return VEC_length (iv_cand_p, data->iv_candidates);
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}
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/* Ith candidate recorded in DATA. */
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static inline struct iv_cand *
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iv_cand (struct ivopts_data *data, unsigned i)
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{
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return VEC_index (iv_cand_p, data->iv_candidates, i);
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}
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/* The single loop exit if it dominates the latch, NULL otherwise. */
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edge
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single_dom_exit (struct loop *loop)
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{
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edge exit = loop->single_exit;
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if (!exit)
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return NULL;
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if (!just_once_each_iteration_p (loop, exit->src))
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return NULL;
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return exit;
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}
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/* Dumps information about the induction variable IV to FILE. */
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extern void dump_iv (FILE *, struct iv *);
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void
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dump_iv (FILE *file, struct iv *iv)
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{
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if (iv->ssa_name)
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{
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fprintf (file, "ssa name ");
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print_generic_expr (file, iv->ssa_name, TDF_SLIM);
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fprintf (file, "\n");
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}
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fprintf (file, " type ");
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print_generic_expr (file, TREE_TYPE (iv->base), TDF_SLIM);
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fprintf (file, "\n");
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if (iv->step)
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{
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fprintf (file, " base ");
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print_generic_expr (file, iv->base, TDF_SLIM);
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fprintf (file, "\n");
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fprintf (file, " step ");
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print_generic_expr (file, iv->step, TDF_SLIM);
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fprintf (file, "\n");
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}
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else
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{
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fprintf (file, " invariant ");
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print_generic_expr (file, iv->base, TDF_SLIM);
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fprintf (file, "\n");
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}
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if (iv->base_object)
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{
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fprintf (file, " base object ");
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print_generic_expr (file, iv->base_object, TDF_SLIM);
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fprintf (file, "\n");
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}
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if (iv->biv_p)
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fprintf (file, " is a biv\n");
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}
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/* Dumps information about the USE to FILE. */
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extern void dump_use (FILE *, struct iv_use *);
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void
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dump_use (FILE *file, struct iv_use *use)
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{
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fprintf (file, "use %d\n", use->id);
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switch (use->type)
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{
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case USE_NONLINEAR_EXPR:
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fprintf (file, " generic\n");
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break;
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case USE_ADDRESS:
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fprintf (file, " address\n");
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break;
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case USE_COMPARE:
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fprintf (file, " compare\n");
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break;
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default:
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gcc_unreachable ();
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}
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fprintf (file, " in statement ");
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print_generic_expr (file, use->stmt, TDF_SLIM);
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fprintf (file, "\n");
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fprintf (file, " at position ");
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if (use->op_p)
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print_generic_expr (file, *use->op_p, TDF_SLIM);
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fprintf (file, "\n");
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dump_iv (file, use->iv);
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if (use->related_cands)
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{
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fprintf (file, " related candidates ");
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dump_bitmap (file, use->related_cands);
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}
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}
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/* Dumps information about the uses to FILE. */
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extern void dump_uses (FILE *, struct ivopts_data *);
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void
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dump_uses (FILE *file, struct ivopts_data *data)
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{
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unsigned i;
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struct iv_use *use;
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||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
{
|
||
|
use = iv_use (data, i);
|
||
|
|
||
|
dump_use (file, use);
|
||
|
fprintf (file, "\n");
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Dumps information about induction variable candidate CAND to FILE. */
|
||
|
|
||
|
extern void dump_cand (FILE *, struct iv_cand *);
|
||
|
void
|
||
|
dump_cand (FILE *file, struct iv_cand *cand)
|
||
|
{
|
||
|
struct iv *iv = cand->iv;
|
||
|
|
||
|
fprintf (file, "candidate %d%s\n",
|
||
|
cand->id, cand->important ? " (important)" : "");
|
||
|
|
||
|
if (cand->depends_on)
|
||
|
{
|
||
|
fprintf (file, " depends on ");
|
||
|
dump_bitmap (file, cand->depends_on);
|
||
|
}
|
||
|
|
||
|
if (!iv)
|
||
|
{
|
||
|
fprintf (file, " final value replacement\n");
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
switch (cand->pos)
|
||
|
{
|
||
|
case IP_NORMAL:
|
||
|
fprintf (file, " incremented before exit test\n");
|
||
|
break;
|
||
|
|
||
|
case IP_END:
|
||
|
fprintf (file, " incremented at end\n");
|
||
|
break;
|
||
|
|
||
|
case IP_ORIGINAL:
|
||
|
fprintf (file, " original biv\n");
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
dump_iv (file, iv);
|
||
|
}
|
||
|
|
||
|
/* Returns the info for ssa version VER. */
|
||
|
|
||
|
static inline struct version_info *
|
||
|
ver_info (struct ivopts_data *data, unsigned ver)
|
||
|
{
|
||
|
return data->version_info + ver;
|
||
|
}
|
||
|
|
||
|
/* Returns the info for ssa name NAME. */
|
||
|
|
||
|
static inline struct version_info *
|
||
|
name_info (struct ivopts_data *data, tree name)
|
||
|
{
|
||
|
return ver_info (data, SSA_NAME_VERSION (name));
|
||
|
}
|
||
|
|
||
|
/* Checks whether there exists number X such that X * B = A, counting modulo
|
||
|
2^BITS. */
|
||
|
|
||
|
static bool
|
||
|
divide (unsigned bits, unsigned HOST_WIDE_INT a, unsigned HOST_WIDE_INT b,
|
||
|
HOST_WIDE_INT *x)
|
||
|
{
|
||
|
unsigned HOST_WIDE_INT mask = ~(~(unsigned HOST_WIDE_INT) 0 << (bits - 1) << 1);
|
||
|
unsigned HOST_WIDE_INT inv, ex, val;
|
||
|
unsigned i;
|
||
|
|
||
|
a &= mask;
|
||
|
b &= mask;
|
||
|
|
||
|
/* First divide the whole equation by 2 as long as possible. */
|
||
|
while (!(a & 1) && !(b & 1))
|
||
|
{
|
||
|
a >>= 1;
|
||
|
b >>= 1;
|
||
|
bits--;
|
||
|
mask >>= 1;
|
||
|
}
|
||
|
|
||
|
if (!(b & 1))
|
||
|
{
|
||
|
/* If b is still even, a is odd and there is no such x. */
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
/* Find the inverse of b. We compute it as
|
||
|
b^(2^(bits - 1) - 1) (mod 2^bits). */
|
||
|
inv = 1;
|
||
|
ex = b;
|
||
|
for (i = 0; i < bits - 1; i++)
|
||
|
{
|
||
|
inv = (inv * ex) & mask;
|
||
|
ex = (ex * ex) & mask;
|
||
|
}
|
||
|
|
||
|
val = (a * inv) & mask;
|
||
|
|
||
|
gcc_assert (((val * b) & mask) == a);
|
||
|
|
||
|
if ((val >> (bits - 1)) & 1)
|
||
|
val |= ~mask;
|
||
|
|
||
|
*x = val;
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Returns true if STMT is after the place where the IP_NORMAL ivs will be
|
||
|
emitted in LOOP. */
|
||
|
|
||
|
static bool
|
||
|
stmt_after_ip_normal_pos (struct loop *loop, tree stmt)
|
||
|
{
|
||
|
basic_block bb = ip_normal_pos (loop), sbb = bb_for_stmt (stmt);
|
||
|
|
||
|
gcc_assert (bb);
|
||
|
|
||
|
if (sbb == loop->latch)
|
||
|
return true;
|
||
|
|
||
|
if (sbb != bb)
|
||
|
return false;
|
||
|
|
||
|
return stmt == last_stmt (bb);
|
||
|
}
|
||
|
|
||
|
/* Returns true if STMT if after the place where the original induction
|
||
|
variable CAND is incremented. */
|
||
|
|
||
|
static bool
|
||
|
stmt_after_ip_original_pos (struct iv_cand *cand, tree stmt)
|
||
|
{
|
||
|
basic_block cand_bb = bb_for_stmt (cand->incremented_at);
|
||
|
basic_block stmt_bb = bb_for_stmt (stmt);
|
||
|
block_stmt_iterator bsi;
|
||
|
|
||
|
if (!dominated_by_p (CDI_DOMINATORS, stmt_bb, cand_bb))
|
||
|
return false;
|
||
|
|
||
|
if (stmt_bb != cand_bb)
|
||
|
return true;
|
||
|
|
||
|
/* Scan the block from the end, since the original ivs are usually
|
||
|
incremented at the end of the loop body. */
|
||
|
for (bsi = bsi_last (stmt_bb); ; bsi_prev (&bsi))
|
||
|
{
|
||
|
if (bsi_stmt (bsi) == cand->incremented_at)
|
||
|
return false;
|
||
|
if (bsi_stmt (bsi) == stmt)
|
||
|
return true;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Returns true if STMT if after the place where the induction variable
|
||
|
CAND is incremented in LOOP. */
|
||
|
|
||
|
static bool
|
||
|
stmt_after_increment (struct loop *loop, struct iv_cand *cand, tree stmt)
|
||
|
{
|
||
|
switch (cand->pos)
|
||
|
{
|
||
|
case IP_END:
|
||
|
return false;
|
||
|
|
||
|
case IP_NORMAL:
|
||
|
return stmt_after_ip_normal_pos (loop, stmt);
|
||
|
|
||
|
case IP_ORIGINAL:
|
||
|
return stmt_after_ip_original_pos (cand, stmt);
|
||
|
|
||
|
default:
|
||
|
gcc_unreachable ();
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Returns true if EXP is a ssa name that occurs in an abnormal phi node. */
|
||
|
|
||
|
static bool
|
||
|
abnormal_ssa_name_p (tree exp)
|
||
|
{
|
||
|
if (!exp)
|
||
|
return false;
|
||
|
|
||
|
if (TREE_CODE (exp) != SSA_NAME)
|
||
|
return false;
|
||
|
|
||
|
return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp) != 0;
|
||
|
}
|
||
|
|
||
|
/* Returns false if BASE or INDEX contains a ssa name that occurs in an
|
||
|
abnormal phi node. Callback for for_each_index. */
|
||
|
|
||
|
static bool
|
||
|
idx_contains_abnormal_ssa_name_p (tree base, tree *index,
|
||
|
void *data ATTRIBUTE_UNUSED)
|
||
|
{
|
||
|
if (TREE_CODE (base) == ARRAY_REF)
|
||
|
{
|
||
|
if (abnormal_ssa_name_p (TREE_OPERAND (base, 2)))
|
||
|
return false;
|
||
|
if (abnormal_ssa_name_p (TREE_OPERAND (base, 3)))
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
return !abnormal_ssa_name_p (*index);
|
||
|
}
|
||
|
|
||
|
/* Returns true if EXPR contains a ssa name that occurs in an
|
||
|
abnormal phi node. */
|
||
|
|
||
|
bool
|
||
|
contains_abnormal_ssa_name_p (tree expr)
|
||
|
{
|
||
|
enum tree_code code;
|
||
|
enum tree_code_class class;
|
||
|
|
||
|
if (!expr)
|
||
|
return false;
|
||
|
|
||
|
code = TREE_CODE (expr);
|
||
|
class = TREE_CODE_CLASS (code);
|
||
|
|
||
|
if (code == SSA_NAME)
|
||
|
return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr) != 0;
|
||
|
|
||
|
if (code == INTEGER_CST
|
||
|
|| is_gimple_min_invariant (expr))
|
||
|
return false;
|
||
|
|
||
|
if (code == ADDR_EXPR)
|
||
|
return !for_each_index (&TREE_OPERAND (expr, 0),
|
||
|
idx_contains_abnormal_ssa_name_p,
|
||
|
NULL);
|
||
|
|
||
|
switch (class)
|
||
|
{
|
||
|
case tcc_binary:
|
||
|
case tcc_comparison:
|
||
|
if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 1)))
|
||
|
return true;
|
||
|
|
||
|
/* Fallthru. */
|
||
|
case tcc_unary:
|
||
|
if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 0)))
|
||
|
return true;
|
||
|
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
gcc_unreachable ();
|
||
|
}
|
||
|
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
/* Element of the table in that we cache the numbers of iterations obtained
|
||
|
from exits of the loop. */
|
||
|
|
||
|
struct nfe_cache_elt
|
||
|
{
|
||
|
/* The edge for that the number of iterations is cached. */
|
||
|
edge exit;
|
||
|
|
||
|
/* Number of iterations corresponding to this exit, or NULL if it cannot be
|
||
|
determined. */
|
||
|
tree niter;
|
||
|
};
|
||
|
|
||
|
/* Hash function for nfe_cache_elt E. */
|
||
|
|
||
|
static hashval_t
|
||
|
nfe_hash (const void *e)
|
||
|
{
|
||
|
const struct nfe_cache_elt *elt = e;
|
||
|
|
||
|
return htab_hash_pointer (elt->exit);
|
||
|
}
|
||
|
|
||
|
/* Equality function for nfe_cache_elt E1 and edge E2. */
|
||
|
|
||
|
static int
|
||
|
nfe_eq (const void *e1, const void *e2)
|
||
|
{
|
||
|
const struct nfe_cache_elt *elt1 = e1;
|
||
|
|
||
|
return elt1->exit == e2;
|
||
|
}
|
||
|
|
||
|
/* Returns tree describing number of iterations determined from
|
||
|
EXIT of DATA->current_loop, or NULL if something goes wrong. */
|
||
|
|
||
|
static tree
|
||
|
niter_for_exit (struct ivopts_data *data, edge exit)
|
||
|
{
|
||
|
struct nfe_cache_elt *nfe_desc;
|
||
|
struct tree_niter_desc desc;
|
||
|
PTR *slot;
|
||
|
|
||
|
slot = htab_find_slot_with_hash (data->niters, exit,
|
||
|
htab_hash_pointer (exit),
|
||
|
INSERT);
|
||
|
|
||
|
if (!*slot)
|
||
|
{
|
||
|
nfe_desc = xmalloc (sizeof (struct nfe_cache_elt));
|
||
|
nfe_desc->exit = exit;
|
||
|
|
||
|
/* Try to determine number of iterations. We must know it
|
||
|
unconditionally (i.e., without possibility of # of iterations
|
||
|
being zero). Also, we cannot safely work with ssa names that
|
||
|
appear in phi nodes on abnormal edges, so that we do not create
|
||
|
overlapping life ranges for them (PR 27283). */
|
||
|
if (number_of_iterations_exit (data->current_loop,
|
||
|
exit, &desc, true)
|
||
|
&& zero_p (desc.may_be_zero)
|
||
|
&& !contains_abnormal_ssa_name_p (desc.niter))
|
||
|
nfe_desc->niter = desc.niter;
|
||
|
else
|
||
|
nfe_desc->niter = NULL_TREE;
|
||
|
}
|
||
|
else
|
||
|
nfe_desc = *slot;
|
||
|
|
||
|
return nfe_desc->niter;
|
||
|
}
|
||
|
|
||
|
/* Returns tree describing number of iterations determined from
|
||
|
single dominating exit of DATA->current_loop, or NULL if something
|
||
|
goes wrong. */
|
||
|
|
||
|
static tree
|
||
|
niter_for_single_dom_exit (struct ivopts_data *data)
|
||
|
{
|
||
|
edge exit = single_dom_exit (data->current_loop);
|
||
|
|
||
|
if (!exit)
|
||
|
return NULL;
|
||
|
|
||
|
return niter_for_exit (data, exit);
|
||
|
}
|
||
|
|
||
|
/* Initializes data structures used by the iv optimization pass, stored
|
||
|
in DATA. */
|
||
|
|
||
|
static void
|
||
|
tree_ssa_iv_optimize_init (struct ivopts_data *data)
|
||
|
{
|
||
|
data->version_info_size = 2 * num_ssa_names;
|
||
|
data->version_info = XCNEWVEC (struct version_info, data->version_info_size);
|
||
|
data->relevant = BITMAP_ALLOC (NULL);
|
||
|
data->important_candidates = BITMAP_ALLOC (NULL);
|
||
|
data->max_inv_id = 0;
|
||
|
data->niters = htab_create (10, nfe_hash, nfe_eq, free);
|
||
|
data->iv_uses = VEC_alloc (iv_use_p, heap, 20);
|
||
|
data->iv_candidates = VEC_alloc (iv_cand_p, heap, 20);
|
||
|
decl_rtl_to_reset = VEC_alloc (tree, heap, 20);
|
||
|
}
|
||
|
|
||
|
/* Returns a memory object to that EXPR points. In case we are able to
|
||
|
determine that it does not point to any such object, NULL is returned. */
|
||
|
|
||
|
static tree
|
||
|
determine_base_object (tree expr)
|
||
|
{
|
||
|
enum tree_code code = TREE_CODE (expr);
|
||
|
tree base, obj, op0, op1;
|
||
|
|
||
|
/* If this is a pointer casted to any type, we need to determine
|
||
|
the base object for the pointer; so handle conversions before
|
||
|
throwing away non-pointer expressions. */
|
||
|
if (TREE_CODE (expr) == NOP_EXPR
|
||
|
|| TREE_CODE (expr) == CONVERT_EXPR)
|
||
|
return determine_base_object (TREE_OPERAND (expr, 0));
|
||
|
|
||
|
if (!POINTER_TYPE_P (TREE_TYPE (expr)))
|
||
|
return NULL_TREE;
|
||
|
|
||
|
switch (code)
|
||
|
{
|
||
|
case INTEGER_CST:
|
||
|
return NULL_TREE;
|
||
|
|
||
|
case ADDR_EXPR:
|
||
|
obj = TREE_OPERAND (expr, 0);
|
||
|
base = get_base_address (obj);
|
||
|
|
||
|
if (!base)
|
||
|
return expr;
|
||
|
|
||
|
if (TREE_CODE (base) == INDIRECT_REF)
|
||
|
return determine_base_object (TREE_OPERAND (base, 0));
|
||
|
|
||
|
return fold_convert (ptr_type_node,
|
||
|
build_fold_addr_expr (base));
|
||
|
|
||
|
case PLUS_EXPR:
|
||
|
case MINUS_EXPR:
|
||
|
op0 = determine_base_object (TREE_OPERAND (expr, 0));
|
||
|
op1 = determine_base_object (TREE_OPERAND (expr, 1));
|
||
|
|
||
|
if (!op1)
|
||
|
return op0;
|
||
|
|
||
|
if (!op0)
|
||
|
return (code == PLUS_EXPR
|
||
|
? op1
|
||
|
: fold_build1 (NEGATE_EXPR, ptr_type_node, op1));
|
||
|
|
||
|
return fold_build2 (code, ptr_type_node, op0, op1);
|
||
|
|
||
|
default:
|
||
|
return fold_convert (ptr_type_node, expr);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Allocates an induction variable with given initial value BASE and step STEP
|
||
|
for loop LOOP. */
|
||
|
|
||
|
static struct iv *
|
||
|
alloc_iv (tree base, tree step)
|
||
|
{
|
||
|
struct iv *iv = XCNEW (struct iv);
|
||
|
|
||
|
if (step && integer_zerop (step))
|
||
|
step = NULL_TREE;
|
||
|
|
||
|
iv->base = base;
|
||
|
iv->base_object = determine_base_object (base);
|
||
|
iv->step = step;
|
||
|
iv->biv_p = false;
|
||
|
iv->have_use_for = false;
|
||
|
iv->use_id = 0;
|
||
|
iv->ssa_name = NULL_TREE;
|
||
|
|
||
|
return iv;
|
||
|
}
|
||
|
|
||
|
/* Sets STEP and BASE for induction variable IV. */
|
||
|
|
||
|
static void
|
||
|
set_iv (struct ivopts_data *data, tree iv, tree base, tree step)
|
||
|
{
|
||
|
struct version_info *info = name_info (data, iv);
|
||
|
|
||
|
gcc_assert (!info->iv);
|
||
|
|
||
|
bitmap_set_bit (data->relevant, SSA_NAME_VERSION (iv));
|
||
|
info->iv = alloc_iv (base, step);
|
||
|
info->iv->ssa_name = iv;
|
||
|
}
|
||
|
|
||
|
/* Finds induction variable declaration for VAR. */
|
||
|
|
||
|
static struct iv *
|
||
|
get_iv (struct ivopts_data *data, tree var)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
|
||
|
if (!name_info (data, var)->iv)
|
||
|
{
|
||
|
bb = bb_for_stmt (SSA_NAME_DEF_STMT (var));
|
||
|
|
||
|
if (!bb
|
||
|
|| !flow_bb_inside_loop_p (data->current_loop, bb))
|
||
|
set_iv (data, var, var, NULL_TREE);
|
||
|
}
|
||
|
|
||
|
return name_info (data, var)->iv;
|
||
|
}
|
||
|
|
||
|
/* Determines the step of a biv defined in PHI. Returns NULL if PHI does
|
||
|
not define a simple affine biv with nonzero step. */
|
||
|
|
||
|
static tree
|
||
|
determine_biv_step (tree phi)
|
||
|
{
|
||
|
struct loop *loop = bb_for_stmt (phi)->loop_father;
|
||
|
tree name = PHI_RESULT (phi);
|
||
|
affine_iv iv;
|
||
|
|
||
|
if (!is_gimple_reg (name))
|
||
|
return NULL_TREE;
|
||
|
|
||
|
if (!simple_iv (loop, phi, name, &iv, true))
|
||
|
return NULL_TREE;
|
||
|
|
||
|
return (zero_p (iv.step) ? NULL_TREE : iv.step);
|
||
|
}
|
||
|
|
||
|
/* Finds basic ivs. */
|
||
|
|
||
|
static bool
|
||
|
find_bivs (struct ivopts_data *data)
|
||
|
{
|
||
|
tree phi, step, type, base;
|
||
|
bool found = false;
|
||
|
struct loop *loop = data->current_loop;
|
||
|
|
||
|
for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi))
|
||
|
{
|
||
|
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi)))
|
||
|
continue;
|
||
|
|
||
|
step = determine_biv_step (phi);
|
||
|
if (!step)
|
||
|
continue;
|
||
|
|
||
|
base = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop));
|
||
|
base = expand_simple_operations (base);
|
||
|
if (contains_abnormal_ssa_name_p (base)
|
||
|
|| contains_abnormal_ssa_name_p (step))
|
||
|
continue;
|
||
|
|
||
|
type = TREE_TYPE (PHI_RESULT (phi));
|
||
|
base = fold_convert (type, base);
|
||
|
if (step)
|
||
|
step = fold_convert (type, step);
|
||
|
|
||
|
set_iv (data, PHI_RESULT (phi), base, step);
|
||
|
found = true;
|
||
|
}
|
||
|
|
||
|
return found;
|
||
|
}
|
||
|
|
||
|
/* Marks basic ivs. */
|
||
|
|
||
|
static void
|
||
|
mark_bivs (struct ivopts_data *data)
|
||
|
{
|
||
|
tree phi, var;
|
||
|
struct iv *iv, *incr_iv;
|
||
|
struct loop *loop = data->current_loop;
|
||
|
basic_block incr_bb;
|
||
|
|
||
|
for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi))
|
||
|
{
|
||
|
iv = get_iv (data, PHI_RESULT (phi));
|
||
|
if (!iv)
|
||
|
continue;
|
||
|
|
||
|
var = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (loop));
|
||
|
incr_iv = get_iv (data, var);
|
||
|
if (!incr_iv)
|
||
|
continue;
|
||
|
|
||
|
/* If the increment is in the subloop, ignore it. */
|
||
|
incr_bb = bb_for_stmt (SSA_NAME_DEF_STMT (var));
|
||
|
if (incr_bb->loop_father != data->current_loop
|
||
|
|| (incr_bb->flags & BB_IRREDUCIBLE_LOOP))
|
||
|
continue;
|
||
|
|
||
|
iv->biv_p = true;
|
||
|
incr_iv->biv_p = true;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Checks whether STMT defines a linear induction variable and stores its
|
||
|
parameters to IV. */
|
||
|
|
||
|
static bool
|
||
|
find_givs_in_stmt_scev (struct ivopts_data *data, tree stmt, affine_iv *iv)
|
||
|
{
|
||
|
tree lhs;
|
||
|
struct loop *loop = data->current_loop;
|
||
|
|
||
|
iv->base = NULL_TREE;
|
||
|
iv->step = NULL_TREE;
|
||
|
|
||
|
if (TREE_CODE (stmt) != MODIFY_EXPR)
|
||
|
return false;
|
||
|
|
||
|
lhs = TREE_OPERAND (stmt, 0);
|
||
|
if (TREE_CODE (lhs) != SSA_NAME)
|
||
|
return false;
|
||
|
|
||
|
if (!simple_iv (loop, stmt, TREE_OPERAND (stmt, 1), iv, true))
|
||
|
return false;
|
||
|
iv->base = expand_simple_operations (iv->base);
|
||
|
|
||
|
if (contains_abnormal_ssa_name_p (iv->base)
|
||
|
|| contains_abnormal_ssa_name_p (iv->step))
|
||
|
return false;
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Finds general ivs in statement STMT. */
|
||
|
|
||
|
static void
|
||
|
find_givs_in_stmt (struct ivopts_data *data, tree stmt)
|
||
|
{
|
||
|
affine_iv iv;
|
||
|
|
||
|
if (!find_givs_in_stmt_scev (data, stmt, &iv))
|
||
|
return;
|
||
|
|
||
|
set_iv (data, TREE_OPERAND (stmt, 0), iv.base, iv.step);
|
||
|
}
|
||
|
|
||
|
/* Finds general ivs in basic block BB. */
|
||
|
|
||
|
static void
|
||
|
find_givs_in_bb (struct ivopts_data *data, basic_block bb)
|
||
|
{
|
||
|
block_stmt_iterator bsi;
|
||
|
|
||
|
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
|
||
|
find_givs_in_stmt (data, bsi_stmt (bsi));
|
||
|
}
|
||
|
|
||
|
/* Finds general ivs. */
|
||
|
|
||
|
static void
|
||
|
find_givs (struct ivopts_data *data)
|
||
|
{
|
||
|
struct loop *loop = data->current_loop;
|
||
|
basic_block *body = get_loop_body_in_dom_order (loop);
|
||
|
unsigned i;
|
||
|
|
||
|
for (i = 0; i < loop->num_nodes; i++)
|
||
|
find_givs_in_bb (data, body[i]);
|
||
|
free (body);
|
||
|
}
|
||
|
|
||
|
/* For each ssa name defined in LOOP determines whether it is an induction
|
||
|
variable and if so, its initial value and step. */
|
||
|
|
||
|
static bool
|
||
|
find_induction_variables (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned i;
|
||
|
bitmap_iterator bi;
|
||
|
|
||
|
if (!find_bivs (data))
|
||
|
return false;
|
||
|
|
||
|
find_givs (data);
|
||
|
mark_bivs (data);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
tree niter = niter_for_single_dom_exit (data);
|
||
|
|
||
|
if (niter)
|
||
|
{
|
||
|
fprintf (dump_file, " number of iterations ");
|
||
|
print_generic_expr (dump_file, niter, TDF_SLIM);
|
||
|
fprintf (dump_file, "\n\n");
|
||
|
};
|
||
|
|
||
|
fprintf (dump_file, "Induction variables:\n\n");
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
|
||
|
{
|
||
|
if (ver_info (data, i)->iv)
|
||
|
dump_iv (dump_file, ver_info (data, i)->iv);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Records a use of type USE_TYPE at *USE_P in STMT whose value is IV. */
|
||
|
|
||
|
static struct iv_use *
|
||
|
record_use (struct ivopts_data *data, tree *use_p, struct iv *iv,
|
||
|
tree stmt, enum use_type use_type)
|
||
|
{
|
||
|
struct iv_use *use = XCNEW (struct iv_use);
|
||
|
|
||
|
use->id = n_iv_uses (data);
|
||
|
use->type = use_type;
|
||
|
use->iv = iv;
|
||
|
use->stmt = stmt;
|
||
|
use->op_p = use_p;
|
||
|
use->related_cands = BITMAP_ALLOC (NULL);
|
||
|
|
||
|
/* To avoid showing ssa name in the dumps, if it was not reset by the
|
||
|
caller. */
|
||
|
iv->ssa_name = NULL_TREE;
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
dump_use (dump_file, use);
|
||
|
|
||
|
VEC_safe_push (iv_use_p, heap, data->iv_uses, use);
|
||
|
|
||
|
return use;
|
||
|
}
|
||
|
|
||
|
/* Checks whether OP is a loop-level invariant and if so, records it.
|
||
|
NONLINEAR_USE is true if the invariant is used in a way we do not
|
||
|
handle specially. */
|
||
|
|
||
|
static void
|
||
|
record_invariant (struct ivopts_data *data, tree op, bool nonlinear_use)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
struct version_info *info;
|
||
|
|
||
|
if (TREE_CODE (op) != SSA_NAME
|
||
|
|| !is_gimple_reg (op))
|
||
|
return;
|
||
|
|
||
|
bb = bb_for_stmt (SSA_NAME_DEF_STMT (op));
|
||
|
if (bb
|
||
|
&& flow_bb_inside_loop_p (data->current_loop, bb))
|
||
|
return;
|
||
|
|
||
|
info = name_info (data, op);
|
||
|
info->name = op;
|
||
|
info->has_nonlin_use |= nonlinear_use;
|
||
|
if (!info->inv_id)
|
||
|
info->inv_id = ++data->max_inv_id;
|
||
|
bitmap_set_bit (data->relevant, SSA_NAME_VERSION (op));
|
||
|
}
|
||
|
|
||
|
/* Checks whether the use OP is interesting and if so, records it. */
|
||
|
|
||
|
static struct iv_use *
|
||
|
find_interesting_uses_op (struct ivopts_data *data, tree op)
|
||
|
{
|
||
|
struct iv *iv;
|
||
|
struct iv *civ;
|
||
|
tree stmt;
|
||
|
struct iv_use *use;
|
||
|
|
||
|
if (TREE_CODE (op) != SSA_NAME)
|
||
|
return NULL;
|
||
|
|
||
|
iv = get_iv (data, op);
|
||
|
if (!iv)
|
||
|
return NULL;
|
||
|
|
||
|
if (iv->have_use_for)
|
||
|
{
|
||
|
use = iv_use (data, iv->use_id);
|
||
|
|
||
|
gcc_assert (use->type == USE_NONLINEAR_EXPR);
|
||
|
return use;
|
||
|
}
|
||
|
|
||
|
if (zero_p (iv->step))
|
||
|
{
|
||
|
record_invariant (data, op, true);
|
||
|
return NULL;
|
||
|
}
|
||
|
iv->have_use_for = true;
|
||
|
|
||
|
civ = XNEW (struct iv);
|
||
|
*civ = *iv;
|
||
|
|
||
|
stmt = SSA_NAME_DEF_STMT (op);
|
||
|
gcc_assert (TREE_CODE (stmt) == PHI_NODE
|
||
|
|| TREE_CODE (stmt) == MODIFY_EXPR);
|
||
|
|
||
|
use = record_use (data, NULL, civ, stmt, USE_NONLINEAR_EXPR);
|
||
|
iv->use_id = use->id;
|
||
|
|
||
|
return use;
|
||
|
}
|
||
|
|
||
|
/* Checks whether the condition *COND_P in STMT is interesting
|
||
|
and if so, records it. */
|
||
|
|
||
|
static void
|
||
|
find_interesting_uses_cond (struct ivopts_data *data, tree stmt, tree *cond_p)
|
||
|
{
|
||
|
tree *op0_p;
|
||
|
tree *op1_p;
|
||
|
struct iv *iv0 = NULL, *iv1 = NULL, *civ;
|
||
|
struct iv const_iv;
|
||
|
tree zero = integer_zero_node;
|
||
|
|
||
|
const_iv.step = NULL_TREE;
|
||
|
|
||
|
if (TREE_CODE (*cond_p) != SSA_NAME
|
||
|
&& !COMPARISON_CLASS_P (*cond_p))
|
||
|
return;
|
||
|
|
||
|
if (TREE_CODE (*cond_p) == SSA_NAME)
|
||
|
{
|
||
|
op0_p = cond_p;
|
||
|
op1_p = &zero;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
op0_p = &TREE_OPERAND (*cond_p, 0);
|
||
|
op1_p = &TREE_OPERAND (*cond_p, 1);
|
||
|
}
|
||
|
|
||
|
if (TREE_CODE (*op0_p) == SSA_NAME)
|
||
|
iv0 = get_iv (data, *op0_p);
|
||
|
else
|
||
|
iv0 = &const_iv;
|
||
|
|
||
|
if (TREE_CODE (*op1_p) == SSA_NAME)
|
||
|
iv1 = get_iv (data, *op1_p);
|
||
|
else
|
||
|
iv1 = &const_iv;
|
||
|
|
||
|
if (/* When comparing with non-invariant value, we may not do any senseful
|
||
|
induction variable elimination. */
|
||
|
(!iv0 || !iv1)
|
||
|
/* Eliminating condition based on two ivs would be nontrivial.
|
||
|
??? TODO -- it is not really important to handle this case. */
|
||
|
|| (!zero_p (iv0->step) && !zero_p (iv1->step)))
|
||
|
{
|
||
|
find_interesting_uses_op (data, *op0_p);
|
||
|
find_interesting_uses_op (data, *op1_p);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if (zero_p (iv0->step) && zero_p (iv1->step))
|
||
|
{
|
||
|
/* If both are invariants, this is a work for unswitching. */
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
civ = XNEW (struct iv);
|
||
|
*civ = zero_p (iv0->step) ? *iv1: *iv0;
|
||
|
record_use (data, cond_p, civ, stmt, USE_COMPARE);
|
||
|
}
|
||
|
|
||
|
/* Returns true if expression EXPR is obviously invariant in LOOP,
|
||
|
i.e. if all its operands are defined outside of the LOOP. */
|
||
|
|
||
|
bool
|
||
|
expr_invariant_in_loop_p (struct loop *loop, tree expr)
|
||
|
{
|
||
|
basic_block def_bb;
|
||
|
unsigned i, len;
|
||
|
|
||
|
if (is_gimple_min_invariant (expr))
|
||
|
return true;
|
||
|
|
||
|
if (TREE_CODE (expr) == SSA_NAME)
|
||
|
{
|
||
|
def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (expr));
|
||
|
if (def_bb
|
||
|
&& flow_bb_inside_loop_p (loop, def_bb))
|
||
|
return false;
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
if (!EXPR_P (expr))
|
||
|
return false;
|
||
|
|
||
|
len = TREE_CODE_LENGTH (TREE_CODE (expr));
|
||
|
for (i = 0; i < len; i++)
|
||
|
if (!expr_invariant_in_loop_p (loop, TREE_OPERAND (expr, i)))
|
||
|
return false;
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Cumulates the steps of indices into DATA and replaces their values with the
|
||
|
initial ones. Returns false when the value of the index cannot be determined.
|
||
|
Callback for for_each_index. */
|
||
|
|
||
|
struct ifs_ivopts_data
|
||
|
{
|
||
|
struct ivopts_data *ivopts_data;
|
||
|
tree stmt;
|
||
|
tree *step_p;
|
||
|
};
|
||
|
|
||
|
static bool
|
||
|
idx_find_step (tree base, tree *idx, void *data)
|
||
|
{
|
||
|
struct ifs_ivopts_data *dta = data;
|
||
|
struct iv *iv;
|
||
|
tree step, iv_base, iv_step, lbound, off;
|
||
|
struct loop *loop = dta->ivopts_data->current_loop;
|
||
|
|
||
|
if (TREE_CODE (base) == MISALIGNED_INDIRECT_REF
|
||
|
|| TREE_CODE (base) == ALIGN_INDIRECT_REF)
|
||
|
return false;
|
||
|
|
||
|
/* If base is a component ref, require that the offset of the reference
|
||
|
be invariant. */
|
||
|
if (TREE_CODE (base) == COMPONENT_REF)
|
||
|
{
|
||
|
off = component_ref_field_offset (base);
|
||
|
return expr_invariant_in_loop_p (loop, off);
|
||
|
}
|
||
|
|
||
|
/* If base is array, first check whether we will be able to move the
|
||
|
reference out of the loop (in order to take its address in strength
|
||
|
reduction). In order for this to work we need both lower bound
|
||
|
and step to be loop invariants. */
|
||
|
if (TREE_CODE (base) == ARRAY_REF)
|
||
|
{
|
||
|
step = array_ref_element_size (base);
|
||
|
lbound = array_ref_low_bound (base);
|
||
|
|
||
|
if (!expr_invariant_in_loop_p (loop, step)
|
||
|
|| !expr_invariant_in_loop_p (loop, lbound))
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
if (TREE_CODE (*idx) != SSA_NAME)
|
||
|
return true;
|
||
|
|
||
|
iv = get_iv (dta->ivopts_data, *idx);
|
||
|
if (!iv)
|
||
|
return false;
|
||
|
|
||
|
/* XXX We produce for a base of *D42 with iv->base being &x[0]
|
||
|
*&x[0], which is not folded and does not trigger the
|
||
|
ARRAY_REF path below. */
|
||
|
*idx = iv->base;
|
||
|
|
||
|
if (!iv->step)
|
||
|
return true;
|
||
|
|
||
|
if (TREE_CODE (base) == ARRAY_REF)
|
||
|
{
|
||
|
step = array_ref_element_size (base);
|
||
|
|
||
|
/* We only handle addresses whose step is an integer constant. */
|
||
|
if (TREE_CODE (step) != INTEGER_CST)
|
||
|
return false;
|
||
|
}
|
||
|
else
|
||
|
/* The step for pointer arithmetics already is 1 byte. */
|
||
|
step = build_int_cst (sizetype, 1);
|
||
|
|
||
|
iv_base = iv->base;
|
||
|
iv_step = iv->step;
|
||
|
if (!convert_affine_scev (dta->ivopts_data->current_loop,
|
||
|
sizetype, &iv_base, &iv_step, dta->stmt,
|
||
|
false))
|
||
|
{
|
||
|
/* The index might wrap. */
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
step = fold_build2 (MULT_EXPR, sizetype, step, iv_step);
|
||
|
|
||
|
if (!*dta->step_p)
|
||
|
*dta->step_p = step;
|
||
|
else
|
||
|
*dta->step_p = fold_build2 (PLUS_EXPR, sizetype, *dta->step_p, step);
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Records use in index IDX. Callback for for_each_index. Ivopts data
|
||
|
object is passed to it in DATA. */
|
||
|
|
||
|
static bool
|
||
|
idx_record_use (tree base, tree *idx,
|
||
|
void *data)
|
||
|
{
|
||
|
find_interesting_uses_op (data, *idx);
|
||
|
if (TREE_CODE (base) == ARRAY_REF)
|
||
|
{
|
||
|
find_interesting_uses_op (data, array_ref_element_size (base));
|
||
|
find_interesting_uses_op (data, array_ref_low_bound (base));
|
||
|
}
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Returns true if memory reference REF may be unaligned. */
|
||
|
|
||
|
static bool
|
||
|
may_be_unaligned_p (tree ref)
|
||
|
{
|
||
|
tree base;
|
||
|
tree base_type;
|
||
|
HOST_WIDE_INT bitsize;
|
||
|
HOST_WIDE_INT bitpos;
|
||
|
tree toffset;
|
||
|
enum machine_mode mode;
|
||
|
int unsignedp, volatilep;
|
||
|
unsigned base_align;
|
||
|
|
||
|
/* TARGET_MEM_REFs are translated directly to valid MEMs on the target,
|
||
|
thus they are not misaligned. */
|
||
|
if (TREE_CODE (ref) == TARGET_MEM_REF)
|
||
|
return false;
|
||
|
|
||
|
/* The test below is basically copy of what expr.c:normal_inner_ref
|
||
|
does to check whether the object must be loaded by parts when
|
||
|
STRICT_ALIGNMENT is true. */
|
||
|
base = get_inner_reference (ref, &bitsize, &bitpos, &toffset, &mode,
|
||
|
&unsignedp, &volatilep, true);
|
||
|
base_type = TREE_TYPE (base);
|
||
|
base_align = TYPE_ALIGN (base_type);
|
||
|
|
||
|
if (mode != BLKmode
|
||
|
&& (base_align < GET_MODE_ALIGNMENT (mode)
|
||
|
|| bitpos % GET_MODE_ALIGNMENT (mode) != 0
|
||
|
|| bitpos % BITS_PER_UNIT != 0))
|
||
|
return true;
|
||
|
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
/* Return true if EXPR may be non-addressable. */
|
||
|
|
||
|
static bool
|
||
|
may_be_nonaddressable_p (tree expr)
|
||
|
{
|
||
|
switch (TREE_CODE (expr))
|
||
|
{
|
||
|
case COMPONENT_REF:
|
||
|
return DECL_NONADDRESSABLE_P (TREE_OPERAND (expr, 1))
|
||
|
|| may_be_nonaddressable_p (TREE_OPERAND (expr, 0));
|
||
|
|
||
|
case ARRAY_REF:
|
||
|
case ARRAY_RANGE_REF:
|
||
|
return may_be_nonaddressable_p (TREE_OPERAND (expr, 0));
|
||
|
|
||
|
case VIEW_CONVERT_EXPR:
|
||
|
/* This kind of view-conversions may wrap non-addressable objects
|
||
|
and make them look addressable. After some processing the
|
||
|
non-addressability may be uncovered again, causing ADDR_EXPRs
|
||
|
of inappropriate objects to be built. */
|
||
|
return AGGREGATE_TYPE_P (TREE_TYPE (expr))
|
||
|
&& !AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 0)));
|
||
|
|
||
|
default:
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
/* Finds addresses in *OP_P inside STMT. */
|
||
|
|
||
|
static void
|
||
|
find_interesting_uses_address (struct ivopts_data *data, tree stmt, tree *op_p)
|
||
|
{
|
||
|
tree base = *op_p, step = NULL;
|
||
|
struct iv *civ;
|
||
|
struct ifs_ivopts_data ifs_ivopts_data;
|
||
|
|
||
|
/* Do not play with volatile memory references. A bit too conservative,
|
||
|
perhaps, but safe. */
|
||
|
if (stmt_ann (stmt)->has_volatile_ops)
|
||
|
goto fail;
|
||
|
|
||
|
/* Ignore bitfields for now. Not really something terribly complicated
|
||
|
to handle. TODO. */
|
||
|
if (TREE_CODE (base) == BIT_FIELD_REF)
|
||
|
goto fail;
|
||
|
|
||
|
if (may_be_nonaddressable_p (base))
|
||
|
goto fail;
|
||
|
|
||
|
if (STRICT_ALIGNMENT
|
||
|
&& may_be_unaligned_p (base))
|
||
|
goto fail;
|
||
|
|
||
|
base = unshare_expr (base);
|
||
|
|
||
|
if (TREE_CODE (base) == TARGET_MEM_REF)
|
||
|
{
|
||
|
tree type = build_pointer_type (TREE_TYPE (base));
|
||
|
tree astep;
|
||
|
|
||
|
if (TMR_BASE (base)
|
||
|
&& TREE_CODE (TMR_BASE (base)) == SSA_NAME)
|
||
|
{
|
||
|
civ = get_iv (data, TMR_BASE (base));
|
||
|
if (!civ)
|
||
|
goto fail;
|
||
|
|
||
|
TMR_BASE (base) = civ->base;
|
||
|
step = civ->step;
|
||
|
}
|
||
|
if (TMR_INDEX (base)
|
||
|
&& TREE_CODE (TMR_INDEX (base)) == SSA_NAME)
|
||
|
{
|
||
|
civ = get_iv (data, TMR_INDEX (base));
|
||
|
if (!civ)
|
||
|
goto fail;
|
||
|
|
||
|
TMR_INDEX (base) = civ->base;
|
||
|
astep = civ->step;
|
||
|
|
||
|
if (astep)
|
||
|
{
|
||
|
if (TMR_STEP (base))
|
||
|
astep = fold_build2 (MULT_EXPR, type, TMR_STEP (base), astep);
|
||
|
|
||
|
if (step)
|
||
|
step = fold_build2 (PLUS_EXPR, type, step, astep);
|
||
|
else
|
||
|
step = astep;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (zero_p (step))
|
||
|
goto fail;
|
||
|
base = tree_mem_ref_addr (type, base);
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
ifs_ivopts_data.ivopts_data = data;
|
||
|
ifs_ivopts_data.stmt = stmt;
|
||
|
ifs_ivopts_data.step_p = &step;
|
||
|
if (!for_each_index (&base, idx_find_step, &ifs_ivopts_data)
|
||
|
|| zero_p (step))
|
||
|
goto fail;
|
||
|
|
||
|
gcc_assert (TREE_CODE (base) != ALIGN_INDIRECT_REF);
|
||
|
gcc_assert (TREE_CODE (base) != MISALIGNED_INDIRECT_REF);
|
||
|
|
||
|
base = build_fold_addr_expr (base);
|
||
|
|
||
|
/* Substituting bases of IVs into the base expression might
|
||
|
have caused folding opportunities. */
|
||
|
if (TREE_CODE (base) == ADDR_EXPR)
|
||
|
{
|
||
|
tree *ref = &TREE_OPERAND (base, 0);
|
||
|
while (handled_component_p (*ref))
|
||
|
ref = &TREE_OPERAND (*ref, 0);
|
||
|
if (TREE_CODE (*ref) == INDIRECT_REF)
|
||
|
*ref = fold_indirect_ref (*ref);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
civ = alloc_iv (base, step);
|
||
|
record_use (data, op_p, civ, stmt, USE_ADDRESS);
|
||
|
return;
|
||
|
|
||
|
fail:
|
||
|
for_each_index (op_p, idx_record_use, data);
|
||
|
}
|
||
|
|
||
|
/* Finds and records invariants used in STMT. */
|
||
|
|
||
|
static void
|
||
|
find_invariants_stmt (struct ivopts_data *data, tree stmt)
|
||
|
{
|
||
|
ssa_op_iter iter;
|
||
|
use_operand_p use_p;
|
||
|
tree op;
|
||
|
|
||
|
FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE)
|
||
|
{
|
||
|
op = USE_FROM_PTR (use_p);
|
||
|
record_invariant (data, op, false);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Finds interesting uses of induction variables in the statement STMT. */
|
||
|
|
||
|
static void
|
||
|
find_interesting_uses_stmt (struct ivopts_data *data, tree stmt)
|
||
|
{
|
||
|
struct iv *iv;
|
||
|
tree op, lhs, rhs;
|
||
|
ssa_op_iter iter;
|
||
|
use_operand_p use_p;
|
||
|
|
||
|
find_invariants_stmt (data, stmt);
|
||
|
|
||
|
if (TREE_CODE (stmt) == COND_EXPR)
|
||
|
{
|
||
|
find_interesting_uses_cond (data, stmt, &COND_EXPR_COND (stmt));
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if (TREE_CODE (stmt) == MODIFY_EXPR)
|
||
|
{
|
||
|
lhs = TREE_OPERAND (stmt, 0);
|
||
|
rhs = TREE_OPERAND (stmt, 1);
|
||
|
|
||
|
if (TREE_CODE (lhs) == SSA_NAME)
|
||
|
{
|
||
|
/* If the statement defines an induction variable, the uses are not
|
||
|
interesting by themselves. */
|
||
|
|
||
|
iv = get_iv (data, lhs);
|
||
|
|
||
|
if (iv && !zero_p (iv->step))
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
switch (TREE_CODE_CLASS (TREE_CODE (rhs)))
|
||
|
{
|
||
|
case tcc_comparison:
|
||
|
find_interesting_uses_cond (data, stmt, &TREE_OPERAND (stmt, 1));
|
||
|
return;
|
||
|
|
||
|
case tcc_reference:
|
||
|
find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 1));
|
||
|
if (REFERENCE_CLASS_P (lhs))
|
||
|
find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 0));
|
||
|
return;
|
||
|
|
||
|
default: ;
|
||
|
}
|
||
|
|
||
|
if (REFERENCE_CLASS_P (lhs)
|
||
|
&& is_gimple_val (rhs))
|
||
|
{
|
||
|
find_interesting_uses_address (data, stmt, &TREE_OPERAND (stmt, 0));
|
||
|
find_interesting_uses_op (data, rhs);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/* TODO -- we should also handle address uses of type
|
||
|
|
||
|
memory = call (whatever);
|
||
|
|
||
|
and
|
||
|
|
||
|
call (memory). */
|
||
|
}
|
||
|
|
||
|
if (TREE_CODE (stmt) == PHI_NODE
|
||
|
&& bb_for_stmt (stmt) == data->current_loop->header)
|
||
|
{
|
||
|
lhs = PHI_RESULT (stmt);
|
||
|
iv = get_iv (data, lhs);
|
||
|
|
||
|
if (iv && !zero_p (iv->step))
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE)
|
||
|
{
|
||
|
op = USE_FROM_PTR (use_p);
|
||
|
|
||
|
if (TREE_CODE (op) != SSA_NAME)
|
||
|
continue;
|
||
|
|
||
|
iv = get_iv (data, op);
|
||
|
if (!iv)
|
||
|
continue;
|
||
|
|
||
|
find_interesting_uses_op (data, op);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Finds interesting uses of induction variables outside of loops
|
||
|
on loop exit edge EXIT. */
|
||
|
|
||
|
static void
|
||
|
find_interesting_uses_outside (struct ivopts_data *data, edge exit)
|
||
|
{
|
||
|
tree phi, def;
|
||
|
|
||
|
for (phi = phi_nodes (exit->dest); phi; phi = PHI_CHAIN (phi))
|
||
|
{
|
||
|
def = PHI_ARG_DEF_FROM_EDGE (phi, exit);
|
||
|
find_interesting_uses_op (data, def);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Finds uses of the induction variables that are interesting. */
|
||
|
|
||
|
static void
|
||
|
find_interesting_uses (struct ivopts_data *data)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
block_stmt_iterator bsi;
|
||
|
tree phi;
|
||
|
basic_block *body = get_loop_body (data->current_loop);
|
||
|
unsigned i;
|
||
|
struct version_info *info;
|
||
|
edge e;
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
fprintf (dump_file, "Uses:\n\n");
|
||
|
|
||
|
for (i = 0; i < data->current_loop->num_nodes; i++)
|
||
|
{
|
||
|
edge_iterator ei;
|
||
|
bb = body[i];
|
||
|
|
||
|
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
|
if (e->dest != EXIT_BLOCK_PTR
|
||
|
&& !flow_bb_inside_loop_p (data->current_loop, e->dest))
|
||
|
find_interesting_uses_outside (data, e);
|
||
|
|
||
|
for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
|
||
|
find_interesting_uses_stmt (data, phi);
|
||
|
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
|
||
|
find_interesting_uses_stmt (data, bsi_stmt (bsi));
|
||
|
}
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
bitmap_iterator bi;
|
||
|
|
||
|
fprintf (dump_file, "\n");
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
|
||
|
{
|
||
|
info = ver_info (data, i);
|
||
|
if (info->inv_id)
|
||
|
{
|
||
|
fprintf (dump_file, " ");
|
||
|
print_generic_expr (dump_file, info->name, TDF_SLIM);
|
||
|
fprintf (dump_file, " is invariant (%d)%s\n",
|
||
|
info->inv_id, info->has_nonlin_use ? "" : ", eliminable");
|
||
|
}
|
||
|
}
|
||
|
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
|
||
|
free (body);
|
||
|
}
|
||
|
|
||
|
/* Strips constant offsets from EXPR and stores them to OFFSET. If INSIDE_ADDR
|
||
|
is true, assume we are inside an address. If TOP_COMPREF is true, assume
|
||
|
we are at the top-level of the processed address. */
|
||
|
|
||
|
static tree
|
||
|
strip_offset_1 (tree expr, bool inside_addr, bool top_compref,
|
||
|
unsigned HOST_WIDE_INT *offset)
|
||
|
{
|
||
|
tree op0 = NULL_TREE, op1 = NULL_TREE, tmp, step;
|
||
|
enum tree_code code;
|
||
|
tree type, orig_type = TREE_TYPE (expr);
|
||
|
unsigned HOST_WIDE_INT off0, off1, st;
|
||
|
tree orig_expr = expr;
|
||
|
|
||
|
STRIP_NOPS (expr);
|
||
|
|
||
|
type = TREE_TYPE (expr);
|
||
|
code = TREE_CODE (expr);
|
||
|
*offset = 0;
|
||
|
|
||
|
switch (code)
|
||
|
{
|
||
|
case INTEGER_CST:
|
||
|
if (!cst_and_fits_in_hwi (expr)
|
||
|
|| zero_p (expr))
|
||
|
return orig_expr;
|
||
|
|
||
|
*offset = int_cst_value (expr);
|
||
|
return build_int_cst (orig_type, 0);
|
||
|
|
||
|
case PLUS_EXPR:
|
||
|
case MINUS_EXPR:
|
||
|
op0 = TREE_OPERAND (expr, 0);
|
||
|
op1 = TREE_OPERAND (expr, 1);
|
||
|
|
||
|
op0 = strip_offset_1 (op0, false, false, &off0);
|
||
|
op1 = strip_offset_1 (op1, false, false, &off1);
|
||
|
|
||
|
*offset = (code == PLUS_EXPR ? off0 + off1 : off0 - off1);
|
||
|
if (op0 == TREE_OPERAND (expr, 0)
|
||
|
&& op1 == TREE_OPERAND (expr, 1))
|
||
|
return orig_expr;
|
||
|
|
||
|
if (zero_p (op1))
|
||
|
expr = op0;
|
||
|
else if (zero_p (op0))
|
||
|
{
|
||
|
if (code == PLUS_EXPR)
|
||
|
expr = op1;
|
||
|
else
|
||
|
expr = fold_build1 (NEGATE_EXPR, type, op1);
|
||
|
}
|
||
|
else
|
||
|
expr = fold_build2 (code, type, op0, op1);
|
||
|
|
||
|
return fold_convert (orig_type, expr);
|
||
|
|
||
|
case ARRAY_REF:
|
||
|
if (!inside_addr)
|
||
|
return orig_expr;
|
||
|
|
||
|
step = array_ref_element_size (expr);
|
||
|
if (!cst_and_fits_in_hwi (step))
|
||
|
break;
|
||
|
|
||
|
st = int_cst_value (step);
|
||
|
op1 = TREE_OPERAND (expr, 1);
|
||
|
op1 = strip_offset_1 (op1, false, false, &off1);
|
||
|
*offset = off1 * st;
|
||
|
|
||
|
if (top_compref
|
||
|
&& zero_p (op1))
|
||
|
{
|
||
|
/* Strip the component reference completely. */
|
||
|
op0 = TREE_OPERAND (expr, 0);
|
||
|
op0 = strip_offset_1 (op0, inside_addr, top_compref, &off0);
|
||
|
*offset += off0;
|
||
|
return op0;
|
||
|
}
|
||
|
break;
|
||
|
|
||
|
case COMPONENT_REF:
|
||
|
if (!inside_addr)
|
||
|
return orig_expr;
|
||
|
|
||
|
tmp = component_ref_field_offset (expr);
|
||
|
if (top_compref
|
||
|
&& cst_and_fits_in_hwi (tmp))
|
||
|
{
|
||
|
/* Strip the component reference completely. */
|
||
|
op0 = TREE_OPERAND (expr, 0);
|
||
|
op0 = strip_offset_1 (op0, inside_addr, top_compref, &off0);
|
||
|
*offset = off0 + int_cst_value (tmp);
|
||
|
return op0;
|
||
|
}
|
||
|
break;
|
||
|
|
||
|
case ADDR_EXPR:
|
||
|
op0 = TREE_OPERAND (expr, 0);
|
||
|
op0 = strip_offset_1 (op0, true, true, &off0);
|
||
|
*offset += off0;
|
||
|
|
||
|
if (op0 == TREE_OPERAND (expr, 0))
|
||
|
return orig_expr;
|
||
|
|
||
|
expr = build_fold_addr_expr (op0);
|
||
|
return fold_convert (orig_type, expr);
|
||
|
|
||
|
case INDIRECT_REF:
|
||
|
inside_addr = false;
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
return orig_expr;
|
||
|
}
|
||
|
|
||
|
/* Default handling of expressions for that we want to recurse into
|
||
|
the first operand. */
|
||
|
op0 = TREE_OPERAND (expr, 0);
|
||
|
op0 = strip_offset_1 (op0, inside_addr, false, &off0);
|
||
|
*offset += off0;
|
||
|
|
||
|
if (op0 == TREE_OPERAND (expr, 0)
|
||
|
&& (!op1 || op1 == TREE_OPERAND (expr, 1)))
|
||
|
return orig_expr;
|
||
|
|
||
|
expr = copy_node (expr);
|
||
|
TREE_OPERAND (expr, 0) = op0;
|
||
|
if (op1)
|
||
|
TREE_OPERAND (expr, 1) = op1;
|
||
|
|
||
|
/* Inside address, we might strip the top level component references,
|
||
|
thus changing type of the expression. Handling of ADDR_EXPR
|
||
|
will fix that. */
|
||
|
expr = fold_convert (orig_type, expr);
|
||
|
|
||
|
return expr;
|
||
|
}
|
||
|
|
||
|
/* Strips constant offsets from EXPR and stores them to OFFSET. */
|
||
|
|
||
|
static tree
|
||
|
strip_offset (tree expr, unsigned HOST_WIDE_INT *offset)
|
||
|
{
|
||
|
return strip_offset_1 (expr, false, false, offset);
|
||
|
}
|
||
|
|
||
|
/* Returns variant of TYPE that can be used as base for different uses.
|
||
|
We return unsigned type with the same precision, which avoids problems
|
||
|
with overflows. */
|
||
|
|
||
|
static tree
|
||
|
generic_type_for (tree type)
|
||
|
{
|
||
|
if (POINTER_TYPE_P (type))
|
||
|
return unsigned_type_for (type);
|
||
|
|
||
|
if (TYPE_UNSIGNED (type))
|
||
|
return type;
|
||
|
|
||
|
return unsigned_type_for (type);
|
||
|
}
|
||
|
|
||
|
/* Records invariants in *EXPR_P. Callback for walk_tree. DATA contains
|
||
|
the bitmap to that we should store it. */
|
||
|
|
||
|
static struct ivopts_data *fd_ivopts_data;
|
||
|
static tree
|
||
|
find_depends (tree *expr_p, int *ws ATTRIBUTE_UNUSED, void *data)
|
||
|
{
|
||
|
bitmap *depends_on = data;
|
||
|
struct version_info *info;
|
||
|
|
||
|
if (TREE_CODE (*expr_p) != SSA_NAME)
|
||
|
return NULL_TREE;
|
||
|
info = name_info (fd_ivopts_data, *expr_p);
|
||
|
|
||
|
if (!info->inv_id || info->has_nonlin_use)
|
||
|
return NULL_TREE;
|
||
|
|
||
|
if (!*depends_on)
|
||
|
*depends_on = BITMAP_ALLOC (NULL);
|
||
|
bitmap_set_bit (*depends_on, info->inv_id);
|
||
|
|
||
|
return NULL_TREE;
|
||
|
}
|
||
|
|
||
|
/* Adds a candidate BASE + STEP * i. Important field is set to IMPORTANT and
|
||
|
position to POS. If USE is not NULL, the candidate is set as related to
|
||
|
it. If both BASE and STEP are NULL, we add a pseudocandidate for the
|
||
|
replacement of the final value of the iv by a direct computation. */
|
||
|
|
||
|
static struct iv_cand *
|
||
|
add_candidate_1 (struct ivopts_data *data,
|
||
|
tree base, tree step, bool important, enum iv_position pos,
|
||
|
struct iv_use *use, tree incremented_at)
|
||
|
{
|
||
|
unsigned i;
|
||
|
struct iv_cand *cand = NULL;
|
||
|
tree type, orig_type;
|
||
|
|
||
|
if (base)
|
||
|
{
|
||
|
orig_type = TREE_TYPE (base);
|
||
|
type = generic_type_for (orig_type);
|
||
|
if (type != orig_type)
|
||
|
{
|
||
|
base = fold_convert (type, base);
|
||
|
if (step)
|
||
|
step = fold_convert (type, step);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
for (i = 0; i < n_iv_cands (data); i++)
|
||
|
{
|
||
|
cand = iv_cand (data, i);
|
||
|
|
||
|
if (cand->pos != pos)
|
||
|
continue;
|
||
|
|
||
|
if (cand->incremented_at != incremented_at)
|
||
|
continue;
|
||
|
|
||
|
if (!cand->iv)
|
||
|
{
|
||
|
if (!base && !step)
|
||
|
break;
|
||
|
|
||
|
continue;
|
||
|
}
|
||
|
|
||
|
if (!base && !step)
|
||
|
continue;
|
||
|
|
||
|
if (!operand_equal_p (base, cand->iv->base, 0))
|
||
|
continue;
|
||
|
|
||
|
if (zero_p (cand->iv->step))
|
||
|
{
|
||
|
if (zero_p (step))
|
||
|
break;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
if (step && operand_equal_p (step, cand->iv->step, 0))
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (i == n_iv_cands (data))
|
||
|
{
|
||
|
cand = XCNEW (struct iv_cand);
|
||
|
cand->id = i;
|
||
|
|
||
|
if (!base && !step)
|
||
|
cand->iv = NULL;
|
||
|
else
|
||
|
cand->iv = alloc_iv (base, step);
|
||
|
|
||
|
cand->pos = pos;
|
||
|
if (pos != IP_ORIGINAL && cand->iv)
|
||
|
{
|
||
|
cand->var_before = create_tmp_var_raw (TREE_TYPE (base), "ivtmp");
|
||
|
cand->var_after = cand->var_before;
|
||
|
}
|
||
|
cand->important = important;
|
||
|
cand->incremented_at = incremented_at;
|
||
|
VEC_safe_push (iv_cand_p, heap, data->iv_candidates, cand);
|
||
|
|
||
|
if (step
|
||
|
&& TREE_CODE (step) != INTEGER_CST)
|
||
|
{
|
||
|
fd_ivopts_data = data;
|
||
|
walk_tree (&step, find_depends, &cand->depends_on, NULL);
|
||
|
}
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
dump_cand (dump_file, cand);
|
||
|
}
|
||
|
|
||
|
if (important && !cand->important)
|
||
|
{
|
||
|
cand->important = true;
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
fprintf (dump_file, "Candidate %d is important\n", cand->id);
|
||
|
}
|
||
|
|
||
|
if (use)
|
||
|
{
|
||
|
bitmap_set_bit (use->related_cands, i);
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
fprintf (dump_file, "Candidate %d is related to use %d\n",
|
||
|
cand->id, use->id);
|
||
|
}
|
||
|
|
||
|
return cand;
|
||
|
}
|
||
|
|
||
|
/* Returns true if incrementing the induction variable at the end of the LOOP
|
||
|
is allowed.
|
||
|
|
||
|
The purpose is to avoid splitting latch edge with a biv increment, thus
|
||
|
creating a jump, possibly confusing other optimization passes and leaving
|
||
|
less freedom to scheduler. So we allow IP_END_POS only if IP_NORMAL_POS
|
||
|
is not available (so we do not have a better alternative), or if the latch
|
||
|
edge is already nonempty. */
|
||
|
|
||
|
static bool
|
||
|
allow_ip_end_pos_p (struct loop *loop)
|
||
|
{
|
||
|
if (!ip_normal_pos (loop))
|
||
|
return true;
|
||
|
|
||
|
if (!empty_block_p (ip_end_pos (loop)))
|
||
|
return true;
|
||
|
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
/* Adds a candidate BASE + STEP * i. Important field is set to IMPORTANT and
|
||
|
position to POS. If USE is not NULL, the candidate is set as related to
|
||
|
it. The candidate computation is scheduled on all available positions. */
|
||
|
|
||
|
static void
|
||
|
add_candidate (struct ivopts_data *data,
|
||
|
tree base, tree step, bool important, struct iv_use *use)
|
||
|
{
|
||
|
if (ip_normal_pos (data->current_loop))
|
||
|
add_candidate_1 (data, base, step, important, IP_NORMAL, use, NULL_TREE);
|
||
|
if (ip_end_pos (data->current_loop)
|
||
|
&& allow_ip_end_pos_p (data->current_loop))
|
||
|
add_candidate_1 (data, base, step, important, IP_END, use, NULL_TREE);
|
||
|
}
|
||
|
|
||
|
/* Add a standard "0 + 1 * iteration" iv candidate for a
|
||
|
type with SIZE bits. */
|
||
|
|
||
|
static void
|
||
|
add_standard_iv_candidates_for_size (struct ivopts_data *data,
|
||
|
unsigned int size)
|
||
|
{
|
||
|
tree type = lang_hooks.types.type_for_size (size, true);
|
||
|
add_candidate (data, build_int_cst (type, 0), build_int_cst (type, 1),
|
||
|
true, NULL);
|
||
|
}
|
||
|
|
||
|
/* Adds standard iv candidates. */
|
||
|
|
||
|
static void
|
||
|
add_standard_iv_candidates (struct ivopts_data *data)
|
||
|
{
|
||
|
add_standard_iv_candidates_for_size (data, INT_TYPE_SIZE);
|
||
|
|
||
|
/* The same for a double-integer type if it is still fast enough. */
|
||
|
if (BITS_PER_WORD >= INT_TYPE_SIZE * 2)
|
||
|
add_standard_iv_candidates_for_size (data, INT_TYPE_SIZE * 2);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Adds candidates bases on the old induction variable IV. */
|
||
|
|
||
|
static void
|
||
|
add_old_iv_candidates (struct ivopts_data *data, struct iv *iv)
|
||
|
{
|
||
|
tree phi, def;
|
||
|
struct iv_cand *cand;
|
||
|
|
||
|
add_candidate (data, iv->base, iv->step, true, NULL);
|
||
|
|
||
|
/* The same, but with initial value zero. */
|
||
|
add_candidate (data,
|
||
|
build_int_cst (TREE_TYPE (iv->base), 0),
|
||
|
iv->step, true, NULL);
|
||
|
|
||
|
phi = SSA_NAME_DEF_STMT (iv->ssa_name);
|
||
|
if (TREE_CODE (phi) == PHI_NODE)
|
||
|
{
|
||
|
/* Additionally record the possibility of leaving the original iv
|
||
|
untouched. */
|
||
|
def = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (data->current_loop));
|
||
|
cand = add_candidate_1 (data,
|
||
|
iv->base, iv->step, true, IP_ORIGINAL, NULL,
|
||
|
SSA_NAME_DEF_STMT (def));
|
||
|
cand->var_before = iv->ssa_name;
|
||
|
cand->var_after = def;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Adds candidates based on the old induction variables. */
|
||
|
|
||
|
static void
|
||
|
add_old_ivs_candidates (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned i;
|
||
|
struct iv *iv;
|
||
|
bitmap_iterator bi;
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
|
||
|
{
|
||
|
iv = ver_info (data, i)->iv;
|
||
|
if (iv && iv->biv_p && !zero_p (iv->step))
|
||
|
add_old_iv_candidates (data, iv);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Adds candidates based on the value of the induction variable IV and USE. */
|
||
|
|
||
|
static void
|
||
|
add_iv_value_candidates (struct ivopts_data *data,
|
||
|
struct iv *iv, struct iv_use *use)
|
||
|
{
|
||
|
unsigned HOST_WIDE_INT offset;
|
||
|
tree base;
|
||
|
|
||
|
add_candidate (data, iv->base, iv->step, false, use);
|
||
|
|
||
|
/* The same, but with initial value zero. Make such variable important,
|
||
|
since it is generic enough so that possibly many uses may be based
|
||
|
on it. */
|
||
|
add_candidate (data, build_int_cst (TREE_TYPE (iv->base), 0),
|
||
|
iv->step, true, use);
|
||
|
|
||
|
/* Third, try removing the constant offset. */
|
||
|
base = strip_offset (iv->base, &offset);
|
||
|
if (offset)
|
||
|
add_candidate (data, base, iv->step, false, use);
|
||
|
}
|
||
|
|
||
|
/* Adds candidates based on the uses. */
|
||
|
|
||
|
static void
|
||
|
add_derived_ivs_candidates (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned i;
|
||
|
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
{
|
||
|
struct iv_use *use = iv_use (data, i);
|
||
|
|
||
|
if (!use)
|
||
|
continue;
|
||
|
|
||
|
switch (use->type)
|
||
|
{
|
||
|
case USE_NONLINEAR_EXPR:
|
||
|
case USE_COMPARE:
|
||
|
case USE_ADDRESS:
|
||
|
/* Just add the ivs based on the value of the iv used here. */
|
||
|
add_iv_value_candidates (data, use->iv, use);
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
gcc_unreachable ();
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Record important candidates and add them to related_cands bitmaps
|
||
|
if needed. */
|
||
|
|
||
|
static void
|
||
|
record_important_candidates (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned i;
|
||
|
struct iv_use *use;
|
||
|
|
||
|
for (i = 0; i < n_iv_cands (data); i++)
|
||
|
{
|
||
|
struct iv_cand *cand = iv_cand (data, i);
|
||
|
|
||
|
if (cand->important)
|
||
|
bitmap_set_bit (data->important_candidates, i);
|
||
|
}
|
||
|
|
||
|
data->consider_all_candidates = (n_iv_cands (data)
|
||
|
<= CONSIDER_ALL_CANDIDATES_BOUND);
|
||
|
|
||
|
if (data->consider_all_candidates)
|
||
|
{
|
||
|
/* We will not need "related_cands" bitmaps in this case,
|
||
|
so release them to decrease peak memory consumption. */
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
{
|
||
|
use = iv_use (data, i);
|
||
|
BITMAP_FREE (use->related_cands);
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
/* Add important candidates to the related_cands bitmaps. */
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
bitmap_ior_into (iv_use (data, i)->related_cands,
|
||
|
data->important_candidates);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Finds the candidates for the induction variables. */
|
||
|
|
||
|
static void
|
||
|
find_iv_candidates (struct ivopts_data *data)
|
||
|
{
|
||
|
/* Add commonly used ivs. */
|
||
|
add_standard_iv_candidates (data);
|
||
|
|
||
|
/* Add old induction variables. */
|
||
|
add_old_ivs_candidates (data);
|
||
|
|
||
|
/* Add induction variables derived from uses. */
|
||
|
add_derived_ivs_candidates (data);
|
||
|
|
||
|
/* Record the important candidates. */
|
||
|
record_important_candidates (data);
|
||
|
}
|
||
|
|
||
|
/* Allocates the data structure mapping the (use, candidate) pairs to costs.
|
||
|
If consider_all_candidates is true, we use a two-dimensional array, otherwise
|
||
|
we allocate a simple list to every use. */
|
||
|
|
||
|
static void
|
||
|
alloc_use_cost_map (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned i, size, s, j;
|
||
|
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
{
|
||
|
struct iv_use *use = iv_use (data, i);
|
||
|
bitmap_iterator bi;
|
||
|
|
||
|
if (data->consider_all_candidates)
|
||
|
size = n_iv_cands (data);
|
||
|
else
|
||
|
{
|
||
|
s = 0;
|
||
|
EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi)
|
||
|
{
|
||
|
s++;
|
||
|
}
|
||
|
|
||
|
/* Round up to the power of two, so that moduling by it is fast. */
|
||
|
for (size = 1; size < s; size <<= 1)
|
||
|
continue;
|
||
|
}
|
||
|
|
||
|
use->n_map_members = size;
|
||
|
use->cost_map = XCNEWVEC (struct cost_pair, size);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Sets cost of (USE, CANDIDATE) pair to COST and record that it depends
|
||
|
on invariants DEPENDS_ON and that the value used in expressing it
|
||
|
is VALUE.*/
|
||
|
|
||
|
static void
|
||
|
set_use_iv_cost (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand, unsigned cost,
|
||
|
bitmap depends_on, tree value)
|
||
|
{
|
||
|
unsigned i, s;
|
||
|
|
||
|
if (cost == INFTY)
|
||
|
{
|
||
|
BITMAP_FREE (depends_on);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if (data->consider_all_candidates)
|
||
|
{
|
||
|
use->cost_map[cand->id].cand = cand;
|
||
|
use->cost_map[cand->id].cost = cost;
|
||
|
use->cost_map[cand->id].depends_on = depends_on;
|
||
|
use->cost_map[cand->id].value = value;
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/* n_map_members is a power of two, so this computes modulo. */
|
||
|
s = cand->id & (use->n_map_members - 1);
|
||
|
for (i = s; i < use->n_map_members; i++)
|
||
|
if (!use->cost_map[i].cand)
|
||
|
goto found;
|
||
|
for (i = 0; i < s; i++)
|
||
|
if (!use->cost_map[i].cand)
|
||
|
goto found;
|
||
|
|
||
|
gcc_unreachable ();
|
||
|
|
||
|
found:
|
||
|
use->cost_map[i].cand = cand;
|
||
|
use->cost_map[i].cost = cost;
|
||
|
use->cost_map[i].depends_on = depends_on;
|
||
|
use->cost_map[i].value = value;
|
||
|
}
|
||
|
|
||
|
/* Gets cost of (USE, CANDIDATE) pair. */
|
||
|
|
||
|
static struct cost_pair *
|
||
|
get_use_iv_cost (struct ivopts_data *data, struct iv_use *use,
|
||
|
struct iv_cand *cand)
|
||
|
{
|
||
|
unsigned i, s;
|
||
|
struct cost_pair *ret;
|
||
|
|
||
|
if (!cand)
|
||
|
return NULL;
|
||
|
|
||
|
if (data->consider_all_candidates)
|
||
|
{
|
||
|
ret = use->cost_map + cand->id;
|
||
|
if (!ret->cand)
|
||
|
return NULL;
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
/* n_map_members is a power of two, so this computes modulo. */
|
||
|
s = cand->id & (use->n_map_members - 1);
|
||
|
for (i = s; i < use->n_map_members; i++)
|
||
|
if (use->cost_map[i].cand == cand)
|
||
|
return use->cost_map + i;
|
||
|
|
||
|
for (i = 0; i < s; i++)
|
||
|
if (use->cost_map[i].cand == cand)
|
||
|
return use->cost_map + i;
|
||
|
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
/* Returns estimate on cost of computing SEQ. */
|
||
|
|
||
|
static unsigned
|
||
|
seq_cost (rtx seq)
|
||
|
{
|
||
|
unsigned cost = 0;
|
||
|
rtx set;
|
||
|
|
||
|
for (; seq; seq = NEXT_INSN (seq))
|
||
|
{
|
||
|
set = single_set (seq);
|
||
|
if (set)
|
||
|
cost += rtx_cost (set, SET);
|
||
|
else
|
||
|
cost++;
|
||
|
}
|
||
|
|
||
|
return cost;
|
||
|
}
|
||
|
|
||
|
/* Produce DECL_RTL for object obj so it looks like it is stored in memory. */
|
||
|
static rtx
|
||
|
produce_memory_decl_rtl (tree obj, int *regno)
|
||
|
{
|
||
|
rtx x;
|
||
|
|
||
|
gcc_assert (obj);
|
||
|
if (TREE_STATIC (obj) || DECL_EXTERNAL (obj))
|
||
|
{
|
||
|
const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (obj));
|
||
|
x = gen_rtx_SYMBOL_REF (Pmode, name);
|
||
|
}
|
||
|
else
|
||
|
x = gen_raw_REG (Pmode, (*regno)++);
|
||
|
|
||
|
return gen_rtx_MEM (DECL_MODE (obj), x);
|
||
|
}
|
||
|
|
||
|
/* Prepares decl_rtl for variables referred in *EXPR_P. Callback for
|
||
|
walk_tree. DATA contains the actual fake register number. */
|
||
|
|
||
|
static tree
|
||
|
prepare_decl_rtl (tree *expr_p, int *ws, void *data)
|
||
|
{
|
||
|
tree obj = NULL_TREE;
|
||
|
rtx x = NULL_RTX;
|
||
|
int *regno = data;
|
||
|
|
||
|
switch (TREE_CODE (*expr_p))
|
||
|
{
|
||
|
case ADDR_EXPR:
|
||
|
for (expr_p = &TREE_OPERAND (*expr_p, 0);
|
||
|
handled_component_p (*expr_p);
|
||
|
expr_p = &TREE_OPERAND (*expr_p, 0))
|
||
|
continue;
|
||
|
obj = *expr_p;
|
||
|
if (DECL_P (obj) && !DECL_RTL_SET_P (obj))
|
||
|
x = produce_memory_decl_rtl (obj, regno);
|
||
|
break;
|
||
|
|
||
|
case SSA_NAME:
|
||
|
*ws = 0;
|
||
|
obj = SSA_NAME_VAR (*expr_p);
|
||
|
if (!DECL_RTL_SET_P (obj))
|
||
|
x = gen_raw_REG (DECL_MODE (obj), (*regno)++);
|
||
|
break;
|
||
|
|
||
|
case VAR_DECL:
|
||
|
case PARM_DECL:
|
||
|
case RESULT_DECL:
|
||
|
*ws = 0;
|
||
|
obj = *expr_p;
|
||
|
|
||
|
if (DECL_RTL_SET_P (obj))
|
||
|
break;
|
||
|
|
||
|
if (DECL_MODE (obj) == BLKmode)
|
||
|
x = produce_memory_decl_rtl (obj, regno);
|
||
|
else
|
||
|
x = gen_raw_REG (DECL_MODE (obj), (*regno)++);
|
||
|
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
if (x)
|
||
|
{
|
||
|
VEC_safe_push (tree, heap, decl_rtl_to_reset, obj);
|
||
|
SET_DECL_RTL (obj, x);
|
||
|
}
|
||
|
|
||
|
return NULL_TREE;
|
||
|
}
|
||
|
|
||
|
/* Determines cost of the computation of EXPR. */
|
||
|
|
||
|
static unsigned
|
||
|
computation_cost (tree expr)
|
||
|
{
|
||
|
rtx seq, rslt;
|
||
|
tree type = TREE_TYPE (expr);
|
||
|
unsigned cost;
|
||
|
/* Avoid using hard regs in ways which may be unsupported. */
|
||
|
int regno = LAST_VIRTUAL_REGISTER + 1;
|
||
|
|
||
|
walk_tree (&expr, prepare_decl_rtl, ®no, NULL);
|
||
|
start_sequence ();
|
||
|
rslt = expand_expr (expr, NULL_RTX, TYPE_MODE (type), EXPAND_NORMAL);
|
||
|
seq = get_insns ();
|
||
|
end_sequence ();
|
||
|
|
||
|
cost = seq_cost (seq);
|
||
|
if (MEM_P (rslt))
|
||
|
cost += address_cost (XEXP (rslt, 0), TYPE_MODE (type));
|
||
|
|
||
|
return cost;
|
||
|
}
|
||
|
|
||
|
/* Returns variable containing the value of candidate CAND at statement AT. */
|
||
|
|
||
|
static tree
|
||
|
var_at_stmt (struct loop *loop, struct iv_cand *cand, tree stmt)
|
||
|
{
|
||
|
if (stmt_after_increment (loop, cand, stmt))
|
||
|
return cand->var_after;
|
||
|
else
|
||
|
return cand->var_before;
|
||
|
}
|
||
|
|
||
|
/* Return the most significant (sign) bit of T. Similar to tree_int_cst_msb,
|
||
|
but the bit is determined from TYPE_PRECISION, not MODE_BITSIZE. */
|
||
|
|
||
|
int
|
||
|
tree_int_cst_sign_bit (tree t)
|
||
|
{
|
||
|
unsigned bitno = TYPE_PRECISION (TREE_TYPE (t)) - 1;
|
||
|
unsigned HOST_WIDE_INT w;
|
||
|
|
||
|
if (bitno < HOST_BITS_PER_WIDE_INT)
|
||
|
w = TREE_INT_CST_LOW (t);
|
||
|
else
|
||
|
{
|
||
|
w = TREE_INT_CST_HIGH (t);
|
||
|
bitno -= HOST_BITS_PER_WIDE_INT;
|
||
|
}
|
||
|
|
||
|
return (w >> bitno) & 1;
|
||
|
}
|
||
|
|
||
|
/* If we can prove that TOP = cst * BOT for some constant cst,
|
||
|
store cst to MUL and return true. Otherwise return false.
|
||
|
The returned value is always sign-extended, regardless of the
|
||
|
signedness of TOP and BOT. */
|
||
|
|
||
|
static bool
|
||
|
constant_multiple_of (tree top, tree bot, double_int *mul)
|
||
|
{
|
||
|
tree mby;
|
||
|
enum tree_code code;
|
||
|
double_int res, p0, p1;
|
||
|
unsigned precision = TYPE_PRECISION (TREE_TYPE (top));
|
||
|
|
||
|
STRIP_NOPS (top);
|
||
|
STRIP_NOPS (bot);
|
||
|
|
||
|
if (operand_equal_p (top, bot, 0))
|
||
|
{
|
||
|
*mul = double_int_one;
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
code = TREE_CODE (top);
|
||
|
switch (code)
|
||
|
{
|
||
|
case MULT_EXPR:
|
||
|
mby = TREE_OPERAND (top, 1);
|
||
|
if (TREE_CODE (mby) != INTEGER_CST)
|
||
|
return false;
|
||
|
|
||
|
if (!constant_multiple_of (TREE_OPERAND (top, 0), bot, &res))
|
||
|
return false;
|
||
|
|
||
|
*mul = double_int_sext (double_int_mul (res, tree_to_double_int (mby)),
|
||
|
precision);
|
||
|
return true;
|
||
|
|
||
|
case PLUS_EXPR:
|
||
|
case MINUS_EXPR:
|
||
|
if (!constant_multiple_of (TREE_OPERAND (top, 0), bot, &p0)
|
||
|
|| !constant_multiple_of (TREE_OPERAND (top, 1), bot, &p1))
|
||
|
return false;
|
||
|
|
||
|
if (code == MINUS_EXPR)
|
||
|
p1 = double_int_neg (p1);
|
||
|
*mul = double_int_sext (double_int_add (p0, p1), precision);
|
||
|
return true;
|
||
|
|
||
|
case INTEGER_CST:
|
||
|
if (TREE_CODE (bot) != INTEGER_CST)
|
||
|
return false;
|
||
|
|
||
|
p0 = double_int_sext (tree_to_double_int (bot), precision);
|
||
|
p1 = double_int_sext (tree_to_double_int (top), precision);
|
||
|
if (double_int_zero_p (p1))
|
||
|
return false;
|
||
|
*mul = double_int_sext (double_int_sdivmod (p0, p1, FLOOR_DIV_EXPR, &res),
|
||
|
precision);
|
||
|
return double_int_zero_p (res);
|
||
|
|
||
|
default:
|
||
|
return false;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Sets COMB to CST. */
|
||
|
|
||
|
static void
|
||
|
aff_combination_const (struct affine_tree_combination *comb, tree type,
|
||
|
unsigned HOST_WIDE_INT cst)
|
||
|
{
|
||
|
unsigned prec = TYPE_PRECISION (type);
|
||
|
|
||
|
comb->type = type;
|
||
|
comb->mask = (((unsigned HOST_WIDE_INT) 2 << (prec - 1)) - 1);
|
||
|
|
||
|
comb->n = 0;
|
||
|
comb->rest = NULL_TREE;
|
||
|
comb->offset = cst & comb->mask;
|
||
|
}
|
||
|
|
||
|
/* Sets COMB to single element ELT. */
|
||
|
|
||
|
static void
|
||
|
aff_combination_elt (struct affine_tree_combination *comb, tree type, tree elt)
|
||
|
{
|
||
|
unsigned prec = TYPE_PRECISION (type);
|
||
|
|
||
|
comb->type = type;
|
||
|
comb->mask = (((unsigned HOST_WIDE_INT) 2 << (prec - 1)) - 1);
|
||
|
|
||
|
comb->n = 1;
|
||
|
comb->elts[0] = elt;
|
||
|
comb->coefs[0] = 1;
|
||
|
comb->rest = NULL_TREE;
|
||
|
comb->offset = 0;
|
||
|
}
|
||
|
|
||
|
/* Scales COMB by SCALE. */
|
||
|
|
||
|
static void
|
||
|
aff_combination_scale (struct affine_tree_combination *comb,
|
||
|
unsigned HOST_WIDE_INT scale)
|
||
|
{
|
||
|
unsigned i, j;
|
||
|
|
||
|
if (scale == 1)
|
||
|
return;
|
||
|
|
||
|
if (scale == 0)
|
||
|
{
|
||
|
aff_combination_const (comb, comb->type, 0);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
comb->offset = (scale * comb->offset) & comb->mask;
|
||
|
for (i = 0, j = 0; i < comb->n; i++)
|
||
|
{
|
||
|
comb->coefs[j] = (scale * comb->coefs[i]) & comb->mask;
|
||
|
comb->elts[j] = comb->elts[i];
|
||
|
if (comb->coefs[j] != 0)
|
||
|
j++;
|
||
|
}
|
||
|
comb->n = j;
|
||
|
|
||
|
if (comb->rest)
|
||
|
{
|
||
|
if (comb->n < MAX_AFF_ELTS)
|
||
|
{
|
||
|
comb->coefs[comb->n] = scale;
|
||
|
comb->elts[comb->n] = comb->rest;
|
||
|
comb->rest = NULL_TREE;
|
||
|
comb->n++;
|
||
|
}
|
||
|
else
|
||
|
comb->rest = fold_build2 (MULT_EXPR, comb->type, comb->rest,
|
||
|
build_int_cst_type (comb->type, scale));
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Adds ELT * SCALE to COMB. */
|
||
|
|
||
|
static void
|
||
|
aff_combination_add_elt (struct affine_tree_combination *comb, tree elt,
|
||
|
unsigned HOST_WIDE_INT scale)
|
||
|
{
|
||
|
unsigned i;
|
||
|
|
||
|
if (scale == 0)
|
||
|
return;
|
||
|
|
||
|
for (i = 0; i < comb->n; i++)
|
||
|
if (operand_equal_p (comb->elts[i], elt, 0))
|
||
|
{
|
||
|
comb->coefs[i] = (comb->coefs[i] + scale) & comb->mask;
|
||
|
if (comb->coefs[i])
|
||
|
return;
|
||
|
|
||
|
comb->n--;
|
||
|
comb->coefs[i] = comb->coefs[comb->n];
|
||
|
comb->elts[i] = comb->elts[comb->n];
|
||
|
|
||
|
if (comb->rest)
|
||
|
{
|
||
|
gcc_assert (comb->n == MAX_AFF_ELTS - 1);
|
||
|
comb->coefs[comb->n] = 1;
|
||
|
comb->elts[comb->n] = comb->rest;
|
||
|
comb->rest = NULL_TREE;
|
||
|
comb->n++;
|
||
|
}
|
||
|
return;
|
||
|
}
|
||
|
if (comb->n < MAX_AFF_ELTS)
|
||
|
{
|
||
|
comb->coefs[comb->n] = scale;
|
||
|
comb->elts[comb->n] = elt;
|
||
|
comb->n++;
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if (scale == 1)
|
||
|
elt = fold_convert (comb->type, elt);
|
||
|
else
|
||
|
elt = fold_build2 (MULT_EXPR, comb->type,
|
||
|
fold_convert (comb->type, elt),
|
||
|
build_int_cst_type (comb->type, scale));
|
||
|
|
||
|
if (comb->rest)
|
||
|
comb->rest = fold_build2 (PLUS_EXPR, comb->type, comb->rest, elt);
|
||
|
else
|
||
|
comb->rest = elt;
|
||
|
}
|
||
|
|
||
|
/* Adds COMB2 to COMB1. */
|
||
|
|
||
|
static void
|
||
|
aff_combination_add (struct affine_tree_combination *comb1,
|
||
|
struct affine_tree_combination *comb2)
|
||
|
{
|
||
|
unsigned i;
|
||
|
|
||
|
comb1->offset = (comb1->offset + comb2->offset) & comb1->mask;
|
||
|
for (i = 0; i < comb2->n; i++)
|
||
|
aff_combination_add_elt (comb1, comb2->elts[i], comb2->coefs[i]);
|
||
|
if (comb2->rest)
|
||
|
aff_combination_add_elt (comb1, comb2->rest, 1);
|
||
|
}
|
||
|
|
||
|
/* Convert COMB to TYPE. */
|
||
|
|
||
|
static void
|
||
|
aff_combination_convert (tree type, struct affine_tree_combination *comb)
|
||
|
{
|
||
|
unsigned prec = TYPE_PRECISION (type);
|
||
|
unsigned i;
|
||
|
|
||
|
/* If the precision of both types is the same, it suffices to change the type
|
||
|
of the whole combination -- the elements are allowed to have another type
|
||
|
equivalent wrto STRIP_NOPS. */
|
||
|
if (prec == TYPE_PRECISION (comb->type))
|
||
|
{
|
||
|
comb->type = type;
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
comb->mask = (((unsigned HOST_WIDE_INT) 2 << (prec - 1)) - 1);
|
||
|
comb->offset = comb->offset & comb->mask;
|
||
|
|
||
|
/* The type of the elements can be different from comb->type only as
|
||
|
much as what STRIP_NOPS would remove. We can just directly cast
|
||
|
to TYPE. */
|
||
|
for (i = 0; i < comb->n; i++)
|
||
|
comb->elts[i] = fold_convert (type, comb->elts[i]);
|
||
|
if (comb->rest)
|
||
|
comb->rest = fold_convert (type, comb->rest);
|
||
|
|
||
|
comb->type = type;
|
||
|
}
|
||
|
|
||
|
/* Splits EXPR into an affine combination of parts. */
|
||
|
|
||
|
static void
|
||
|
tree_to_aff_combination (tree expr, tree type,
|
||
|
struct affine_tree_combination *comb)
|
||
|
{
|
||
|
struct affine_tree_combination tmp;
|
||
|
enum tree_code code;
|
||
|
tree cst, core, toffset;
|
||
|
HOST_WIDE_INT bitpos, bitsize;
|
||
|
enum machine_mode mode;
|
||
|
int unsignedp, volatilep;
|
||
|
|
||
|
STRIP_NOPS (expr);
|
||
|
|
||
|
code = TREE_CODE (expr);
|
||
|
switch (code)
|
||
|
{
|
||
|
case INTEGER_CST:
|
||
|
aff_combination_const (comb, type, int_cst_value (expr));
|
||
|
return;
|
||
|
|
||
|
case PLUS_EXPR:
|
||
|
case MINUS_EXPR:
|
||
|
tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
|
||
|
tree_to_aff_combination (TREE_OPERAND (expr, 1), type, &tmp);
|
||
|
if (code == MINUS_EXPR)
|
||
|
aff_combination_scale (&tmp, -1);
|
||
|
aff_combination_add (comb, &tmp);
|
||
|
return;
|
||
|
|
||
|
case MULT_EXPR:
|
||
|
cst = TREE_OPERAND (expr, 1);
|
||
|
if (TREE_CODE (cst) != INTEGER_CST)
|
||
|
break;
|
||
|
tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
|
||
|
aff_combination_scale (comb, int_cst_value (cst));
|
||
|
return;
|
||
|
|
||
|
case NEGATE_EXPR:
|
||
|
tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
|
||
|
aff_combination_scale (comb, -1);
|
||
|
return;
|
||
|
|
||
|
case ADDR_EXPR:
|
||
|
core = get_inner_reference (TREE_OPERAND (expr, 0), &bitsize, &bitpos,
|
||
|
&toffset, &mode, &unsignedp, &volatilep,
|
||
|
false);
|
||
|
if (bitpos % BITS_PER_UNIT != 0)
|
||
|
break;
|
||
|
aff_combination_const (comb, type, bitpos / BITS_PER_UNIT);
|
||
|
core = build_fold_addr_expr (core);
|
||
|
if (TREE_CODE (core) == ADDR_EXPR)
|
||
|
aff_combination_add_elt (comb, core, 1);
|
||
|
else
|
||
|
{
|
||
|
tree_to_aff_combination (core, type, &tmp);
|
||
|
aff_combination_add (comb, &tmp);
|
||
|
}
|
||
|
if (toffset)
|
||
|
{
|
||
|
tree_to_aff_combination (toffset, type, &tmp);
|
||
|
aff_combination_add (comb, &tmp);
|
||
|
}
|
||
|
return;
|
||
|
|
||
|
default:
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
aff_combination_elt (comb, type, expr);
|
||
|
}
|
||
|
|
||
|
/* Creates EXPR + ELT * SCALE in TYPE. MASK is the mask for width of TYPE. */
|
||
|
|
||
|
static tree
|
||
|
add_elt_to_tree (tree expr, tree type, tree elt, unsigned HOST_WIDE_INT scale,
|
||
|
unsigned HOST_WIDE_INT mask)
|
||
|
{
|
||
|
enum tree_code code;
|
||
|
|
||
|
scale &= mask;
|
||
|
elt = fold_convert (type, elt);
|
||
|
|
||
|
if (scale == 1)
|
||
|
{
|
||
|
if (!expr)
|
||
|
return elt;
|
||
|
|
||
|
return fold_build2 (PLUS_EXPR, type, expr, elt);
|
||
|
}
|
||
|
|
||
|
if (scale == mask)
|
||
|
{
|
||
|
if (!expr)
|
||
|
return fold_build1 (NEGATE_EXPR, type, elt);
|
||
|
|
||
|
return fold_build2 (MINUS_EXPR, type, expr, elt);
|
||
|
}
|
||
|
|
||
|
if (!expr)
|
||
|
return fold_build2 (MULT_EXPR, type, elt,
|
||
|
build_int_cst_type (type, scale));
|
||
|
|
||
|
if ((scale | (mask >> 1)) == mask)
|
||
|
{
|
||
|
/* Scale is negative. */
|
||
|
code = MINUS_EXPR;
|
||
|
scale = (-scale) & mask;
|
||
|
}
|
||
|
else
|
||
|
code = PLUS_EXPR;
|
||
|
|
||
|
elt = fold_build2 (MULT_EXPR, type, elt,
|
||
|
build_int_cst_type (type, scale));
|
||
|
return fold_build2 (code, type, expr, elt);
|
||
|
}
|
||
|
|
||
|
/* Copies the tree elements of COMB to ensure that they are not shared. */
|
||
|
|
||
|
static void
|
||
|
unshare_aff_combination (struct affine_tree_combination *comb)
|
||
|
{
|
||
|
unsigned i;
|
||
|
|
||
|
for (i = 0; i < comb->n; i++)
|
||
|
comb->elts[i] = unshare_expr (comb->elts[i]);
|
||
|
if (comb->rest)
|
||
|
comb->rest = unshare_expr (comb->rest);
|
||
|
}
|
||
|
|
||
|
/* Makes tree from the affine combination COMB. */
|
||
|
|
||
|
static tree
|
||
|
aff_combination_to_tree (struct affine_tree_combination *comb)
|
||
|
{
|
||
|
tree type = comb->type;
|
||
|
tree expr = comb->rest;
|
||
|
unsigned i;
|
||
|
unsigned HOST_WIDE_INT off, sgn;
|
||
|
|
||
|
if (comb->n == 0 && comb->offset == 0)
|
||
|
{
|
||
|
if (expr)
|
||
|
{
|
||
|
/* Handle the special case produced by get_computation_aff when
|
||
|
the type does not fit in HOST_WIDE_INT. */
|
||
|
return fold_convert (type, expr);
|
||
|
}
|
||
|
else
|
||
|
return build_int_cst (type, 0);
|
||
|
}
|
||
|
|
||
|
gcc_assert (comb->n == MAX_AFF_ELTS || comb->rest == NULL_TREE);
|
||
|
|
||
|
for (i = 0; i < comb->n; i++)
|
||
|
expr = add_elt_to_tree (expr, type, comb->elts[i], comb->coefs[i],
|
||
|
comb->mask);
|
||
|
|
||
|
if ((comb->offset | (comb->mask >> 1)) == comb->mask)
|
||
|
{
|
||
|
/* Offset is negative. */
|
||
|
off = (-comb->offset) & comb->mask;
|
||
|
sgn = comb->mask;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
off = comb->offset;
|
||
|
sgn = 1;
|
||
|
}
|
||
|
return add_elt_to_tree (expr, type, build_int_cst_type (type, off), sgn,
|
||
|
comb->mask);
|
||
|
}
|
||
|
|
||
|
/* Folds EXPR using the affine expressions framework. */
|
||
|
|
||
|
static tree
|
||
|
fold_affine_expr (tree expr)
|
||
|
{
|
||
|
tree type = TREE_TYPE (expr);
|
||
|
struct affine_tree_combination comb;
|
||
|
|
||
|
if (TYPE_PRECISION (type) > HOST_BITS_PER_WIDE_INT)
|
||
|
return expr;
|
||
|
|
||
|
tree_to_aff_combination (expr, type, &comb);
|
||
|
return aff_combination_to_tree (&comb);
|
||
|
}
|
||
|
|
||
|
/* If A is (TYPE) BA and B is (TYPE) BB, and the types of BA and BB have the
|
||
|
same precision that is at least as wide as the precision of TYPE, stores
|
||
|
BA to A and BB to B, and returns the type of BA. Otherwise, returns the
|
||
|
type of A and B. */
|
||
|
|
||
|
static tree
|
||
|
determine_common_wider_type (tree *a, tree *b)
|
||
|
{
|
||
|
tree wider_type = NULL;
|
||
|
tree suba, subb;
|
||
|
tree atype = TREE_TYPE (*a);
|
||
|
|
||
|
if ((TREE_CODE (*a) == NOP_EXPR
|
||
|
|| TREE_CODE (*a) == CONVERT_EXPR))
|
||
|
{
|
||
|
suba = TREE_OPERAND (*a, 0);
|
||
|
wider_type = TREE_TYPE (suba);
|
||
|
if (TYPE_PRECISION (wider_type) < TYPE_PRECISION (atype))
|
||
|
return atype;
|
||
|
}
|
||
|
else
|
||
|
return atype;
|
||
|
|
||
|
if ((TREE_CODE (*b) == NOP_EXPR
|
||
|
|| TREE_CODE (*b) == CONVERT_EXPR))
|
||
|
{
|
||
|
subb = TREE_OPERAND (*b, 0);
|
||
|
if (TYPE_PRECISION (wider_type) != TYPE_PRECISION (TREE_TYPE (subb)))
|
||
|
return atype;
|
||
|
}
|
||
|
else
|
||
|
return atype;
|
||
|
|
||
|
*a = suba;
|
||
|
*b = subb;
|
||
|
return wider_type;
|
||
|
}
|
||
|
|
||
|
/* Determines the expression by that USE is expressed from induction variable
|
||
|
CAND at statement AT in LOOP. The expression is stored in a decomposed
|
||
|
form into AFF. Returns false if USE cannot be expressed using CAND. */
|
||
|
|
||
|
static bool
|
||
|
get_computation_aff (struct loop *loop,
|
||
|
struct iv_use *use, struct iv_cand *cand, tree at,
|
||
|
struct affine_tree_combination *aff)
|
||
|
{
|
||
|
tree ubase = use->iv->base;
|
||
|
tree ustep = use->iv->step;
|
||
|
tree cbase = cand->iv->base;
|
||
|
tree cstep = cand->iv->step;
|
||
|
tree utype = TREE_TYPE (ubase), ctype = TREE_TYPE (cbase);
|
||
|
tree common_type;
|
||
|
tree uutype;
|
||
|
tree expr, delta;
|
||
|
tree ratio;
|
||
|
unsigned HOST_WIDE_INT ustepi, cstepi;
|
||
|
HOST_WIDE_INT ratioi;
|
||
|
struct affine_tree_combination cbase_aff, expr_aff;
|
||
|
tree cstep_orig = cstep, ustep_orig = ustep;
|
||
|
double_int rat;
|
||
|
|
||
|
if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype))
|
||
|
{
|
||
|
/* We do not have a precision to express the values of use. */
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
expr = var_at_stmt (loop, cand, at);
|
||
|
|
||
|
if (TREE_TYPE (expr) != ctype)
|
||
|
{
|
||
|
/* This may happen with the original ivs. */
|
||
|
expr = fold_convert (ctype, expr);
|
||
|
}
|
||
|
|
||
|
if (TYPE_UNSIGNED (utype))
|
||
|
uutype = utype;
|
||
|
else
|
||
|
{
|
||
|
uutype = unsigned_type_for (utype);
|
||
|
ubase = fold_convert (uutype, ubase);
|
||
|
ustep = fold_convert (uutype, ustep);
|
||
|
}
|
||
|
|
||
|
if (uutype != ctype)
|
||
|
{
|
||
|
expr = fold_convert (uutype, expr);
|
||
|
cbase = fold_convert (uutype, cbase);
|
||
|
cstep = fold_convert (uutype, cstep);
|
||
|
|
||
|
/* If the conversion is not noop, we must take it into account when
|
||
|
considering the value of the step. */
|
||
|
if (TYPE_PRECISION (utype) < TYPE_PRECISION (ctype))
|
||
|
cstep_orig = cstep;
|
||
|
}
|
||
|
|
||
|
if (cst_and_fits_in_hwi (cstep_orig)
|
||
|
&& cst_and_fits_in_hwi (ustep_orig))
|
||
|
{
|
||
|
ustepi = int_cst_value (ustep_orig);
|
||
|
cstepi = int_cst_value (cstep_orig);
|
||
|
|
||
|
if (!divide (TYPE_PRECISION (uutype), ustepi, cstepi, &ratioi))
|
||
|
{
|
||
|
/* TODO maybe consider case when ustep divides cstep and the ratio is
|
||
|
a power of 2 (so that the division is fast to execute)? We would
|
||
|
need to be much more careful with overflows etc. then. */
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
ratio = build_int_cst_type (uutype, ratioi);
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
if (!constant_multiple_of (ustep_orig, cstep_orig, &rat))
|
||
|
return false;
|
||
|
ratio = double_int_to_tree (uutype, rat);
|
||
|
|
||
|
/* Ratioi is only used to detect special cases when the multiplicative
|
||
|
factor is 1 or -1, so if rat does not fit to HOST_WIDE_INT, we may
|
||
|
set it to 0. */
|
||
|
if (double_int_fits_in_shwi_p (rat))
|
||
|
ratioi = double_int_to_shwi (rat);
|
||
|
else
|
||
|
ratioi = 0;
|
||
|
}
|
||
|
|
||
|
/* In case both UBASE and CBASE are shortened to UUTYPE from some common
|
||
|
type, we achieve better folding by computing their difference in this
|
||
|
wider type, and cast the result to UUTYPE. We do not need to worry about
|
||
|
overflows, as all the arithmetics will in the end be performed in UUTYPE
|
||
|
anyway. */
|
||
|
common_type = determine_common_wider_type (&ubase, &cbase);
|
||
|
|
||
|
/* We may need to shift the value if we are after the increment. */
|
||
|
if (stmt_after_increment (loop, cand, at))
|
||
|
{
|
||
|
if (uutype != common_type)
|
||
|
cstep = fold_convert (common_type, cstep);
|
||
|
cbase = fold_build2 (PLUS_EXPR, common_type, cbase, cstep);
|
||
|
}
|
||
|
|
||
|
/* use = ubase - ratio * cbase + ratio * var.
|
||
|
|
||
|
In general case ubase + ratio * (var - cbase) could be better (one less
|
||
|
multiplication), but often it is possible to eliminate redundant parts
|
||
|
of computations from (ubase - ratio * cbase) term, and if it does not
|
||
|
happen, fold is able to apply the distributive law to obtain this form
|
||
|
anyway. */
|
||
|
|
||
|
if (TYPE_PRECISION (common_type) > HOST_BITS_PER_WIDE_INT)
|
||
|
{
|
||
|
/* Let's compute in trees and just return the result in AFF. This case
|
||
|
should not be very common, and fold itself is not that bad either,
|
||
|
so making the aff. functions more complicated to handle this case
|
||
|
is not that urgent. */
|
||
|
if (ratioi == 1)
|
||
|
{
|
||
|
delta = fold_build2 (MINUS_EXPR, common_type, ubase, cbase);
|
||
|
if (uutype != common_type)
|
||
|
delta = fold_convert (uutype, delta);
|
||
|
expr = fold_build2 (PLUS_EXPR, uutype, expr, delta);
|
||
|
}
|
||
|
else if (ratioi == -1)
|
||
|
{
|
||
|
delta = fold_build2 (PLUS_EXPR, common_type, ubase, cbase);
|
||
|
if (uutype != common_type)
|
||
|
delta = fold_convert (uutype, delta);
|
||
|
expr = fold_build2 (MINUS_EXPR, uutype, delta, expr);
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
delta = fold_build2 (MULT_EXPR, common_type, cbase, ratio);
|
||
|
delta = fold_build2 (MINUS_EXPR, common_type, ubase, delta);
|
||
|
if (uutype != common_type)
|
||
|
delta = fold_convert (uutype, delta);
|
||
|
expr = fold_build2 (MULT_EXPR, uutype, ratio, expr);
|
||
|
expr = fold_build2 (PLUS_EXPR, uutype, delta, expr);
|
||
|
}
|
||
|
|
||
|
aff->type = uutype;
|
||
|
aff->n = 0;
|
||
|
aff->offset = 0;
|
||
|
aff->mask = 0;
|
||
|
aff->rest = expr;
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* If we got here, the types fits in HOST_WIDE_INT, thus it must be
|
||
|
possible to compute ratioi. */
|
||
|
gcc_assert (ratioi);
|
||
|
|
||
|
tree_to_aff_combination (ubase, common_type, aff);
|
||
|
tree_to_aff_combination (cbase, common_type, &cbase_aff);
|
||
|
tree_to_aff_combination (expr, uutype, &expr_aff);
|
||
|
aff_combination_scale (&cbase_aff, -ratioi);
|
||
|
aff_combination_scale (&expr_aff, ratioi);
|
||
|
aff_combination_add (aff, &cbase_aff);
|
||
|
if (common_type != uutype)
|
||
|
aff_combination_convert (uutype, aff);
|
||
|
aff_combination_add (aff, &expr_aff);
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Determines the expression by that USE is expressed from induction variable
|
||
|
CAND at statement AT in LOOP. The computation is unshared. */
|
||
|
|
||
|
static tree
|
||
|
get_computation_at (struct loop *loop,
|
||
|
struct iv_use *use, struct iv_cand *cand, tree at)
|
||
|
{
|
||
|
struct affine_tree_combination aff;
|
||
|
tree type = TREE_TYPE (use->iv->base);
|
||
|
|
||
|
if (!get_computation_aff (loop, use, cand, at, &aff))
|
||
|
return NULL_TREE;
|
||
|
unshare_aff_combination (&aff);
|
||
|
return fold_convert (type, aff_combination_to_tree (&aff));
|
||
|
}
|
||
|
|
||
|
/* Determines the expression by that USE is expressed from induction variable
|
||
|
CAND in LOOP. The computation is unshared. */
|
||
|
|
||
|
static tree
|
||
|
get_computation (struct loop *loop, struct iv_use *use, struct iv_cand *cand)
|
||
|
{
|
||
|
return get_computation_at (loop, use, cand, use->stmt);
|
||
|
}
|
||
|
|
||
|
/* Returns cost of addition in MODE. */
|
||
|
|
||
|
static unsigned
|
||
|
add_cost (enum machine_mode mode)
|
||
|
{
|
||
|
static unsigned costs[NUM_MACHINE_MODES];
|
||
|
rtx seq;
|
||
|
unsigned cost;
|
||
|
|
||
|
if (costs[mode])
|
||
|
return costs[mode];
|
||
|
|
||
|
start_sequence ();
|
||
|
force_operand (gen_rtx_fmt_ee (PLUS, mode,
|
||
|
gen_raw_REG (mode, LAST_VIRTUAL_REGISTER + 1),
|
||
|
gen_raw_REG (mode, LAST_VIRTUAL_REGISTER + 2)),
|
||
|
NULL_RTX);
|
||
|
seq = get_insns ();
|
||
|
end_sequence ();
|
||
|
|
||
|
cost = seq_cost (seq);
|
||
|
if (!cost)
|
||
|
cost = 1;
|
||
|
|
||
|
costs[mode] = cost;
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
fprintf (dump_file, "Addition in %s costs %d\n",
|
||
|
GET_MODE_NAME (mode), cost);
|
||
|
return cost;
|
||
|
}
|
||
|
|
||
|
/* Entry in a hashtable of already known costs for multiplication. */
|
||
|
struct mbc_entry
|
||
|
{
|
||
|
HOST_WIDE_INT cst; /* The constant to multiply by. */
|
||
|
enum machine_mode mode; /* In mode. */
|
||
|
unsigned cost; /* The cost. */
|
||
|
};
|
||
|
|
||
|
/* Counts hash value for the ENTRY. */
|
||
|
|
||
|
static hashval_t
|
||
|
mbc_entry_hash (const void *entry)
|
||
|
{
|
||
|
const struct mbc_entry *e = entry;
|
||
|
|
||
|
return 57 * (hashval_t) e->mode + (hashval_t) (e->cst % 877);
|
||
|
}
|
||
|
|
||
|
/* Compares the hash table entries ENTRY1 and ENTRY2. */
|
||
|
|
||
|
static int
|
||
|
mbc_entry_eq (const void *entry1, const void *entry2)
|
||
|
{
|
||
|
const struct mbc_entry *e1 = entry1;
|
||
|
const struct mbc_entry *e2 = entry2;
|
||
|
|
||
|
return (e1->mode == e2->mode
|
||
|
&& e1->cst == e2->cst);
|
||
|
}
|
||
|
|
||
|
/* Returns cost of multiplication by constant CST in MODE. */
|
||
|
|
||
|
unsigned
|
||
|
multiply_by_cost (HOST_WIDE_INT cst, enum machine_mode mode)
|
||
|
{
|
||
|
static htab_t costs;
|
||
|
struct mbc_entry **cached, act;
|
||
|
rtx seq;
|
||
|
unsigned cost;
|
||
|
|
||
|
if (!costs)
|
||
|
costs = htab_create (100, mbc_entry_hash, mbc_entry_eq, free);
|
||
|
|
||
|
act.mode = mode;
|
||
|
act.cst = cst;
|
||
|
cached = (struct mbc_entry **) htab_find_slot (costs, &act, INSERT);
|
||
|
if (*cached)
|
||
|
return (*cached)->cost;
|
||
|
|
||
|
*cached = XNEW (struct mbc_entry);
|
||
|
(*cached)->mode = mode;
|
||
|
(*cached)->cst = cst;
|
||
|
|
||
|
start_sequence ();
|
||
|
expand_mult (mode, gen_raw_REG (mode, LAST_VIRTUAL_REGISTER + 1),
|
||
|
gen_int_mode (cst, mode), NULL_RTX, 0);
|
||
|
seq = get_insns ();
|
||
|
end_sequence ();
|
||
|
|
||
|
cost = seq_cost (seq);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
fprintf (dump_file, "Multiplication by %d in %s costs %d\n",
|
||
|
(int) cst, GET_MODE_NAME (mode), cost);
|
||
|
|
||
|
(*cached)->cost = cost;
|
||
|
|
||
|
return cost;
|
||
|
}
|
||
|
|
||
|
/* Returns true if multiplying by RATIO is allowed in address. */
|
||
|
|
||
|
bool
|
||
|
multiplier_allowed_in_address_p (HOST_WIDE_INT ratio)
|
||
|
{
|
||
|
#define MAX_RATIO 128
|
||
|
static sbitmap valid_mult;
|
||
|
|
||
|
if (!valid_mult)
|
||
|
{
|
||
|
rtx reg1 = gen_raw_REG (Pmode, LAST_VIRTUAL_REGISTER + 1);
|
||
|
rtx addr;
|
||
|
HOST_WIDE_INT i;
|
||
|
|
||
|
valid_mult = sbitmap_alloc (2 * MAX_RATIO + 1);
|
||
|
sbitmap_zero (valid_mult);
|
||
|
addr = gen_rtx_fmt_ee (MULT, Pmode, reg1, NULL_RTX);
|
||
|
for (i = -MAX_RATIO; i <= MAX_RATIO; i++)
|
||
|
{
|
||
|
XEXP (addr, 1) = gen_int_mode (i, Pmode);
|
||
|
if (memory_address_p (Pmode, addr))
|
||
|
SET_BIT (valid_mult, i + MAX_RATIO);
|
||
|
}
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, " allowed multipliers:");
|
||
|
for (i = -MAX_RATIO; i <= MAX_RATIO; i++)
|
||
|
if (TEST_BIT (valid_mult, i + MAX_RATIO))
|
||
|
fprintf (dump_file, " %d", (int) i);
|
||
|
fprintf (dump_file, "\n");
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (ratio > MAX_RATIO || ratio < -MAX_RATIO)
|
||
|
return false;
|
||
|
|
||
|
return TEST_BIT (valid_mult, ratio + MAX_RATIO);
|
||
|
}
|
||
|
|
||
|
/* Returns cost of address in shape symbol + var + OFFSET + RATIO * index.
|
||
|
If SYMBOL_PRESENT is false, symbol is omitted. If VAR_PRESENT is false,
|
||
|
variable is omitted. The created memory accesses MODE.
|
||
|
|
||
|
TODO -- there must be some better way. This all is quite crude. */
|
||
|
|
||
|
static unsigned
|
||
|
get_address_cost (bool symbol_present, bool var_present,
|
||
|
unsigned HOST_WIDE_INT offset, HOST_WIDE_INT ratio)
|
||
|
{
|
||
|
static bool initialized = false;
|
||
|
static HOST_WIDE_INT rat, off;
|
||
|
static HOST_WIDE_INT min_offset, max_offset;
|
||
|
static unsigned costs[2][2][2][2];
|
||
|
unsigned cost, acost;
|
||
|
bool offset_p, ratio_p;
|
||
|
HOST_WIDE_INT s_offset;
|
||
|
unsigned HOST_WIDE_INT mask;
|
||
|
unsigned bits;
|
||
|
|
||
|
if (!initialized)
|
||
|
{
|
||
|
HOST_WIDE_INT i;
|
||
|
int old_cse_not_expected;
|
||
|
unsigned sym_p, var_p, off_p, rat_p, add_c;
|
||
|
rtx seq, addr, base;
|
||
|
rtx reg0, reg1;
|
||
|
|
||
|
initialized = true;
|
||
|
|
||
|
reg1 = gen_raw_REG (Pmode, LAST_VIRTUAL_REGISTER + 1);
|
||
|
|
||
|
addr = gen_rtx_fmt_ee (PLUS, Pmode, reg1, NULL_RTX);
|
||
|
for (i = 1; i <= 1 << 20; i <<= 1)
|
||
|
{
|
||
|
XEXP (addr, 1) = gen_int_mode (i, Pmode);
|
||
|
if (!memory_address_p (Pmode, addr))
|
||
|
break;
|
||
|
}
|
||
|
max_offset = i >> 1;
|
||
|
off = max_offset;
|
||
|
|
||
|
for (i = 1; i <= 1 << 20; i <<= 1)
|
||
|
{
|
||
|
XEXP (addr, 1) = gen_int_mode (-i, Pmode);
|
||
|
if (!memory_address_p (Pmode, addr))
|
||
|
break;
|
||
|
}
|
||
|
min_offset = -(i >> 1);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "get_address_cost:\n");
|
||
|
fprintf (dump_file, " min offset %d\n", (int) min_offset);
|
||
|
fprintf (dump_file, " max offset %d\n", (int) max_offset);
|
||
|
}
|
||
|
|
||
|
rat = 1;
|
||
|
for (i = 2; i <= MAX_RATIO; i++)
|
||
|
if (multiplier_allowed_in_address_p (i))
|
||
|
{
|
||
|
rat = i;
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
/* Compute the cost of various addressing modes. */
|
||
|
acost = 0;
|
||
|
reg0 = gen_raw_REG (Pmode, LAST_VIRTUAL_REGISTER + 1);
|
||
|
reg1 = gen_raw_REG (Pmode, LAST_VIRTUAL_REGISTER + 2);
|
||
|
|
||
|
for (i = 0; i < 16; i++)
|
||
|
{
|
||
|
sym_p = i & 1;
|
||
|
var_p = (i >> 1) & 1;
|
||
|
off_p = (i >> 2) & 1;
|
||
|
rat_p = (i >> 3) & 1;
|
||
|
|
||
|
addr = reg0;
|
||
|
if (rat_p)
|
||
|
addr = gen_rtx_fmt_ee (MULT, Pmode, addr, gen_int_mode (rat, Pmode));
|
||
|
|
||
|
if (var_p)
|
||
|
addr = gen_rtx_fmt_ee (PLUS, Pmode, addr, reg1);
|
||
|
|
||
|
if (sym_p)
|
||
|
{
|
||
|
base = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (""));
|
||
|
if (off_p)
|
||
|
base = gen_rtx_fmt_e (CONST, Pmode,
|
||
|
gen_rtx_fmt_ee (PLUS, Pmode,
|
||
|
base,
|
||
|
gen_int_mode (off, Pmode)));
|
||
|
}
|
||
|
else if (off_p)
|
||
|
base = gen_int_mode (off, Pmode);
|
||
|
else
|
||
|
base = NULL_RTX;
|
||
|
|
||
|
if (base)
|
||
|
addr = gen_rtx_fmt_ee (PLUS, Pmode, addr, base);
|
||
|
|
||
|
start_sequence ();
|
||
|
/* To avoid splitting addressing modes, pretend that no cse will
|
||
|
follow. */
|
||
|
old_cse_not_expected = cse_not_expected;
|
||
|
cse_not_expected = true;
|
||
|
addr = memory_address (Pmode, addr);
|
||
|
cse_not_expected = old_cse_not_expected;
|
||
|
seq = get_insns ();
|
||
|
end_sequence ();
|
||
|
|
||
|
acost = seq_cost (seq);
|
||
|
acost += address_cost (addr, Pmode);
|
||
|
|
||
|
if (!acost)
|
||
|
acost = 1;
|
||
|
costs[sym_p][var_p][off_p][rat_p] = acost;
|
||
|
}
|
||
|
|
||
|
/* On some targets, it is quite expensive to load symbol to a register,
|
||
|
which makes addresses that contain symbols look much more expensive.
|
||
|
However, the symbol will have to be loaded in any case before the
|
||
|
loop (and quite likely we have it in register already), so it does not
|
||
|
make much sense to penalize them too heavily. So make some final
|
||
|
tweaks for the SYMBOL_PRESENT modes:
|
||
|
|
||
|
If VAR_PRESENT is false, and the mode obtained by changing symbol to
|
||
|
var is cheaper, use this mode with small penalty.
|
||
|
If VAR_PRESENT is true, try whether the mode with
|
||
|
SYMBOL_PRESENT = false is cheaper even with cost of addition, and
|
||
|
if this is the case, use it. */
|
||
|
add_c = add_cost (Pmode);
|
||
|
for (i = 0; i < 8; i++)
|
||
|
{
|
||
|
var_p = i & 1;
|
||
|
off_p = (i >> 1) & 1;
|
||
|
rat_p = (i >> 2) & 1;
|
||
|
|
||
|
acost = costs[0][1][off_p][rat_p] + 1;
|
||
|
if (var_p)
|
||
|
acost += add_c;
|
||
|
|
||
|
if (acost < costs[1][var_p][off_p][rat_p])
|
||
|
costs[1][var_p][off_p][rat_p] = acost;
|
||
|
}
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "Address costs:\n");
|
||
|
|
||
|
for (i = 0; i < 16; i++)
|
||
|
{
|
||
|
sym_p = i & 1;
|
||
|
var_p = (i >> 1) & 1;
|
||
|
off_p = (i >> 2) & 1;
|
||
|
rat_p = (i >> 3) & 1;
|
||
|
|
||
|
fprintf (dump_file, " ");
|
||
|
if (sym_p)
|
||
|
fprintf (dump_file, "sym + ");
|
||
|
if (var_p)
|
||
|
fprintf (dump_file, "var + ");
|
||
|
if (off_p)
|
||
|
fprintf (dump_file, "cst + ");
|
||
|
if (rat_p)
|
||
|
fprintf (dump_file, "rat * ");
|
||
|
|
||
|
acost = costs[sym_p][var_p][off_p][rat_p];
|
||
|
fprintf (dump_file, "index costs %d\n", acost);
|
||
|
}
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
}
|
||
|
|
||
|
bits = GET_MODE_BITSIZE (Pmode);
|
||
|
mask = ~(~(unsigned HOST_WIDE_INT) 0 << (bits - 1) << 1);
|
||
|
offset &= mask;
|
||
|
if ((offset >> (bits - 1) & 1))
|
||
|
offset |= ~mask;
|
||
|
s_offset = offset;
|
||
|
|
||
|
cost = 0;
|
||
|
offset_p = (s_offset != 0
|
||
|
&& min_offset <= s_offset && s_offset <= max_offset);
|
||
|
ratio_p = (ratio != 1
|
||
|
&& multiplier_allowed_in_address_p (ratio));
|
||
|
|
||
|
if (ratio != 1 && !ratio_p)
|
||
|
cost += multiply_by_cost (ratio, Pmode);
|
||
|
|
||
|
if (s_offset && !offset_p && !symbol_present)
|
||
|
{
|
||
|
cost += add_cost (Pmode);
|
||
|
var_present = true;
|
||
|
}
|
||
|
|
||
|
acost = costs[symbol_present][var_present][offset_p][ratio_p];
|
||
|
return cost + acost;
|
||
|
}
|
||
|
|
||
|
/* Estimates cost of forcing expression EXPR into a variable. */
|
||
|
|
||
|
unsigned
|
||
|
force_expr_to_var_cost (tree expr)
|
||
|
{
|
||
|
static bool costs_initialized = false;
|
||
|
static unsigned integer_cost;
|
||
|
static unsigned symbol_cost;
|
||
|
static unsigned address_cost;
|
||
|
tree op0, op1;
|
||
|
unsigned cost0, cost1, cost;
|
||
|
enum machine_mode mode;
|
||
|
|
||
|
if (!costs_initialized)
|
||
|
{
|
||
|
tree var = create_tmp_var_raw (integer_type_node, "test_var");
|
||
|
rtx x = gen_rtx_MEM (DECL_MODE (var),
|
||
|
gen_rtx_SYMBOL_REF (Pmode, "test_var"));
|
||
|
tree addr;
|
||
|
tree type = build_pointer_type (integer_type_node);
|
||
|
|
||
|
integer_cost = computation_cost (build_int_cst (integer_type_node,
|
||
|
2000));
|
||
|
|
||
|
SET_DECL_RTL (var, x);
|
||
|
TREE_STATIC (var) = 1;
|
||
|
addr = build1 (ADDR_EXPR, type, var);
|
||
|
symbol_cost = computation_cost (addr) + 1;
|
||
|
|
||
|
address_cost
|
||
|
= computation_cost (build2 (PLUS_EXPR, type,
|
||
|
addr,
|
||
|
build_int_cst (type, 2000))) + 1;
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "force_expr_to_var_cost:\n");
|
||
|
fprintf (dump_file, " integer %d\n", (int) integer_cost);
|
||
|
fprintf (dump_file, " symbol %d\n", (int) symbol_cost);
|
||
|
fprintf (dump_file, " address %d\n", (int) address_cost);
|
||
|
fprintf (dump_file, " other %d\n", (int) target_spill_cost);
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
|
||
|
costs_initialized = true;
|
||
|
}
|
||
|
|
||
|
STRIP_NOPS (expr);
|
||
|
|
||
|
if (SSA_VAR_P (expr))
|
||
|
return 0;
|
||
|
|
||
|
if (TREE_INVARIANT (expr))
|
||
|
{
|
||
|
if (TREE_CODE (expr) == INTEGER_CST)
|
||
|
return integer_cost;
|
||
|
|
||
|
if (TREE_CODE (expr) == ADDR_EXPR)
|
||
|
{
|
||
|
tree obj = TREE_OPERAND (expr, 0);
|
||
|
|
||
|
if (TREE_CODE (obj) == VAR_DECL
|
||
|
|| TREE_CODE (obj) == PARM_DECL
|
||
|
|| TREE_CODE (obj) == RESULT_DECL)
|
||
|
return symbol_cost;
|
||
|
}
|
||
|
|
||
|
return address_cost;
|
||
|
}
|
||
|
|
||
|
switch (TREE_CODE (expr))
|
||
|
{
|
||
|
case PLUS_EXPR:
|
||
|
case MINUS_EXPR:
|
||
|
case MULT_EXPR:
|
||
|
op0 = TREE_OPERAND (expr, 0);
|
||
|
op1 = TREE_OPERAND (expr, 1);
|
||
|
STRIP_NOPS (op0);
|
||
|
STRIP_NOPS (op1);
|
||
|
|
||
|
if (is_gimple_val (op0))
|
||
|
cost0 = 0;
|
||
|
else
|
||
|
cost0 = force_expr_to_var_cost (op0);
|
||
|
|
||
|
if (is_gimple_val (op1))
|
||
|
cost1 = 0;
|
||
|
else
|
||
|
cost1 = force_expr_to_var_cost (op1);
|
||
|
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
/* Just an arbitrary value, FIXME. */
|
||
|
return target_spill_cost;
|
||
|
}
|
||
|
|
||
|
mode = TYPE_MODE (TREE_TYPE (expr));
|
||
|
switch (TREE_CODE (expr))
|
||
|
{
|
||
|
case PLUS_EXPR:
|
||
|
case MINUS_EXPR:
|
||
|
cost = add_cost (mode);
|
||
|
break;
|
||
|
|
||
|
case MULT_EXPR:
|
||
|
if (cst_and_fits_in_hwi (op0))
|
||
|
cost = multiply_by_cost (int_cst_value (op0), mode);
|
||
|
else if (cst_and_fits_in_hwi (op1))
|
||
|
cost = multiply_by_cost (int_cst_value (op1), mode);
|
||
|
else
|
||
|
return target_spill_cost;
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
gcc_unreachable ();
|
||
|
}
|
||
|
|
||
|
cost += cost0;
|
||
|
cost += cost1;
|
||
|
|
||
|
/* Bound the cost by target_spill_cost. The parts of complicated
|
||
|
computations often are either loop invariant or at least can
|
||
|
be shared between several iv uses, so letting this grow without
|
||
|
limits would not give reasonable results. */
|
||
|
return cost < target_spill_cost ? cost : target_spill_cost;
|
||
|
}
|
||
|
|
||
|
/* Estimates cost of forcing EXPR into a variable. DEPENDS_ON is a set of the
|
||
|
invariants the computation depends on. */
|
||
|
|
||
|
static unsigned
|
||
|
force_var_cost (struct ivopts_data *data,
|
||
|
tree expr, bitmap *depends_on)
|
||
|
{
|
||
|
if (depends_on)
|
||
|
{
|
||
|
fd_ivopts_data = data;
|
||
|
walk_tree (&expr, find_depends, depends_on, NULL);
|
||
|
}
|
||
|
|
||
|
return force_expr_to_var_cost (expr);
|
||
|
}
|
||
|
|
||
|
/* Estimates cost of expressing address ADDR as var + symbol + offset. The
|
||
|
value of offset is added to OFFSET, SYMBOL_PRESENT and VAR_PRESENT are set
|
||
|
to false if the corresponding part is missing. DEPENDS_ON is a set of the
|
||
|
invariants the computation depends on. */
|
||
|
|
||
|
static unsigned
|
||
|
split_address_cost (struct ivopts_data *data,
|
||
|
tree addr, bool *symbol_present, bool *var_present,
|
||
|
unsigned HOST_WIDE_INT *offset, bitmap *depends_on)
|
||
|
{
|
||
|
tree core;
|
||
|
HOST_WIDE_INT bitsize;
|
||
|
HOST_WIDE_INT bitpos;
|
||
|
tree toffset;
|
||
|
enum machine_mode mode;
|
||
|
int unsignedp, volatilep;
|
||
|
|
||
|
core = get_inner_reference (addr, &bitsize, &bitpos, &toffset, &mode,
|
||
|
&unsignedp, &volatilep, false);
|
||
|
|
||
|
if (toffset != 0
|
||
|
|| bitpos % BITS_PER_UNIT != 0
|
||
|
|| TREE_CODE (core) != VAR_DECL)
|
||
|
{
|
||
|
*symbol_present = false;
|
||
|
*var_present = true;
|
||
|
fd_ivopts_data = data;
|
||
|
walk_tree (&addr, find_depends, depends_on, NULL);
|
||
|
return target_spill_cost;
|
||
|
}
|
||
|
|
||
|
*offset += bitpos / BITS_PER_UNIT;
|
||
|
if (TREE_STATIC (core)
|
||
|
|| DECL_EXTERNAL (core))
|
||
|
{
|
||
|
*symbol_present = true;
|
||
|
*var_present = false;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
*symbol_present = false;
|
||
|
*var_present = true;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/* Estimates cost of expressing difference of addresses E1 - E2 as
|
||
|
var + symbol + offset. The value of offset is added to OFFSET,
|
||
|
SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding
|
||
|
part is missing. DEPENDS_ON is a set of the invariants the computation
|
||
|
depends on. */
|
||
|
|
||
|
static unsigned
|
||
|
ptr_difference_cost (struct ivopts_data *data,
|
||
|
tree e1, tree e2, bool *symbol_present, bool *var_present,
|
||
|
unsigned HOST_WIDE_INT *offset, bitmap *depends_on)
|
||
|
{
|
||
|
HOST_WIDE_INT diff = 0;
|
||
|
unsigned cost;
|
||
|
|
||
|
gcc_assert (TREE_CODE (e1) == ADDR_EXPR);
|
||
|
|
||
|
if (ptr_difference_const (e1, e2, &diff))
|
||
|
{
|
||
|
*offset += diff;
|
||
|
*symbol_present = false;
|
||
|
*var_present = false;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
if (e2 == integer_zero_node)
|
||
|
return split_address_cost (data, TREE_OPERAND (e1, 0),
|
||
|
symbol_present, var_present, offset, depends_on);
|
||
|
|
||
|
*symbol_present = false;
|
||
|
*var_present = true;
|
||
|
|
||
|
cost = force_var_cost (data, e1, depends_on);
|
||
|
cost += force_var_cost (data, e2, depends_on);
|
||
|
cost += add_cost (Pmode);
|
||
|
|
||
|
return cost;
|
||
|
}
|
||
|
|
||
|
/* Estimates cost of expressing difference E1 - E2 as
|
||
|
var + symbol + offset. The value of offset is added to OFFSET,
|
||
|
SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding
|
||
|
part is missing. DEPENDS_ON is a set of the invariants the computation
|
||
|
depends on. */
|
||
|
|
||
|
static unsigned
|
||
|
difference_cost (struct ivopts_data *data,
|
||
|
tree e1, tree e2, bool *symbol_present, bool *var_present,
|
||
|
unsigned HOST_WIDE_INT *offset, bitmap *depends_on)
|
||
|
{
|
||
|
unsigned cost;
|
||
|
enum machine_mode mode = TYPE_MODE (TREE_TYPE (e1));
|
||
|
unsigned HOST_WIDE_INT off1, off2;
|
||
|
|
||
|
e1 = strip_offset (e1, &off1);
|
||
|
e2 = strip_offset (e2, &off2);
|
||
|
*offset += off1 - off2;
|
||
|
|
||
|
STRIP_NOPS (e1);
|
||
|
STRIP_NOPS (e2);
|
||
|
|
||
|
if (TREE_CODE (e1) == ADDR_EXPR)
|
||
|
return ptr_difference_cost (data, e1, e2, symbol_present, var_present, offset,
|
||
|
depends_on);
|
||
|
*symbol_present = false;
|
||
|
|
||
|
if (operand_equal_p (e1, e2, 0))
|
||
|
{
|
||
|
*var_present = false;
|
||
|
return 0;
|
||
|
}
|
||
|
*var_present = true;
|
||
|
if (zero_p (e2))
|
||
|
return force_var_cost (data, e1, depends_on);
|
||
|
|
||
|
if (zero_p (e1))
|
||
|
{
|
||
|
cost = force_var_cost (data, e2, depends_on);
|
||
|
cost += multiply_by_cost (-1, mode);
|
||
|
|
||
|
return cost;
|
||
|
}
|
||
|
|
||
|
cost = force_var_cost (data, e1, depends_on);
|
||
|
cost += force_var_cost (data, e2, depends_on);
|
||
|
cost += add_cost (mode);
|
||
|
|
||
|
return cost;
|
||
|
}
|
||
|
|
||
|
/* Determines the cost of the computation by that USE is expressed
|
||
|
from induction variable CAND. If ADDRESS_P is true, we just need
|
||
|
to create an address from it, otherwise we want to get it into
|
||
|
register. A set of invariants we depend on is stored in
|
||
|
DEPENDS_ON. AT is the statement at that the value is computed. */
|
||
|
|
||
|
static unsigned
|
||
|
get_computation_cost_at (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand,
|
||
|
bool address_p, bitmap *depends_on, tree at)
|
||
|
{
|
||
|
tree ubase = use->iv->base, ustep = use->iv->step;
|
||
|
tree cbase, cstep;
|
||
|
tree utype = TREE_TYPE (ubase), ctype;
|
||
|
unsigned HOST_WIDE_INT ustepi, cstepi, offset = 0;
|
||
|
HOST_WIDE_INT ratio, aratio;
|
||
|
bool var_present, symbol_present;
|
||
|
unsigned cost = 0, n_sums;
|
||
|
|
||
|
*depends_on = NULL;
|
||
|
|
||
|
/* Only consider real candidates. */
|
||
|
if (!cand->iv)
|
||
|
return INFTY;
|
||
|
|
||
|
cbase = cand->iv->base;
|
||
|
cstep = cand->iv->step;
|
||
|
ctype = TREE_TYPE (cbase);
|
||
|
|
||
|
if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype))
|
||
|
{
|
||
|
/* We do not have a precision to express the values of use. */
|
||
|
return INFTY;
|
||
|
}
|
||
|
|
||
|
if (address_p)
|
||
|
{
|
||
|
/* Do not try to express address of an object with computation based
|
||
|
on address of a different object. This may cause problems in rtl
|
||
|
level alias analysis (that does not expect this to be happening,
|
||
|
as this is illegal in C), and would be unlikely to be useful
|
||
|
anyway. */
|
||
|
if (use->iv->base_object
|
||
|
&& cand->iv->base_object
|
||
|
&& !operand_equal_p (use->iv->base_object, cand->iv->base_object, 0))
|
||
|
return INFTY;
|
||
|
}
|
||
|
|
||
|
if (TYPE_PRECISION (utype) != TYPE_PRECISION (ctype))
|
||
|
{
|
||
|
/* TODO -- add direct handling of this case. */
|
||
|
goto fallback;
|
||
|
}
|
||
|
|
||
|
/* CSTEPI is removed from the offset in case statement is after the
|
||
|
increment. If the step is not constant, we use zero instead.
|
||
|
This is a bit imprecise (there is the extra addition), but
|
||
|
redundancy elimination is likely to transform the code so that
|
||
|
it uses value of the variable before increment anyway,
|
||
|
so it is not that much unrealistic. */
|
||
|
if (cst_and_fits_in_hwi (cstep))
|
||
|
cstepi = int_cst_value (cstep);
|
||
|
else
|
||
|
cstepi = 0;
|
||
|
|
||
|
if (cst_and_fits_in_hwi (ustep)
|
||
|
&& cst_and_fits_in_hwi (cstep))
|
||
|
{
|
||
|
ustepi = int_cst_value (ustep);
|
||
|
|
||
|
if (!divide (TYPE_PRECISION (utype), ustepi, cstepi, &ratio))
|
||
|
return INFTY;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
double_int rat;
|
||
|
|
||
|
if (!constant_multiple_of (ustep, cstep, &rat))
|
||
|
return INFTY;
|
||
|
|
||
|
if (double_int_fits_in_shwi_p (rat))
|
||
|
ratio = double_int_to_shwi (rat);
|
||
|
else
|
||
|
return INFTY;
|
||
|
}
|
||
|
|
||
|
/* use = ubase + ratio * (var - cbase). If either cbase is a constant
|
||
|
or ratio == 1, it is better to handle this like
|
||
|
|
||
|
ubase - ratio * cbase + ratio * var
|
||
|
|
||
|
(also holds in the case ratio == -1, TODO. */
|
||
|
|
||
|
if (cst_and_fits_in_hwi (cbase))
|
||
|
{
|
||
|
offset = - ratio * int_cst_value (cbase);
|
||
|
cost += difference_cost (data,
|
||
|
ubase, integer_zero_node,
|
||
|
&symbol_present, &var_present, &offset,
|
||
|
depends_on);
|
||
|
}
|
||
|
else if (ratio == 1)
|
||
|
{
|
||
|
cost += difference_cost (data,
|
||
|
ubase, cbase,
|
||
|
&symbol_present, &var_present, &offset,
|
||
|
depends_on);
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
cost += force_var_cost (data, cbase, depends_on);
|
||
|
cost += add_cost (TYPE_MODE (ctype));
|
||
|
cost += difference_cost (data,
|
||
|
ubase, integer_zero_node,
|
||
|
&symbol_present, &var_present, &offset,
|
||
|
depends_on);
|
||
|
}
|
||
|
|
||
|
/* If we are after the increment, the value of the candidate is higher by
|
||
|
one iteration. */
|
||
|
if (stmt_after_increment (data->current_loop, cand, at))
|
||
|
offset -= ratio * cstepi;
|
||
|
|
||
|
/* Now the computation is in shape symbol + var1 + const + ratio * var2.
|
||
|
(symbol/var/const parts may be omitted). If we are looking for an address,
|
||
|
find the cost of addressing this. */
|
||
|
if (address_p)
|
||
|
return cost + get_address_cost (symbol_present, var_present, offset, ratio);
|
||
|
|
||
|
/* Otherwise estimate the costs for computing the expression. */
|
||
|
aratio = ratio > 0 ? ratio : -ratio;
|
||
|
if (!symbol_present && !var_present && !offset)
|
||
|
{
|
||
|
if (ratio != 1)
|
||
|
cost += multiply_by_cost (ratio, TYPE_MODE (ctype));
|
||
|
|
||
|
return cost;
|
||
|
}
|
||
|
|
||
|
if (aratio != 1)
|
||
|
cost += multiply_by_cost (aratio, TYPE_MODE (ctype));
|
||
|
|
||
|
n_sums = 1;
|
||
|
if (var_present
|
||
|
/* Symbol + offset should be compile-time computable. */
|
||
|
&& (symbol_present || offset))
|
||
|
n_sums++;
|
||
|
|
||
|
return cost + n_sums * add_cost (TYPE_MODE (ctype));
|
||
|
|
||
|
fallback:
|
||
|
{
|
||
|
/* Just get the expression, expand it and measure the cost. */
|
||
|
tree comp = get_computation_at (data->current_loop, use, cand, at);
|
||
|
|
||
|
if (!comp)
|
||
|
return INFTY;
|
||
|
|
||
|
if (address_p)
|
||
|
comp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (comp)), comp);
|
||
|
|
||
|
return computation_cost (comp);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Determines the cost of the computation by that USE is expressed
|
||
|
from induction variable CAND. If ADDRESS_P is true, we just need
|
||
|
to create an address from it, otherwise we want to get it into
|
||
|
register. A set of invariants we depend on is stored in
|
||
|
DEPENDS_ON. */
|
||
|
|
||
|
static unsigned
|
||
|
get_computation_cost (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand,
|
||
|
bool address_p, bitmap *depends_on)
|
||
|
{
|
||
|
return get_computation_cost_at (data,
|
||
|
use, cand, address_p, depends_on, use->stmt);
|
||
|
}
|
||
|
|
||
|
/* Determines cost of basing replacement of USE on CAND in a generic
|
||
|
expression. */
|
||
|
|
||
|
static bool
|
||
|
determine_use_iv_cost_generic (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand)
|
||
|
{
|
||
|
bitmap depends_on;
|
||
|
unsigned cost;
|
||
|
|
||
|
/* The simple case first -- if we need to express value of the preserved
|
||
|
original biv, the cost is 0. This also prevents us from counting the
|
||
|
cost of increment twice -- once at this use and once in the cost of
|
||
|
the candidate. */
|
||
|
if (cand->pos == IP_ORIGINAL
|
||
|
&& cand->incremented_at == use->stmt)
|
||
|
{
|
||
|
set_use_iv_cost (data, use, cand, 0, NULL, NULL_TREE);
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
cost = get_computation_cost (data, use, cand, false, &depends_on);
|
||
|
set_use_iv_cost (data, use, cand, cost, depends_on, NULL_TREE);
|
||
|
|
||
|
return cost != INFTY;
|
||
|
}
|
||
|
|
||
|
/* Determines cost of basing replacement of USE on CAND in an address. */
|
||
|
|
||
|
static bool
|
||
|
determine_use_iv_cost_address (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand)
|
||
|
{
|
||
|
bitmap depends_on;
|
||
|
unsigned cost = get_computation_cost (data, use, cand, true, &depends_on);
|
||
|
|
||
|
set_use_iv_cost (data, use, cand, cost, depends_on, NULL_TREE);
|
||
|
|
||
|
return cost != INFTY;
|
||
|
}
|
||
|
|
||
|
/* Computes value of induction variable IV in iteration NITER. */
|
||
|
|
||
|
static tree
|
||
|
iv_value (struct iv *iv, tree niter)
|
||
|
{
|
||
|
tree val;
|
||
|
tree type = TREE_TYPE (iv->base);
|
||
|
|
||
|
niter = fold_convert (type, niter);
|
||
|
val = fold_build2 (MULT_EXPR, type, iv->step, niter);
|
||
|
|
||
|
return fold_build2 (PLUS_EXPR, type, iv->base, val);
|
||
|
}
|
||
|
|
||
|
/* Computes value of candidate CAND at position AT in iteration NITER. */
|
||
|
|
||
|
static tree
|
||
|
cand_value_at (struct loop *loop, struct iv_cand *cand, tree at, tree niter)
|
||
|
{
|
||
|
tree val = iv_value (cand->iv, niter);
|
||
|
tree type = TREE_TYPE (cand->iv->base);
|
||
|
|
||
|
if (stmt_after_increment (loop, cand, at))
|
||
|
val = fold_build2 (PLUS_EXPR, type, val, cand->iv->step);
|
||
|
|
||
|
return val;
|
||
|
}
|
||
|
|
||
|
/* Returns period of induction variable iv. */
|
||
|
|
||
|
static tree
|
||
|
iv_period (struct iv *iv)
|
||
|
{
|
||
|
tree step = iv->step, period, type;
|
||
|
tree pow2div;
|
||
|
|
||
|
gcc_assert (step && TREE_CODE (step) == INTEGER_CST);
|
||
|
|
||
|
/* Period of the iv is gcd (step, type range). Since type range is power
|
||
|
of two, it suffices to determine the maximum power of two that divides
|
||
|
step. */
|
||
|
pow2div = num_ending_zeros (step);
|
||
|
type = unsigned_type_for (TREE_TYPE (step));
|
||
|
|
||
|
period = build_low_bits_mask (type,
|
||
|
(TYPE_PRECISION (type)
|
||
|
- tree_low_cst (pow2div, 1)));
|
||
|
|
||
|
return period;
|
||
|
}
|
||
|
|
||
|
/* Returns the comparison operator used when eliminating the iv USE. */
|
||
|
|
||
|
static enum tree_code
|
||
|
iv_elimination_compare (struct ivopts_data *data, struct iv_use *use)
|
||
|
{
|
||
|
struct loop *loop = data->current_loop;
|
||
|
basic_block ex_bb;
|
||
|
edge exit;
|
||
|
|
||
|
ex_bb = bb_for_stmt (use->stmt);
|
||
|
exit = EDGE_SUCC (ex_bb, 0);
|
||
|
if (flow_bb_inside_loop_p (loop, exit->dest))
|
||
|
exit = EDGE_SUCC (ex_bb, 1);
|
||
|
|
||
|
return (exit->flags & EDGE_TRUE_VALUE ? EQ_EXPR : NE_EXPR);
|
||
|
}
|
||
|
|
||
|
/* Check whether it is possible to express the condition in USE by comparison
|
||
|
of candidate CAND. If so, store the value compared with to BOUND. */
|
||
|
|
||
|
static bool
|
||
|
may_eliminate_iv (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand, tree *bound)
|
||
|
{
|
||
|
basic_block ex_bb;
|
||
|
edge exit;
|
||
|
tree nit, nit_type;
|
||
|
tree wider_type, period, per_type;
|
||
|
struct loop *loop = data->current_loop;
|
||
|
|
||
|
if (TREE_CODE (cand->iv->step) != INTEGER_CST)
|
||
|
return false;
|
||
|
|
||
|
/* For now works only for exits that dominate the loop latch. TODO -- extend
|
||
|
for other conditions inside loop body. */
|
||
|
ex_bb = bb_for_stmt (use->stmt);
|
||
|
if (use->stmt != last_stmt (ex_bb)
|
||
|
|| TREE_CODE (use->stmt) != COND_EXPR)
|
||
|
return false;
|
||
|
if (!dominated_by_p (CDI_DOMINATORS, loop->latch, ex_bb))
|
||
|
return false;
|
||
|
|
||
|
exit = EDGE_SUCC (ex_bb, 0);
|
||
|
if (flow_bb_inside_loop_p (loop, exit->dest))
|
||
|
exit = EDGE_SUCC (ex_bb, 1);
|
||
|
if (flow_bb_inside_loop_p (loop, exit->dest))
|
||
|
return false;
|
||
|
|
||
|
nit = niter_for_exit (data, exit);
|
||
|
if (!nit)
|
||
|
return false;
|
||
|
|
||
|
nit_type = TREE_TYPE (nit);
|
||
|
|
||
|
/* Determine whether we may use the variable to test whether niter iterations
|
||
|
elapsed. This is the case iff the period of the induction variable is
|
||
|
greater than the number of iterations. */
|
||
|
period = iv_period (cand->iv);
|
||
|
if (!period)
|
||
|
return false;
|
||
|
per_type = TREE_TYPE (period);
|
||
|
|
||
|
wider_type = TREE_TYPE (period);
|
||
|
if (TYPE_PRECISION (nit_type) < TYPE_PRECISION (per_type))
|
||
|
wider_type = per_type;
|
||
|
else
|
||
|
wider_type = nit_type;
|
||
|
|
||
|
if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node,
|
||
|
fold_convert (wider_type, period),
|
||
|
fold_convert (wider_type, nit))))
|
||
|
return false;
|
||
|
|
||
|
*bound = fold_affine_expr (cand_value_at (loop, cand, use->stmt, nit));
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Determines cost of basing replacement of USE on CAND in a condition. */
|
||
|
|
||
|
static bool
|
||
|
determine_use_iv_cost_condition (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand)
|
||
|
{
|
||
|
tree bound = NULL_TREE, op, cond;
|
||
|
bitmap depends_on = NULL;
|
||
|
unsigned cost;
|
||
|
|
||
|
/* Only consider real candidates. */
|
||
|
if (!cand->iv)
|
||
|
{
|
||
|
set_use_iv_cost (data, use, cand, INFTY, NULL, NULL_TREE);
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
if (may_eliminate_iv (data, use, cand, &bound))
|
||
|
{
|
||
|
cost = force_var_cost (data, bound, &depends_on);
|
||
|
|
||
|
set_use_iv_cost (data, use, cand, cost, depends_on, bound);
|
||
|
return cost != INFTY;
|
||
|
}
|
||
|
|
||
|
/* The induction variable elimination failed; just express the original
|
||
|
giv. If it is compared with an invariant, note that we cannot get
|
||
|
rid of it. */
|
||
|
cost = get_computation_cost (data, use, cand, false, &depends_on);
|
||
|
|
||
|
cond = *use->op_p;
|
||
|
if (TREE_CODE (cond) != SSA_NAME)
|
||
|
{
|
||
|
op = TREE_OPERAND (cond, 0);
|
||
|
if (TREE_CODE (op) == SSA_NAME && !zero_p (get_iv (data, op)->step))
|
||
|
op = TREE_OPERAND (cond, 1);
|
||
|
if (TREE_CODE (op) == SSA_NAME)
|
||
|
{
|
||
|
op = get_iv (data, op)->base;
|
||
|
fd_ivopts_data = data;
|
||
|
walk_tree (&op, find_depends, &depends_on, NULL);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
set_use_iv_cost (data, use, cand, cost, depends_on, NULL);
|
||
|
return cost != INFTY;
|
||
|
}
|
||
|
|
||
|
/* Determines cost of basing replacement of USE on CAND. Returns false
|
||
|
if USE cannot be based on CAND. */
|
||
|
|
||
|
static bool
|
||
|
determine_use_iv_cost (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand)
|
||
|
{
|
||
|
switch (use->type)
|
||
|
{
|
||
|
case USE_NONLINEAR_EXPR:
|
||
|
return determine_use_iv_cost_generic (data, use, cand);
|
||
|
|
||
|
case USE_ADDRESS:
|
||
|
return determine_use_iv_cost_address (data, use, cand);
|
||
|
|
||
|
case USE_COMPARE:
|
||
|
return determine_use_iv_cost_condition (data, use, cand);
|
||
|
|
||
|
default:
|
||
|
gcc_unreachable ();
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Determines costs of basing the use of the iv on an iv candidate. */
|
||
|
|
||
|
static void
|
||
|
determine_use_iv_costs (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned i, j;
|
||
|
struct iv_use *use;
|
||
|
struct iv_cand *cand;
|
||
|
bitmap to_clear = BITMAP_ALLOC (NULL);
|
||
|
|
||
|
alloc_use_cost_map (data);
|
||
|
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
{
|
||
|
use = iv_use (data, i);
|
||
|
|
||
|
if (data->consider_all_candidates)
|
||
|
{
|
||
|
for (j = 0; j < n_iv_cands (data); j++)
|
||
|
{
|
||
|
cand = iv_cand (data, j);
|
||
|
determine_use_iv_cost (data, use, cand);
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
bitmap_iterator bi;
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi)
|
||
|
{
|
||
|
cand = iv_cand (data, j);
|
||
|
if (!determine_use_iv_cost (data, use, cand))
|
||
|
bitmap_set_bit (to_clear, j);
|
||
|
}
|
||
|
|
||
|
/* Remove the candidates for that the cost is infinite from
|
||
|
the list of related candidates. */
|
||
|
bitmap_and_compl_into (use->related_cands, to_clear);
|
||
|
bitmap_clear (to_clear);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
BITMAP_FREE (to_clear);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "Use-candidate costs:\n");
|
||
|
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
{
|
||
|
use = iv_use (data, i);
|
||
|
|
||
|
fprintf (dump_file, "Use %d:\n", i);
|
||
|
fprintf (dump_file, " cand\tcost\tdepends on\n");
|
||
|
for (j = 0; j < use->n_map_members; j++)
|
||
|
{
|
||
|
if (!use->cost_map[j].cand
|
||
|
|| use->cost_map[j].cost == INFTY)
|
||
|
continue;
|
||
|
|
||
|
fprintf (dump_file, " %d\t%d\t",
|
||
|
use->cost_map[j].cand->id,
|
||
|
use->cost_map[j].cost);
|
||
|
if (use->cost_map[j].depends_on)
|
||
|
bitmap_print (dump_file,
|
||
|
use->cost_map[j].depends_on, "","");
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Determines cost of the candidate CAND. */
|
||
|
|
||
|
static void
|
||
|
determine_iv_cost (struct ivopts_data *data, struct iv_cand *cand)
|
||
|
{
|
||
|
unsigned cost_base, cost_step;
|
||
|
tree base;
|
||
|
|
||
|
if (!cand->iv)
|
||
|
{
|
||
|
cand->cost = 0;
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/* There are two costs associated with the candidate -- its increment
|
||
|
and its initialization. The second is almost negligible for any loop
|
||
|
that rolls enough, so we take it just very little into account. */
|
||
|
|
||
|
base = cand->iv->base;
|
||
|
cost_base = force_var_cost (data, base, NULL);
|
||
|
cost_step = add_cost (TYPE_MODE (TREE_TYPE (base)));
|
||
|
|
||
|
cand->cost = cost_step + cost_base / AVG_LOOP_NITER (current_loop);
|
||
|
|
||
|
/* Prefer the original iv unless we may gain something by replacing it;
|
||
|
this is not really relevant for artificial ivs created by other
|
||
|
passes. */
|
||
|
if (cand->pos == IP_ORIGINAL
|
||
|
&& !DECL_ARTIFICIAL (SSA_NAME_VAR (cand->var_before)))
|
||
|
cand->cost--;
|
||
|
|
||
|
/* Prefer not to insert statements into latch unless there are some
|
||
|
already (so that we do not create unnecessary jumps). */
|
||
|
if (cand->pos == IP_END
|
||
|
&& empty_block_p (ip_end_pos (data->current_loop)))
|
||
|
cand->cost++;
|
||
|
}
|
||
|
|
||
|
/* Determines costs of computation of the candidates. */
|
||
|
|
||
|
static void
|
||
|
determine_iv_costs (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned i;
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "Candidate costs:\n");
|
||
|
fprintf (dump_file, " cand\tcost\n");
|
||
|
}
|
||
|
|
||
|
for (i = 0; i < n_iv_cands (data); i++)
|
||
|
{
|
||
|
struct iv_cand *cand = iv_cand (data, i);
|
||
|
|
||
|
determine_iv_cost (data, cand);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
fprintf (dump_file, " %d\t%d\n", i, cand->cost);
|
||
|
}
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
|
||
|
/* Calculates cost for having SIZE induction variables. */
|
||
|
|
||
|
static unsigned
|
||
|
ivopts_global_cost_for_size (struct ivopts_data *data, unsigned size)
|
||
|
{
|
||
|
return global_cost_for_size (size, data->regs_used, n_iv_uses (data));
|
||
|
}
|
||
|
|
||
|
/* For each size of the induction variable set determine the penalty. */
|
||
|
|
||
|
static void
|
||
|
determine_set_costs (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned j, n;
|
||
|
tree phi, op;
|
||
|
struct loop *loop = data->current_loop;
|
||
|
bitmap_iterator bi;
|
||
|
|
||
|
/* We use the following model (definitely improvable, especially the
|
||
|
cost function -- TODO):
|
||
|
|
||
|
We estimate the number of registers available (using MD data), name it A.
|
||
|
|
||
|
We estimate the number of registers used by the loop, name it U. This
|
||
|
number is obtained as the number of loop phi nodes (not counting virtual
|
||
|
registers and bivs) + the number of variables from outside of the loop.
|
||
|
|
||
|
We set a reserve R (free regs that are used for temporary computations,
|
||
|
etc.). For now the reserve is a constant 3.
|
||
|
|
||
|
Let I be the number of induction variables.
|
||
|
|
||
|
-- if U + I + R <= A, the cost is I * SMALL_COST (just not to encourage
|
||
|
make a lot of ivs without a reason).
|
||
|
-- if A - R < U + I <= A, the cost is I * PRES_COST
|
||
|
-- if U + I > A, the cost is I * PRES_COST and
|
||
|
number of uses * SPILL_COST * (U + I - A) / (U + I) is added. */
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "Global costs:\n");
|
||
|
fprintf (dump_file, " target_avail_regs %d\n", target_avail_regs);
|
||
|
fprintf (dump_file, " target_small_cost %d\n", target_small_cost);
|
||
|
fprintf (dump_file, " target_pres_cost %d\n", target_pres_cost);
|
||
|
fprintf (dump_file, " target_spill_cost %d\n", target_spill_cost);
|
||
|
}
|
||
|
|
||
|
n = 0;
|
||
|
for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi))
|
||
|
{
|
||
|
op = PHI_RESULT (phi);
|
||
|
|
||
|
if (!is_gimple_reg (op))
|
||
|
continue;
|
||
|
|
||
|
if (get_iv (data, op))
|
||
|
continue;
|
||
|
|
||
|
n++;
|
||
|
}
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi)
|
||
|
{
|
||
|
struct version_info *info = ver_info (data, j);
|
||
|
|
||
|
if (info->inv_id && info->has_nonlin_use)
|
||
|
n++;
|
||
|
}
|
||
|
|
||
|
data->regs_used = n;
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
fprintf (dump_file, " regs_used %d\n", n);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, " cost for size:\n");
|
||
|
fprintf (dump_file, " ivs\tcost\n");
|
||
|
for (j = 0; j <= 2 * target_avail_regs; j++)
|
||
|
fprintf (dump_file, " %d\t%d\n", j,
|
||
|
ivopts_global_cost_for_size (data, j));
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Returns true if A is a cheaper cost pair than B. */
|
||
|
|
||
|
static bool
|
||
|
cheaper_cost_pair (struct cost_pair *a, struct cost_pair *b)
|
||
|
{
|
||
|
if (!a)
|
||
|
return false;
|
||
|
|
||
|
if (!b)
|
||
|
return true;
|
||
|
|
||
|
if (a->cost < b->cost)
|
||
|
return true;
|
||
|
|
||
|
if (a->cost > b->cost)
|
||
|
return false;
|
||
|
|
||
|
/* In case the costs are the same, prefer the cheaper candidate. */
|
||
|
if (a->cand->cost < b->cand->cost)
|
||
|
return true;
|
||
|
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
/* Computes the cost field of IVS structure. */
|
||
|
|
||
|
static void
|
||
|
iv_ca_recount_cost (struct ivopts_data *data, struct iv_ca *ivs)
|
||
|
{
|
||
|
unsigned cost = 0;
|
||
|
|
||
|
cost += ivs->cand_use_cost;
|
||
|
cost += ivs->cand_cost;
|
||
|
cost += ivopts_global_cost_for_size (data, ivs->n_regs);
|
||
|
|
||
|
ivs->cost = cost;
|
||
|
}
|
||
|
|
||
|
/* Remove invariants in set INVS to set IVS. */
|
||
|
|
||
|
static void
|
||
|
iv_ca_set_remove_invariants (struct iv_ca *ivs, bitmap invs)
|
||
|
{
|
||
|
bitmap_iterator bi;
|
||
|
unsigned iid;
|
||
|
|
||
|
if (!invs)
|
||
|
return;
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (invs, 0, iid, bi)
|
||
|
{
|
||
|
ivs->n_invariant_uses[iid]--;
|
||
|
if (ivs->n_invariant_uses[iid] == 0)
|
||
|
ivs->n_regs--;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Set USE not to be expressed by any candidate in IVS. */
|
||
|
|
||
|
static void
|
||
|
iv_ca_set_no_cp (struct ivopts_data *data, struct iv_ca *ivs,
|
||
|
struct iv_use *use)
|
||
|
{
|
||
|
unsigned uid = use->id, cid;
|
||
|
struct cost_pair *cp;
|
||
|
|
||
|
cp = ivs->cand_for_use[uid];
|
||
|
if (!cp)
|
||
|
return;
|
||
|
cid = cp->cand->id;
|
||
|
|
||
|
ivs->bad_uses++;
|
||
|
ivs->cand_for_use[uid] = NULL;
|
||
|
ivs->n_cand_uses[cid]--;
|
||
|
|
||
|
if (ivs->n_cand_uses[cid] == 0)
|
||
|
{
|
||
|
bitmap_clear_bit (ivs->cands, cid);
|
||
|
/* Do not count the pseudocandidates. */
|
||
|
if (cp->cand->iv)
|
||
|
ivs->n_regs--;
|
||
|
ivs->n_cands--;
|
||
|
ivs->cand_cost -= cp->cand->cost;
|
||
|
|
||
|
iv_ca_set_remove_invariants (ivs, cp->cand->depends_on);
|
||
|
}
|
||
|
|
||
|
ivs->cand_use_cost -= cp->cost;
|
||
|
|
||
|
iv_ca_set_remove_invariants (ivs, cp->depends_on);
|
||
|
iv_ca_recount_cost (data, ivs);
|
||
|
}
|
||
|
|
||
|
/* Add invariants in set INVS to set IVS. */
|
||
|
|
||
|
static void
|
||
|
iv_ca_set_add_invariants (struct iv_ca *ivs, bitmap invs)
|
||
|
{
|
||
|
bitmap_iterator bi;
|
||
|
unsigned iid;
|
||
|
|
||
|
if (!invs)
|
||
|
return;
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (invs, 0, iid, bi)
|
||
|
{
|
||
|
ivs->n_invariant_uses[iid]++;
|
||
|
if (ivs->n_invariant_uses[iid] == 1)
|
||
|
ivs->n_regs++;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Set cost pair for USE in set IVS to CP. */
|
||
|
|
||
|
static void
|
||
|
iv_ca_set_cp (struct ivopts_data *data, struct iv_ca *ivs,
|
||
|
struct iv_use *use, struct cost_pair *cp)
|
||
|
{
|
||
|
unsigned uid = use->id, cid;
|
||
|
|
||
|
if (ivs->cand_for_use[uid] == cp)
|
||
|
return;
|
||
|
|
||
|
if (ivs->cand_for_use[uid])
|
||
|
iv_ca_set_no_cp (data, ivs, use);
|
||
|
|
||
|
if (cp)
|
||
|
{
|
||
|
cid = cp->cand->id;
|
||
|
|
||
|
ivs->bad_uses--;
|
||
|
ivs->cand_for_use[uid] = cp;
|
||
|
ivs->n_cand_uses[cid]++;
|
||
|
if (ivs->n_cand_uses[cid] == 1)
|
||
|
{
|
||
|
bitmap_set_bit (ivs->cands, cid);
|
||
|
/* Do not count the pseudocandidates. */
|
||
|
if (cp->cand->iv)
|
||
|
ivs->n_regs++;
|
||
|
ivs->n_cands++;
|
||
|
ivs->cand_cost += cp->cand->cost;
|
||
|
|
||
|
iv_ca_set_add_invariants (ivs, cp->cand->depends_on);
|
||
|
}
|
||
|
|
||
|
ivs->cand_use_cost += cp->cost;
|
||
|
iv_ca_set_add_invariants (ivs, cp->depends_on);
|
||
|
iv_ca_recount_cost (data, ivs);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Extend set IVS by expressing USE by some of the candidates in it
|
||
|
if possible. */
|
||
|
|
||
|
static void
|
||
|
iv_ca_add_use (struct ivopts_data *data, struct iv_ca *ivs,
|
||
|
struct iv_use *use)
|
||
|
{
|
||
|
struct cost_pair *best_cp = NULL, *cp;
|
||
|
bitmap_iterator bi;
|
||
|
unsigned i;
|
||
|
|
||
|
gcc_assert (ivs->upto >= use->id);
|
||
|
|
||
|
if (ivs->upto == use->id)
|
||
|
{
|
||
|
ivs->upto++;
|
||
|
ivs->bad_uses++;
|
||
|
}
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, i, bi)
|
||
|
{
|
||
|
cp = get_use_iv_cost (data, use, iv_cand (data, i));
|
||
|
|
||
|
if (cheaper_cost_pair (cp, best_cp))
|
||
|
best_cp = cp;
|
||
|
}
|
||
|
|
||
|
iv_ca_set_cp (data, ivs, use, best_cp);
|
||
|
}
|
||
|
|
||
|
/* Get cost for assignment IVS. */
|
||
|
|
||
|
static unsigned
|
||
|
iv_ca_cost (struct iv_ca *ivs)
|
||
|
{
|
||
|
return (ivs->bad_uses ? INFTY : ivs->cost);
|
||
|
}
|
||
|
|
||
|
/* Returns true if all dependences of CP are among invariants in IVS. */
|
||
|
|
||
|
static bool
|
||
|
iv_ca_has_deps (struct iv_ca *ivs, struct cost_pair *cp)
|
||
|
{
|
||
|
unsigned i;
|
||
|
bitmap_iterator bi;
|
||
|
|
||
|
if (!cp->depends_on)
|
||
|
return true;
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (cp->depends_on, 0, i, bi)
|
||
|
{
|
||
|
if (ivs->n_invariant_uses[i] == 0)
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Creates change of expressing USE by NEW_CP instead of OLD_CP and chains
|
||
|
it before NEXT_CHANGE. */
|
||
|
|
||
|
static struct iv_ca_delta *
|
||
|
iv_ca_delta_add (struct iv_use *use, struct cost_pair *old_cp,
|
||
|
struct cost_pair *new_cp, struct iv_ca_delta *next_change)
|
||
|
{
|
||
|
struct iv_ca_delta *change = XNEW (struct iv_ca_delta);
|
||
|
|
||
|
change->use = use;
|
||
|
change->old_cp = old_cp;
|
||
|
change->new_cp = new_cp;
|
||
|
change->next_change = next_change;
|
||
|
|
||
|
return change;
|
||
|
}
|
||
|
|
||
|
/* Joins two lists of changes L1 and L2. Destructive -- old lists
|
||
|
are rewritten. */
|
||
|
|
||
|
static struct iv_ca_delta *
|
||
|
iv_ca_delta_join (struct iv_ca_delta *l1, struct iv_ca_delta *l2)
|
||
|
{
|
||
|
struct iv_ca_delta *last;
|
||
|
|
||
|
if (!l2)
|
||
|
return l1;
|
||
|
|
||
|
if (!l1)
|
||
|
return l2;
|
||
|
|
||
|
for (last = l1; last->next_change; last = last->next_change)
|
||
|
continue;
|
||
|
last->next_change = l2;
|
||
|
|
||
|
return l1;
|
||
|
}
|
||
|
|
||
|
/* Returns candidate by that USE is expressed in IVS. */
|
||
|
|
||
|
static struct cost_pair *
|
||
|
iv_ca_cand_for_use (struct iv_ca *ivs, struct iv_use *use)
|
||
|
{
|
||
|
return ivs->cand_for_use[use->id];
|
||
|
}
|
||
|
|
||
|
/* Reverse the list of changes DELTA, forming the inverse to it. */
|
||
|
|
||
|
static struct iv_ca_delta *
|
||
|
iv_ca_delta_reverse (struct iv_ca_delta *delta)
|
||
|
{
|
||
|
struct iv_ca_delta *act, *next, *prev = NULL;
|
||
|
struct cost_pair *tmp;
|
||
|
|
||
|
for (act = delta; act; act = next)
|
||
|
{
|
||
|
next = act->next_change;
|
||
|
act->next_change = prev;
|
||
|
prev = act;
|
||
|
|
||
|
tmp = act->old_cp;
|
||
|
act->old_cp = act->new_cp;
|
||
|
act->new_cp = tmp;
|
||
|
}
|
||
|
|
||
|
return prev;
|
||
|
}
|
||
|
|
||
|
/* Commit changes in DELTA to IVS. If FORWARD is false, the changes are
|
||
|
reverted instead. */
|
||
|
|
||
|
static void
|
||
|
iv_ca_delta_commit (struct ivopts_data *data, struct iv_ca *ivs,
|
||
|
struct iv_ca_delta *delta, bool forward)
|
||
|
{
|
||
|
struct cost_pair *from, *to;
|
||
|
struct iv_ca_delta *act;
|
||
|
|
||
|
if (!forward)
|
||
|
delta = iv_ca_delta_reverse (delta);
|
||
|
|
||
|
for (act = delta; act; act = act->next_change)
|
||
|
{
|
||
|
from = act->old_cp;
|
||
|
to = act->new_cp;
|
||
|
gcc_assert (iv_ca_cand_for_use (ivs, act->use) == from);
|
||
|
iv_ca_set_cp (data, ivs, act->use, to);
|
||
|
}
|
||
|
|
||
|
if (!forward)
|
||
|
iv_ca_delta_reverse (delta);
|
||
|
}
|
||
|
|
||
|
/* Returns true if CAND is used in IVS. */
|
||
|
|
||
|
static bool
|
||
|
iv_ca_cand_used_p (struct iv_ca *ivs, struct iv_cand *cand)
|
||
|
{
|
||
|
return ivs->n_cand_uses[cand->id] > 0;
|
||
|
}
|
||
|
|
||
|
/* Returns number of induction variable candidates in the set IVS. */
|
||
|
|
||
|
static unsigned
|
||
|
iv_ca_n_cands (struct iv_ca *ivs)
|
||
|
{
|
||
|
return ivs->n_cands;
|
||
|
}
|
||
|
|
||
|
/* Free the list of changes DELTA. */
|
||
|
|
||
|
static void
|
||
|
iv_ca_delta_free (struct iv_ca_delta **delta)
|
||
|
{
|
||
|
struct iv_ca_delta *act, *next;
|
||
|
|
||
|
for (act = *delta; act; act = next)
|
||
|
{
|
||
|
next = act->next_change;
|
||
|
free (act);
|
||
|
}
|
||
|
|
||
|
*delta = NULL;
|
||
|
}
|
||
|
|
||
|
/* Allocates new iv candidates assignment. */
|
||
|
|
||
|
static struct iv_ca *
|
||
|
iv_ca_new (struct ivopts_data *data)
|
||
|
{
|
||
|
struct iv_ca *nw = XNEW (struct iv_ca);
|
||
|
|
||
|
nw->upto = 0;
|
||
|
nw->bad_uses = 0;
|
||
|
nw->cand_for_use = XCNEWVEC (struct cost_pair *, n_iv_uses (data));
|
||
|
nw->n_cand_uses = XCNEWVEC (unsigned, n_iv_cands (data));
|
||
|
nw->cands = BITMAP_ALLOC (NULL);
|
||
|
nw->n_cands = 0;
|
||
|
nw->n_regs = 0;
|
||
|
nw->cand_use_cost = 0;
|
||
|
nw->cand_cost = 0;
|
||
|
nw->n_invariant_uses = XCNEWVEC (unsigned, data->max_inv_id + 1);
|
||
|
nw->cost = 0;
|
||
|
|
||
|
return nw;
|
||
|
}
|
||
|
|
||
|
/* Free memory occupied by the set IVS. */
|
||
|
|
||
|
static void
|
||
|
iv_ca_free (struct iv_ca **ivs)
|
||
|
{
|
||
|
free ((*ivs)->cand_for_use);
|
||
|
free ((*ivs)->n_cand_uses);
|
||
|
BITMAP_FREE ((*ivs)->cands);
|
||
|
free ((*ivs)->n_invariant_uses);
|
||
|
free (*ivs);
|
||
|
*ivs = NULL;
|
||
|
}
|
||
|
|
||
|
/* Dumps IVS to FILE. */
|
||
|
|
||
|
static void
|
||
|
iv_ca_dump (struct ivopts_data *data, FILE *file, struct iv_ca *ivs)
|
||
|
{
|
||
|
const char *pref = " invariants ";
|
||
|
unsigned i;
|
||
|
|
||
|
fprintf (file, " cost %d\n", iv_ca_cost (ivs));
|
||
|
bitmap_print (file, ivs->cands, " candidates ","\n");
|
||
|
|
||
|
for (i = 1; i <= data->max_inv_id; i++)
|
||
|
if (ivs->n_invariant_uses[i])
|
||
|
{
|
||
|
fprintf (file, "%s%d", pref, i);
|
||
|
pref = ", ";
|
||
|
}
|
||
|
fprintf (file, "\n");
|
||
|
}
|
||
|
|
||
|
/* Try changing candidate in IVS to CAND for each use. Return cost of the
|
||
|
new set, and store differences in DELTA. Number of induction variables
|
||
|
in the new set is stored to N_IVS. */
|
||
|
|
||
|
static unsigned
|
||
|
iv_ca_extend (struct ivopts_data *data, struct iv_ca *ivs,
|
||
|
struct iv_cand *cand, struct iv_ca_delta **delta,
|
||
|
unsigned *n_ivs)
|
||
|
{
|
||
|
unsigned i, cost;
|
||
|
struct iv_use *use;
|
||
|
struct cost_pair *old_cp, *new_cp;
|
||
|
|
||
|
*delta = NULL;
|
||
|
for (i = 0; i < ivs->upto; i++)
|
||
|
{
|
||
|
use = iv_use (data, i);
|
||
|
old_cp = iv_ca_cand_for_use (ivs, use);
|
||
|
|
||
|
if (old_cp
|
||
|
&& old_cp->cand == cand)
|
||
|
continue;
|
||
|
|
||
|
new_cp = get_use_iv_cost (data, use, cand);
|
||
|
if (!new_cp)
|
||
|
continue;
|
||
|
|
||
|
if (!iv_ca_has_deps (ivs, new_cp))
|
||
|
continue;
|
||
|
|
||
|
if (!cheaper_cost_pair (new_cp, old_cp))
|
||
|
continue;
|
||
|
|
||
|
*delta = iv_ca_delta_add (use, old_cp, new_cp, *delta);
|
||
|
}
|
||
|
|
||
|
iv_ca_delta_commit (data, ivs, *delta, true);
|
||
|
cost = iv_ca_cost (ivs);
|
||
|
if (n_ivs)
|
||
|
*n_ivs = iv_ca_n_cands (ivs);
|
||
|
iv_ca_delta_commit (data, ivs, *delta, false);
|
||
|
|
||
|
return cost;
|
||
|
}
|
||
|
|
||
|
/* Try narrowing set IVS by removing CAND. Return the cost of
|
||
|
the new set and store the differences in DELTA. */
|
||
|
|
||
|
static unsigned
|
||
|
iv_ca_narrow (struct ivopts_data *data, struct iv_ca *ivs,
|
||
|
struct iv_cand *cand, struct iv_ca_delta **delta)
|
||
|
{
|
||
|
unsigned i, ci;
|
||
|
struct iv_use *use;
|
||
|
struct cost_pair *old_cp, *new_cp, *cp;
|
||
|
bitmap_iterator bi;
|
||
|
struct iv_cand *cnd;
|
||
|
unsigned cost;
|
||
|
|
||
|
*delta = NULL;
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
{
|
||
|
use = iv_use (data, i);
|
||
|
|
||
|
old_cp = iv_ca_cand_for_use (ivs, use);
|
||
|
if (old_cp->cand != cand)
|
||
|
continue;
|
||
|
|
||
|
new_cp = NULL;
|
||
|
|
||
|
if (data->consider_all_candidates)
|
||
|
{
|
||
|
EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, ci, bi)
|
||
|
{
|
||
|
if (ci == cand->id)
|
||
|
continue;
|
||
|
|
||
|
cnd = iv_cand (data, ci);
|
||
|
|
||
|
cp = get_use_iv_cost (data, use, cnd);
|
||
|
if (!cp)
|
||
|
continue;
|
||
|
if (!iv_ca_has_deps (ivs, cp))
|
||
|
continue;
|
||
|
|
||
|
if (!cheaper_cost_pair (cp, new_cp))
|
||
|
continue;
|
||
|
|
||
|
new_cp = cp;
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
EXECUTE_IF_AND_IN_BITMAP (use->related_cands, ivs->cands, 0, ci, bi)
|
||
|
{
|
||
|
if (ci == cand->id)
|
||
|
continue;
|
||
|
|
||
|
cnd = iv_cand (data, ci);
|
||
|
|
||
|
cp = get_use_iv_cost (data, use, cnd);
|
||
|
if (!cp)
|
||
|
continue;
|
||
|
if (!iv_ca_has_deps (ivs, cp))
|
||
|
continue;
|
||
|
|
||
|
if (!cheaper_cost_pair (cp, new_cp))
|
||
|
continue;
|
||
|
|
||
|
new_cp = cp;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (!new_cp)
|
||
|
{
|
||
|
iv_ca_delta_free (delta);
|
||
|
return INFTY;
|
||
|
}
|
||
|
|
||
|
*delta = iv_ca_delta_add (use, old_cp, new_cp, *delta);
|
||
|
}
|
||
|
|
||
|
iv_ca_delta_commit (data, ivs, *delta, true);
|
||
|
cost = iv_ca_cost (ivs);
|
||
|
iv_ca_delta_commit (data, ivs, *delta, false);
|
||
|
|
||
|
return cost;
|
||
|
}
|
||
|
|
||
|
/* Try optimizing the set of candidates IVS by removing candidates different
|
||
|
from to EXCEPT_CAND from it. Return cost of the new set, and store
|
||
|
differences in DELTA. */
|
||
|
|
||
|
static unsigned
|
||
|
iv_ca_prune (struct ivopts_data *data, struct iv_ca *ivs,
|
||
|
struct iv_cand *except_cand, struct iv_ca_delta **delta)
|
||
|
{
|
||
|
bitmap_iterator bi;
|
||
|
struct iv_ca_delta *act_delta, *best_delta;
|
||
|
unsigned i, best_cost, acost;
|
||
|
struct iv_cand *cand;
|
||
|
|
||
|
best_delta = NULL;
|
||
|
best_cost = iv_ca_cost (ivs);
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, i, bi)
|
||
|
{
|
||
|
cand = iv_cand (data, i);
|
||
|
|
||
|
if (cand == except_cand)
|
||
|
continue;
|
||
|
|
||
|
acost = iv_ca_narrow (data, ivs, cand, &act_delta);
|
||
|
|
||
|
if (acost < best_cost)
|
||
|
{
|
||
|
best_cost = acost;
|
||
|
iv_ca_delta_free (&best_delta);
|
||
|
best_delta = act_delta;
|
||
|
}
|
||
|
else
|
||
|
iv_ca_delta_free (&act_delta);
|
||
|
}
|
||
|
|
||
|
if (!best_delta)
|
||
|
{
|
||
|
*delta = NULL;
|
||
|
return best_cost;
|
||
|
}
|
||
|
|
||
|
/* Recurse to possibly remove other unnecessary ivs. */
|
||
|
iv_ca_delta_commit (data, ivs, best_delta, true);
|
||
|
best_cost = iv_ca_prune (data, ivs, except_cand, delta);
|
||
|
iv_ca_delta_commit (data, ivs, best_delta, false);
|
||
|
*delta = iv_ca_delta_join (best_delta, *delta);
|
||
|
return best_cost;
|
||
|
}
|
||
|
|
||
|
/* Tries to extend the sets IVS in the best possible way in order
|
||
|
to express the USE. */
|
||
|
|
||
|
static bool
|
||
|
try_add_cand_for (struct ivopts_data *data, struct iv_ca *ivs,
|
||
|
struct iv_use *use)
|
||
|
{
|
||
|
unsigned best_cost, act_cost;
|
||
|
unsigned i;
|
||
|
bitmap_iterator bi;
|
||
|
struct iv_cand *cand;
|
||
|
struct iv_ca_delta *best_delta = NULL, *act_delta;
|
||
|
struct cost_pair *cp;
|
||
|
|
||
|
iv_ca_add_use (data, ivs, use);
|
||
|
best_cost = iv_ca_cost (ivs);
|
||
|
|
||
|
cp = iv_ca_cand_for_use (ivs, use);
|
||
|
if (cp)
|
||
|
{
|
||
|
best_delta = iv_ca_delta_add (use, NULL, cp, NULL);
|
||
|
iv_ca_set_no_cp (data, ivs, use);
|
||
|
}
|
||
|
|
||
|
/* First try important candidates. Only if it fails, try the specific ones.
|
||
|
Rationale -- in loops with many variables the best choice often is to use
|
||
|
just one generic biv. If we added here many ivs specific to the uses,
|
||
|
the optimization algorithm later would be likely to get stuck in a local
|
||
|
minimum, thus causing us to create too many ivs. The approach from
|
||
|
few ivs to more seems more likely to be successful -- starting from few
|
||
|
ivs, replacing an expensive use by a specific iv should always be a
|
||
|
win. */
|
||
|
EXECUTE_IF_SET_IN_BITMAP (data->important_candidates, 0, i, bi)
|
||
|
{
|
||
|
cand = iv_cand (data, i);
|
||
|
|
||
|
if (iv_ca_cand_used_p (ivs, cand))
|
||
|
continue;
|
||
|
|
||
|
cp = get_use_iv_cost (data, use, cand);
|
||
|
if (!cp)
|
||
|
continue;
|
||
|
|
||
|
iv_ca_set_cp (data, ivs, use, cp);
|
||
|
act_cost = iv_ca_extend (data, ivs, cand, &act_delta, NULL);
|
||
|
iv_ca_set_no_cp (data, ivs, use);
|
||
|
act_delta = iv_ca_delta_add (use, NULL, cp, act_delta);
|
||
|
|
||
|
if (act_cost < best_cost)
|
||
|
{
|
||
|
best_cost = act_cost;
|
||
|
|
||
|
iv_ca_delta_free (&best_delta);
|
||
|
best_delta = act_delta;
|
||
|
}
|
||
|
else
|
||
|
iv_ca_delta_free (&act_delta);
|
||
|
}
|
||
|
|
||
|
if (best_cost == INFTY)
|
||
|
{
|
||
|
for (i = 0; i < use->n_map_members; i++)
|
||
|
{
|
||
|
cp = use->cost_map + i;
|
||
|
cand = cp->cand;
|
||
|
if (!cand)
|
||
|
continue;
|
||
|
|
||
|
/* Already tried this. */
|
||
|
if (cand->important)
|
||
|
continue;
|
||
|
|
||
|
if (iv_ca_cand_used_p (ivs, cand))
|
||
|
continue;
|
||
|
|
||
|
act_delta = NULL;
|
||
|
iv_ca_set_cp (data, ivs, use, cp);
|
||
|
act_cost = iv_ca_extend (data, ivs, cand, &act_delta, NULL);
|
||
|
iv_ca_set_no_cp (data, ivs, use);
|
||
|
act_delta = iv_ca_delta_add (use, iv_ca_cand_for_use (ivs, use),
|
||
|
cp, act_delta);
|
||
|
|
||
|
if (act_cost < best_cost)
|
||
|
{
|
||
|
best_cost = act_cost;
|
||
|
|
||
|
if (best_delta)
|
||
|
iv_ca_delta_free (&best_delta);
|
||
|
best_delta = act_delta;
|
||
|
}
|
||
|
else
|
||
|
iv_ca_delta_free (&act_delta);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
iv_ca_delta_commit (data, ivs, best_delta, true);
|
||
|
iv_ca_delta_free (&best_delta);
|
||
|
|
||
|
return (best_cost != INFTY);
|
||
|
}
|
||
|
|
||
|
/* Finds an initial assignment of candidates to uses. */
|
||
|
|
||
|
static struct iv_ca *
|
||
|
get_initial_solution (struct ivopts_data *data)
|
||
|
{
|
||
|
struct iv_ca *ivs = iv_ca_new (data);
|
||
|
unsigned i;
|
||
|
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
if (!try_add_cand_for (data, ivs, iv_use (data, i)))
|
||
|
{
|
||
|
iv_ca_free (&ivs);
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
return ivs;
|
||
|
}
|
||
|
|
||
|
/* Tries to improve set of induction variables IVS. */
|
||
|
|
||
|
static bool
|
||
|
try_improve_iv_set (struct ivopts_data *data, struct iv_ca *ivs)
|
||
|
{
|
||
|
unsigned i, acost, best_cost = iv_ca_cost (ivs), n_ivs;
|
||
|
struct iv_ca_delta *best_delta = NULL, *act_delta, *tmp_delta;
|
||
|
struct iv_cand *cand;
|
||
|
|
||
|
/* Try extending the set of induction variables by one. */
|
||
|
for (i = 0; i < n_iv_cands (data); i++)
|
||
|
{
|
||
|
cand = iv_cand (data, i);
|
||
|
|
||
|
if (iv_ca_cand_used_p (ivs, cand))
|
||
|
continue;
|
||
|
|
||
|
acost = iv_ca_extend (data, ivs, cand, &act_delta, &n_ivs);
|
||
|
if (!act_delta)
|
||
|
continue;
|
||
|
|
||
|
/* If we successfully added the candidate and the set is small enough,
|
||
|
try optimizing it by removing other candidates. */
|
||
|
if (n_ivs <= ALWAYS_PRUNE_CAND_SET_BOUND)
|
||
|
{
|
||
|
iv_ca_delta_commit (data, ivs, act_delta, true);
|
||
|
acost = iv_ca_prune (data, ivs, cand, &tmp_delta);
|
||
|
iv_ca_delta_commit (data, ivs, act_delta, false);
|
||
|
act_delta = iv_ca_delta_join (act_delta, tmp_delta);
|
||
|
}
|
||
|
|
||
|
if (acost < best_cost)
|
||
|
{
|
||
|
best_cost = acost;
|
||
|
iv_ca_delta_free (&best_delta);
|
||
|
best_delta = act_delta;
|
||
|
}
|
||
|
else
|
||
|
iv_ca_delta_free (&act_delta);
|
||
|
}
|
||
|
|
||
|
if (!best_delta)
|
||
|
{
|
||
|
/* Try removing the candidates from the set instead. */
|
||
|
best_cost = iv_ca_prune (data, ivs, NULL, &best_delta);
|
||
|
|
||
|
/* Nothing more we can do. */
|
||
|
if (!best_delta)
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
iv_ca_delta_commit (data, ivs, best_delta, true);
|
||
|
gcc_assert (best_cost == iv_ca_cost (ivs));
|
||
|
iv_ca_delta_free (&best_delta);
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Attempts to find the optimal set of induction variables. We do simple
|
||
|
greedy heuristic -- we try to replace at most one candidate in the selected
|
||
|
solution and remove the unused ivs while this improves the cost. */
|
||
|
|
||
|
static struct iv_ca *
|
||
|
find_optimal_iv_set (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned i;
|
||
|
struct iv_ca *set;
|
||
|
struct iv_use *use;
|
||
|
|
||
|
/* Get the initial solution. */
|
||
|
set = get_initial_solution (data);
|
||
|
if (!set)
|
||
|
{
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
fprintf (dump_file, "Unable to substitute for ivs, failed.\n");
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "Initial set of candidates:\n");
|
||
|
iv_ca_dump (data, dump_file, set);
|
||
|
}
|
||
|
|
||
|
while (try_improve_iv_set (data, set))
|
||
|
{
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "Improved to:\n");
|
||
|
iv_ca_dump (data, dump_file, set);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
fprintf (dump_file, "Final cost %d\n\n", iv_ca_cost (set));
|
||
|
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
{
|
||
|
use = iv_use (data, i);
|
||
|
use->selected = iv_ca_cand_for_use (set, use)->cand;
|
||
|
}
|
||
|
|
||
|
return set;
|
||
|
}
|
||
|
|
||
|
/* Creates a new induction variable corresponding to CAND. */
|
||
|
|
||
|
static void
|
||
|
create_new_iv (struct ivopts_data *data, struct iv_cand *cand)
|
||
|
{
|
||
|
block_stmt_iterator incr_pos;
|
||
|
tree base;
|
||
|
bool after = false;
|
||
|
|
||
|
if (!cand->iv)
|
||
|
return;
|
||
|
|
||
|
switch (cand->pos)
|
||
|
{
|
||
|
case IP_NORMAL:
|
||
|
incr_pos = bsi_last (ip_normal_pos (data->current_loop));
|
||
|
break;
|
||
|
|
||
|
case IP_END:
|
||
|
incr_pos = bsi_last (ip_end_pos (data->current_loop));
|
||
|
after = true;
|
||
|
break;
|
||
|
|
||
|
case IP_ORIGINAL:
|
||
|
/* Mark that the iv is preserved. */
|
||
|
name_info (data, cand->var_before)->preserve_biv = true;
|
||
|
name_info (data, cand->var_after)->preserve_biv = true;
|
||
|
|
||
|
/* Rewrite the increment so that it uses var_before directly. */
|
||
|
find_interesting_uses_op (data, cand->var_after)->selected = cand;
|
||
|
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
gimple_add_tmp_var (cand->var_before);
|
||
|
add_referenced_var (cand->var_before);
|
||
|
|
||
|
base = unshare_expr (cand->iv->base);
|
||
|
|
||
|
create_iv (base, unshare_expr (cand->iv->step),
|
||
|
cand->var_before, data->current_loop,
|
||
|
&incr_pos, after, &cand->var_before, &cand->var_after);
|
||
|
}
|
||
|
|
||
|
/* Creates new induction variables described in SET. */
|
||
|
|
||
|
static void
|
||
|
create_new_ivs (struct ivopts_data *data, struct iv_ca *set)
|
||
|
{
|
||
|
unsigned i;
|
||
|
struct iv_cand *cand;
|
||
|
bitmap_iterator bi;
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (set->cands, 0, i, bi)
|
||
|
{
|
||
|
cand = iv_cand (data, i);
|
||
|
create_new_iv (data, cand);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Removes statement STMT (real or a phi node). If INCLUDING_DEFINED_NAME
|
||
|
is true, remove also the ssa name defined by the statement. */
|
||
|
|
||
|
static void
|
||
|
remove_statement (tree stmt, bool including_defined_name)
|
||
|
{
|
||
|
if (TREE_CODE (stmt) == PHI_NODE)
|
||
|
{
|
||
|
if (!including_defined_name)
|
||
|
{
|
||
|
/* Prevent the ssa name defined by the statement from being removed. */
|
||
|
SET_PHI_RESULT (stmt, NULL);
|
||
|
}
|
||
|
remove_phi_node (stmt, NULL_TREE);
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
block_stmt_iterator bsi = bsi_for_stmt (stmt);
|
||
|
|
||
|
bsi_remove (&bsi, true);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Rewrites USE (definition of iv used in a nonlinear expression)
|
||
|
using candidate CAND. */
|
||
|
|
||
|
static void
|
||
|
rewrite_use_nonlinear_expr (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand)
|
||
|
{
|
||
|
tree comp;
|
||
|
tree op, stmts, tgt, ass;
|
||
|
block_stmt_iterator bsi, pbsi;
|
||
|
|
||
|
/* An important special case -- if we are asked to express value of
|
||
|
the original iv by itself, just exit; there is no need to
|
||
|
introduce a new computation (that might also need casting the
|
||
|
variable to unsigned and back). */
|
||
|
if (cand->pos == IP_ORIGINAL
|
||
|
&& cand->incremented_at == use->stmt)
|
||
|
{
|
||
|
tree step, ctype, utype;
|
||
|
enum tree_code incr_code = PLUS_EXPR;
|
||
|
|
||
|
gcc_assert (TREE_CODE (use->stmt) == MODIFY_EXPR);
|
||
|
gcc_assert (TREE_OPERAND (use->stmt, 0) == cand->var_after);
|
||
|
|
||
|
step = cand->iv->step;
|
||
|
ctype = TREE_TYPE (step);
|
||
|
utype = TREE_TYPE (cand->var_after);
|
||
|
if (TREE_CODE (step) == NEGATE_EXPR)
|
||
|
{
|
||
|
incr_code = MINUS_EXPR;
|
||
|
step = TREE_OPERAND (step, 0);
|
||
|
}
|
||
|
|
||
|
/* Check whether we may leave the computation unchanged.
|
||
|
This is the case only if it does not rely on other
|
||
|
computations in the loop -- otherwise, the computation
|
||
|
we rely upon may be removed in remove_unused_ivs,
|
||
|
thus leading to ICE. */
|
||
|
op = TREE_OPERAND (use->stmt, 1);
|
||
|
if (TREE_CODE (op) == PLUS_EXPR
|
||
|
|| TREE_CODE (op) == MINUS_EXPR)
|
||
|
{
|
||
|
if (TREE_OPERAND (op, 0) == cand->var_before)
|
||
|
op = TREE_OPERAND (op, 1);
|
||
|
else if (TREE_CODE (op) == PLUS_EXPR
|
||
|
&& TREE_OPERAND (op, 1) == cand->var_before)
|
||
|
op = TREE_OPERAND (op, 0);
|
||
|
else
|
||
|
op = NULL_TREE;
|
||
|
}
|
||
|
else
|
||
|
op = NULL_TREE;
|
||
|
|
||
|
if (op
|
||
|
&& (TREE_CODE (op) == INTEGER_CST
|
||
|
|| operand_equal_p (op, step, 0)))
|
||
|
return;
|
||
|
|
||
|
/* Otherwise, add the necessary computations to express
|
||
|
the iv. */
|
||
|
op = fold_convert (ctype, cand->var_before);
|
||
|
comp = fold_convert (utype,
|
||
|
build2 (incr_code, ctype, op,
|
||
|
unshare_expr (step)));
|
||
|
}
|
||
|
else
|
||
|
comp = get_computation (data->current_loop, use, cand);
|
||
|
|
||
|
switch (TREE_CODE (use->stmt))
|
||
|
{
|
||
|
case PHI_NODE:
|
||
|
tgt = PHI_RESULT (use->stmt);
|
||
|
|
||
|
/* If we should keep the biv, do not replace it. */
|
||
|
if (name_info (data, tgt)->preserve_biv)
|
||
|
return;
|
||
|
|
||
|
pbsi = bsi = bsi_start (bb_for_stmt (use->stmt));
|
||
|
while (!bsi_end_p (pbsi)
|
||
|
&& TREE_CODE (bsi_stmt (pbsi)) == LABEL_EXPR)
|
||
|
{
|
||
|
bsi = pbsi;
|
||
|
bsi_next (&pbsi);
|
||
|
}
|
||
|
break;
|
||
|
|
||
|
case MODIFY_EXPR:
|
||
|
tgt = TREE_OPERAND (use->stmt, 0);
|
||
|
bsi = bsi_for_stmt (use->stmt);
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
gcc_unreachable ();
|
||
|
}
|
||
|
|
||
|
op = force_gimple_operand (comp, &stmts, false, SSA_NAME_VAR (tgt));
|
||
|
|
||
|
if (TREE_CODE (use->stmt) == PHI_NODE)
|
||
|
{
|
||
|
if (stmts)
|
||
|
bsi_insert_after (&bsi, stmts, BSI_CONTINUE_LINKING);
|
||
|
ass = build2 (MODIFY_EXPR, TREE_TYPE (tgt), tgt, op);
|
||
|
bsi_insert_after (&bsi, ass, BSI_NEW_STMT);
|
||
|
remove_statement (use->stmt, false);
|
||
|
SSA_NAME_DEF_STMT (tgt) = ass;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
if (stmts)
|
||
|
bsi_insert_before (&bsi, stmts, BSI_SAME_STMT);
|
||
|
TREE_OPERAND (use->stmt, 1) = op;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Replaces ssa name in index IDX by its basic variable. Callback for
|
||
|
for_each_index. */
|
||
|
|
||
|
static bool
|
||
|
idx_remove_ssa_names (tree base, tree *idx,
|
||
|
void *data ATTRIBUTE_UNUSED)
|
||
|
{
|
||
|
tree *op;
|
||
|
|
||
|
if (TREE_CODE (*idx) == SSA_NAME)
|
||
|
*idx = SSA_NAME_VAR (*idx);
|
||
|
|
||
|
if (TREE_CODE (base) == ARRAY_REF)
|
||
|
{
|
||
|
op = &TREE_OPERAND (base, 2);
|
||
|
if (*op
|
||
|
&& TREE_CODE (*op) == SSA_NAME)
|
||
|
*op = SSA_NAME_VAR (*op);
|
||
|
op = &TREE_OPERAND (base, 3);
|
||
|
if (*op
|
||
|
&& TREE_CODE (*op) == SSA_NAME)
|
||
|
*op = SSA_NAME_VAR (*op);
|
||
|
}
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
/* Unshares REF and replaces ssa names inside it by their basic variables. */
|
||
|
|
||
|
static tree
|
||
|
unshare_and_remove_ssa_names (tree ref)
|
||
|
{
|
||
|
ref = unshare_expr (ref);
|
||
|
for_each_index (&ref, idx_remove_ssa_names, NULL);
|
||
|
|
||
|
return ref;
|
||
|
}
|
||
|
|
||
|
/* Extract the alias analysis info for the memory reference REF. There are
|
||
|
several ways how this information may be stored and what precisely is
|
||
|
its semantics depending on the type of the reference, but there always is
|
||
|
somewhere hidden one _DECL node that is used to determine the set of
|
||
|
virtual operands for the reference. The code below deciphers this jungle
|
||
|
and extracts this single useful piece of information. */
|
||
|
|
||
|
static tree
|
||
|
get_ref_tag (tree ref, tree orig)
|
||
|
{
|
||
|
tree var = get_base_address (ref);
|
||
|
tree aref = NULL_TREE, tag, sv;
|
||
|
HOST_WIDE_INT offset, size, maxsize;
|
||
|
|
||
|
for (sv = orig; handled_component_p (sv); sv = TREE_OPERAND (sv, 0))
|
||
|
{
|
||
|
aref = get_ref_base_and_extent (sv, &offset, &size, &maxsize);
|
||
|
if (ref)
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
if (aref && SSA_VAR_P (aref) && get_subvars_for_var (aref))
|
||
|
return unshare_expr (sv);
|
||
|
|
||
|
if (!var)
|
||
|
return NULL_TREE;
|
||
|
|
||
|
if (TREE_CODE (var) == INDIRECT_REF)
|
||
|
{
|
||
|
/* If the base is a dereference of a pointer, first check its name memory
|
||
|
tag. If it does not have one, use its symbol memory tag. */
|
||
|
var = TREE_OPERAND (var, 0);
|
||
|
if (TREE_CODE (var) != SSA_NAME)
|
||
|
return NULL_TREE;
|
||
|
|
||
|
if (SSA_NAME_PTR_INFO (var))
|
||
|
{
|
||
|
tag = SSA_NAME_PTR_INFO (var)->name_mem_tag;
|
||
|
if (tag)
|
||
|
return tag;
|
||
|
}
|
||
|
|
||
|
var = SSA_NAME_VAR (var);
|
||
|
tag = var_ann (var)->symbol_mem_tag;
|
||
|
gcc_assert (tag != NULL_TREE);
|
||
|
return tag;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
if (!DECL_P (var))
|
||
|
return NULL_TREE;
|
||
|
|
||
|
tag = var_ann (var)->symbol_mem_tag;
|
||
|
if (tag)
|
||
|
return tag;
|
||
|
|
||
|
return var;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Copies the reference information from OLD_REF to NEW_REF. */
|
||
|
|
||
|
static void
|
||
|
copy_ref_info (tree new_ref, tree old_ref)
|
||
|
{
|
||
|
if (TREE_CODE (old_ref) == TARGET_MEM_REF)
|
||
|
copy_mem_ref_info (new_ref, old_ref);
|
||
|
else
|
||
|
{
|
||
|
TMR_ORIGINAL (new_ref) = unshare_and_remove_ssa_names (old_ref);
|
||
|
TMR_TAG (new_ref) = get_ref_tag (old_ref, TMR_ORIGINAL (new_ref));
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Rewrites USE (address that is an iv) using candidate CAND. */
|
||
|
|
||
|
static void
|
||
|
rewrite_use_address (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand)
|
||
|
{
|
||
|
struct affine_tree_combination aff;
|
||
|
block_stmt_iterator bsi = bsi_for_stmt (use->stmt);
|
||
|
tree ref;
|
||
|
|
||
|
get_computation_aff (data->current_loop, use, cand, use->stmt, &aff);
|
||
|
unshare_aff_combination (&aff);
|
||
|
|
||
|
ref = create_mem_ref (&bsi, TREE_TYPE (*use->op_p), &aff);
|
||
|
copy_ref_info (ref, *use->op_p);
|
||
|
*use->op_p = ref;
|
||
|
}
|
||
|
|
||
|
/* Rewrites USE (the condition such that one of the arguments is an iv) using
|
||
|
candidate CAND. */
|
||
|
|
||
|
static void
|
||
|
rewrite_use_compare (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand)
|
||
|
{
|
||
|
tree comp;
|
||
|
tree *op_p, cond, op, stmts, bound;
|
||
|
block_stmt_iterator bsi = bsi_for_stmt (use->stmt);
|
||
|
enum tree_code compare;
|
||
|
struct cost_pair *cp = get_use_iv_cost (data, use, cand);
|
||
|
|
||
|
bound = cp->value;
|
||
|
if (bound)
|
||
|
{
|
||
|
tree var = var_at_stmt (data->current_loop, cand, use->stmt);
|
||
|
tree var_type = TREE_TYPE (var);
|
||
|
|
||
|
compare = iv_elimination_compare (data, use);
|
||
|
bound = fold_convert (var_type, bound);
|
||
|
op = force_gimple_operand (unshare_expr (bound), &stmts,
|
||
|
true, NULL_TREE);
|
||
|
|
||
|
if (stmts)
|
||
|
bsi_insert_before (&bsi, stmts, BSI_SAME_STMT);
|
||
|
|
||
|
*use->op_p = build2 (compare, boolean_type_node, var, op);
|
||
|
update_stmt (use->stmt);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/* The induction variable elimination failed; just express the original
|
||
|
giv. */
|
||
|
comp = get_computation (data->current_loop, use, cand);
|
||
|
|
||
|
cond = *use->op_p;
|
||
|
op_p = &TREE_OPERAND (cond, 0);
|
||
|
if (TREE_CODE (*op_p) != SSA_NAME
|
||
|
|| zero_p (get_iv (data, *op_p)->step))
|
||
|
op_p = &TREE_OPERAND (cond, 1);
|
||
|
|
||
|
op = force_gimple_operand (comp, &stmts, true, SSA_NAME_VAR (*op_p));
|
||
|
if (stmts)
|
||
|
bsi_insert_before (&bsi, stmts, BSI_SAME_STMT);
|
||
|
|
||
|
*op_p = op;
|
||
|
}
|
||
|
|
||
|
/* Rewrites USE using candidate CAND. */
|
||
|
|
||
|
static void
|
||
|
rewrite_use (struct ivopts_data *data,
|
||
|
struct iv_use *use, struct iv_cand *cand)
|
||
|
{
|
||
|
switch (use->type)
|
||
|
{
|
||
|
case USE_NONLINEAR_EXPR:
|
||
|
rewrite_use_nonlinear_expr (data, use, cand);
|
||
|
break;
|
||
|
|
||
|
case USE_ADDRESS:
|
||
|
rewrite_use_address (data, use, cand);
|
||
|
break;
|
||
|
|
||
|
case USE_COMPARE:
|
||
|
rewrite_use_compare (data, use, cand);
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
gcc_unreachable ();
|
||
|
}
|
||
|
mark_new_vars_to_rename (use->stmt);
|
||
|
}
|
||
|
|
||
|
/* Rewrite the uses using the selected induction variables. */
|
||
|
|
||
|
static void
|
||
|
rewrite_uses (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned i;
|
||
|
struct iv_cand *cand;
|
||
|
struct iv_use *use;
|
||
|
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
{
|
||
|
use = iv_use (data, i);
|
||
|
cand = use->selected;
|
||
|
gcc_assert (cand);
|
||
|
|
||
|
rewrite_use (data, use, cand);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Removes the ivs that are not used after rewriting. */
|
||
|
|
||
|
static void
|
||
|
remove_unused_ivs (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned j;
|
||
|
bitmap_iterator bi;
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi)
|
||
|
{
|
||
|
struct version_info *info;
|
||
|
|
||
|
info = ver_info (data, j);
|
||
|
if (info->iv
|
||
|
&& !zero_p (info->iv->step)
|
||
|
&& !info->inv_id
|
||
|
&& !info->iv->have_use_for
|
||
|
&& !info->preserve_biv)
|
||
|
remove_statement (SSA_NAME_DEF_STMT (info->iv->ssa_name), true);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Frees data allocated by the optimization of a single loop. */
|
||
|
|
||
|
static void
|
||
|
free_loop_data (struct ivopts_data *data)
|
||
|
{
|
||
|
unsigned i, j;
|
||
|
bitmap_iterator bi;
|
||
|
tree obj;
|
||
|
|
||
|
htab_empty (data->niters);
|
||
|
|
||
|
EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
|
||
|
{
|
||
|
struct version_info *info;
|
||
|
|
||
|
info = ver_info (data, i);
|
||
|
if (info->iv)
|
||
|
free (info->iv);
|
||
|
info->iv = NULL;
|
||
|
info->has_nonlin_use = false;
|
||
|
info->preserve_biv = false;
|
||
|
info->inv_id = 0;
|
||
|
}
|
||
|
bitmap_clear (data->relevant);
|
||
|
bitmap_clear (data->important_candidates);
|
||
|
|
||
|
for (i = 0; i < n_iv_uses (data); i++)
|
||
|
{
|
||
|
struct iv_use *use = iv_use (data, i);
|
||
|
|
||
|
free (use->iv);
|
||
|
BITMAP_FREE (use->related_cands);
|
||
|
for (j = 0; j < use->n_map_members; j++)
|
||
|
if (use->cost_map[j].depends_on)
|
||
|
BITMAP_FREE (use->cost_map[j].depends_on);
|
||
|
free (use->cost_map);
|
||
|
free (use);
|
||
|
}
|
||
|
VEC_truncate (iv_use_p, data->iv_uses, 0);
|
||
|
|
||
|
for (i = 0; i < n_iv_cands (data); i++)
|
||
|
{
|
||
|
struct iv_cand *cand = iv_cand (data, i);
|
||
|
|
||
|
if (cand->iv)
|
||
|
free (cand->iv);
|
||
|
if (cand->depends_on)
|
||
|
BITMAP_FREE (cand->depends_on);
|
||
|
free (cand);
|
||
|
}
|
||
|
VEC_truncate (iv_cand_p, data->iv_candidates, 0);
|
||
|
|
||
|
if (data->version_info_size < num_ssa_names)
|
||
|
{
|
||
|
data->version_info_size = 2 * num_ssa_names;
|
||
|
free (data->version_info);
|
||
|
data->version_info = XCNEWVEC (struct version_info, data->version_info_size);
|
||
|
}
|
||
|
|
||
|
data->max_inv_id = 0;
|
||
|
|
||
|
for (i = 0; VEC_iterate (tree, decl_rtl_to_reset, i, obj); i++)
|
||
|
SET_DECL_RTL (obj, NULL_RTX);
|
||
|
|
||
|
VEC_truncate (tree, decl_rtl_to_reset, 0);
|
||
|
}
|
||
|
|
||
|
/* Finalizes data structures used by the iv optimization pass. LOOPS is the
|
||
|
loop tree. */
|
||
|
|
||
|
static void
|
||
|
tree_ssa_iv_optimize_finalize (struct ivopts_data *data)
|
||
|
{
|
||
|
free_loop_data (data);
|
||
|
free (data->version_info);
|
||
|
BITMAP_FREE (data->relevant);
|
||
|
BITMAP_FREE (data->important_candidates);
|
||
|
htab_delete (data->niters);
|
||
|
|
||
|
VEC_free (tree, heap, decl_rtl_to_reset);
|
||
|
VEC_free (iv_use_p, heap, data->iv_uses);
|
||
|
VEC_free (iv_cand_p, heap, data->iv_candidates);
|
||
|
}
|
||
|
|
||
|
/* Optimizes the LOOP. Returns true if anything changed. */
|
||
|
|
||
|
static bool
|
||
|
tree_ssa_iv_optimize_loop (struct ivopts_data *data, struct loop *loop)
|
||
|
{
|
||
|
bool changed = false;
|
||
|
struct iv_ca *iv_ca;
|
||
|
edge exit;
|
||
|
|
||
|
data->current_loop = loop;
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "Processing loop %d\n", loop->num);
|
||
|
|
||
|
exit = single_dom_exit (loop);
|
||
|
if (exit)
|
||
|
{
|
||
|
fprintf (dump_file, " single exit %d -> %d, exit condition ",
|
||
|
exit->src->index, exit->dest->index);
|
||
|
print_generic_expr (dump_file, last_stmt (exit->src), TDF_SLIM);
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
|
||
|
fprintf (dump_file, "\n");
|
||
|
}
|
||
|
|
||
|
/* For each ssa name determines whether it behaves as an induction variable
|
||
|
in some loop. */
|
||
|
if (!find_induction_variables (data))
|
||
|
goto finish;
|
||
|
|
||
|
/* Finds interesting uses (item 1). */
|
||
|
find_interesting_uses (data);
|
||
|
if (n_iv_uses (data) > MAX_CONSIDERED_USES)
|
||
|
goto finish;
|
||
|
|
||
|
/* Finds candidates for the induction variables (item 2). */
|
||
|
find_iv_candidates (data);
|
||
|
|
||
|
/* Calculates the costs (item 3, part 1). */
|
||
|
determine_use_iv_costs (data);
|
||
|
determine_iv_costs (data);
|
||
|
determine_set_costs (data);
|
||
|
|
||
|
/* Find the optimal set of induction variables (item 3, part 2). */
|
||
|
iv_ca = find_optimal_iv_set (data);
|
||
|
if (!iv_ca)
|
||
|
goto finish;
|
||
|
changed = true;
|
||
|
|
||
|
/* Create the new induction variables (item 4, part 1). */
|
||
|
create_new_ivs (data, iv_ca);
|
||
|
iv_ca_free (&iv_ca);
|
||
|
|
||
|
/* Rewrite the uses (item 4, part 2). */
|
||
|
rewrite_uses (data);
|
||
|
|
||
|
/* Remove the ivs that are unused after rewriting. */
|
||
|
remove_unused_ivs (data);
|
||
|
|
||
|
/* We have changed the structure of induction variables; it might happen
|
||
|
that definitions in the scev database refer to some of them that were
|
||
|
eliminated. */
|
||
|
scev_reset ();
|
||
|
|
||
|
finish:
|
||
|
free_loop_data (data);
|
||
|
|
||
|
return changed;
|
||
|
}
|
||
|
|
||
|
/* Main entry point. Optimizes induction variables in LOOPS. */
|
||
|
|
||
|
void
|
||
|
tree_ssa_iv_optimize (struct loops *loops)
|
||
|
{
|
||
|
struct loop *loop;
|
||
|
struct ivopts_data data;
|
||
|
|
||
|
tree_ssa_iv_optimize_init (&data);
|
||
|
|
||
|
/* Optimize the loops starting with the innermost ones. */
|
||
|
loop = loops->tree_root;
|
||
|
while (loop->inner)
|
||
|
loop = loop->inner;
|
||
|
|
||
|
/* Scan the loops, inner ones first. */
|
||
|
while (loop != loops->tree_root)
|
||
|
{
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
flow_loop_dump (loop, dump_file, NULL, 1);
|
||
|
|
||
|
tree_ssa_iv_optimize_loop (&data, loop);
|
||
|
|
||
|
if (loop->next)
|
||
|
{
|
||
|
loop = loop->next;
|
||
|
while (loop->inner)
|
||
|
loop = loop->inner;
|
||
|
}
|
||
|
else
|
||
|
loop = loop->outer;
|
||
|
}
|
||
|
|
||
|
tree_ssa_iv_optimize_finalize (&data);
|
||
|
}
|