X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Ftree-outof-ssa.c;h=82cc0ffea59e9752f737914a6f58d2a80ce0f445;hb=a0d20ccbd97fde9c2af1f7345e3eb1313dea570f;hp=3910501f1ea2d912a5bdb346a3564ee9083efe2c;hpb=8c0963c4a8751406a784d5c4c34001e18272463a;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/tree-outof-ssa.c b/gcc/tree-outof-ssa.c index 3910501f1ea..82cc0ffea59 100644 --- a/gcc/tree-outof-ssa.c +++ b/gcc/tree-outof-ssa.c @@ -1,12 +1,12 @@ /* Convert a program in SSA form into Normal form. - Copyright (C) 2004 Free Software Foundation, Inc. + Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc. Contributed by Andrew Macleod This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) +the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, @@ -15,46 +15,25 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License -along with GCC; see the file COPYING. If not, write to -the Free Software Foundation, 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. */ +along with GCC; see the file COPYING3. If not see +. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "tree.h" -#include "flags.h" -#include "rtl.h" -#include "tm_p.h" #include "ggc.h" -#include "langhooks.h" -#include "hard-reg-set.h" #include "basic-block.h" -#include "output.h" -#include "errors.h" -#include "expr.h" -#include "function.h" #include "diagnostic.h" #include "bitmap.h" #include "tree-flow.h" -#include "tree-gimple.h" -#include "tree-inline.h" -#include "varray.h" #include "timevar.h" -#include "tree-alias-common.h" -#include "hashtab.h" #include "tree-dump.h" #include "tree-ssa-live.h" #include "tree-pass.h" +#include "toplev.h" -/* Flags to pass to remove_ssa_form. */ - -#define SSANORM_PERFORM_TER 0x1 -#define SSANORM_COMBINE_TEMPS 0x2 -#define SSANORM_REMOVE_ALL_PHIS 0x4 -#define SSANORM_COALESCE_PARTITIONS 0x8 -#define SSANORM_USE_COALESCE_LIST 0x10 /* Used to hold all the components required to do SSA PHI elimination. The node and pred/succ list is a simple linear list of nodes and @@ -82,16 +61,16 @@ typedef struct _elim_graph { int size; /* List of nodes in the elimination graph. */ - varray_type nodes; + VEC(tree,heap) *nodes; /* The predecessor and successor edge list. */ - varray_type edge_list; + VEC(int,heap) *edge_list; /* Visited vector. */ sbitmap visited; /* Stack for visited nodes. */ - varray_type stack; + VEC(int,heap) *stack; /* The variable partition map. */ var_map map; @@ -100,40 +79,10 @@ typedef struct _elim_graph { edge e; /* List of constant copies to emit. These are pushed on in pairs. */ - varray_type const_copies; + VEC(tree,heap) *const_copies; } *elim_graph; -/* Local functions. */ -static tree create_temp (tree); -static void insert_copy_on_edge (edge, tree, tree); -static elim_graph new_elim_graph (int); -static inline void delete_elim_graph (elim_graph); -static inline void clear_elim_graph (elim_graph); -static inline int elim_graph_size (elim_graph); -static inline void elim_graph_add_node (elim_graph, tree); -static inline void elim_graph_add_edge (elim_graph, int, int); -static inline int elim_graph_remove_succ_edge (elim_graph, int); - -static inline void eliminate_name (elim_graph, tree); -static void eliminate_build (elim_graph, basic_block, int); -static void elim_forward (elim_graph, int); -static int elim_unvisited_predecessor (elim_graph, int); -static void elim_backward (elim_graph, int); -static void elim_create (elim_graph, int); -static void eliminate_phi (edge, int, elim_graph); -static tree_live_info_p coalesce_ssa_name (var_map, int); -static void assign_vars (var_map); -static bool replace_use_variable (var_map, use_operand_p, tree *); -static bool replace_def_variable (var_map, def_operand_p, tree *); -static void eliminate_virtual_phis (void); -static void coalesce_abnormal_edges (var_map, conflict_graph, root_var_p); -static void print_exprs (FILE *, const char *, tree, const char *, tree, - const char *); -static void print_exprs_edge (FILE *, edge, const char *, tree, const char *, - tree); - - /* Create a temporary variable based on the type of variable T. Use T's name as the prefix. */ @@ -157,15 +106,30 @@ create_temp (tree t) if (name == NULL) name = "temp"; tmp = create_tmp_var (type, name); + + if (DECL_DEBUG_EXPR_IS_FROM (t) && DECL_DEBUG_EXPR (t)) + { + SET_DECL_DEBUG_EXPR (tmp, DECL_DEBUG_EXPR (t)); + DECL_DEBUG_EXPR_IS_FROM (tmp) = 1; + } + else if (!DECL_IGNORED_P (t)) + { + SET_DECL_DEBUG_EXPR (tmp, t); + DECL_DEBUG_EXPR_IS_FROM (tmp) = 1; + } DECL_ARTIFICIAL (tmp) = DECL_ARTIFICIAL (t); - add_referenced_tmp_var (tmp); + DECL_IGNORED_P (tmp) = DECL_IGNORED_P (t); + DECL_GIMPLE_REG_P (tmp) = DECL_GIMPLE_REG_P (t); + add_referenced_var (tmp); - /* add_referenced_tmp_var will create the annotation and set up some + /* add_referenced_var will create the annotation and set up some of the flags in the annotation. However, some flags we need to inherit from our original variable. */ - var_ann (tmp)->type_mem_tag = var_ann (t)->type_mem_tag; + set_symbol_mem_tag (tmp, symbol_mem_tag (t)); if (is_call_clobbered (t)) - mark_call_clobbered (tmp); + mark_call_clobbered (tmp, var_ann (t)->escape_mask); + if (bitmap_bit_p (gimple_call_used_vars (cfun), DECL_UID (t))) + bitmap_set_bit (gimple_call_used_vars (cfun), DECL_UID (tmp)); return tmp; } @@ -177,9 +141,9 @@ create_temp (tree t) static void insert_copy_on_edge (edge e, tree dest, tree src) { - tree copy; + gimple copy; - copy = build (MODIFY_EXPR, TREE_TYPE (dest), dest, src); + copy = gimple_build_assign (dest, src); set_is_used (dest); if (TREE_CODE (src) == ADDR_EXPR) @@ -193,11 +157,11 @@ insert_copy_on_edge (edge e, tree dest, tree src) "Inserting a copy on edge BB%d->BB%d :", e->src->index, e->dest->index); - print_generic_expr (dump_file, copy, dump_flags); + print_gimple_stmt (dump_file, copy, 0, dump_flags); fprintf (dump_file, "\n"); } - bsi_insert_on_edge (e, copy); + gsi_insert_on_edge (e, copy); } @@ -209,10 +173,10 @@ new_elim_graph (int size) { elim_graph g = (elim_graph) xmalloc (sizeof (struct _elim_graph)); - VARRAY_TREE_INIT (g->nodes, 30, "Elimination Node List"); - VARRAY_TREE_INIT (g->const_copies, 20, "Elimination Constant Copies"); - VARRAY_INT_INIT (g->edge_list, 20, "Elimination Edge List"); - VARRAY_INT_INIT (g->stack, 30, " Elimination Stack"); + g->nodes = VEC_alloc (tree, heap, 30); + g->const_copies = VEC_alloc (tree, heap, 20); + g->edge_list = VEC_alloc (int, heap, 20); + g->stack = VEC_alloc (int, heap, 30); g->visited = sbitmap_alloc (size); @@ -225,8 +189,8 @@ new_elim_graph (int size) static inline void clear_elim_graph (elim_graph g) { - VARRAY_POP_ALL (g->nodes); - VARRAY_POP_ALL (g->edge_list); + VEC_truncate (tree, g->nodes, 0); + VEC_truncate (int, g->edge_list, 0); } @@ -236,6 +200,10 @@ static inline void delete_elim_graph (elim_graph g) { sbitmap_free (g->visited); + VEC_free (int, heap, g->stack); + VEC_free (int, heap, g->edge_list); + VEC_free (tree, heap, g->const_copies); + VEC_free (tree, heap, g->nodes); free (g); } @@ -245,7 +213,7 @@ delete_elim_graph (elim_graph g) static inline int elim_graph_size (elim_graph g) { - return VARRAY_ACTIVE_SIZE (g->nodes); + return VEC_length (tree, g->nodes); } @@ -255,10 +223,12 @@ static inline void elim_graph_add_node (elim_graph g, tree node) { int x; - for (x = 0; x < elim_graph_size (g); x++) - if (VARRAY_TREE (g->nodes, x) == node) + tree t; + + for (x = 0; VEC_iterate (tree, g->nodes, x, t); x++) + if (t == node) return; - VARRAY_PUSH_TREE (g->nodes, node); + VEC_safe_push (tree, heap, g->nodes, node); } @@ -267,8 +237,8 @@ elim_graph_add_node (elim_graph g, tree node) static inline void elim_graph_add_edge (elim_graph g, int pred, int succ) { - VARRAY_PUSH_INT (g->edge_list, pred); - VARRAY_PUSH_INT (g->edge_list, succ); + VEC_safe_push (int, heap, g->edge_list, pred); + VEC_safe_push (int, heap, g->edge_list, succ); } @@ -280,12 +250,12 @@ elim_graph_remove_succ_edge (elim_graph g, int node) { int y; unsigned x; - for (x = 0; x < VARRAY_ACTIVE_SIZE (g->edge_list); x += 2) - if (VARRAY_INT (g->edge_list, x) == node) + for (x = 0; x < VEC_length (int, g->edge_list); x += 2) + if (VEC_index (int, g->edge_list, x) == node) { - VARRAY_INT (g->edge_list, x) = -1; - y = VARRAY_INT (g->edge_list, x + 1); - VARRAY_INT (g->edge_list, x + 1) = -1; + VEC_replace (int, g->edge_list, x, -1); + y = VEC_index (int, g->edge_list, x + 1); + VEC_replace (int, g->edge_list, x + 1, -1); return y; } return -1; @@ -300,12 +270,12 @@ elim_graph_remove_succ_edge (elim_graph g, int node) do { \ unsigned x_; \ int y_; \ - for (x_ = 0; x_ < VARRAY_ACTIVE_SIZE ((GRAPH)->edge_list); x_ += 2) \ + for (x_ = 0; x_ < VEC_length (int, (GRAPH)->edge_list); x_ += 2) \ { \ - y_ = VARRAY_INT ((GRAPH)->edge_list, x_); \ + y_ = VEC_index (int, (GRAPH)->edge_list, x_); \ if (y_ != (NODE)) \ continue; \ - (VAR) = VARRAY_INT ((GRAPH)->edge_list, x_ + 1); \ + (VAR) = VEC_index (int, (GRAPH)->edge_list, x_ + 1); \ CODE; \ } \ } while (0) @@ -319,12 +289,12 @@ do { \ do { \ unsigned x_; \ int y_; \ - for (x_ = 0; x_ < VARRAY_ACTIVE_SIZE ((GRAPH)->edge_list); x_ += 2) \ + for (x_ = 0; x_ < VEC_length (int, (GRAPH)->edge_list); x_ += 2) \ { \ - y_ = VARRAY_INT ((GRAPH)->edge_list, x_ + 1); \ + y_ = VEC_index (int, (GRAPH)->edge_list, x_ + 1); \ if (y_ != (NODE)) \ continue; \ - (VAR) = VARRAY_INT ((GRAPH)->edge_list, x_); \ + (VAR) = VEC_index (int, (GRAPH)->edge_list, x_); \ CODE; \ } \ } while (0) @@ -339,36 +309,29 @@ eliminate_name (elim_graph g, tree T) } -/* Build elimination graph G for basic block BB on incoming PHI edge I. */ +/* Build elimination graph G for basic block BB on incoming PHI edge + G->e. */ static void -eliminate_build (elim_graph g, basic_block B, int i) +eliminate_build (elim_graph g, basic_block B) { - tree phi; tree T0, Ti; int p0, pi; + gimple_stmt_iterator gsi; clear_elim_graph (g); - for (phi = phi_nodes (B); phi; phi = PHI_CHAIN (phi)) + for (gsi = gsi_start_phis (B); !gsi_end_p (gsi); gsi_next (&gsi)) { - T0 = var_to_partition_to_var (g->map, PHI_RESULT (phi)); + gimple phi = gsi_stmt (gsi); + + T0 = var_to_partition_to_var (g->map, gimple_phi_result (phi)); /* Ignore results which are not in partitions. */ if (T0 == NULL_TREE) continue; - if (PHI_ARG_EDGE (phi, i) == g->e) - Ti = PHI_ARG_DEF (phi, i); - else - { - /* On rare occasions, a PHI node may not have the arguments - in the same order as all of the other PHI nodes. If they don't - match, find the appropriate index here. */ - pi = phi_arg_from_edge (phi, g->e); - gcc_assert (pi != -1); - Ti = PHI_ARG_DEF (phi, pi); - } + Ti = PHI_ARG_DEF (phi, g->e->dest_idx); /* If this argument is a constant, or a SSA_NAME which is being left in SSA form, just queue a copy to be emitted on this @@ -379,8 +342,8 @@ eliminate_build (elim_graph g, basic_block B, int i) { /* Save constant copies until all other copies have been emitted on this edge. */ - VARRAY_PUSH_TREE (g->const_copies, T0); - VARRAY_PUSH_TREE (g->const_copies, Ti); + VEC_safe_push (tree, heap, g->const_copies, T0); + VEC_safe_push (tree, heap, g->const_copies, Ti); } else { @@ -410,7 +373,7 @@ elim_forward (elim_graph g, int T) if (!TEST_BIT (g->visited, S)) elim_forward (g, S); }); - VARRAY_PUSH_INT (g->stack, T); + VEC_safe_push (int, heap, g->stack, T); } @@ -483,389 +446,68 @@ elim_create (elim_graph g, int T) } -/* Eliminate all the phi nodes on edge E in graph G. I is the usual PHI - index that edge E's values are found on. */ + +/* Eliminate all the phi nodes on edge E in graph G. */ static void -eliminate_phi (edge e, int i, elim_graph g) +eliminate_phi (edge e, elim_graph g) { - int num_nodes = 0; int x; basic_block B = e->dest; - gcc_assert (i != -1); - gcc_assert (VARRAY_ACTIVE_SIZE (g->const_copies) == 0); + gcc_assert (VEC_length (tree, g->const_copies) == 0); - /* Abnormal edges already have everything coalesced, or the coalescer - would have aborted. */ + /* Abnormal edges already have everything coalesced. */ if (e->flags & EDGE_ABNORMAL) return; - num_nodes = num_var_partitions (g->map); g->e = e; - eliminate_build (g, B, i); + eliminate_build (g, B); if (elim_graph_size (g) != 0) { + tree var; + sbitmap_zero (g->visited); - VARRAY_POP_ALL (g->stack); + VEC_truncate (int, g->stack, 0); - for (x = 0; x < elim_graph_size (g); x++) + for (x = 0; VEC_iterate (tree, g->nodes, x, var); x++) { - tree var = VARRAY_TREE (g->nodes, x); int p = var_to_partition (g->map, var); if (!TEST_BIT (g->visited, p)) elim_forward (g, p); } sbitmap_zero (g->visited); - while (VARRAY_ACTIVE_SIZE (g->stack) > 0) + while (VEC_length (int, g->stack) > 0) { - x = VARRAY_TOP_INT (g->stack); - VARRAY_POP (g->stack); + 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 (VARRAY_ACTIVE_SIZE (g->const_copies) > 0) + while (VEC_length (tree, g->const_copies) > 0) { tree src, dest; - src = VARRAY_TOP_TREE (g->const_copies); - VARRAY_POP (g->const_copies); - dest = VARRAY_TOP_TREE (g->const_copies); - VARRAY_POP (g->const_copies); + 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; - - /* 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 (e = bb->succ; e; e = e->succ_next) - 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; - - y = phi_arg_from_edge (phi, e); - gcc_assert (y != -1); - - tmp = PHI_ARG_DEF (phi, y); -#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 (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); - } -#ifdef ENABLE_CHECKING - if (var_union (map, var, tmp) == 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 (var_union (map, var, tmp) != NO_PARTITION); -#endif - conflict_graph_merge_regs (graph, x, y); - } - } -} - - -/* 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) -{ - int num, x, i; - sbitmap live; - tree var, phi; - root_var_p rv; - tree_live_info_p liveinfo; - var_ann_t ann; - conflict_graph graph; - basic_block bb; - coalesce_list_p cl = NULL; - - if (num_var_partitions (map) <= 1) - return NULL; - - /* If no preference given, use cheap coalescing of all partitions. */ - if ((flags & (SSANORM_COALESCE_PARTITIONS | SSANORM_USE_COALESCE_LIST)) == 0) - flags |= SSANORM_COALESCE_PARTITIONS; - - 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); - - if (flags & SSANORM_USE_COALESCE_LIST) - { - cl = create_coalesce_list (map); - - /* Add all potential copies via PHI arguments to the list. */ - 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); - 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) - add_coalesce (cl, p, p2, 1); - } - } - } - - /* Coalesce all the result decls together. */ - var = NULL_TREE; - i = 0; - for (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, 1); - } - } - } - - /* 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. */ - - live = sbitmap_alloc (num_var_partitions (map)); - sbitmap_zero (live); - - /* Set 'live' vector to indicate live on entry partitions. */ - num = num_var_partitions (map); - for (x = 0 ; x < num; x++) - { - 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, - { - var = root_var (rv, root_var_find (rv, x)); - 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. */ - if (flags & SSANORM_USE_COALESCE_LIST) - 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; + int x, num; + tree var, root; 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++) @@ -873,63 +515,35 @@ assign_vars (var_map map) 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; + /* It must already be coalesced. */ + gcc_assert (ann->out_of_ssa_tag == 1); if (dump_file && (dump_flags & TDF_DETAILS)) { - fprintf (dump_file, "partition %d has variable ", x); + fprintf (dump_file, "partition %d already 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) + else + { + root = SSA_NAME_VAR (var); + ann = var_ann (root); + /* If ROOT is already associated, create a new one. */ + 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; + root = create_temp (root); + ann = var_ann (root); } - - 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); - + /* ROOT has not been coalesced yet, so use it. */ if (dump_file && (dump_flags & TDF_DETAILS)) { - fprintf (dump_file, " --> New temp: '"); - print_generic_expr (dump_file, var, TDF_SLIM); - fprintf (dump_file, "'\n"); + fprintf (dump_file, "Partition %d is assigned to var ", x); + print_generic_stmt (dump_file, root, TDF_SLIM); } + change_partition_var (map, root, x); } } - - root_var_delete (rv); } @@ -939,7 +553,7 @@ assign_vars (var_map map) If the stmt is changed, return true. */ static inline bool -replace_use_variable (var_map map, use_operand_p p, tree *expr) +replace_use_variable (var_map map, use_operand_p p, gimple *expr) { tree new_var; tree var = USE_FROM_PTR (p); @@ -950,10 +564,7 @@ replace_use_variable (var_map map, use_operand_p p, tree *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; + SET_USE (p, gimple_assign_rhs_to_tree (expr[version])); return true; } } @@ -980,19 +591,9 @@ 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; - } - } + /* Do nothing if we are replacing this variable with an expression. */ + if (expr && expr[SSA_NAME_VERSION (var)]) + return true; new_var = var_to_partition_to_var (map, var); if (new_var) @@ -1005,26 +606,70 @@ replace_def_variable (var_map map, def_operand_p def_p, tree *expr) } -/* Remove any PHI node which is a virtual PHI. */ +/* Remove each argument from PHI. If an arg was the last use of an SSA_NAME, + check to see if this allows another PHI node to be removed. */ + +static void +remove_gimple_phi_args (gimple phi) +{ + use_operand_p arg_p; + ssa_op_iter iter; + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Removing Dead PHI definition: "); + print_gimple_stmt (dump_file, phi, 0, TDF_SLIM); + } + + FOR_EACH_PHI_ARG (arg_p, phi, iter, SSA_OP_USE) + { + tree arg = USE_FROM_PTR (arg_p); + if (TREE_CODE (arg) == SSA_NAME) + { + /* Remove the reference to the existing argument. */ + SET_USE (arg_p, NULL_TREE); + if (has_zero_uses (arg)) + { + gimple stmt; + gimple_stmt_iterator gsi; + + stmt = SSA_NAME_DEF_STMT (arg); + + /* Also remove the def if it is a PHI node. */ + if (gimple_code (stmt) == GIMPLE_PHI) + { + remove_gimple_phi_args (stmt); + gsi = gsi_for_stmt (stmt); + remove_phi_node (&gsi, true); + } + + } + } + } +} + +/* Remove any PHI node which is a virtual PHI, or a PHI with no uses. */ static void -eliminate_virtual_phis (void) +eliminate_useless_phis (void) { basic_block bb; - tree phi, next; + gimple_stmt_iterator gsi; + tree result; FOR_EACH_BB (bb) { - for (phi = phi_nodes (bb); phi; phi = next) + for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); ) { - next = PHI_CHAIN (phi); - if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi)))) + gimple phi = gsi_stmt (gsi); + result = gimple_phi_result (phi); + if (!is_gimple_reg (SSA_NAME_VAR (result))) { #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++) + size_t i; + /* There should be no arguments which are not virtual, or the + results will be incorrect. */ + for (i = 0; i < gimple_phi_num_args (phi); i++) { tree arg = PHI_ARG_DEF (phi, i); if (TREE_CODE (arg) == SSA_NAME @@ -1033,945 +678,683 @@ eliminate_virtual_phis (void) 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); + print_gimple_stmt (stderr, phi, 0, TDF_SLIM); internal_error ("SSA corruption"); } } #endif - remove_phi_node (phi, NULL_TREE, bb); + remove_phi_node (&gsi, true); + } + else + { + /* Also remove real PHIs with no uses. */ + if (has_zero_uses (result)) + { + remove_gimple_phi_args (phi); + remove_phi_node (&gsi, true); + } + else + gsi_next (&gsi); } } } } -/* 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. */ +/* 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 -coalesce_vars (var_map map, tree_live_info_p liveinfo) +rewrite_trees (var_map map, gimple *values) { + elim_graph g; basic_block bb; - type_var_p tv; - tree var; - int 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++) + gimple_stmt_iterator gsi; + edge e; + gimple_seq 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) { - var = partition_to_var (map, x); - p = var_to_partition (map, var); - if (p != x) - live_merge_and_clear (liveinfo, p, x); + for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) + { + gimple phi = gsi_stmt (gsi); + tree T0 = var_to_partition_to_var (map, gimple_phi_result (phi)); + if (T0 == NULL_TREE) + { + size_t i; + for (i = 0; i < gimple_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_gimple_stmt (stderr, phi, 0, TDF_SLIM); + internal_error ("SSA corruption"); + } + } + } + } } +#endif - /* When PHI nodes are turned into copies, the result of each PHI node - becomes live on entry to the block. Mark these now. */ + /* Replace PHI nodes with any required copies. */ + g = new_elim_graph (map->num_partitions); + g->map = map; FOR_EACH_BB (bb) { - tree phi, arg; - int p; - for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) + for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) { - p = var_to_partition (map, PHI_RESULT (phi)); + gimple stmt = gsi_stmt (gsi); + use_operand_p use_p, copy_use_p; + def_operand_p def_p; + bool remove = false, is_copy = false; + int num_uses = 0; + ssa_op_iter iter; - /* Skip virtual PHI nodes. */ - if (p == NO_PARTITION) - continue; + changed = false; - make_live_on_entry (liveinfo, bb, p); + if (gimple_assign_copy_p (stmt)) + is_copy = true; - /* 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 < PHI_NUM_ARGS (phi); x++) + copy_use_p = NULL_USE_OPERAND_P; + FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) { - arg = PHI_ARG_DEF (phi, x); - if (!phi_ssa_name_p (arg)) - continue; - p2 = var_to_partition (map, arg); - if (p2 == NO_PARTITION) - continue; - if (p != p2) - add_coalesce (cl, p, p2, 1); + if (replace_use_variable (map, use_p, values)) + changed = true; + copy_use_p = use_p; + num_uses++; } - } - } - - /* Re-calculate live on exit info. */ - calculate_live_on_exit (liveinfo); + if (num_uses != 1) + is_copy = false; - 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); + def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_DEF); - fprintf (dump_file, "Coalesce list from phi nodes:\n"); - dump_coalesce_list (dump_file, cl); - } + 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) + gsi_remove (&gsi, true); + else + { + if (changed) + if (maybe_clean_or_replace_eh_stmt (stmt, stmt)) + gimple_purge_dead_eh_edges (bb); + gsi_next (&gsi); + } + } - 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); + phi = phi_nodes (bb); + if (phi) + { + edge_iterator ei; + FOR_EACH_EDGE (e, ei, bb->preds) + eliminate_phi (e, g); + } + } - graph = build_tree_conflict_graph (liveinfo, tv, cl); + delete_elim_graph (g); +} - 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); +/* 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(gimple_seq,heap) *stmt_list; +static bitmap leader_has_match = NULL; +static edge leader_match = NULL; - 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. +/* Pass this function to make_forwarder_block so that all the edges with + matching PENDING_STMT lists to 'curr_stmt_list' get redirected. E is the + edge to test for a match. */ - 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 +static inline bool +same_stmt_list_p (edge e) { - 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; - 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_dependance (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 = (temp_expr_table_p) xmalloc (sizeof (struct temp_expr_table_d)); - t->map = map; - - t->version_info = xcalloc (num_ssa_names + 1, sizeof (void *)); - t->partition_dep_list = xcalloc (num_var_partitions (map) + 1, - sizeof (value_expr_p)); - - t->replaceable = BITMAP_XMALLOC (); - t->partition_in_use = BITMAP_XMALLOC (); - - t->saw_replaceable = false; - t->virtual_partition = num_var_partitions (map); - t->free_list = NULL; - t->pending_dependence = NULL; - - return t; + return (e->aux == (PTR) leader_match) ? true : false; } -/* Free TER table T. If there are valid replacements, return the expression - vector. */ +/* Return TRUE if S1 and S2 are equivalent copies. */ -static tree * -free_temp_expr_table (temp_expr_table_p t) +static inline bool +identical_copies_p (const_gimple s1, const_gimple s2) { - value_expr_p p; - tree *ret = NULL; - #ifdef ENABLE_CHECKING - int x; - for (x = 0; x <= num_var_partitions (t->map); x++) - if (t->partition_dep_list[x] != NULL) - gcc_unreachable (); + gcc_assert (is_gimple_assign (s1)); + gcc_assert (is_gimple_assign (s2)); + gcc_assert (DECL_P (gimple_assign_lhs (s1))); + gcc_assert (DECL_P (gimple_assign_lhs (s2))); #endif - while ((p = t->free_list)) - { - t->free_list = p->next; - free (p); - } - - BITMAP_XFREE (t->partition_in_use); - BITMAP_XFREE (t->replaceable); - - 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; -} - + if (gimple_assign_lhs (s1) != gimple_assign_lhs (s2)) + return false; -/* Add value list node P to the free list in TABLE. */ + if (gimple_assign_rhs1 (s1) != gimple_assign_rhs1 (s2)) + return false; -static inline void -free_value_expr (temp_expr_table_p table, value_expr_p p) -{ - p->next = table->free_list; - table->free_list = p; + return true; } -/* Find VALUE if its 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. */ +/* Compare the PENDING_STMT list for edges E1 and E2. Return true if the lists + contain the same sequence of copies. */ -static inline value_expr_p -find_value_in_list (value_expr_p list, int value, value_expr_p *last_ptr) +static inline bool +identical_stmt_lists_p (const_edge e1, const_edge e2) { - value_expr_p curr; - value_expr_p last = NULL; + gimple_seq t1 = PENDING_STMT (e1); + gimple_seq t2 = PENDING_STMT (e2); + gimple_stmt_iterator gsi1, gsi2; - for (curr = list; curr; last = curr, curr = curr->next) + for (gsi1 = gsi_start (t1), gsi2 = gsi_start (t2); + !gsi_end_p (gsi1) && !gsi_end_p (gsi2); + gsi_next (&gsi1), gsi_next (&gsi2)) { - if (curr->value == value) + if (!identical_copies_p (gsi_stmt (gsi1), gsi_stmt (gsi2))) 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 (!gsi_end_p (gsi1) || !gsi_end_p (gsi2)) + return false; - if (!find_value_in_list (*list, value, NULL)) - { - info = new_value_expr (tab); - info->value = value; - info->next = *list; - *list = info; - } + return true; } -/* 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. */ +/* Allocate data structures used in analyze_edges_for_bb. */ -static inline void -add_info_to_list (temp_expr_table_p tab, value_expr_p *list, value_expr_p info) +static void +init_analyze_edges_for_bb (void) { - if (find_value_in_list (*list, info->value, NULL)) - free_value_expr (tab, info); - else - { - info->next = *list; - *list = info; - } + edge_leader = VEC_alloc (edge, heap, 25); + stmt_list = VEC_alloc (gimple_seq, heap, 25); + leader_has_match = BITMAP_ALLOC (NULL); } -/* Look for VALUE in LIST. If found, remove it from the list and return it's - pointer. */ +/* Free data structures used in analyze_edges_for_bb. */ -static value_expr_p -remove_value_from_list (value_expr_p *list, int value) +static void +fini_analyze_edges_for_bb (void) { - 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; + VEC_free (edge, heap, edge_leader); + VEC_free (gimple_seq, heap, stmt_list); + BITMAP_FREE (leader_has_match); } - -/* 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_dependance (temp_expr_table_p tab, int version, tree var) +/* A helper function to be called via walk_tree. Return DATA if it is + contained in subtree TP. */ + +static tree +contains_tree_r (tree * tp, int *walk_subtrees, void *data) { - int i, x; - value_expr_p info; - - i = SSA_NAME_VERSION (var); - if (bitmap_bit_p (tab->replaceable, i)) + if (*tp == data) { - /* 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); - } + *walk_subtrees = 0; + return (tree) data; } 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); - } + return NULL_TREE; } +/* A threshold for the number of insns contained in the latch block. + It is used to prevent blowing the loop with too many copies from + the latch. */ +#define MAX_STMTS_IN_LATCH 2 -/* Check if expression STMT is suitable for replacement in table TAB. If so, - create an expression entry. Return true if this stmt is replaceable. */ +/* Return TRUE if the stmts on SINGLE-EDGE can be moved to the + body of the loop. This should be permitted only if SINGLE-EDGE is a + single-basic-block latch edge and thus cleaning the latch will help + to create a single-basic-block loop. Otherwise return FALSE. */ static bool -check_replaceable (temp_expr_table_p tab, tree stmt) +process_single_block_loop_latch (edge single_edge) { - stmt_ann_t ann; - vuse_optype vuseops; - def_optype defs; - use_optype uses; - tree var, def; - int num_use_ops, version; - var_map map = tab->map; - ssa_op_iter iter; - - if (TREE_CODE (stmt) != MODIFY_EXPR) + gimple_seq stmts; + basic_block b_exit, b_pheader, b_loop = single_edge->src; + edge_iterator ei; + edge e; + gimple_stmt_iterator gsi, gsi_exit; + gimple_stmt_iterator tsi; + tree expr; + gimple stmt; + unsigned int count = 0; + + if (single_edge == NULL || (single_edge->dest != single_edge->src) + || (EDGE_COUNT (b_loop->succs) != 2) + || (EDGE_COUNT (b_loop->preds) != 2)) return false; - - ann = stmt_ann (stmt); - defs = DEF_OPS (ann); - /* Punt if there is more than 1 def, or more than 1 use. */ - if (NUM_DEFS (defs) != 1) - return false; - def = DEF_OP (defs, 0); - if (version_ref_count (map, def) != 1) - return false; + /* Get the stmts on the latch edge. */ + stmts = PENDING_STMT (single_edge); - /* Assignments to variables assigned to hard registers are not - replaceable. */ - if (DECL_HARD_REGISTER (SSA_NAME_VAR (def))) - return false; + /* Find the successor edge which is not the latch edge. */ + FOR_EACH_EDGE (e, ei, b_loop->succs) + if (e->dest != b_loop) + break; - /* There must be no V_MAY_DEFS. */ - if (NUM_V_MAY_DEFS (V_MAY_DEF_OPS (ann)) != 0) - return false; + b_exit = e->dest; - /* There must be no V_MUST_DEFS. */ - if (NUM_V_MUST_DEFS (V_MUST_DEF_OPS (ann)) != 0) + /* Check that the exit block has only the loop as a predecessor, + and that there are no pending stmts on that edge as well. */ + if (EDGE_COUNT (b_exit->preds) != 1 || PENDING_STMT (e)) 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)))) + /* Find the predecessor edge which is not the latch edge. */ + FOR_EACH_EDGE (e, ei, b_loop->preds) + if (e->src != b_loop) + break; + + b_pheader = e->src; + + if (b_exit == b_pheader || b_exit == b_loop || b_pheader == b_loop) return false; - uses = USE_OPS (ann); - num_use_ops = NUM_USES (uses); - vuseops = VUSE_OPS (ann); + gsi_exit = gsi_after_labels (b_exit); - /* Any expression which has no virtual operands and no real operands - should have been propagated if it's possible to do anything with them. - If this happens here, it probably exists that way for a reason, so we - won't touch it. An example is: - b_4 = &tab - There are no virtual uses nor any real uses, so we just leave this - alone to be safe. */ + /* Get the last stmt in the loop body. */ + gsi = gsi_last_bb (single_edge->src); + stmt = gsi_stmt (gsi); - if (num_use_ops == 0 && NUM_VUSES (vuseops) == 0) + if (gimple_code (stmt) != GIMPLE_COND) return false; - version = SSA_NAME_VERSION (def); - /* Add this expression to the dependency list for each use partition. */ - FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_USE) + expr = build2 (gimple_cond_code (stmt), boolean_type_node, + gimple_cond_lhs (stmt), gimple_cond_rhs (stmt)); + /* Iterate over the insns on the latch and count them. */ + for (tsi = gsi_start (stmts); !gsi_end_p (tsi); gsi_next (&tsi)) { - add_dependance (tab, version, var); + gimple stmt1 = gsi_stmt (tsi); + tree var; + + count++; + /* Check that the condition does not contain any new definition + created in the latch as the stmts from the latch intended + to precede it. */ + if (gimple_code (stmt1) != GIMPLE_ASSIGN) + return false; + var = gimple_assign_lhs (stmt1); + if (TREE_THIS_VOLATILE (var) + || TYPE_VOLATILE (TREE_TYPE (var)) + || walk_tree (&expr, contains_tree_r, var, NULL)) + return false; } + /* Check that the latch does not contain more than MAX_STMTS_IN_LATCH + insns. The purpose of this restriction is to prevent blowing the + loop with too many copies from the latch. */ + if (count > MAX_STMTS_IN_LATCH) + return false; - /* If there are VUSES, add a dependence on virtual defs. */ - if (NUM_VUSES (vuseops) != 0) + /* Apply the transformation - clean up the latch block: + + var = something; + L1: + x1 = expr; + if (cond) goto L2 else goto L3; + L2: + var = x1; + goto L1 + L3: + ... + + ==> + + var = something; + L1: + x1 = expr; + tmp_var = var; + var = x1; + if (cond) goto L1 else goto L2; + L2: + var = tmp_var; + ... + */ + for (tsi = gsi_start (stmts); !gsi_end_p (tsi); gsi_next (&tsi)) { - 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)); + gimple stmt1 = gsi_stmt (tsi); + tree var, tmp_var; + gimple copy; + + /* Create a new variable to load back the value of var in case + we exit the loop. */ + var = gimple_assign_lhs (stmt1); + tmp_var = create_temp (var); + copy = gimple_build_assign (tmp_var, var); + set_is_used (tmp_var); + gsi_insert_before (&gsi, copy, GSI_SAME_STMT); + copy = gimple_build_assign (var, tmp_var); + gsi_insert_before (&gsi_exit, copy, GSI_SAME_STMT); } + PENDING_STMT (single_edge) = 0; + /* Insert the new stmts to the loop body. */ + gsi_insert_seq_before (&gsi, stmts, GSI_NEW_STMT); + + if (dump_file) + fprintf (dump_file, + "\nCleaned-up latch block of loop with single BB: %d\n\n", + single_edge->dest->index); + 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. */ +/* 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 -finish_expr (temp_expr_table_p tab, int version, bool replace) +analyze_edges_for_bb (basic_block bb) { - value_expr_p info, tmp; - int partition; + edge e; + edge_iterator ei; + int count; + unsigned int x; + bool have_opportunity; + gimple_stmt_iterator gsi; + gimple 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; + } - /* 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) + if (!have_opportunity) { - 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); + FOR_EACH_EDGE (e, ei, bb->preds) + if (PENDING_STMT (e)) + gsi_commit_one_edge_insert (e, NULL); + return; } - if (replace) - { - tab->saw_replaceable = true; - bitmap_set_bit (tab->replaceable, version); - } - else + /* 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) { - gcc_assert (!bitmap_bit_p (tab->replaceable, version)); - tab->version_info[version] = NULL; + if (PENDING_STMT (e)) + { + gcc_assert (!(e->flags & EDGE_ABNORMAL)); + if (e->flags & EDGE_FALLTHRU) + { + gsi = gsi_start_bb (e->src); + if (!gsi_end_p (gsi)) + { + stmt = gsi_stmt (gsi); + gsi_next (&gsi); + gcc_assert (stmt != NULL); + is_label = (gimple_code (stmt) == GIMPLE_LABEL); + /* Punt if it has non-label stmts, or isn't local. */ + if (!is_label + || DECL_NONLOCAL (gimple_label_label (stmt)) + || !gsi_end_p (gsi)) + { + gsi_commit_one_edge_insert (e, NULL); + continue; + } + } + } + single_edge = e; + count++; + } } -} - - -/* 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]) + /* If there aren't at least 2 edges, no sharing will happen. */ + if (count < 2) { - 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]; + if (single_edge) + { + /* Add stmts to the edge unless processed specially as a + single-block loop latch edge. */ + if (!process_single_block_loop_latch (single_edge)) + gsi_commit_one_edge_insert (single_edge, NULL); + } + return; } - 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; - stmt_ann_t ann; - int partition; - var_map map = tab->map; - value_expr_p p; - ssa_op_iter iter; + /* Ensure that we have empty worklists. */ +#ifdef ENABLE_CHECKING + gcc_assert (VEC_length (edge, edge_leader) == 0); + gcc_assert (VEC_length (gimple_seq, stmt_list) == 0); + gcc_assert (bitmap_empty_p (leader_has_match)); +#endif - for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) + /* 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) { - stmt = bsi_stmt (bsi); - ann = stmt_ann (stmt); - - /* Determine if this stmt finishes an existing expression. */ - FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_USE) + if (PENDING_STMT (e)) { - if (tab->version_info[SSA_NAME_VERSION (def)]) + bool found = false; + + /* Look for the same stmt list in edge leaders list. */ + for (x = 0; VEC_iterate (edge, edge_leader, x, leader); x++) { - /* Mark expression as replaceable unless stmt is volatile. */ - if (!ann->has_volatile_ops) - mark_replaceable (tab, def); - else - finish_expr (tab, SSA_NAME_VERSION (def), false); + 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; + } } - } - - /* 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); + /* 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 (gimple_seq, heap, stmt_list, PENDING_STMT (e)); + } } + } - /* A V_MAY_DEF kills any expression using a virtual operand. */ - if (NUM_V_MAY_DEFS (V_MAY_DEF_OPS (ann)) > 0) - kill_virtual_exprs (tab, true); - - /* A V_MUST_DEF kills any expression using a virtual operand. */ - if (NUM_V_MUST_DEFS (V_MUST_DEF_OPS (ann)) > 0) - 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; - int i; - temp_expr_table_p table; - tree *ret; - - table = new_temp_expr_table (map); - FOR_EACH_BB (bb) + /* If there are no similar lists, just issue the stmts. */ + if (!have_opportunity) { - find_replaceable_in_bb (table, bb); - EXECUTE_IF_SET_IN_BITMAP ((table->partition_in_use), 0, i, - { - kill_expr (table, i, false); - }); + for (x = 0; VEC_iterate (edge, edge_leader, x, leader); x++) + gsi_commit_one_edge_insert (leader, NULL); + VEC_truncate (edge, edge_leader, 0); + VEC_truncate (gimple_seq, stmt_list, 0); + bitmap_clear (leader_has_match); + return; } - ret = free_temp_expr_table (table); - return ret; -} + 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; + gimple_stmt_iterator gsi; + gimple_seq 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 (gimple_seq, 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_gimple_seq (dump_file, curr_stmt_list, 0, 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); + } -/* Dump TER expression table EXPR to file F. */ + gsi = gsi_last_bb (leader->dest); + gsi_insert_seq_after (&gsi, curr_stmt_list, GSI_NEW_STMT); -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]) + leader_match = NULL; + /* We should never get a new block now. */ + } + else { - stmt = expr[x]; - var = DEF_OP (STMT_DEF_OPS (stmt), 0); - print_generic_expr (f, var, TDF_SLIM); - fprintf (f, " replace with --> "); - print_generic_expr (f, TREE_OPERAND (stmt, 1), TDF_SLIM); - fprintf (f, "\n"); + PENDING_STMT (leader) = VEC_index (gimple_seq, stmt_list, x); + gsi_commit_one_edge_insert (leader, NULL); } - fprintf (f, "\n"); -} - -/* Helper function for discover_nonconstant_array_refs. - Look for ARRAY_REF nodes with non-constant indexes and mark them - addressable. */ - -static tree -discover_nonconstant_array_refs_r (tree * tp, int *walk_subtrees, - void *data ATTRIBUTE_UNUSED) -{ - tree t = *tp; - - if (TYPE_P (t) || DECL_P (t)) - *walk_subtrees = 0; - else if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF) - { - while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF) - && is_gimple_min_invariant (TREE_OPERAND (t, 1)) - && (!TREE_OPERAND (t, 2) - || is_gimple_min_invariant (TREE_OPERAND (t, 2)))) - || (TREE_CODE (t) == COMPONENT_REF - && (!TREE_OPERAND (t,2) - || is_gimple_min_invariant (TREE_OPERAND (t, 2)))) - || TREE_CODE (t) == BIT_FIELD_REF - || TREE_CODE (t) == REALPART_EXPR - || TREE_CODE (t) == IMAGPART_EXPR - || TREE_CODE (t) == VIEW_CONVERT_EXPR - || TREE_CODE (t) == NOP_EXPR - || TREE_CODE (t) == CONVERT_EXPR) - t = TREE_OPERAND (t, 0); - - if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF) - { - t = get_base_address (t); - if (t && DECL_P (t)) - TREE_ADDRESSABLE (t) = 1; - } - - *walk_subtrees = 0; - } - - return NULL_TREE; + + /* Clear the working data structures. */ + VEC_truncate (edge, edge_leader, 0); + VEC_truncate (gimple_seq, stmt_list, 0); + bitmap_clear (leader_has_match); } -/* RTL expansion is not able to compile array references with variable - offsets for arrays stored in single register. Discover such - expressions and mark variables as addressable to avoid this - scenario. */ +/* 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 -discover_nonconstant_array_refs (void) +perform_edge_inserts (void) { basic_block bb; - block_stmt_iterator bsi; - FOR_EACH_BB (bb) - { - for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) - walk_tree (bsi_stmt_ptr (bsi), discover_nonconstant_array_refs_r, - NULL , NULL); - } -} + 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); -/* 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. */ + /* Allocate data structures used in analyze_edges_for_bb. */ + init_analyze_edges_for_bb (); -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; + analyze_edges_for_bb (bb); - 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; + analyze_edges_for_bb (EXIT_BLOCK_PTR); - for (i = 0; i < PHI_NUM_ARGS (phi); i++) - { - tree arg = PHI_ARG_DEF (phi, i); + /* Free data structures used in analyze_edges_for_bb. */ + fini_analyze_edges_for_bb (); - 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"); - } - } - } - } - } +#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 - - /* 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); ) - { - size_t num_uses, num_defs; - use_optype uses; - def_optype defs; - tree stmt = bsi_stmt (si); - use_operand_p use_p; - def_operand_p def_p; - int remove = 0, is_copy = 0; - stmt_ann_t ann; - ssa_op_iter iter; - - get_stmt_operands (stmt); - ann = stmt_ann (stmt); - changed = false; - - if (TREE_CODE (stmt) == MODIFY_EXPR - && (TREE_CODE (TREE_OPERAND (stmt, 1)) == SSA_NAME)) - is_copy = 1; - - uses = USE_OPS (ann); - num_uses = NUM_USES (uses); - FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) - { - if (replace_use_variable (map, use_p, values)) - changed = true; - } - - defs = DEF_OPS (ann); - num_defs = NUM_DEFS (defs); - - /* Mark this stmt for removal if it is the list of replaceable - expressions. */ - if (values && num_defs == 1) - { - tree def = DEF_OP (defs, 0); - tree val; - val = values[SSA_NAME_VERSION (def)]; - if (val) - remove = 1; - } - if (!remove) - { - FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, iter, SSA_OP_DEF) - { - 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 - && num_uses == 1 - && (DEF_FROM_PTR (def_p) == USE_OP (uses, 0))) - remove = 1; - } - if (changed & !remove) - modify_stmt (stmt); - } - - /* Remove any stmts marked for removal. */ - if (remove) - bsi_remove (&si); - else - bsi_next (&si); - } - - phi = phi_nodes (bb); - if (phi) - { - for (e = bb->pred; e; e = e->pred_next) - eliminate_phi (e, phi_arg_from_edge (phi, e), g); - } - } - - delete_elim_graph (g); - - /* If any copies were inserted on edges, actually insert them now. */ - bsi_commit_edge_inserts (NULL); } -/* Remove the variables specified in MAP from SSA form. Any debug information - is sent to DUMP. FLAGS indicate what options should be used. */ +/* Remove the ssa-names in the current function and translate them into normal + compiler variables. PERFORM_TER is true if Temporary Expression Replacement + should also be used. */ static void -remove_ssa_form (FILE *dump, var_map map, int flags) +remove_ssa_form (bool perform_ter) { - tree_live_info_p liveinfo; basic_block bb; - tree phi, next; - FILE *save; - tree *values = NULL; - - save = dump_file; - dump_file = dump; - - /* 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); + gimple *values = NULL; + var_map map; + gimple_stmt_iterator gsi; - liveinfo = coalesce_ssa_name (map, flags); + map = coalesce_ssa_name (); - /* Make sure even single occurrence variables are in the list now. */ - if ((flags & SSANORM_COMBINE_TEMPS) == 0) - compact_var_map (map, VARMAP_NORMAL); + /* Return to viewing the variable list as just all reference variables after + coalescing has been performed. */ + partition_view_normal (map, false); if (dump_file && (dump_flags & TDF_DETAILS)) { @@ -1979,7 +1362,7 @@ remove_ssa_form (FILE *dump, var_map map, int flags) dump_var_map (dump_file, map); } - if (flags & SSANORM_PERFORM_TER) + if (perform_ter) { values = find_replaceable_exprs (map); if (values && dump_file && (dump_flags & TDF_DETAILS)) @@ -1991,94 +1374,151 @@ remove_ssa_form (FILE *dump, var_map map, int flags) if (dump_file && (dump_flags & TDF_DETAILS)) { - fprintf (dump_file, "After Root variable replacement:\n"); + fprintf (dump_file, "After Base 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. */ + /* Remove PHI nodes which have been translated back to real variables. */ + FOR_EACH_BB (bb) + for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi);) + remove_phi_node (&gsi, true); + + /* If any copies were inserted on edges, analyze and insert them now. */ + perform_edge_inserts (); + + delete_var_map (map); +} + + +/* 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; + gimple_stmt_iterator gsi; + FOR_EACH_BB (bb) { - for (phi = phi_nodes (bb); phi; phi = next) + for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) { - next = PHI_CHAIN (phi); - if ((flags & SSANORM_REMOVE_ALL_PHIS) - || var_to_partition (map, PHI_RESULT (phi)) != NO_PARTITION) - remove_phi_node (phi, NULL_TREE, bb); + gimple phi = gsi_stmt (gsi); + tree result = gimple_phi_result (phi); + tree result_var; + size_t i; + + if (!is_gimple_reg (result)) + continue; + + result_var = SSA_NAME_VAR (result); + for (i = 0; i < gimple_phi_num_args (phi); i++) + { + tree arg = gimple_phi_arg_def (phi, i); + edge e = gimple_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 then a copy statement will be + needed. */ + if ((e->flags & EDGE_DFS_BACK) + && (TREE_CODE (arg) != SSA_NAME + || SSA_NAME_VAR (arg) != result_var)) + { + tree name; + gimple stmt, last = NULL; + gimple_stmt_iterator gsi2; + + gsi2 = gsi_last_bb (gimple_phi_arg_edge (phi, i)->src); + if (!gsi_end_p (gsi2)) + last = gsi_stmt (gsi2); + + /* 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 = gimple_build_assign (result_var, + gimple_phi_arg_def (phi, i)); + name = make_ssa_name (result_var, stmt); + gimple_assign_set_lhs (stmt, name); + + /* Insert the new statement into the block and update + the PHI node. */ + if (last && stmt_ends_bb_p (last)) + gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT); + else + gsi_insert_after (&gsi2, stmt, GSI_NEW_STMT); + SET_PHI_ARG_DEF (phi, i, name); + } + } } } - - dump_file = save; } -/* Take the current function out of SSA form, as described in +/* Take the current function out of SSA form, translating PHIs as described in R. Morgan, ``Building an Optimizing Compiler'', Butterworth-Heinemann, Boston, MA, 1998. pp 176-186. */ -static void +static unsigned int rewrite_out_of_ssa (void) { - var_map map; - int var_flags = 0; - int ssa_flags = (SSANORM_REMOVE_ALL_PHIS | SSANORM_USE_COALESCE_LIST); - - 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; + /* 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. - map = create_ssa_var_map (var_flags); + A significant number of such cases can be handled here by inserting + copies into the loop itself. */ + insert_backedge_copies (); - if (flag_tree_combine_temps) - ssa_flags |= SSANORM_COMBINE_TEMPS; - if (flag_tree_ter && !flag_mudflap) - ssa_flags |= SSANORM_PERFORM_TER; - remove_ssa_form (dump_file, map, ssa_flags); + /* Eliminate PHIs which are of no use, such as virtual or dead phis. */ + eliminate_useless_phis (); if (dump_file && (dump_flags & TDF_DETAILS)) - dump_tree_cfg (dump_file, dump_flags & ~TDF_DETAILS); + gimple_dump_cfg (dump_file, dump_flags & ~TDF_DETAILS); - /* Do some cleanups which reduce the amount of data the - tree->rtl expanders deal with. */ - cfg_remove_useless_stmts (); + remove_ssa_form (flag_tree_ter && !flag_mudflap); - /* Flush out flow graph and SSA data. */ - delete_var_map (map); + if (dump_file && (dump_flags & TDF_DETAILS)) + gimple_dump_cfg (dump_file, dump_flags & ~TDF_DETAILS); - /* Mark arrays indexed with non-constant indices with TREE_ADDRESSABLE. */ - discover_nonconstant_array_refs (); + cfun->gimple_df->in_ssa_p = false; + return 0; } /* Define the parameters of the out of SSA pass. */ -struct tree_opt_pass pass_del_ssa = +struct gimple_opt_pass pass_del_ssa = { + { + GIMPLE_PASS, "optimized", /* name */ NULL, /* gate */ rewrite_out_of_ssa, /* execute */ @@ -2086,12 +1526,14 @@ struct tree_opt_pass pass_del_ssa = NULL, /* next */ 0, /* static_pass_number */ TV_TREE_SSA_TO_NORMAL, /* tv_id */ - PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */ + PROP_cfg | PROP_ssa, /* 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_flags_finish */ - 0 /* letter */ + TODO_dump_func + | TODO_ggc_collect + | TODO_remove_unused_locals /* todo_flags_finish */ + } };