2582 lines
68 KiB
C
2582 lines
68 KiB
C
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/* Convert a program in SSA form into Normal form.
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Copyright (C) 2004, 2005 Free Software Foundation, Inc.
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Contributed by Andrew Macleod <amacleod@redhat.com>
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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
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GCC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License 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
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the Free Software Foundation, 51 Franklin Street, Fifth Floor,
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Boston, MA 02110-1301, USA. */
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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 "flags.h"
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#include "rtl.h"
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#include "tm_p.h"
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#include "ggc.h"
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#include "langhooks.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 "expr.h"
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#include "function.h"
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#include "diagnostic.h"
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#include "bitmap.h"
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#include "tree-flow.h"
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#include "tree-gimple.h"
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#include "tree-inline.h"
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#include "varray.h"
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#include "timevar.h"
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#include "hashtab.h"
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#include "tree-dump.h"
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#include "tree-ssa-live.h"
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#include "tree-pass.h"
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#include "toplev.h"
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#include "vecprim.h"
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/* Flags to pass to remove_ssa_form. */
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#define SSANORM_PERFORM_TER 0x1
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#define SSANORM_COMBINE_TEMPS 0x2
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#define SSANORM_COALESCE_PARTITIONS 0x4
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/* Used to hold all the components required to do SSA PHI elimination.
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The node and pred/succ list is a simple linear list of nodes and
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edges represented as pairs of nodes.
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The predecessor and successor list: Nodes are entered in pairs, where
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[0] ->PRED, [1]->SUCC. All the even indexes in the array represent
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predecessors, all the odd elements are successors.
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Rationale:
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When implemented as bitmaps, very large programs SSA->Normal times were
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being dominated by clearing the interference graph.
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Typically this list of edges is extremely small since it only includes
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PHI results and uses from a single edge which have not coalesced with
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each other. This means that no virtual PHI nodes are included, and
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empirical evidence suggests that the number of edges rarely exceed
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3, and in a bootstrap of GCC, the maximum size encountered was 7.
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This also limits the number of possible nodes that are involved to
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rarely more than 6, and in the bootstrap of gcc, the maximum number
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of nodes encountered was 12. */
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typedef struct _elim_graph {
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/* Size of the elimination vectors. */
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int size;
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/* List of nodes in the elimination graph. */
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VEC(tree,heap) *nodes;
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/* The predecessor and successor edge list. */
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VEC(int,heap) *edge_list;
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/* Visited vector. */
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sbitmap visited;
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/* Stack for visited nodes. */
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VEC(int,heap) *stack;
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/* The variable partition map. */
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var_map map;
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/* Edge being eliminated by this graph. */
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edge e;
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/* List of constant copies to emit. These are pushed on in pairs. */
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VEC(tree,heap) *const_copies;
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} *elim_graph;
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/* Local functions. */
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static tree create_temp (tree);
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static void insert_copy_on_edge (edge, tree, tree);
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static elim_graph new_elim_graph (int);
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static inline void delete_elim_graph (elim_graph);
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static inline void clear_elim_graph (elim_graph);
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static inline int elim_graph_size (elim_graph);
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static inline void elim_graph_add_node (elim_graph, tree);
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static inline void elim_graph_add_edge (elim_graph, int, int);
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static inline int elim_graph_remove_succ_edge (elim_graph, int);
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static inline void eliminate_name (elim_graph, tree);
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static void eliminate_build (elim_graph, basic_block);
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static void elim_forward (elim_graph, int);
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static int elim_unvisited_predecessor (elim_graph, int);
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static void elim_backward (elim_graph, int);
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static void elim_create (elim_graph, int);
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static void eliminate_phi (edge, elim_graph);
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static tree_live_info_p coalesce_ssa_name (var_map, int);
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static void assign_vars (var_map);
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static bool replace_use_variable (var_map, use_operand_p, tree *);
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static bool replace_def_variable (var_map, def_operand_p, tree *);
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static void eliminate_virtual_phis (void);
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static void coalesce_abnormal_edges (var_map, conflict_graph, root_var_p);
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static void print_exprs (FILE *, const char *, tree, const char *, tree,
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const char *);
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static void print_exprs_edge (FILE *, edge, const char *, tree, const char *,
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tree);
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/* Create a temporary variable based on the type of variable T. Use T's name
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as the prefix. */
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static tree
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create_temp (tree t)
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{
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tree tmp;
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const char *name = NULL;
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tree type;
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if (TREE_CODE (t) == SSA_NAME)
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t = SSA_NAME_VAR (t);
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gcc_assert (TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == PARM_DECL);
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type = TREE_TYPE (t);
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tmp = DECL_NAME (t);
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if (tmp)
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name = IDENTIFIER_POINTER (tmp);
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if (name == NULL)
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name = "temp";
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tmp = create_tmp_var (type, name);
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if (DECL_DEBUG_EXPR_IS_FROM (t) && DECL_DEBUG_EXPR (t))
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{
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SET_DECL_DEBUG_EXPR (tmp, DECL_DEBUG_EXPR (t));
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DECL_DEBUG_EXPR_IS_FROM (tmp) = 1;
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}
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else if (!DECL_IGNORED_P (t))
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{
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SET_DECL_DEBUG_EXPR (tmp, t);
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DECL_DEBUG_EXPR_IS_FROM (tmp) = 1;
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}
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DECL_ARTIFICIAL (tmp) = DECL_ARTIFICIAL (t);
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DECL_IGNORED_P (tmp) = DECL_IGNORED_P (t);
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add_referenced_var (tmp);
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/* add_referenced_var will create the annotation and set up some
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of the flags in the annotation. However, some flags we need to
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inherit from our original variable. */
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var_ann (tmp)->symbol_mem_tag = var_ann (t)->symbol_mem_tag;
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if (is_call_clobbered (t))
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mark_call_clobbered (tmp, var_ann (t)->escape_mask);
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return tmp;
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}
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/* This helper function fill insert a copy from a constant or variable SRC to
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variable DEST on edge E. */
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static void
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insert_copy_on_edge (edge e, tree dest, tree src)
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{
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tree copy;
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copy = build2 (MODIFY_EXPR, TREE_TYPE (dest), dest, src);
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set_is_used (dest);
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if (TREE_CODE (src) == ADDR_EXPR)
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src = TREE_OPERAND (src, 0);
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if (TREE_CODE (src) == VAR_DECL || TREE_CODE (src) == PARM_DECL)
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set_is_used (src);
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if (dump_file && (dump_flags & TDF_DETAILS))
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{
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fprintf (dump_file,
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"Inserting a copy on edge BB%d->BB%d :",
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e->src->index,
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e->dest->index);
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print_generic_expr (dump_file, copy, dump_flags);
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fprintf (dump_file, "\n");
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}
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bsi_insert_on_edge (e, copy);
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}
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/* Create an elimination graph with SIZE nodes and associated data
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structures. */
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static elim_graph
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new_elim_graph (int size)
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{
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elim_graph g = (elim_graph) xmalloc (sizeof (struct _elim_graph));
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g->nodes = VEC_alloc (tree, heap, 30);
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g->const_copies = VEC_alloc (tree, heap, 20);
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g->edge_list = VEC_alloc (int, heap, 20);
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g->stack = VEC_alloc (int, heap, 30);
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g->visited = sbitmap_alloc (size);
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return g;
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}
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/* Empty elimination graph G. */
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static inline void
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clear_elim_graph (elim_graph g)
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{
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VEC_truncate (tree, g->nodes, 0);
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VEC_truncate (int, g->edge_list, 0);
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}
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/* Delete elimination graph G. */
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static inline void
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delete_elim_graph (elim_graph g)
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{
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sbitmap_free (g->visited);
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VEC_free (int, heap, g->stack);
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VEC_free (int, heap, g->edge_list);
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VEC_free (tree, heap, g->const_copies);
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VEC_free (tree, heap, g->nodes);
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free (g);
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}
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/* Return the number of nodes in graph G. */
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static inline int
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elim_graph_size (elim_graph g)
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{
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return VEC_length (tree, g->nodes);
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}
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/* Add NODE to graph G, if it doesn't exist already. */
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static inline void
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elim_graph_add_node (elim_graph g, tree node)
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{
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int x;
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tree t;
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for (x = 0; VEC_iterate (tree, g->nodes, x, t); x++)
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if (t == node)
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return;
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VEC_safe_push (tree, heap, g->nodes, node);
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}
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/* Add the edge PRED->SUCC to graph G. */
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static inline void
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elim_graph_add_edge (elim_graph g, int pred, int succ)
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{
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VEC_safe_push (int, heap, g->edge_list, pred);
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VEC_safe_push (int, heap, g->edge_list, succ);
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}
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/* Remove an edge from graph G for which NODE is the predecessor, and
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return the successor node. -1 is returned if there is no such edge. */
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static inline int
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elim_graph_remove_succ_edge (elim_graph g, int node)
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{
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int y;
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unsigned x;
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for (x = 0; x < VEC_length (int, g->edge_list); x += 2)
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if (VEC_index (int, g->edge_list, x) == node)
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{
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VEC_replace (int, g->edge_list, x, -1);
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y = VEC_index (int, g->edge_list, x + 1);
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VEC_replace (int, g->edge_list, x + 1, -1);
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return y;
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}
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return -1;
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}
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/* Find all the nodes in GRAPH which are successors to NODE in the
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edge list. VAR will hold the partition number found. CODE is the
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code fragment executed for every node found. */
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#define FOR_EACH_ELIM_GRAPH_SUCC(GRAPH, NODE, VAR, CODE) \
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do { \
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unsigned x_; \
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int y_; \
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for (x_ = 0; x_ < VEC_length (int, (GRAPH)->edge_list); x_ += 2) \
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{ \
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y_ = VEC_index (int, (GRAPH)->edge_list, x_); \
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if (y_ != (NODE)) \
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continue; \
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(VAR) = VEC_index (int, (GRAPH)->edge_list, x_ + 1); \
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CODE; \
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} \
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} while (0)
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/* Find all the nodes which are predecessors of NODE in the edge list for
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GRAPH. VAR will hold the partition number found. CODE is the
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code fragment executed for every node found. */
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#define FOR_EACH_ELIM_GRAPH_PRED(GRAPH, NODE, VAR, CODE) \
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do { \
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unsigned x_; \
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int y_; \
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for (x_ = 0; x_ < VEC_length (int, (GRAPH)->edge_list); x_ += 2) \
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{ \
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y_ = VEC_index (int, (GRAPH)->edge_list, x_ + 1); \
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if (y_ != (NODE)) \
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continue; \
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(VAR) = VEC_index (int, (GRAPH)->edge_list, x_); \
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CODE; \
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} \
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} while (0)
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/* Add T to elimination graph G. */
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static inline void
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eliminate_name (elim_graph g, tree T)
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{
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elim_graph_add_node (g, T);
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}
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/* Build elimination graph G for basic block BB on incoming PHI edge
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G->e. */
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static void
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eliminate_build (elim_graph g, basic_block B)
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{
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tree phi;
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tree T0, Ti;
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int p0, pi;
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clear_elim_graph (g);
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for (phi = phi_nodes (B); phi; phi = PHI_CHAIN (phi))
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{
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T0 = var_to_partition_to_var (g->map, PHI_RESULT (phi));
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/* Ignore results which are not in partitions. */
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if (T0 == NULL_TREE)
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continue;
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Ti = PHI_ARG_DEF (phi, g->e->dest_idx);
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/* If this argument is a constant, or a SSA_NAME which is being
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left in SSA form, just queue a copy to be emitted on this
|
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edge. */
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if (!phi_ssa_name_p (Ti)
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|| (TREE_CODE (Ti) == SSA_NAME
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&& var_to_partition (g->map, Ti) == NO_PARTITION))
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{
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/* Save constant copies until all other copies have been emitted
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on this edge. */
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VEC_safe_push (tree, heap, g->const_copies, T0);
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VEC_safe_push (tree, heap, g->const_copies, Ti);
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}
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else
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{
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Ti = var_to_partition_to_var (g->map, Ti);
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if (T0 != Ti)
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{
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eliminate_name (g, T0);
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eliminate_name (g, Ti);
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p0 = var_to_partition (g->map, T0);
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pi = var_to_partition (g->map, Ti);
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elim_graph_add_edge (g, p0, pi);
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}
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}
|
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}
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}
|
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/* Push successors of T onto the elimination stack for G. */
|
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static void
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elim_forward (elim_graph g, int T)
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{
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int S;
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SET_BIT (g->visited, T);
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FOR_EACH_ELIM_GRAPH_SUCC (g, T, S,
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{
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if (!TEST_BIT (g->visited, S))
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elim_forward (g, S);
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|
});
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VEC_safe_push (int, heap, g->stack, T);
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}
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/* Return 1 if there unvisited predecessors of T in graph G. */
|
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|
static int
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elim_unvisited_predecessor (elim_graph g, int T)
|
||
|
{
|
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|
int P;
|
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|
FOR_EACH_ELIM_GRAPH_PRED (g, T, P,
|
||
|
{
|
||
|
if (!TEST_BIT (g->visited, P))
|
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|
return 1;
|
||
|
});
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/* Process predecessors first, and insert a copy. */
|
||
|
|
||
|
static void
|
||
|
elim_backward (elim_graph g, int T)
|
||
|
{
|
||
|
int P;
|
||
|
SET_BIT (g->visited, T);
|
||
|
FOR_EACH_ELIM_GRAPH_PRED (g, T, P,
|
||
|
{
|
||
|
if (!TEST_BIT (g->visited, P))
|
||
|
{
|
||
|
elim_backward (g, P);
|
||
|
insert_copy_on_edge (g->e,
|
||
|
partition_to_var (g->map, P),
|
||
|
partition_to_var (g->map, T));
|
||
|
}
|
||
|
});
|
||
|
}
|
||
|
|
||
|
/* Insert required copies for T in graph G. Check for a strongly connected
|
||
|
region, and create a temporary to break the cycle if one is found. */
|
||
|
|
||
|
static void
|
||
|
elim_create (elim_graph g, int T)
|
||
|
{
|
||
|
tree U;
|
||
|
int P, S;
|
||
|
|
||
|
if (elim_unvisited_predecessor (g, T))
|
||
|
{
|
||
|
U = create_temp (partition_to_var (g->map, T));
|
||
|
insert_copy_on_edge (g->e, U, partition_to_var (g->map, T));
|
||
|
FOR_EACH_ELIM_GRAPH_PRED (g, T, P,
|
||
|
{
|
||
|
if (!TEST_BIT (g->visited, P))
|
||
|
{
|
||
|
elim_backward (g, P);
|
||
|
insert_copy_on_edge (g->e, partition_to_var (g->map, P), U);
|
||
|
}
|
||
|
});
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
S = elim_graph_remove_succ_edge (g, T);
|
||
|
if (S != -1)
|
||
|
{
|
||
|
SET_BIT (g->visited, T);
|
||
|
insert_copy_on_edge (g->e,
|
||
|
partition_to_var (g->map, T),
|
||
|
partition_to_var (g->map, S));
|
||
|
}
|
||
|
}
|
||
|
|
||
|
}
|
||
|
|
||
|
/* Eliminate all the phi nodes on edge E in graph G. */
|
||
|
|
||
|
static void
|
||
|
eliminate_phi (edge e, elim_graph g)
|
||
|
{
|
||
|
int x;
|
||
|
basic_block B = e->dest;
|
||
|
|
||
|
gcc_assert (VEC_length (tree, g->const_copies) == 0);
|
||
|
|
||
|
/* Abnormal edges already have everything coalesced. */
|
||
|
if (e->flags & EDGE_ABNORMAL)
|
||
|
return;
|
||
|
|
||
|
g->e = e;
|
||
|
|
||
|
eliminate_build (g, B);
|
||
|
|
||
|
if (elim_graph_size (g) != 0)
|
||
|
{
|
||
|
tree var;
|
||
|
|
||
|
sbitmap_zero (g->visited);
|
||
|
VEC_truncate (int, g->stack, 0);
|
||
|
|
||
|
for (x = 0; VEC_iterate (tree, g->nodes, x, var); x++)
|
||
|
{
|
||
|
int p = var_to_partition (g->map, var);
|
||
|
if (!TEST_BIT (g->visited, p))
|
||
|
elim_forward (g, p);
|
||
|
}
|
||
|
|
||
|
sbitmap_zero (g->visited);
|
||
|
while (VEC_length (int, g->stack) > 0)
|
||
|
{
|
||
|
x = VEC_pop (int, g->stack);
|
||
|
if (!TEST_BIT (g->visited, x))
|
||
|
elim_create (g, x);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* If there are any pending constant copies, issue them now. */
|
||
|
while (VEC_length (tree, g->const_copies) > 0)
|
||
|
{
|
||
|
tree src, dest;
|
||
|
src = VEC_pop (tree, g->const_copies);
|
||
|
dest = VEC_pop (tree, g->const_copies);
|
||
|
insert_copy_on_edge (e, dest, src);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Shortcut routine to print messages to file F of the form:
|
||
|
"STR1 EXPR1 STR2 EXPR2 STR3." */
|
||
|
|
||
|
static void
|
||
|
print_exprs (FILE *f, const char *str1, tree expr1, const char *str2,
|
||
|
tree expr2, const char *str3)
|
||
|
{
|
||
|
fprintf (f, "%s", str1);
|
||
|
print_generic_expr (f, expr1, TDF_SLIM);
|
||
|
fprintf (f, "%s", str2);
|
||
|
print_generic_expr (f, expr2, TDF_SLIM);
|
||
|
fprintf (f, "%s", str3);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Shortcut routine to print abnormal edge messages to file F of the form:
|
||
|
"STR1 EXPR1 STR2 EXPR2 across edge E. */
|
||
|
|
||
|
static void
|
||
|
print_exprs_edge (FILE *f, edge e, const char *str1, tree expr1,
|
||
|
const char *str2, tree expr2)
|
||
|
{
|
||
|
print_exprs (f, str1, expr1, str2, expr2, " across an abnormal edge");
|
||
|
fprintf (f, " from BB%d->BB%d\n", e->src->index,
|
||
|
e->dest->index);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Coalesce partitions in MAP which are live across abnormal edges in GRAPH.
|
||
|
RV is the root variable groupings of the partitions in MAP. Since code
|
||
|
cannot be inserted on these edges, failure to coalesce something across
|
||
|
an abnormal edge is an error. */
|
||
|
|
||
|
static void
|
||
|
coalesce_abnormal_edges (var_map map, conflict_graph graph, root_var_p rv)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
edge e;
|
||
|
tree phi, var, tmp;
|
||
|
int x, y, z;
|
||
|
edge_iterator ei;
|
||
|
|
||
|
/* Code cannot be inserted on abnormal edges. Look for all abnormal
|
||
|
edges, and coalesce any PHI results with their arguments across
|
||
|
that edge. */
|
||
|
|
||
|
FOR_EACH_BB (bb)
|
||
|
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
|
if (e->dest != EXIT_BLOCK_PTR && e->flags & EDGE_ABNORMAL)
|
||
|
for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi))
|
||
|
{
|
||
|
/* Visit each PHI on the destination side of this abnormal
|
||
|
edge, and attempt to coalesce the argument with the result. */
|
||
|
var = PHI_RESULT (phi);
|
||
|
x = var_to_partition (map, var);
|
||
|
|
||
|
/* Ignore results which are not relevant. */
|
||
|
if (x == NO_PARTITION)
|
||
|
continue;
|
||
|
|
||
|
tmp = PHI_ARG_DEF (phi, e->dest_idx);
|
||
|
#ifdef ENABLE_CHECKING
|
||
|
if (!phi_ssa_name_p (tmp))
|
||
|
{
|
||
|
print_exprs_edge (stderr, e,
|
||
|
"\nConstant argument in PHI. Can't insert :",
|
||
|
var, " = ", tmp);
|
||
|
internal_error ("SSA corruption");
|
||
|
}
|
||
|
#else
|
||
|
gcc_assert (phi_ssa_name_p (tmp));
|
||
|
#endif
|
||
|
y = var_to_partition (map, tmp);
|
||
|
gcc_assert (x != NO_PARTITION);
|
||
|
gcc_assert (y != NO_PARTITION);
|
||
|
#ifdef ENABLE_CHECKING
|
||
|
if (root_var_find (rv, x) != root_var_find (rv, y))
|
||
|
{
|
||
|
print_exprs_edge (stderr, e, "\nDifferent root vars: ",
|
||
|
root_var (rv, root_var_find (rv, x)),
|
||
|
" and ",
|
||
|
root_var (rv, root_var_find (rv, y)));
|
||
|
internal_error ("SSA corruption");
|
||
|
}
|
||
|
#else
|
||
|
gcc_assert (root_var_find (rv, x) == root_var_find (rv, y));
|
||
|
#endif
|
||
|
|
||
|
if (x != y)
|
||
|
{
|
||
|
#ifdef ENABLE_CHECKING
|
||
|
if (conflict_graph_conflict_p (graph, x, y))
|
||
|
{
|
||
|
print_exprs_edge (stderr, e, "\n Conflict ",
|
||
|
partition_to_var (map, x),
|
||
|
" and ", partition_to_var (map, y));
|
||
|
internal_error ("SSA corruption");
|
||
|
}
|
||
|
#else
|
||
|
gcc_assert (!conflict_graph_conflict_p (graph, x, y));
|
||
|
#endif
|
||
|
|
||
|
/* Now map the partitions back to their real variables. */
|
||
|
var = partition_to_var (map, x);
|
||
|
tmp = partition_to_var (map, y);
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
print_exprs_edge (dump_file, e,
|
||
|
"ABNORMAL: Coalescing ",
|
||
|
var, " and ", tmp);
|
||
|
}
|
||
|
z = var_union (map, var, tmp);
|
||
|
#ifdef ENABLE_CHECKING
|
||
|
if (z == NO_PARTITION)
|
||
|
{
|
||
|
print_exprs_edge (stderr, e, "\nUnable to coalesce",
|
||
|
partition_to_var (map, x), " and ",
|
||
|
partition_to_var (map, y));
|
||
|
internal_error ("SSA corruption");
|
||
|
}
|
||
|
#else
|
||
|
gcc_assert (z != NO_PARTITION);
|
||
|
#endif
|
||
|
gcc_assert (z == x || z == y);
|
||
|
if (z == x)
|
||
|
conflict_graph_merge_regs (graph, x, y);
|
||
|
else
|
||
|
conflict_graph_merge_regs (graph, y, x);
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Coalesce potential copies via PHI arguments. */
|
||
|
|
||
|
static void
|
||
|
coalesce_phi_operands (var_map map, coalesce_list_p cl)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
tree phi;
|
||
|
|
||
|
FOR_EACH_BB (bb)
|
||
|
{
|
||
|
for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
|
||
|
{
|
||
|
tree res = PHI_RESULT (phi);
|
||
|
int p = var_to_partition (map, res);
|
||
|
int x;
|
||
|
|
||
|
if (p == NO_PARTITION)
|
||
|
continue;
|
||
|
|
||
|
for (x = 0; x < PHI_NUM_ARGS (phi); x++)
|
||
|
{
|
||
|
tree arg = PHI_ARG_DEF (phi, x);
|
||
|
int p2;
|
||
|
|
||
|
if (TREE_CODE (arg) != SSA_NAME)
|
||
|
continue;
|
||
|
if (SSA_NAME_VAR (res) != SSA_NAME_VAR (arg))
|
||
|
continue;
|
||
|
p2 = var_to_partition (map, PHI_ARG_DEF (phi, x));
|
||
|
if (p2 != NO_PARTITION)
|
||
|
{
|
||
|
edge e = PHI_ARG_EDGE (phi, x);
|
||
|
add_coalesce (cl, p, p2,
|
||
|
coalesce_cost (EDGE_FREQUENCY (e),
|
||
|
maybe_hot_bb_p (bb),
|
||
|
EDGE_CRITICAL_P (e)));
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Coalesce all the result decls together. */
|
||
|
|
||
|
static void
|
||
|
coalesce_result_decls (var_map map, coalesce_list_p cl)
|
||
|
{
|
||
|
unsigned int i, x;
|
||
|
tree var = NULL;
|
||
|
|
||
|
for (i = x = 0; x < num_var_partitions (map); x++)
|
||
|
{
|
||
|
tree p = partition_to_var (map, x);
|
||
|
if (TREE_CODE (SSA_NAME_VAR (p)) == RESULT_DECL)
|
||
|
{
|
||
|
if (var == NULL_TREE)
|
||
|
{
|
||
|
var = p;
|
||
|
i = x;
|
||
|
}
|
||
|
else
|
||
|
add_coalesce (cl, i, x,
|
||
|
coalesce_cost (EXIT_BLOCK_PTR->frequency,
|
||
|
maybe_hot_bb_p (EXIT_BLOCK_PTR),
|
||
|
false));
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Coalesce matching constraints in asms. */
|
||
|
|
||
|
static void
|
||
|
coalesce_asm_operands (var_map map, coalesce_list_p cl)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
|
||
|
FOR_EACH_BB (bb)
|
||
|
{
|
||
|
block_stmt_iterator bsi;
|
||
|
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
|
||
|
{
|
||
|
tree stmt = bsi_stmt (bsi);
|
||
|
unsigned long noutputs, i;
|
||
|
tree *outputs, link;
|
||
|
|
||
|
if (TREE_CODE (stmt) != ASM_EXPR)
|
||
|
continue;
|
||
|
|
||
|
noutputs = list_length (ASM_OUTPUTS (stmt));
|
||
|
outputs = (tree *) alloca (noutputs * sizeof (tree));
|
||
|
for (i = 0, link = ASM_OUTPUTS (stmt); link;
|
||
|
++i, link = TREE_CHAIN (link))
|
||
|
outputs[i] = TREE_VALUE (link);
|
||
|
|
||
|
for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link))
|
||
|
{
|
||
|
const char *constraint
|
||
|
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
|
||
|
tree input = TREE_VALUE (link);
|
||
|
char *end;
|
||
|
unsigned long match;
|
||
|
int p1, p2;
|
||
|
|
||
|
if (TREE_CODE (input) != SSA_NAME && !DECL_P (input))
|
||
|
continue;
|
||
|
|
||
|
match = strtoul (constraint, &end, 10);
|
||
|
if (match >= noutputs || end == constraint)
|
||
|
continue;
|
||
|
|
||
|
if (TREE_CODE (outputs[match]) != SSA_NAME
|
||
|
&& !DECL_P (outputs[match]))
|
||
|
continue;
|
||
|
|
||
|
p1 = var_to_partition (map, outputs[match]);
|
||
|
if (p1 == NO_PARTITION)
|
||
|
continue;
|
||
|
p2 = var_to_partition (map, input);
|
||
|
if (p2 == NO_PARTITION)
|
||
|
continue;
|
||
|
|
||
|
add_coalesce (cl, p1, p2, coalesce_cost (REG_BR_PROB_BASE,
|
||
|
maybe_hot_bb_p (bb),
|
||
|
false));
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Reduce the number of live ranges in MAP. Live range information is
|
||
|
returned if FLAGS indicates that we are combining temporaries, otherwise
|
||
|
NULL is returned. The only partitions which are associated with actual
|
||
|
variables at this point are those which are forced to be coalesced for
|
||
|
various reason. (live on entry, live across abnormal edges, etc.). */
|
||
|
|
||
|
static tree_live_info_p
|
||
|
coalesce_ssa_name (var_map map, int flags)
|
||
|
{
|
||
|
unsigned num, x;
|
||
|
sbitmap live;
|
||
|
root_var_p rv;
|
||
|
tree_live_info_p liveinfo;
|
||
|
conflict_graph graph;
|
||
|
coalesce_list_p cl = NULL;
|
||
|
sbitmap_iterator sbi;
|
||
|
|
||
|
if (num_var_partitions (map) <= 1)
|
||
|
return NULL;
|
||
|
|
||
|
liveinfo = calculate_live_on_entry (map);
|
||
|
calculate_live_on_exit (liveinfo);
|
||
|
rv = root_var_init (map);
|
||
|
|
||
|
/* Remove single element variable from the list. */
|
||
|
root_var_compact (rv);
|
||
|
|
||
|
cl = create_coalesce_list (map);
|
||
|
|
||
|
coalesce_phi_operands (map, cl);
|
||
|
coalesce_result_decls (map, cl);
|
||
|
coalesce_asm_operands (map, cl);
|
||
|
|
||
|
/* Build a conflict graph. */
|
||
|
graph = build_tree_conflict_graph (liveinfo, rv, cl);
|
||
|
|
||
|
if (cl)
|
||
|
{
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "Before sorting:\n");
|
||
|
dump_coalesce_list (dump_file, cl);
|
||
|
}
|
||
|
|
||
|
sort_coalesce_list (cl);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "\nAfter sorting:\n");
|
||
|
dump_coalesce_list (dump_file, cl);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Put the single element variables back in. */
|
||
|
root_var_decompact (rv);
|
||
|
|
||
|
/* First, coalesce all live on entry variables to their root variable.
|
||
|
This will ensure the first use is coming from the correct location. */
|
||
|
|
||
|
num = num_var_partitions (map);
|
||
|
live = sbitmap_alloc (num);
|
||
|
sbitmap_zero (live);
|
||
|
|
||
|
/* Set 'live' vector to indicate live on entry partitions. */
|
||
|
for (x = 0 ; x < num; x++)
|
||
|
{
|
||
|
tree var = partition_to_var (map, x);
|
||
|
if (default_def (SSA_NAME_VAR (var)) == var)
|
||
|
SET_BIT (live, x);
|
||
|
}
|
||
|
|
||
|
if ((flags & SSANORM_COMBINE_TEMPS) == 0)
|
||
|
{
|
||
|
delete_tree_live_info (liveinfo);
|
||
|
liveinfo = NULL;
|
||
|
}
|
||
|
|
||
|
/* Assign root variable as partition representative for each live on entry
|
||
|
partition. */
|
||
|
EXECUTE_IF_SET_IN_SBITMAP (live, 0, x, sbi)
|
||
|
{
|
||
|
tree var = root_var (rv, root_var_find (rv, x));
|
||
|
var_ann_t ann = var_ann (var);
|
||
|
/* If these aren't already coalesced... */
|
||
|
if (partition_to_var (map, x) != var)
|
||
|
{
|
||
|
/* This root variable should have not already been assigned
|
||
|
to another partition which is not coalesced with this one. */
|
||
|
gcc_assert (!ann->out_of_ssa_tag);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
print_exprs (dump_file, "Must coalesce ",
|
||
|
partition_to_var (map, x),
|
||
|
" with the root variable ", var, ".\n");
|
||
|
}
|
||
|
|
||
|
change_partition_var (map, var, x);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
sbitmap_free (live);
|
||
|
|
||
|
/* Coalesce partitions live across abnormal edges. */
|
||
|
coalesce_abnormal_edges (map, graph, rv);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
dump_var_map (dump_file, map);
|
||
|
|
||
|
/* Coalesce partitions. */
|
||
|
coalesce_tpa_members (rv, graph, map, cl,
|
||
|
((dump_flags & TDF_DETAILS) ? dump_file
|
||
|
: NULL));
|
||
|
|
||
|
if (flags & SSANORM_COALESCE_PARTITIONS)
|
||
|
coalesce_tpa_members (rv, graph, map, NULL,
|
||
|
((dump_flags & TDF_DETAILS) ? dump_file
|
||
|
: NULL));
|
||
|
if (cl)
|
||
|
delete_coalesce_list (cl);
|
||
|
root_var_delete (rv);
|
||
|
conflict_graph_delete (graph);
|
||
|
|
||
|
return liveinfo;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Take the ssa-name var_map MAP, and assign real variables to each
|
||
|
partition. */
|
||
|
|
||
|
static void
|
||
|
assign_vars (var_map map)
|
||
|
{
|
||
|
int x, i, num, rep;
|
||
|
tree t, var;
|
||
|
var_ann_t ann;
|
||
|
root_var_p rv;
|
||
|
|
||
|
rv = root_var_init (map);
|
||
|
if (!rv)
|
||
|
return;
|
||
|
|
||
|
/* Coalescing may already have forced some partitions to their root
|
||
|
variable. Find these and tag them. */
|
||
|
|
||
|
num = num_var_partitions (map);
|
||
|
for (x = 0; x < num; x++)
|
||
|
{
|
||
|
var = partition_to_var (map, x);
|
||
|
if (TREE_CODE (var) != SSA_NAME)
|
||
|
{
|
||
|
/* Coalescing will already have verified that more than one
|
||
|
partition doesn't have the same root variable. Simply marked
|
||
|
the variable as assigned. */
|
||
|
ann = var_ann (var);
|
||
|
ann->out_of_ssa_tag = 1;
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "partition %d has variable ", x);
|
||
|
print_generic_expr (dump_file, var, TDF_SLIM);
|
||
|
fprintf (dump_file, " assigned to it.\n");
|
||
|
}
|
||
|
|
||
|
}
|
||
|
}
|
||
|
|
||
|
num = root_var_num (rv);
|
||
|
for (x = 0; x < num; x++)
|
||
|
{
|
||
|
var = root_var (rv, x);
|
||
|
ann = var_ann (var);
|
||
|
for (i = root_var_first_partition (rv, x);
|
||
|
i != ROOT_VAR_NONE;
|
||
|
i = root_var_next_partition (rv, i))
|
||
|
{
|
||
|
t = partition_to_var (map, i);
|
||
|
|
||
|
if (t == var || TREE_CODE (t) != SSA_NAME)
|
||
|
continue;
|
||
|
|
||
|
rep = var_to_partition (map, t);
|
||
|
|
||
|
if (!ann->out_of_ssa_tag)
|
||
|
{
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
print_exprs (dump_file, "", t, " --> ", var, "\n");
|
||
|
change_partition_var (map, var, rep);
|
||
|
continue;
|
||
|
}
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
print_exprs (dump_file, "", t, " not coalesced with ", var,
|
||
|
"");
|
||
|
|
||
|
var = create_temp (t);
|
||
|
change_partition_var (map, var, rep);
|
||
|
ann = var_ann (var);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, " --> New temp: '");
|
||
|
print_generic_expr (dump_file, var, TDF_SLIM);
|
||
|
fprintf (dump_file, "'\n");
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
root_var_delete (rv);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Replace use operand P with whatever variable it has been rewritten to based
|
||
|
on the partitions in MAP. EXPR is an optional expression vector over SSA
|
||
|
versions which is used to replace P with an expression instead of a variable.
|
||
|
If the stmt is changed, return true. */
|
||
|
|
||
|
static inline bool
|
||
|
replace_use_variable (var_map map, use_operand_p p, tree *expr)
|
||
|
{
|
||
|
tree new_var;
|
||
|
tree var = USE_FROM_PTR (p);
|
||
|
|
||
|
/* Check if we are replacing this variable with an expression. */
|
||
|
if (expr)
|
||
|
{
|
||
|
int version = SSA_NAME_VERSION (var);
|
||
|
if (expr[version])
|
||
|
{
|
||
|
tree new_expr = TREE_OPERAND (expr[version], 1);
|
||
|
SET_USE (p, new_expr);
|
||
|
/* Clear the stmt's RHS, or GC might bite us. */
|
||
|
TREE_OPERAND (expr[version], 1) = NULL_TREE;
|
||
|
return true;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
new_var = var_to_partition_to_var (map, var);
|
||
|
if (new_var)
|
||
|
{
|
||
|
SET_USE (p, new_var);
|
||
|
set_is_used (new_var);
|
||
|
return true;
|
||
|
}
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Replace def operand DEF_P with whatever variable it has been rewritten to
|
||
|
based on the partitions in MAP. EXPR is an optional expression vector over
|
||
|
SSA versions which is used to replace DEF_P with an expression instead of a
|
||
|
variable. If the stmt is changed, return true. */
|
||
|
|
||
|
static inline bool
|
||
|
replace_def_variable (var_map map, def_operand_p def_p, tree *expr)
|
||
|
{
|
||
|
tree new_var;
|
||
|
tree var = DEF_FROM_PTR (def_p);
|
||
|
|
||
|
/* Check if we are replacing this variable with an expression. */
|
||
|
if (expr)
|
||
|
{
|
||
|
int version = SSA_NAME_VERSION (var);
|
||
|
if (expr[version])
|
||
|
{
|
||
|
tree new_expr = TREE_OPERAND (expr[version], 1);
|
||
|
SET_DEF (def_p, new_expr);
|
||
|
/* Clear the stmt's RHS, or GC might bite us. */
|
||
|
TREE_OPERAND (expr[version], 1) = NULL_TREE;
|
||
|
return true;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
new_var = var_to_partition_to_var (map, var);
|
||
|
if (new_var)
|
||
|
{
|
||
|
SET_DEF (def_p, new_var);
|
||
|
set_is_used (new_var);
|
||
|
return true;
|
||
|
}
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Remove any PHI node which is a virtual PHI. */
|
||
|
|
||
|
static void
|
||
|
eliminate_virtual_phis (void)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
tree phi, next;
|
||
|
|
||
|
FOR_EACH_BB (bb)
|
||
|
{
|
||
|
for (phi = phi_nodes (bb); phi; phi = next)
|
||
|
{
|
||
|
next = PHI_CHAIN (phi);
|
||
|
if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi))))
|
||
|
{
|
||
|
#ifdef ENABLE_CHECKING
|
||
|
int i;
|
||
|
/* There should be no arguments of this PHI which are in
|
||
|
the partition list, or we get incorrect results. */
|
||
|
for (i = 0; i < PHI_NUM_ARGS (phi); i++)
|
||
|
{
|
||
|
tree arg = PHI_ARG_DEF (phi, i);
|
||
|
if (TREE_CODE (arg) == SSA_NAME
|
||
|
&& is_gimple_reg (SSA_NAME_VAR (arg)))
|
||
|
{
|
||
|
fprintf (stderr, "Argument of PHI is not virtual (");
|
||
|
print_generic_expr (stderr, arg, TDF_SLIM);
|
||
|
fprintf (stderr, "), but the result is :");
|
||
|
print_generic_stmt (stderr, phi, TDF_SLIM);
|
||
|
internal_error ("SSA corruption");
|
||
|
}
|
||
|
}
|
||
|
#endif
|
||
|
remove_phi_node (phi, NULL_TREE);
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
/* This routine will coalesce variables in MAP of the same type which do not
|
||
|
interfere with each other. LIVEINFO is the live range info for variables
|
||
|
of interest. This will both reduce the memory footprint of the stack, and
|
||
|
allow us to coalesce together local copies of globals and scalarized
|
||
|
component refs. */
|
||
|
|
||
|
static void
|
||
|
coalesce_vars (var_map map, tree_live_info_p liveinfo)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
type_var_p tv;
|
||
|
tree var;
|
||
|
unsigned x, p, p2;
|
||
|
coalesce_list_p cl;
|
||
|
conflict_graph graph;
|
||
|
|
||
|
cl = create_coalesce_list (map);
|
||
|
|
||
|
/* Merge all the live on entry vectors for coalesced partitions. */
|
||
|
for (x = 0; x < num_var_partitions (map); x++)
|
||
|
{
|
||
|
var = partition_to_var (map, x);
|
||
|
p = var_to_partition (map, var);
|
||
|
if (p != x)
|
||
|
live_merge_and_clear (liveinfo, p, x);
|
||
|
}
|
||
|
|
||
|
/* When PHI nodes are turned into copies, the result of each PHI node
|
||
|
becomes live on entry to the block. Mark these now. */
|
||
|
FOR_EACH_BB (bb)
|
||
|
{
|
||
|
tree phi, arg;
|
||
|
unsigned p;
|
||
|
|
||
|
for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
|
||
|
{
|
||
|
p = var_to_partition (map, PHI_RESULT (phi));
|
||
|
|
||
|
/* Skip virtual PHI nodes. */
|
||
|
if (p == (unsigned)NO_PARTITION)
|
||
|
continue;
|
||
|
|
||
|
make_live_on_entry (liveinfo, bb, p);
|
||
|
|
||
|
/* Each argument is a potential copy operation. Add any arguments
|
||
|
which are not coalesced to the result to the coalesce list. */
|
||
|
for (x = 0; x < (unsigned)PHI_NUM_ARGS (phi); x++)
|
||
|
{
|
||
|
arg = PHI_ARG_DEF (phi, x);
|
||
|
if (!phi_ssa_name_p (arg))
|
||
|
continue;
|
||
|
p2 = var_to_partition (map, arg);
|
||
|
if (p2 == (unsigned)NO_PARTITION)
|
||
|
continue;
|
||
|
if (p != p2)
|
||
|
{
|
||
|
edge e = PHI_ARG_EDGE (phi, x);
|
||
|
|
||
|
add_coalesce (cl, p, p2,
|
||
|
coalesce_cost (EDGE_FREQUENCY (e),
|
||
|
maybe_hot_bb_p (bb),
|
||
|
EDGE_CRITICAL_P (e)));
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Re-calculate live on exit info. */
|
||
|
calculate_live_on_exit (liveinfo);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "Live range info for variable memory coalescing.\n");
|
||
|
dump_live_info (dump_file, liveinfo, LIVEDUMP_ALL);
|
||
|
|
||
|
fprintf (dump_file, "Coalesce list from phi nodes:\n");
|
||
|
dump_coalesce_list (dump_file, cl);
|
||
|
}
|
||
|
|
||
|
|
||
|
tv = type_var_init (map);
|
||
|
if (dump_file)
|
||
|
type_var_dump (dump_file, tv);
|
||
|
type_var_compact (tv);
|
||
|
if (dump_file)
|
||
|
type_var_dump (dump_file, tv);
|
||
|
|
||
|
graph = build_tree_conflict_graph (liveinfo, tv, cl);
|
||
|
|
||
|
type_var_decompact (tv);
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "type var list now looks like:n");
|
||
|
type_var_dump (dump_file, tv);
|
||
|
|
||
|
fprintf (dump_file, "Coalesce list after conflict graph build:\n");
|
||
|
dump_coalesce_list (dump_file, cl);
|
||
|
}
|
||
|
|
||
|
sort_coalesce_list (cl);
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "Coalesce list after sorting:\n");
|
||
|
dump_coalesce_list (dump_file, cl);
|
||
|
}
|
||
|
|
||
|
coalesce_tpa_members (tv, graph, map, cl,
|
||
|
((dump_flags & TDF_DETAILS) ? dump_file : NULL));
|
||
|
|
||
|
type_var_delete (tv);
|
||
|
delete_coalesce_list (cl);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Temporary Expression Replacement (TER)
|
||
|
|
||
|
Replace SSA version variables during out-of-ssa with their defining
|
||
|
expression if there is only one use of the variable.
|
||
|
|
||
|
A pass is made through the function, one block at a time. No cross block
|
||
|
information is tracked.
|
||
|
|
||
|
Variables which only have one use, and whose defining stmt is considered
|
||
|
a replaceable expression (see check_replaceable) are entered into
|
||
|
consideration by adding a list of dependent partitions to the version_info
|
||
|
vector for that ssa_name_version. This information comes from the partition
|
||
|
mapping for each USE. At the same time, the partition_dep_list vector for
|
||
|
these partitions have this version number entered into their lists.
|
||
|
|
||
|
When the use of a replaceable ssa_variable is encountered, the dependence
|
||
|
list in version_info[] is moved to the "pending_dependence" list in case
|
||
|
the current expression is also replaceable. (To be determined later in
|
||
|
processing this stmt.) version_info[] for the version is then updated to
|
||
|
point to the defining stmt and the 'replaceable' bit is set.
|
||
|
|
||
|
Any partition which is defined by a statement 'kills' any expression which
|
||
|
is dependent on this partition. Every ssa version in the partitions'
|
||
|
dependence list is removed from future consideration.
|
||
|
|
||
|
All virtual references are lumped together. Any expression which is
|
||
|
dependent on any virtual variable (via a VUSE) has a dependence added
|
||
|
to the special partition defined by VIRTUAL_PARTITION.
|
||
|
|
||
|
Whenever a V_MAY_DEF is seen, all expressions dependent this
|
||
|
VIRTUAL_PARTITION are removed from consideration.
|
||
|
|
||
|
At the end of a basic block, all expression are removed from consideration
|
||
|
in preparation for the next block.
|
||
|
|
||
|
The end result is a vector over SSA_NAME_VERSION which is passed back to
|
||
|
rewrite_out_of_ssa. As the SSA variables are being rewritten, instead of
|
||
|
replacing the SSA_NAME tree element with the partition it was assigned,
|
||
|
it is replaced with the RHS of the defining expression. */
|
||
|
|
||
|
|
||
|
/* Dependency list element. This can contain either a partition index or a
|
||
|
version number, depending on which list it is in. */
|
||
|
|
||
|
typedef struct value_expr_d
|
||
|
{
|
||
|
int value;
|
||
|
struct value_expr_d *next;
|
||
|
} *value_expr_p;
|
||
|
|
||
|
|
||
|
/* Temporary Expression Replacement (TER) table information. */
|
||
|
|
||
|
typedef struct temp_expr_table_d
|
||
|
{
|
||
|
var_map map;
|
||
|
void **version_info;
|
||
|
bitmap *expr_vars;
|
||
|
value_expr_p *partition_dep_list;
|
||
|
bitmap replaceable;
|
||
|
bool saw_replaceable;
|
||
|
int virtual_partition;
|
||
|
bitmap partition_in_use;
|
||
|
value_expr_p free_list;
|
||
|
value_expr_p pending_dependence;
|
||
|
} *temp_expr_table_p;
|
||
|
|
||
|
/* Used to indicate a dependency on V_MAY_DEFs. */
|
||
|
#define VIRTUAL_PARTITION(table) (table->virtual_partition)
|
||
|
|
||
|
static temp_expr_table_p new_temp_expr_table (var_map);
|
||
|
static tree *free_temp_expr_table (temp_expr_table_p);
|
||
|
static inline value_expr_p new_value_expr (temp_expr_table_p);
|
||
|
static inline void free_value_expr (temp_expr_table_p, value_expr_p);
|
||
|
static inline value_expr_p find_value_in_list (value_expr_p, int,
|
||
|
value_expr_p *);
|
||
|
static inline void add_value_to_list (temp_expr_table_p, value_expr_p *, int);
|
||
|
static inline void add_info_to_list (temp_expr_table_p, value_expr_p *,
|
||
|
value_expr_p);
|
||
|
static value_expr_p remove_value_from_list (value_expr_p *, int);
|
||
|
static void add_dependence (temp_expr_table_p, int, tree);
|
||
|
static bool check_replaceable (temp_expr_table_p, tree);
|
||
|
static void finish_expr (temp_expr_table_p, int, bool);
|
||
|
static void mark_replaceable (temp_expr_table_p, tree);
|
||
|
static inline void kill_expr (temp_expr_table_p, int, bool);
|
||
|
static inline void kill_virtual_exprs (temp_expr_table_p, bool);
|
||
|
static void find_replaceable_in_bb (temp_expr_table_p, basic_block);
|
||
|
static tree *find_replaceable_exprs (var_map);
|
||
|
static void dump_replaceable_exprs (FILE *, tree *);
|
||
|
|
||
|
|
||
|
/* Create a new TER table for MAP. */
|
||
|
|
||
|
static temp_expr_table_p
|
||
|
new_temp_expr_table (var_map map)
|
||
|
{
|
||
|
temp_expr_table_p t;
|
||
|
|
||
|
t = XNEW (struct temp_expr_table_d);
|
||
|
t->map = map;
|
||
|
|
||
|
t->version_info = XCNEWVEC (void *, num_ssa_names + 1);
|
||
|
t->expr_vars = XCNEWVEC (bitmap, num_ssa_names + 1);
|
||
|
t->partition_dep_list = XCNEWVEC (value_expr_p,
|
||
|
num_var_partitions (map) + 1);
|
||
|
|
||
|
t->replaceable = BITMAP_ALLOC (NULL);
|
||
|
t->partition_in_use = BITMAP_ALLOC (NULL);
|
||
|
|
||
|
t->saw_replaceable = false;
|
||
|
t->virtual_partition = num_var_partitions (map);
|
||
|
t->free_list = NULL;
|
||
|
t->pending_dependence = NULL;
|
||
|
|
||
|
return t;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Free TER table T. If there are valid replacements, return the expression
|
||
|
vector. */
|
||
|
|
||
|
static tree *
|
||
|
free_temp_expr_table (temp_expr_table_p t)
|
||
|
{
|
||
|
value_expr_p p;
|
||
|
tree *ret = NULL;
|
||
|
unsigned i;
|
||
|
|
||
|
#ifdef ENABLE_CHECKING
|
||
|
unsigned x;
|
||
|
for (x = 0; x <= num_var_partitions (t->map); x++)
|
||
|
gcc_assert (!t->partition_dep_list[x]);
|
||
|
#endif
|
||
|
|
||
|
while ((p = t->free_list))
|
||
|
{
|
||
|
t->free_list = p->next;
|
||
|
free (p);
|
||
|
}
|
||
|
|
||
|
BITMAP_FREE (t->partition_in_use);
|
||
|
BITMAP_FREE (t->replaceable);
|
||
|
|
||
|
for (i = 0; i <= num_ssa_names; i++)
|
||
|
if (t->expr_vars[i])
|
||
|
BITMAP_FREE (t->expr_vars[i]);
|
||
|
free (t->expr_vars);
|
||
|
|
||
|
free (t->partition_dep_list);
|
||
|
if (t->saw_replaceable)
|
||
|
ret = (tree *)t->version_info;
|
||
|
else
|
||
|
free (t->version_info);
|
||
|
|
||
|
free (t);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Allocate a new value list node. Take it from the free list in TABLE if
|
||
|
possible. */
|
||
|
|
||
|
static inline value_expr_p
|
||
|
new_value_expr (temp_expr_table_p table)
|
||
|
{
|
||
|
value_expr_p p;
|
||
|
if (table->free_list)
|
||
|
{
|
||
|
p = table->free_list;
|
||
|
table->free_list = p->next;
|
||
|
}
|
||
|
else
|
||
|
p = (value_expr_p) xmalloc (sizeof (struct value_expr_d));
|
||
|
|
||
|
return p;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Add value list node P to the free list in TABLE. */
|
||
|
|
||
|
static inline void
|
||
|
free_value_expr (temp_expr_table_p table, value_expr_p p)
|
||
|
{
|
||
|
p->next = table->free_list;
|
||
|
table->free_list = p;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Find VALUE if it's in LIST. Return a pointer to the list object if found,
|
||
|
else return NULL. If LAST_PTR is provided, it will point to the previous
|
||
|
item upon return, or NULL if this is the first item in the list. */
|
||
|
|
||
|
static inline value_expr_p
|
||
|
find_value_in_list (value_expr_p list, int value, value_expr_p *last_ptr)
|
||
|
{
|
||
|
value_expr_p curr;
|
||
|
value_expr_p last = NULL;
|
||
|
|
||
|
for (curr = list; curr; last = curr, curr = curr->next)
|
||
|
{
|
||
|
if (curr->value == value)
|
||
|
break;
|
||
|
}
|
||
|
if (last_ptr)
|
||
|
*last_ptr = last;
|
||
|
return curr;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Add VALUE to LIST, if it isn't already present. TAB is the expression
|
||
|
table */
|
||
|
|
||
|
static inline void
|
||
|
add_value_to_list (temp_expr_table_p tab, value_expr_p *list, int value)
|
||
|
{
|
||
|
value_expr_p info;
|
||
|
|
||
|
if (!find_value_in_list (*list, value, NULL))
|
||
|
{
|
||
|
info = new_value_expr (tab);
|
||
|
info->value = value;
|
||
|
info->next = *list;
|
||
|
*list = info;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Add value node INFO if it's value isn't already in LIST. Free INFO if
|
||
|
it is already in the list. TAB is the expression table. */
|
||
|
|
||
|
static inline void
|
||
|
add_info_to_list (temp_expr_table_p tab, value_expr_p *list, value_expr_p info)
|
||
|
{
|
||
|
if (find_value_in_list (*list, info->value, NULL))
|
||
|
free_value_expr (tab, info);
|
||
|
else
|
||
|
{
|
||
|
info->next = *list;
|
||
|
*list = info;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Look for VALUE in LIST. If found, remove it from the list and return it's
|
||
|
pointer. */
|
||
|
|
||
|
static value_expr_p
|
||
|
remove_value_from_list (value_expr_p *list, int value)
|
||
|
{
|
||
|
value_expr_p info, last;
|
||
|
|
||
|
info = find_value_in_list (*list, value, &last);
|
||
|
if (!info)
|
||
|
return NULL;
|
||
|
if (!last)
|
||
|
*list = info->next;
|
||
|
else
|
||
|
last->next = info->next;
|
||
|
|
||
|
return info;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Add a dependency between the def of ssa VERSION and VAR. If VAR is
|
||
|
replaceable by an expression, add a dependence each of the elements of the
|
||
|
expression. These are contained in the pending list. TAB is the
|
||
|
expression table. */
|
||
|
|
||
|
static void
|
||
|
add_dependence (temp_expr_table_p tab, int version, tree var)
|
||
|
{
|
||
|
int i, x;
|
||
|
value_expr_p info;
|
||
|
|
||
|
i = SSA_NAME_VERSION (var);
|
||
|
if (bitmap_bit_p (tab->replaceable, i))
|
||
|
{
|
||
|
/* This variable is being substituted, so use whatever dependences
|
||
|
were queued up when we marked this as replaceable earlier. */
|
||
|
while ((info = tab->pending_dependence))
|
||
|
{
|
||
|
tab->pending_dependence = info->next;
|
||
|
/* Get the partition this variable was dependent on. Reuse this
|
||
|
object to represent the current expression instead. */
|
||
|
x = info->value;
|
||
|
info->value = version;
|
||
|
add_info_to_list (tab, &(tab->partition_dep_list[x]), info);
|
||
|
add_value_to_list (tab,
|
||
|
(value_expr_p *)&(tab->version_info[version]), x);
|
||
|
bitmap_set_bit (tab->partition_in_use, x);
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
i = var_to_partition (tab->map, var);
|
||
|
gcc_assert (i != NO_PARTITION);
|
||
|
add_value_to_list (tab, &(tab->partition_dep_list[i]), version);
|
||
|
add_value_to_list (tab,
|
||
|
(value_expr_p *)&(tab->version_info[version]), i);
|
||
|
bitmap_set_bit (tab->partition_in_use, i);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Check if expression STMT is suitable for replacement in table TAB. If so,
|
||
|
create an expression entry. Return true if this stmt is replaceable. */
|
||
|
|
||
|
static bool
|
||
|
check_replaceable (temp_expr_table_p tab, tree stmt)
|
||
|
{
|
||
|
tree var, def, basevar;
|
||
|
int version;
|
||
|
var_map map = tab->map;
|
||
|
ssa_op_iter iter;
|
||
|
tree call_expr;
|
||
|
bitmap def_vars, use_vars;
|
||
|
|
||
|
if (TREE_CODE (stmt) != MODIFY_EXPR)
|
||
|
return false;
|
||
|
|
||
|
/* Punt if there is more than 1 def, or more than 1 use. */
|
||
|
def = SINGLE_SSA_TREE_OPERAND (stmt, SSA_OP_DEF);
|
||
|
if (!def)
|
||
|
return false;
|
||
|
|
||
|
if (version_ref_count (map, def) != 1)
|
||
|
return false;
|
||
|
|
||
|
/* There must be no V_MAY_DEFS or V_MUST_DEFS. */
|
||
|
if (!(ZERO_SSA_OPERANDS (stmt, (SSA_OP_VMAYDEF | SSA_OP_VMUSTDEF))))
|
||
|
return false;
|
||
|
|
||
|
/* Float expressions must go through memory if float-store is on. */
|
||
|
if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (stmt, 1))))
|
||
|
return false;
|
||
|
|
||
|
/* An assignment with a register variable on the RHS is not
|
||
|
replaceable. */
|
||
|
if (TREE_CODE (TREE_OPERAND (stmt, 1)) == VAR_DECL
|
||
|
&& DECL_HARD_REGISTER (TREE_OPERAND (stmt, 1)))
|
||
|
return false;
|
||
|
|
||
|
/* Calls to functions with side-effects cannot be replaced. */
|
||
|
if ((call_expr = get_call_expr_in (stmt)) != NULL_TREE)
|
||
|
{
|
||
|
int call_flags = call_expr_flags (call_expr);
|
||
|
if (TREE_SIDE_EFFECTS (call_expr)
|
||
|
&& !(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN)))
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
version = SSA_NAME_VERSION (def);
|
||
|
basevar = SSA_NAME_VAR (def);
|
||
|
def_vars = BITMAP_ALLOC (NULL);
|
||
|
bitmap_set_bit (def_vars, DECL_UID (basevar));
|
||
|
|
||
|
/* Add this expression to the dependency list for each use partition. */
|
||
|
FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_USE)
|
||
|
{
|
||
|
add_dependence (tab, version, var);
|
||
|
|
||
|
use_vars = tab->expr_vars[SSA_NAME_VERSION (var)];
|
||
|
if (use_vars)
|
||
|
bitmap_ior_into (def_vars, use_vars);
|
||
|
}
|
||
|
tab->expr_vars[version] = def_vars;
|
||
|
|
||
|
/* If there are VUSES, add a dependence on virtual defs. */
|
||
|
if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_VUSE))
|
||
|
{
|
||
|
add_value_to_list (tab, (value_expr_p *)&(tab->version_info[version]),
|
||
|
VIRTUAL_PARTITION (tab));
|
||
|
add_value_to_list (tab,
|
||
|
&(tab->partition_dep_list[VIRTUAL_PARTITION (tab)]),
|
||
|
version);
|
||
|
bitmap_set_bit (tab->partition_in_use, VIRTUAL_PARTITION (tab));
|
||
|
}
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* This function will remove the expression for VERSION from replacement
|
||
|
consideration.n table TAB If 'replace' is true, it is marked as
|
||
|
replaceable, otherwise not. */
|
||
|
|
||
|
static void
|
||
|
finish_expr (temp_expr_table_p tab, int version, bool replace)
|
||
|
{
|
||
|
value_expr_p info, tmp;
|
||
|
int partition;
|
||
|
|
||
|
/* Remove this expression from its dependent lists. The partition dependence
|
||
|
list is retained and transfered later to whomever uses this version. */
|
||
|
for (info = (value_expr_p) tab->version_info[version]; info; info = tmp)
|
||
|
{
|
||
|
partition = info->value;
|
||
|
gcc_assert (tab->partition_dep_list[partition]);
|
||
|
tmp = remove_value_from_list (&(tab->partition_dep_list[partition]),
|
||
|
version);
|
||
|
gcc_assert (tmp);
|
||
|
free_value_expr (tab, tmp);
|
||
|
/* Only clear the bit when the dependency list is emptied via
|
||
|
a replacement. Otherwise kill_expr will take care of it. */
|
||
|
if (!(tab->partition_dep_list[partition]) && replace)
|
||
|
bitmap_clear_bit (tab->partition_in_use, partition);
|
||
|
tmp = info->next;
|
||
|
if (!replace)
|
||
|
free_value_expr (tab, info);
|
||
|
}
|
||
|
|
||
|
if (replace)
|
||
|
{
|
||
|
tab->saw_replaceable = true;
|
||
|
bitmap_set_bit (tab->replaceable, version);
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
gcc_assert (!bitmap_bit_p (tab->replaceable, version));
|
||
|
tab->version_info[version] = NULL;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Mark the expression associated with VAR as replaceable, and enter
|
||
|
the defining stmt into the version_info table TAB. */
|
||
|
|
||
|
static void
|
||
|
mark_replaceable (temp_expr_table_p tab, tree var)
|
||
|
{
|
||
|
value_expr_p info;
|
||
|
int version = SSA_NAME_VERSION (var);
|
||
|
finish_expr (tab, version, true);
|
||
|
|
||
|
/* Move the dependence list to the pending list. */
|
||
|
if (tab->version_info[version])
|
||
|
{
|
||
|
info = (value_expr_p) tab->version_info[version];
|
||
|
for ( ; info->next; info = info->next)
|
||
|
continue;
|
||
|
info->next = tab->pending_dependence;
|
||
|
tab->pending_dependence = (value_expr_p)tab->version_info[version];
|
||
|
}
|
||
|
|
||
|
tab->version_info[version] = SSA_NAME_DEF_STMT (var);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* This function marks any expression in TAB which is dependent on PARTITION
|
||
|
as NOT replaceable. CLEAR_BIT is used to determine whether partition_in_use
|
||
|
should have its bit cleared. Since this routine can be called within an
|
||
|
EXECUTE_IF_SET_IN_BITMAP, the bit can't always be cleared. */
|
||
|
|
||
|
static inline void
|
||
|
kill_expr (temp_expr_table_p tab, int partition, bool clear_bit)
|
||
|
{
|
||
|
value_expr_p ptr;
|
||
|
|
||
|
/* Mark every active expr dependent on this var as not replaceable. */
|
||
|
while ((ptr = tab->partition_dep_list[partition]) != NULL)
|
||
|
finish_expr (tab, ptr->value, false);
|
||
|
|
||
|
if (clear_bit)
|
||
|
bitmap_clear_bit (tab->partition_in_use, partition);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* This function kills all expressions in TAB which are dependent on virtual
|
||
|
DEFs. CLEAR_BIT determines whether partition_in_use gets cleared. */
|
||
|
|
||
|
static inline void
|
||
|
kill_virtual_exprs (temp_expr_table_p tab, bool clear_bit)
|
||
|
{
|
||
|
kill_expr (tab, VIRTUAL_PARTITION (tab), clear_bit);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* This function processes basic block BB, and looks for variables which can
|
||
|
be replaced by their expressions. Results are stored in TAB. */
|
||
|
|
||
|
static void
|
||
|
find_replaceable_in_bb (temp_expr_table_p tab, basic_block bb)
|
||
|
{
|
||
|
block_stmt_iterator bsi;
|
||
|
tree stmt, def, use;
|
||
|
stmt_ann_t ann;
|
||
|
int partition;
|
||
|
var_map map = tab->map;
|
||
|
value_expr_p p;
|
||
|
ssa_op_iter iter;
|
||
|
|
||
|
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
|
||
|
{
|
||
|
stmt = bsi_stmt (bsi);
|
||
|
ann = stmt_ann (stmt);
|
||
|
|
||
|
/* Determine if this stmt finishes an existing expression. */
|
||
|
FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE)
|
||
|
{
|
||
|
unsigned ver = SSA_NAME_VERSION (use);
|
||
|
|
||
|
if (tab->version_info[ver])
|
||
|
{
|
||
|
bool same_root_var = false;
|
||
|
ssa_op_iter iter2;
|
||
|
bitmap vars = tab->expr_vars[ver];
|
||
|
|
||
|
/* See if the root variables are the same. If they are, we
|
||
|
do not want to do the replacement to avoid problems with
|
||
|
code size, see PR tree-optimization/17549. */
|
||
|
FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter2, SSA_OP_DEF)
|
||
|
{
|
||
|
if (bitmap_bit_p (vars, DECL_UID (SSA_NAME_VAR (def))))
|
||
|
{
|
||
|
same_root_var = true;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Mark expression as replaceable unless stmt is volatile
|
||
|
or DEF sets the same root variable as STMT. */
|
||
|
if (!ann->has_volatile_ops && !same_root_var)
|
||
|
mark_replaceable (tab, use);
|
||
|
else
|
||
|
finish_expr (tab, ver, false);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Next, see if this stmt kills off an active expression. */
|
||
|
FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
|
||
|
{
|
||
|
partition = var_to_partition (map, def);
|
||
|
if (partition != NO_PARTITION && tab->partition_dep_list[partition])
|
||
|
kill_expr (tab, partition, true);
|
||
|
}
|
||
|
|
||
|
/* Now see if we are creating a new expression or not. */
|
||
|
if (!ann->has_volatile_ops)
|
||
|
check_replaceable (tab, stmt);
|
||
|
|
||
|
/* Free any unused dependency lists. */
|
||
|
while ((p = tab->pending_dependence))
|
||
|
{
|
||
|
tab->pending_dependence = p->next;
|
||
|
free_value_expr (tab, p);
|
||
|
}
|
||
|
|
||
|
/* A V_{MAY,MUST}_DEF kills any expression using a virtual operand. */
|
||
|
if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_DEFS))
|
||
|
kill_virtual_exprs (tab, true);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
/* This function is the driver routine for replacement of temporary expressions
|
||
|
in the SSA->normal phase, operating on MAP. If there are replaceable
|
||
|
expressions, a table is returned which maps SSA versions to the
|
||
|
expressions they should be replaced with. A NULL_TREE indicates no
|
||
|
replacement should take place. If there are no replacements at all,
|
||
|
NULL is returned by the function, otherwise an expression vector indexed
|
||
|
by SSA_NAME version numbers. */
|
||
|
|
||
|
static tree *
|
||
|
find_replaceable_exprs (var_map map)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
unsigned i;
|
||
|
temp_expr_table_p table;
|
||
|
tree *ret;
|
||
|
|
||
|
table = new_temp_expr_table (map);
|
||
|
FOR_EACH_BB (bb)
|
||
|
{
|
||
|
bitmap_iterator bi;
|
||
|
|
||
|
find_replaceable_in_bb (table, bb);
|
||
|
EXECUTE_IF_SET_IN_BITMAP ((table->partition_in_use), 0, i, bi)
|
||
|
{
|
||
|
kill_expr (table, i, false);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
ret = free_temp_expr_table (table);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Dump TER expression table EXPR to file F. */
|
||
|
|
||
|
static void
|
||
|
dump_replaceable_exprs (FILE *f, tree *expr)
|
||
|
{
|
||
|
tree stmt, var;
|
||
|
int x;
|
||
|
fprintf (f, "\nReplacing Expressions\n");
|
||
|
for (x = 0; x < (int)num_ssa_names + 1; x++)
|
||
|
if (expr[x])
|
||
|
{
|
||
|
stmt = expr[x];
|
||
|
var = SINGLE_SSA_TREE_OPERAND (stmt, SSA_OP_DEF);
|
||
|
gcc_assert (var != NULL_TREE);
|
||
|
print_generic_expr (f, var, TDF_SLIM);
|
||
|
fprintf (f, " replace with --> ");
|
||
|
print_generic_expr (f, TREE_OPERAND (stmt, 1), TDF_SLIM);
|
||
|
fprintf (f, "\n");
|
||
|
}
|
||
|
fprintf (f, "\n");
|
||
|
}
|
||
|
|
||
|
|
||
|
/* This function will rewrite the current program using the variable mapping
|
||
|
found in MAP. If the replacement vector VALUES is provided, any
|
||
|
occurrences of partitions with non-null entries in the vector will be
|
||
|
replaced with the expression in the vector instead of its mapped
|
||
|
variable. */
|
||
|
|
||
|
static void
|
||
|
rewrite_trees (var_map map, tree *values)
|
||
|
{
|
||
|
elim_graph g;
|
||
|
basic_block bb;
|
||
|
block_stmt_iterator si;
|
||
|
edge e;
|
||
|
tree phi;
|
||
|
bool changed;
|
||
|
|
||
|
#ifdef ENABLE_CHECKING
|
||
|
/* Search for PHIs where the destination has no partition, but one
|
||
|
or more arguments has a partition. This should not happen and can
|
||
|
create incorrect code. */
|
||
|
FOR_EACH_BB (bb)
|
||
|
{
|
||
|
tree phi;
|
||
|
|
||
|
for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
|
||
|
{
|
||
|
tree T0 = var_to_partition_to_var (map, PHI_RESULT (phi));
|
||
|
|
||
|
if (T0 == NULL_TREE)
|
||
|
{
|
||
|
int i;
|
||
|
|
||
|
for (i = 0; i < PHI_NUM_ARGS (phi); i++)
|
||
|
{
|
||
|
tree arg = PHI_ARG_DEF (phi, i);
|
||
|
|
||
|
if (TREE_CODE (arg) == SSA_NAME
|
||
|
&& var_to_partition (map, arg) != NO_PARTITION)
|
||
|
{
|
||
|
fprintf (stderr, "Argument of PHI is in a partition :(");
|
||
|
print_generic_expr (stderr, arg, TDF_SLIM);
|
||
|
fprintf (stderr, "), but the result is not :");
|
||
|
print_generic_stmt (stderr, phi, TDF_SLIM);
|
||
|
internal_error ("SSA corruption");
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
/* Replace PHI nodes with any required copies. */
|
||
|
g = new_elim_graph (map->num_partitions);
|
||
|
g->map = map;
|
||
|
FOR_EACH_BB (bb)
|
||
|
{
|
||
|
for (si = bsi_start (bb); !bsi_end_p (si); )
|
||
|
{
|
||
|
tree stmt = bsi_stmt (si);
|
||
|
use_operand_p use_p, copy_use_p;
|
||
|
def_operand_p def_p;
|
||
|
bool remove = false, is_copy = false;
|
||
|
int num_uses = 0;
|
||
|
stmt_ann_t ann;
|
||
|
ssa_op_iter iter;
|
||
|
|
||
|
ann = stmt_ann (stmt);
|
||
|
changed = false;
|
||
|
|
||
|
if (TREE_CODE (stmt) == MODIFY_EXPR
|
||
|
&& (TREE_CODE (TREE_OPERAND (stmt, 1)) == SSA_NAME))
|
||
|
is_copy = true;
|
||
|
|
||
|
copy_use_p = NULL_USE_OPERAND_P;
|
||
|
FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE)
|
||
|
{
|
||
|
if (replace_use_variable (map, use_p, values))
|
||
|
changed = true;
|
||
|
copy_use_p = use_p;
|
||
|
num_uses++;
|
||
|
}
|
||
|
|
||
|
if (num_uses != 1)
|
||
|
is_copy = false;
|
||
|
|
||
|
def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_DEF);
|
||
|
|
||
|
if (def_p != NULL)
|
||
|
{
|
||
|
/* Mark this stmt for removal if it is the list of replaceable
|
||
|
expressions. */
|
||
|
if (values && values[SSA_NAME_VERSION (DEF_FROM_PTR (def_p))])
|
||
|
remove = true;
|
||
|
else
|
||
|
{
|
||
|
if (replace_def_variable (map, def_p, NULL))
|
||
|
changed = true;
|
||
|
/* If both SSA_NAMEs coalesce to the same variable,
|
||
|
mark the now redundant copy for removal. */
|
||
|
if (is_copy)
|
||
|
{
|
||
|
gcc_assert (copy_use_p != NULL_USE_OPERAND_P);
|
||
|
if (DEF_FROM_PTR (def_p) == USE_FROM_PTR (copy_use_p))
|
||
|
remove = true;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, iter, SSA_OP_DEF)
|
||
|
if (replace_def_variable (map, def_p, NULL))
|
||
|
changed = true;
|
||
|
|
||
|
/* Remove any stmts marked for removal. */
|
||
|
if (remove)
|
||
|
bsi_remove (&si, true);
|
||
|
else
|
||
|
bsi_next (&si);
|
||
|
}
|
||
|
|
||
|
phi = phi_nodes (bb);
|
||
|
if (phi)
|
||
|
{
|
||
|
edge_iterator ei;
|
||
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
|
eliminate_phi (e, g);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
delete_elim_graph (g);
|
||
|
}
|
||
|
|
||
|
|
||
|
DEF_VEC_ALLOC_P(edge,heap);
|
||
|
|
||
|
/* These are the local work structures used to determine the best place to
|
||
|
insert the copies that were placed on edges by the SSA->normal pass.. */
|
||
|
static VEC(edge,heap) *edge_leader;
|
||
|
static VEC(tree,heap) *stmt_list;
|
||
|
static bitmap leader_has_match = NULL;
|
||
|
static edge leader_match = NULL;
|
||
|
|
||
|
|
||
|
/* Pass this function to make_forwarder_block so that all the edges with
|
||
|
matching PENDING_STMT lists to 'curr_stmt_list' get redirected. */
|
||
|
static bool
|
||
|
same_stmt_list_p (edge e)
|
||
|
{
|
||
|
return (e->aux == (PTR) leader_match) ? true : false;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Return TRUE if S1 and S2 are equivalent copies. */
|
||
|
static inline bool
|
||
|
identical_copies_p (tree s1, tree s2)
|
||
|
{
|
||
|
#ifdef ENABLE_CHECKING
|
||
|
gcc_assert (TREE_CODE (s1) == MODIFY_EXPR);
|
||
|
gcc_assert (TREE_CODE (s2) == MODIFY_EXPR);
|
||
|
gcc_assert (DECL_P (TREE_OPERAND (s1, 0)));
|
||
|
gcc_assert (DECL_P (TREE_OPERAND (s2, 0)));
|
||
|
#endif
|
||
|
|
||
|
if (TREE_OPERAND (s1, 0) != TREE_OPERAND (s2, 0))
|
||
|
return false;
|
||
|
|
||
|
s1 = TREE_OPERAND (s1, 1);
|
||
|
s2 = TREE_OPERAND (s2, 1);
|
||
|
|
||
|
if (s1 != s2)
|
||
|
return false;
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Compare the PENDING_STMT list for two edges, and return true if the lists
|
||
|
contain the same sequence of copies. */
|
||
|
|
||
|
static inline bool
|
||
|
identical_stmt_lists_p (edge e1, edge e2)
|
||
|
{
|
||
|
tree t1 = PENDING_STMT (e1);
|
||
|
tree t2 = PENDING_STMT (e2);
|
||
|
tree_stmt_iterator tsi1, tsi2;
|
||
|
|
||
|
gcc_assert (TREE_CODE (t1) == STATEMENT_LIST);
|
||
|
gcc_assert (TREE_CODE (t2) == STATEMENT_LIST);
|
||
|
|
||
|
for (tsi1 = tsi_start (t1), tsi2 = tsi_start (t2);
|
||
|
!tsi_end_p (tsi1) && !tsi_end_p (tsi2);
|
||
|
tsi_next (&tsi1), tsi_next (&tsi2))
|
||
|
{
|
||
|
if (!identical_copies_p (tsi_stmt (tsi1), tsi_stmt (tsi2)))
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
if (!tsi_end_p (tsi1) || ! tsi_end_p (tsi2))
|
||
|
return false;
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Allocate data structures used in analyze_edges_for_bb. */
|
||
|
|
||
|
static void
|
||
|
init_analyze_edges_for_bb (void)
|
||
|
{
|
||
|
edge_leader = VEC_alloc (edge, heap, 25);
|
||
|
stmt_list = VEC_alloc (tree, heap, 25);
|
||
|
leader_has_match = BITMAP_ALLOC (NULL);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Free data structures used in analyze_edges_for_bb. */
|
||
|
|
||
|
static void
|
||
|
fini_analyze_edges_for_bb (void)
|
||
|
{
|
||
|
VEC_free (edge, heap, edge_leader);
|
||
|
VEC_free (tree, heap, stmt_list);
|
||
|
BITMAP_FREE (leader_has_match);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Look at all the incoming edges to block BB, and decide where the best place
|
||
|
to insert the stmts on each edge are, and perform those insertions. */
|
||
|
|
||
|
static void
|
||
|
analyze_edges_for_bb (basic_block bb)
|
||
|
{
|
||
|
edge e;
|
||
|
edge_iterator ei;
|
||
|
int count;
|
||
|
unsigned int x;
|
||
|
bool have_opportunity;
|
||
|
block_stmt_iterator bsi;
|
||
|
tree stmt;
|
||
|
edge single_edge = NULL;
|
||
|
bool is_label;
|
||
|
edge leader;
|
||
|
|
||
|
count = 0;
|
||
|
|
||
|
/* Blocks which contain at least one abnormal edge cannot use
|
||
|
make_forwarder_block. Look for these blocks, and commit any PENDING_STMTs
|
||
|
found on edges in these block. */
|
||
|
have_opportunity = true;
|
||
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
|
if (e->flags & EDGE_ABNORMAL)
|
||
|
{
|
||
|
have_opportunity = false;
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
if (!have_opportunity)
|
||
|
{
|
||
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
|
if (PENDING_STMT (e))
|
||
|
bsi_commit_one_edge_insert (e, NULL);
|
||
|
return;
|
||
|
}
|
||
|
/* Find out how many edges there are with interesting pending stmts on them.
|
||
|
Commit the stmts on edges we are not interested in. */
|
||
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
|
{
|
||
|
if (PENDING_STMT (e))
|
||
|
{
|
||
|
gcc_assert (!(e->flags & EDGE_ABNORMAL));
|
||
|
if (e->flags & EDGE_FALLTHRU)
|
||
|
{
|
||
|
bsi = bsi_start (e->src);
|
||
|
if (!bsi_end_p (bsi))
|
||
|
{
|
||
|
stmt = bsi_stmt (bsi);
|
||
|
bsi_next (&bsi);
|
||
|
gcc_assert (stmt != NULL_TREE);
|
||
|
is_label = (TREE_CODE (stmt) == LABEL_EXPR);
|
||
|
/* Punt if it has non-label stmts, or isn't local. */
|
||
|
if (!is_label || DECL_NONLOCAL (TREE_OPERAND (stmt, 0))
|
||
|
|| !bsi_end_p (bsi))
|
||
|
{
|
||
|
bsi_commit_one_edge_insert (e, NULL);
|
||
|
continue;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
single_edge = e;
|
||
|
count++;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* If there aren't at least 2 edges, no sharing will happen. */
|
||
|
if (count < 2)
|
||
|
{
|
||
|
if (single_edge)
|
||
|
bsi_commit_one_edge_insert (single_edge, NULL);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/* Ensure that we have empty worklists. */
|
||
|
#ifdef ENABLE_CHECKING
|
||
|
gcc_assert (VEC_length (edge, edge_leader) == 0);
|
||
|
gcc_assert (VEC_length (tree, stmt_list) == 0);
|
||
|
gcc_assert (bitmap_empty_p (leader_has_match));
|
||
|
#endif
|
||
|
|
||
|
/* Find the "leader" block for each set of unique stmt lists. Preference is
|
||
|
given to FALLTHRU blocks since they would need a GOTO to arrive at another
|
||
|
block. The leader edge destination is the block which all the other edges
|
||
|
with the same stmt list will be redirected to. */
|
||
|
have_opportunity = false;
|
||
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
|
{
|
||
|
if (PENDING_STMT (e))
|
||
|
{
|
||
|
bool found = false;
|
||
|
|
||
|
/* Look for the same stmt list in edge leaders list. */
|
||
|
for (x = 0; VEC_iterate (edge, edge_leader, x, leader); x++)
|
||
|
{
|
||
|
if (identical_stmt_lists_p (leader, e))
|
||
|
{
|
||
|
/* Give this edge the same stmt list pointer. */
|
||
|
PENDING_STMT (e) = NULL;
|
||
|
e->aux = leader;
|
||
|
bitmap_set_bit (leader_has_match, x);
|
||
|
have_opportunity = found = true;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* If no similar stmt list, add this edge to the leader list. */
|
||
|
if (!found)
|
||
|
{
|
||
|
VEC_safe_push (edge, heap, edge_leader, e);
|
||
|
VEC_safe_push (tree, heap, stmt_list, PENDING_STMT (e));
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* If there are no similar lists, just issue the stmts. */
|
||
|
if (!have_opportunity)
|
||
|
{
|
||
|
for (x = 0; VEC_iterate (edge, edge_leader, x, leader); x++)
|
||
|
bsi_commit_one_edge_insert (leader, NULL);
|
||
|
VEC_truncate (edge, edge_leader, 0);
|
||
|
VEC_truncate (tree, stmt_list, 0);
|
||
|
bitmap_clear (leader_has_match);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
|
||
|
if (dump_file)
|
||
|
fprintf (dump_file, "\nOpportunities in BB %d for stmt/block reduction:\n",
|
||
|
bb->index);
|
||
|
|
||
|
|
||
|
/* For each common list, create a forwarding block and issue the stmt's
|
||
|
in that block. */
|
||
|
for (x = 0; VEC_iterate (edge, edge_leader, x, leader); x++)
|
||
|
if (bitmap_bit_p (leader_has_match, x))
|
||
|
{
|
||
|
edge new_edge;
|
||
|
block_stmt_iterator bsi;
|
||
|
tree curr_stmt_list;
|
||
|
|
||
|
leader_match = leader;
|
||
|
|
||
|
/* The tree_* cfg manipulation routines use the PENDING_EDGE field
|
||
|
for various PHI manipulations, so it gets cleared when calls are
|
||
|
made to make_forwarder_block(). So make sure the edge is clear,
|
||
|
and use the saved stmt list. */
|
||
|
PENDING_STMT (leader) = NULL;
|
||
|
leader->aux = leader;
|
||
|
curr_stmt_list = VEC_index (tree, stmt_list, x);
|
||
|
|
||
|
new_edge = make_forwarder_block (leader->dest, same_stmt_list_p,
|
||
|
NULL);
|
||
|
bb = new_edge->dest;
|
||
|
if (dump_file)
|
||
|
{
|
||
|
fprintf (dump_file, "Splitting BB %d for Common stmt list. ",
|
||
|
leader->dest->index);
|
||
|
fprintf (dump_file, "Original block is now BB%d.\n", bb->index);
|
||
|
print_generic_stmt (dump_file, curr_stmt_list, TDF_VOPS);
|
||
|
}
|
||
|
|
||
|
FOR_EACH_EDGE (e, ei, new_edge->src->preds)
|
||
|
{
|
||
|
e->aux = NULL;
|
||
|
if (dump_file)
|
||
|
fprintf (dump_file, " Edge (%d->%d) lands here.\n",
|
||
|
e->src->index, e->dest->index);
|
||
|
}
|
||
|
|
||
|
bsi = bsi_last (leader->dest);
|
||
|
bsi_insert_after (&bsi, curr_stmt_list, BSI_NEW_STMT);
|
||
|
|
||
|
leader_match = NULL;
|
||
|
/* We should never get a new block now. */
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
PENDING_STMT (leader) = VEC_index (tree, stmt_list, x);
|
||
|
bsi_commit_one_edge_insert (leader, NULL);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Clear the working data structures. */
|
||
|
VEC_truncate (edge, edge_leader, 0);
|
||
|
VEC_truncate (tree, stmt_list, 0);
|
||
|
bitmap_clear (leader_has_match);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* This function will analyze the insertions which were performed on edges,
|
||
|
and decide whether they should be left on that edge, or whether it is more
|
||
|
efficient to emit some subset of them in a single block. All stmts are
|
||
|
inserted somewhere. */
|
||
|
|
||
|
static void
|
||
|
perform_edge_inserts (void)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
|
||
|
if (dump_file)
|
||
|
fprintf(dump_file, "Analyzing Edge Insertions.\n");
|
||
|
|
||
|
/* analyze_edges_for_bb calls make_forwarder_block, which tries to
|
||
|
incrementally update the dominator information. Since we don't
|
||
|
need dominator information after this pass, go ahead and free the
|
||
|
dominator information. */
|
||
|
free_dominance_info (CDI_DOMINATORS);
|
||
|
free_dominance_info (CDI_POST_DOMINATORS);
|
||
|
|
||
|
/* Allocate data structures used in analyze_edges_for_bb. */
|
||
|
init_analyze_edges_for_bb ();
|
||
|
|
||
|
FOR_EACH_BB (bb)
|
||
|
analyze_edges_for_bb (bb);
|
||
|
|
||
|
analyze_edges_for_bb (EXIT_BLOCK_PTR);
|
||
|
|
||
|
/* Free data structures used in analyze_edges_for_bb. */
|
||
|
fini_analyze_edges_for_bb ();
|
||
|
|
||
|
#ifdef ENABLE_CHECKING
|
||
|
{
|
||
|
edge_iterator ei;
|
||
|
edge e;
|
||
|
FOR_EACH_BB (bb)
|
||
|
{
|
||
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
|
{
|
||
|
if (PENDING_STMT (e))
|
||
|
error (" Pending stmts not issued on PRED edge (%d, %d)\n",
|
||
|
e->src->index, e->dest->index);
|
||
|
}
|
||
|
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
|
{
|
||
|
if (PENDING_STMT (e))
|
||
|
error (" Pending stmts not issued on SUCC edge (%d, %d)\n",
|
||
|
e->src->index, e->dest->index);
|
||
|
}
|
||
|
}
|
||
|
FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
|
||
|
{
|
||
|
if (PENDING_STMT (e))
|
||
|
error (" Pending stmts not issued on ENTRY edge (%d, %d)\n",
|
||
|
e->src->index, e->dest->index);
|
||
|
}
|
||
|
FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
|
||
|
{
|
||
|
if (PENDING_STMT (e))
|
||
|
error (" Pending stmts not issued on EXIT edge (%d, %d)\n",
|
||
|
e->src->index, e->dest->index);
|
||
|
}
|
||
|
}
|
||
|
#endif
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Remove the variables specified in MAP from SSA form. FLAGS indicate what
|
||
|
options should be used. */
|
||
|
|
||
|
static void
|
||
|
remove_ssa_form (var_map map, int flags)
|
||
|
{
|
||
|
tree_live_info_p liveinfo;
|
||
|
basic_block bb;
|
||
|
tree phi, next;
|
||
|
tree *values = NULL;
|
||
|
|
||
|
/* If we are not combining temps, don't calculate live ranges for variables
|
||
|
with only one SSA version. */
|
||
|
if ((flags & SSANORM_COMBINE_TEMPS) == 0)
|
||
|
compact_var_map (map, VARMAP_NO_SINGLE_DEFS);
|
||
|
else
|
||
|
compact_var_map (map, VARMAP_NORMAL);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
dump_var_map (dump_file, map);
|
||
|
|
||
|
liveinfo = coalesce_ssa_name (map, flags);
|
||
|
|
||
|
/* Make sure even single occurrence variables are in the list now. */
|
||
|
if ((flags & SSANORM_COMBINE_TEMPS) == 0)
|
||
|
compact_var_map (map, VARMAP_NORMAL);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "After Coalescing:\n");
|
||
|
dump_var_map (dump_file, map);
|
||
|
}
|
||
|
|
||
|
if (flags & SSANORM_PERFORM_TER)
|
||
|
{
|
||
|
values = find_replaceable_exprs (map);
|
||
|
if (values && dump_file && (dump_flags & TDF_DETAILS))
|
||
|
dump_replaceable_exprs (dump_file, values);
|
||
|
}
|
||
|
|
||
|
/* Assign real variables to the partitions now. */
|
||
|
assign_vars (map);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "After Root variable replacement:\n");
|
||
|
dump_var_map (dump_file, map);
|
||
|
}
|
||
|
|
||
|
if ((flags & SSANORM_COMBINE_TEMPS) && liveinfo)
|
||
|
{
|
||
|
coalesce_vars (map, liveinfo);
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
{
|
||
|
fprintf (dump_file, "After variable memory coalescing:\n");
|
||
|
dump_var_map (dump_file, map);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (liveinfo)
|
||
|
delete_tree_live_info (liveinfo);
|
||
|
|
||
|
rewrite_trees (map, values);
|
||
|
|
||
|
if (values)
|
||
|
free (values);
|
||
|
|
||
|
/* Remove phi nodes which have been translated back to real variables. */
|
||
|
FOR_EACH_BB (bb)
|
||
|
{
|
||
|
for (phi = phi_nodes (bb); phi; phi = next)
|
||
|
{
|
||
|
next = PHI_CHAIN (phi);
|
||
|
remove_phi_node (phi, NULL_TREE);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* we no longer maintain the SSA operand cache at this point. */
|
||
|
fini_ssa_operands ();
|
||
|
|
||
|
/* If any copies were inserted on edges, analyze and insert them now. */
|
||
|
perform_edge_inserts ();
|
||
|
}
|
||
|
|
||
|
/* Search every PHI node for arguments associated with backedges which
|
||
|
we can trivially determine will need a copy (the argument is either
|
||
|
not an SSA_NAME or the argument has a different underlying variable
|
||
|
than the PHI result).
|
||
|
|
||
|
Insert a copy from the PHI argument to a new destination at the
|
||
|
end of the block with the backedge to the top of the loop. Update
|
||
|
the PHI argument to reference this new destination. */
|
||
|
|
||
|
static void
|
||
|
insert_backedge_copies (void)
|
||
|
{
|
||
|
basic_block bb;
|
||
|
|
||
|
FOR_EACH_BB (bb)
|
||
|
{
|
||
|
tree phi;
|
||
|
|
||
|
for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
|
||
|
{
|
||
|
tree result = PHI_RESULT (phi);
|
||
|
tree result_var;
|
||
|
int i;
|
||
|
|
||
|
if (!is_gimple_reg (result))
|
||
|
continue;
|
||
|
|
||
|
result_var = SSA_NAME_VAR (result);
|
||
|
for (i = 0; i < PHI_NUM_ARGS (phi); i++)
|
||
|
{
|
||
|
tree arg = PHI_ARG_DEF (phi, i);
|
||
|
edge e = PHI_ARG_EDGE (phi, i);
|
||
|
|
||
|
/* If the argument is not an SSA_NAME, then we will
|
||
|
need a constant initialization. If the argument is
|
||
|
an SSA_NAME with a different underlying variable and
|
||
|
we are not combining temporaries, then we will
|
||
|
need a copy statement. */
|
||
|
if ((e->flags & EDGE_DFS_BACK)
|
||
|
&& (TREE_CODE (arg) != SSA_NAME
|
||
|
|| (!flag_tree_combine_temps
|
||
|
&& SSA_NAME_VAR (arg) != result_var)))
|
||
|
{
|
||
|
tree stmt, name, last = NULL;
|
||
|
block_stmt_iterator bsi;
|
||
|
|
||
|
bsi = bsi_last (PHI_ARG_EDGE (phi, i)->src);
|
||
|
if (!bsi_end_p (bsi))
|
||
|
last = bsi_stmt (bsi);
|
||
|
|
||
|
/* In theory the only way we ought to get back to the
|
||
|
start of a loop should be with a COND_EXPR or GOTO_EXPR.
|
||
|
However, better safe than sorry.
|
||
|
|
||
|
If the block ends with a control statement or
|
||
|
something that might throw, then we have to
|
||
|
insert this assignment before the last
|
||
|
statement. Else insert it after the last statement. */
|
||
|
if (last && stmt_ends_bb_p (last))
|
||
|
{
|
||
|
/* If the last statement in the block is the definition
|
||
|
site of the PHI argument, then we can't insert
|
||
|
anything after it. */
|
||
|
if (TREE_CODE (arg) == SSA_NAME
|
||
|
&& SSA_NAME_DEF_STMT (arg) == last)
|
||
|
continue;
|
||
|
}
|
||
|
|
||
|
/* Create a new instance of the underlying
|
||
|
variable of the PHI result. */
|
||
|
stmt = build2 (MODIFY_EXPR, TREE_TYPE (result_var),
|
||
|
NULL_TREE, PHI_ARG_DEF (phi, i));
|
||
|
name = make_ssa_name (result_var, stmt);
|
||
|
TREE_OPERAND (stmt, 0) = name;
|
||
|
|
||
|
/* Insert the new statement into the block and update
|
||
|
the PHI node. */
|
||
|
if (last && stmt_ends_bb_p (last))
|
||
|
bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
|
||
|
else
|
||
|
bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
|
||
|
SET_PHI_ARG_DEF (phi, i, name);
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Take the current function out of SSA form, as described in
|
||
|
R. Morgan, ``Building an Optimizing Compiler'',
|
||
|
Butterworth-Heinemann, Boston, MA, 1998. pp 176-186. */
|
||
|
|
||
|
static unsigned int
|
||
|
rewrite_out_of_ssa (void)
|
||
|
{
|
||
|
var_map map;
|
||
|
int var_flags = 0;
|
||
|
int ssa_flags = 0;
|
||
|
|
||
|
/* If elimination of a PHI requires inserting a copy on a backedge,
|
||
|
then we will have to split the backedge which has numerous
|
||
|
undesirable performance effects.
|
||
|
|
||
|
A significant number of such cases can be handled here by inserting
|
||
|
copies into the loop itself. */
|
||
|
insert_backedge_copies ();
|
||
|
|
||
|
if (!flag_tree_live_range_split)
|
||
|
ssa_flags |= SSANORM_COALESCE_PARTITIONS;
|
||
|
|
||
|
eliminate_virtual_phis ();
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
dump_tree_cfg (dump_file, dump_flags & ~TDF_DETAILS);
|
||
|
|
||
|
/* We cannot allow unssa to un-gimplify trees before we instrument them. */
|
||
|
if (flag_tree_ter && !flag_mudflap)
|
||
|
var_flags = SSA_VAR_MAP_REF_COUNT;
|
||
|
|
||
|
map = create_ssa_var_map (var_flags);
|
||
|
|
||
|
if (flag_tree_combine_temps)
|
||
|
ssa_flags |= SSANORM_COMBINE_TEMPS;
|
||
|
if (flag_tree_ter && !flag_mudflap)
|
||
|
ssa_flags |= SSANORM_PERFORM_TER;
|
||
|
|
||
|
remove_ssa_form (map, ssa_flags);
|
||
|
|
||
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
|
dump_tree_cfg (dump_file, dump_flags & ~TDF_DETAILS);
|
||
|
|
||
|
/* Flush out flow graph and SSA data. */
|
||
|
delete_var_map (map);
|
||
|
|
||
|
in_ssa_p = false;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* Define the parameters of the out of SSA pass. */
|
||
|
|
||
|
struct tree_opt_pass pass_del_ssa =
|
||
|
{
|
||
|
"optimized", /* name */
|
||
|
NULL, /* gate */
|
||
|
rewrite_out_of_ssa, /* execute */
|
||
|
NULL, /* sub */
|
||
|
NULL, /* next */
|
||
|
0, /* static_pass_number */
|
||
|
TV_TREE_SSA_TO_NORMAL, /* tv_id */
|
||
|
PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
|
||
|
0, /* properties_provided */
|
||
|
/* ??? If TER is enabled, we also kill gimple. */
|
||
|
PROP_ssa, /* properties_destroyed */
|
||
|
TODO_verify_ssa | TODO_verify_flow
|
||
|
| TODO_verify_stmts, /* todo_flags_start */
|
||
|
TODO_dump_func
|
||
|
| TODO_ggc_collect
|
||
|
| TODO_remove_unused_locals, /* todo_flags_finish */
|
||
|
0 /* letter */
|
||
|
};
|