X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Ftree-dfa.c;h=d00324a348e0c5d5727e10e0ac76906419d0e57d;hb=0b7fec894793d3931271aa6498ccf3f93099b730;hp=beb83fbe829bfc3ea33a64298d9fa37af4b7f8c4;hpb=0af8b3215f7f533b70dadad48f54a9f4c16cc62e;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/tree-dfa.c b/gcc/tree-dfa.c index beb83fbe829..d00324a348e 100644 --- a/gcc/tree-dfa.c +++ b/gcc/tree-dfa.c @@ -1,12 +1,13 @@ /* Data flow functions for trees. - Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. + Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009 + Free Software Foundation, Inc. Contributed by Diego Novillo 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, @@ -15,9 +16,8 @@ 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, 51 Franklin Street, Fifth Floor, -Boston, MA 02110-1301, USA. */ +along with GCC; see the file COPYING3. If not see +. */ #include "config.h" #include "system.h" @@ -39,7 +39,7 @@ Boston, MA 02110-1301, USA. */ #include "function.h" #include "diagnostic.h" #include "tree-dump.h" -#include "tree-gimple.h" +#include "gimple.h" #include "tree-flow.h" #include "tree-inline.h" #include "tree-pass.h" @@ -52,38 +52,20 @@ Boston, MA 02110-1301, USA. */ /* Counters used to display DFA and SSA statistics. */ struct dfa_stats_d { - long num_stmt_anns; long num_var_anns; long num_defs; long num_uses; long num_phis; long num_phi_args; - int max_num_phi_args; - long num_v_may_defs; + size_t max_num_phi_args; + long num_vdefs; long num_vuses; - long num_v_must_defs; -}; - - -/* State information for find_vars_r. */ -struct walk_state -{ - /* Hash table used to avoid adding the same variable more than once. */ - htab_t vars_found; }; /* Local functions. */ static void collect_dfa_stats (struct dfa_stats_d *); -static tree collect_dfa_stats_r (tree *, int *, void *); static tree find_vars_r (tree *, int *, void *); -static void add_referenced_var (tree, struct walk_state *); - - -/* Global declarations. */ - -/* Array of all variables referenced in the function. */ -htab_t referenced_vars; /*--------------------------------------------------------------------------- @@ -97,30 +79,28 @@ htab_t referenced_vars; various attributes for each variable used by alias analysis and the optimizer. */ -static void +static unsigned int find_referenced_vars (void) { - htab_t vars_found; basic_block bb; - block_stmt_iterator si; - struct walk_state walk_state; - - vars_found = htab_create (50, htab_hash_pointer, htab_eq_pointer, NULL); - memset (&walk_state, 0, sizeof (walk_state)); - walk_state.vars_found = vars_found; + gimple_stmt_iterator si; FOR_EACH_BB (bb) - for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si)) - { - tree *stmt_p = bsi_stmt_ptr (si); - walk_tree (stmt_p, find_vars_r, &walk_state, NULL); - } + { + for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) + find_referenced_vars_in (gsi_stmt (si)); - htab_delete (vars_found); + for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) + find_referenced_vars_in (gsi_stmt (si)); + } + + return 0; } -struct tree_opt_pass pass_referenced_vars = +struct gimple_opt_pass pass_referenced_vars = { + { + GIMPLE_PASS, NULL, /* name */ NULL, /* gate */ find_referenced_vars, /* execute */ @@ -131,9 +111,9 @@ struct tree_opt_pass pass_referenced_vars = PROP_gimple_leh | PROP_cfg, /* properties_required */ PROP_referenced_vars, /* properties_provided */ 0, /* properties_destroyed */ - 0, /* todo_flags_start */ - 0, /* todo_flags_finish */ - 0 /* letter */ + TODO_dump_func, /* todo_flags_start */ + TODO_dump_func /* todo_flags_finish */ + } }; @@ -149,57 +129,49 @@ create_var_ann (tree t) gcc_assert (t); gcc_assert (DECL_P (t)); - gcc_assert (!t->common.ann || t->common.ann->common.type == VAR_ANN); - - ann = ggc_alloc (sizeof (*ann)); - memset ((void *) ann, 0, sizeof (*ann)); + gcc_assert (!t->base.ann || t->base.ann->common.type == VAR_ANN); + ann = GGC_CNEW (struct var_ann_d); ann->common.type = VAR_ANN; - - t->common.ann = (tree_ann_t) ann; + t->base.ann = (tree_ann_t) ann; return ann; } +/* Renumber all of the gimple stmt uids. */ -/* Create a new annotation for a statement node T. */ - -stmt_ann_t -create_stmt_ann (tree t) +void +renumber_gimple_stmt_uids (void) { - stmt_ann_t ann; - - gcc_assert (is_gimple_stmt (t)); - gcc_assert (!t->common.ann || t->common.ann->common.type == STMT_ANN); - - ann = ggc_alloc (sizeof (*ann)); - memset ((void *) ann, 0, sizeof (*ann)); - - ann->common.type = STMT_ANN; - - /* Since we just created the annotation, mark the statement modified. */ - ann->modified = true; - - t->common.ann = (tree_ann_t) ann; + basic_block bb; - return ann; + set_gimple_stmt_max_uid (cfun, 0); + FOR_ALL_BB (bb) + { + gimple_stmt_iterator bsi; + for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) + { + gimple stmt = gsi_stmt (bsi); + gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun)); + } + } } /* Create a new annotation for a tree T. */ -tree_ann_t -create_tree_ann (tree t) +tree_ann_common_t +create_tree_common_ann (tree t) { - tree_ann_t ann; + tree_ann_common_t ann; gcc_assert (t); - gcc_assert (!t->common.ann || t->common.ann->common.type == TREE_ANN_COMMON); + gcc_assert (!t->base.ann || t->base.ann->common.type == TREE_ANN_COMMON); - ann = ggc_alloc (sizeof (*ann)); - memset ((void *) ann, 0, sizeof (*ann)); + ann = GGC_CNEW (struct tree_ann_common_d); - ann->common.type = TREE_ANN_COMMON; - t->common.ann = ann; + ann->type = TREE_ANN_COMMON; + ann->rn = -1; + t->base.ann = (tree_ann_t) ann; return ann; } @@ -210,9 +182,14 @@ tree make_rename_temp (tree type, const char *prefix) { tree t = create_tmp_var (type, prefix); - if (referenced_vars) + + if (TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE + || TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE) + DECL_GIMPLE_REG_P (t) = 1; + + if (gimple_referenced_vars (cfun)) { - add_referenced_tmp_var (t); + add_referenced_var (t); mark_sym_for_renaming (t); } @@ -240,8 +217,9 @@ dump_referenced_vars (FILE *file) { fprintf (file, "Variable: "); dump_variable (file, var); - fprintf (file, "\n"); } + + fprintf (file, "\n"); } @@ -254,37 +232,6 @@ debug_referenced_vars (void) } -/* Dump sub-variables for VAR to FILE. */ - -void -dump_subvars_for (FILE *file, tree var) -{ - subvar_t sv = get_subvars_for_var (var); - - if (!sv) - return; - - fprintf (file, "{ "); - - for (; sv; sv = sv->next) - { - print_generic_expr (file, sv->var, dump_flags); - fprintf (file, " "); - } - - fprintf (file, "}"); -} - - -/* Dumb sub-variables for VAR to stderr. */ - -void -debug_subvars_for (tree var) -{ - dump_subvars_for (stderr, var); -} - - /* Dump variable VAR and its may-aliases to FILE. */ void @@ -309,20 +256,11 @@ dump_variable (FILE *file, tree var) ann = var_ann (var); - fprintf (file, ", UID %u", (unsigned) DECL_UID (var)); + fprintf (file, ", UID D.%u", (unsigned) DECL_UID (var)); fprintf (file, ", "); print_generic_expr (file, TREE_TYPE (var), dump_flags); - if (ann->type_mem_tag) - { - fprintf (file, ", type memory tag: "); - print_generic_expr (file, ann->type_mem_tag, dump_flags); - } - - if (ann->is_alias_tag) - fprintf (file, ", is an alias tag"); - if (TREE_ADDRESSABLE (var)) fprintf (file, ", is addressable"); @@ -334,23 +272,21 @@ dump_variable (FILE *file, tree var) if (is_call_clobbered (var)) fprintf (file, ", call clobbered"); - - if (default_def (var)) + else if (is_call_used (var)) + fprintf (file, ", call used"); + + if (ann->noalias_state == NO_ALIAS) + fprintf (file, ", NO_ALIAS (does not alias other NO_ALIAS symbols)"); + else if (ann->noalias_state == NO_ALIAS_GLOBAL) + fprintf (file, ", NO_ALIAS_GLOBAL (does not alias other NO_ALIAS symbols" + " and global vars)"); + else if (ann->noalias_state == NO_ALIAS_ANYTHING) + fprintf (file, ", NO_ALIAS_ANYTHING (does not alias any other symbols)"); + + if (gimple_default_def (cfun, var)) { fprintf (file, ", default def: "); - print_generic_expr (file, default_def (var), dump_flags); - } - - if (ann->may_aliases) - { - fprintf (file, ", may aliases: "); - dump_may_aliases_for (file, var); - } - - if (get_subvars_for_var (var)) - { - fprintf (file, ", sub-vars: "); - dump_subvars_for (file, var); + print_generic_expr (file, gimple_default_def (cfun, var), dump_flags); } fprintf (file, "\n"); @@ -394,11 +330,6 @@ dump_dfa_stats (FILE *file) fprintf (file, fmt_str_1, "Referenced variables", (unsigned long)num_referenced_vars, SCALE (size), LABEL (size)); - size = dfa_stats.num_stmt_anns * sizeof (struct stmt_ann_d); - total += size; - fprintf (file, fmt_str_1, "Statements annotated", dfa_stats.num_stmt_anns, - SCALE (size), LABEL (size)); - size = dfa_stats.num_var_anns * sizeof (struct var_ann_d); total += size; fprintf (file, fmt_str_1, "Variables annotated", dfa_stats.num_var_anns, @@ -419,17 +350,12 @@ dump_dfa_stats (FILE *file) fprintf (file, fmt_str_1, "VUSE operands", dfa_stats.num_vuses, SCALE (size), LABEL (size)); - size = dfa_stats.num_v_may_defs * sizeof (tree *); + size = dfa_stats.num_vdefs * sizeof (tree *); total += size; - fprintf (file, fmt_str_1, "V_MAY_DEF operands", dfa_stats.num_v_may_defs, + fprintf (file, fmt_str_1, "VDEF operands", dfa_stats.num_vdefs, SCALE (size), LABEL (size)); - size = dfa_stats.num_v_must_defs * sizeof (tree *); - total += size; - fprintf (file, fmt_str_1, "V_MUST_DEF operands", dfa_stats.num_v_must_defs, - SCALE (size), LABEL (size)); - - size = dfa_stats.num_phis * sizeof (struct tree_phi_node); + size = dfa_stats.num_phis * sizeof (struct gimple_statement_phi); total += size; fprintf (file, fmt_str_1, "PHI nodes", dfa_stats.num_phis, SCALE (size), LABEL (size)); @@ -446,9 +372,9 @@ dump_dfa_stats (FILE *file) fprintf (file, "\n"); if (dfa_stats.num_phis) - fprintf (file, "Average number of arguments per PHI node: %.1f (max: %d)\n", + fprintf (file, "Average number of arguments per PHI node: %.1f (max: %ld)\n", (float) dfa_stats.num_phi_args / (float) dfa_stats.num_phis, - dfa_stats.max_num_phi_args); + (long) dfa_stats.max_num_phi_args); fprintf (file, "\n"); } @@ -463,80 +389,48 @@ debug_dfa_stats (void) } -/* Collect DFA statistics and store them in the structure pointed by +/* Collect DFA statistics and store them in the structure pointed to by DFA_STATS_P. */ static void -collect_dfa_stats (struct dfa_stats_d *dfa_stats_p) +collect_dfa_stats (struct dfa_stats_d *dfa_stats_p ATTRIBUTE_UNUSED) { - struct pointer_set_t *pset; basic_block bb; - block_stmt_iterator i; + referenced_var_iterator vi; + tree var; gcc_assert (dfa_stats_p); memset ((void *)dfa_stats_p, 0, sizeof (struct dfa_stats_d)); - /* Walk all the trees in the function counting references. Start at - basic block 0, but don't stop at block boundaries. */ - pset = pointer_set_create (); - - for (i = bsi_start (BASIC_BLOCK (0)); !bsi_end_p (i); bsi_next (&i)) - walk_tree (bsi_stmt_ptr (i), collect_dfa_stats_r, (void *) dfa_stats_p, - pset); - - pointer_set_destroy (pset); + /* Count all the variable annotations. */ + FOR_EACH_REFERENCED_VAR (var, vi) + if (var_ann (var)) + dfa_stats_p->num_var_anns++; + /* Walk all the statements in the function counting references. */ FOR_EACH_BB (bb) { - tree phi; - for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) + gimple_stmt_iterator si; + + for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) { + gimple phi = gsi_stmt (si); dfa_stats_p->num_phis++; - dfa_stats_p->num_phi_args += PHI_NUM_ARGS (phi); - if (PHI_NUM_ARGS (phi) > dfa_stats_p->max_num_phi_args) - dfa_stats_p->max_num_phi_args = PHI_NUM_ARGS (phi); + dfa_stats_p->num_phi_args += gimple_phi_num_args (phi); + if (gimple_phi_num_args (phi) > dfa_stats_p->max_num_phi_args) + dfa_stats_p->max_num_phi_args = gimple_phi_num_args (phi); } - } -} - -/* Callback for walk_tree to collect DFA statistics for a tree and its - children. */ - -static tree -collect_dfa_stats_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, - void *data) -{ - tree t = *tp; - struct dfa_stats_d *dfa_stats_p = (struct dfa_stats_d *)data; - - if (t->common.ann) - { - switch (ann_type (t->common.ann)) + for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) { - case STMT_ANN: - { - dfa_stats_p->num_stmt_anns++; - dfa_stats_p->num_defs += NUM_SSA_OPERANDS (t, SSA_OP_DEF); - dfa_stats_p->num_uses += NUM_SSA_OPERANDS (t, SSA_OP_USE); - dfa_stats_p->num_v_may_defs += NUM_SSA_OPERANDS (t, SSA_OP_VMAYDEF); - dfa_stats_p->num_vuses += NUM_SSA_OPERANDS (t, SSA_OP_VUSE); - dfa_stats_p->num_v_must_defs += - NUM_SSA_OPERANDS (t, SSA_OP_VMUSTDEF); - break; - } - - case VAR_ANN: - dfa_stats_p->num_var_anns++; - break; - - default: - break; + gimple stmt = gsi_stmt (si); + dfa_stats_p->num_defs += NUM_SSA_OPERANDS (stmt, SSA_OP_DEF); + dfa_stats_p->num_uses += NUM_SSA_OPERANDS (stmt, SSA_OP_USE); + dfa_stats_p->num_vdefs += gimple_vdef (stmt) ? 1 : 0; + dfa_stats_p->num_vuses += gimple_vuse (stmt) ? 1 : 0; } } - - return NULL; } @@ -547,14 +441,17 @@ collect_dfa_stats_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, the function. */ static tree -find_vars_r (tree *tp, int *walk_subtrees, void *data) +find_vars_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) { - struct walk_state *walk_state = (struct walk_state *) data; + /* If we are reading the lto info back in, we need to rescan the + referenced vars. */ + if (TREE_CODE (*tp) == SSA_NAME) + add_referenced_var (SSA_NAME_VAR (*tp)); /* If T is a regular variable that the optimizers are interested in, add it to the list of variables. */ - if (SSA_VAR_P (*tp)) - add_referenced_var (*tp, walk_state); + else if (SSA_VAR_P (*tp)) + add_referenced_var (*tp); /* Type, _DECL and constant nodes have no interesting children. Ignore them. */ @@ -564,98 +461,170 @@ find_vars_r (tree *tp, int *walk_subtrees, void *data) return NULL_TREE; } +/* Find referenced variables in STMT. In contrast with + find_new_referenced_vars, this function will not mark newly found + variables for renaming. */ -/* Lookup UID in the referenced_vars hashtable and return the associated - variable or NULL if it is not there. */ - -tree -referenced_var_lookup_if_exists (unsigned int uid) +void +find_referenced_vars_in (gimple stmt) { - struct int_tree_map *h, in; - in.uid = uid; - h = htab_find_with_hash (referenced_vars, &in, uid); - if (h) - return h->to; - return NULL_TREE; + size_t i; + + if (gimple_code (stmt) != GIMPLE_PHI) + { + for (i = 0; i < gimple_num_ops (stmt); i++) + walk_tree (gimple_op_ptr (stmt, i), find_vars_r, NULL, NULL); + } + else + { + walk_tree (gimple_phi_result_ptr (stmt), find_vars_r, NULL, NULL); + + for (i = 0; i < gimple_phi_num_args (stmt); i++) + { + tree arg = gimple_phi_arg_def (stmt, i); + walk_tree (&arg, find_vars_r, NULL, NULL); + } + } } + /* Lookup UID in the referenced_vars hashtable and return the associated variable. */ tree referenced_var_lookup (unsigned int uid) { - struct int_tree_map *h, in; + tree h; + struct tree_decl_minimal in; in.uid = uid; - h = htab_find_with_hash (referenced_vars, &in, uid); + h = (tree) htab_find_with_hash (gimple_referenced_vars (cfun), &in, uid); gcc_assert (h || uid == 0); + return h; +} + +/* Check if TO is in the referenced_vars hash table and insert it if not. + Return true if it required insertion. */ + +bool +referenced_var_check_and_insert (tree to) +{ + tree h, *loc; + struct tree_decl_minimal in; + unsigned int uid = DECL_UID (to); + + in.uid = uid; + h = (tree) htab_find_with_hash (gimple_referenced_vars (cfun), &in, uid); if (h) - return h->to; - return NULL_TREE; + { + /* DECL_UID has already been entered in the table. Verify that it is + the same entry as TO. See PR 27793. */ + gcc_assert (h == to); + return false; + } + + loc = (tree *) htab_find_slot_with_hash (gimple_referenced_vars (cfun), + &in, uid, INSERT); + *loc = to; + return true; } -/* Insert the pair UID, TO into the referenced_vars hashtable. */ +/* Lookup VAR UID in the default_defs hashtable and return the associated + variable. */ -static void -referenced_var_insert (unsigned int uid, tree to) +tree +gimple_default_def (struct function *fn, tree var) +{ + struct tree_decl_minimal ind; + struct tree_ssa_name in; + gcc_assert (SSA_VAR_P (var)); + in.var = (tree)&ind; + ind.uid = DECL_UID (var); + return (tree) htab_find_with_hash (DEFAULT_DEFS (fn), &in, DECL_UID (var)); +} + +/* Insert the pair VAR's UID, DEF into the default_defs hashtable. */ + +void +set_default_def (tree var, tree def) { - struct int_tree_map *h; + struct tree_decl_minimal ind; + struct tree_ssa_name in; void **loc; - h = ggc_alloc (sizeof (struct int_tree_map)); - h->uid = uid; - h->to = to; - loc = htab_find_slot_with_hash (referenced_vars, h, uid, INSERT); - *(struct int_tree_map **) loc = h; -} + gcc_assert (SSA_VAR_P (var)); + in.var = (tree)&ind; + ind.uid = DECL_UID (var); + if (!def) + { + loc = htab_find_slot_with_hash (DEFAULT_DEFS (cfun), &in, + DECL_UID (var), INSERT); + gcc_assert (*loc); + htab_remove_elt (DEFAULT_DEFS (cfun), *loc); + return; + } + gcc_assert (TREE_CODE (def) == SSA_NAME && SSA_NAME_VAR (def) == var); + loc = htab_find_slot_with_hash (DEFAULT_DEFS (cfun), &in, + DECL_UID (var), INSERT); + + /* Default definition might be changed by tail call optimization. */ + if (*loc) + SSA_NAME_IS_DEFAULT_DEF (*(tree *) loc) = false; + *(tree *) loc = def; -/* Add VAR to the list of dereferenced variables. + /* Mark DEF as the default definition for VAR. */ + SSA_NAME_IS_DEFAULT_DEF (def) = true; +} - WALK_STATE contains a hash table used to avoid adding the same - variable more than once. Note that this function assumes that - VAR is a valid SSA variable. If WALK_STATE is NULL, no - duplicate checking is done. */ +/* Add VAR to the list of referenced variables if it isn't already there. */ -static void -add_referenced_var (tree var, struct walk_state *walk_state) +bool +add_referenced_var (tree var) { - void **slot; var_ann_t v_ann; v_ann = get_var_ann (var); - - if (walk_state) - slot = htab_find_slot (walk_state->vars_found, (void *) var, INSERT); - else - slot = NULL; - - if (slot == NULL || *slot == NULL) + gcc_assert (DECL_P (var)); + + /* Insert VAR into the referenced_vars has table if it isn't present. */ + if (referenced_var_check_and_insert (var)) { - /* This is the first time we find this variable, add it to the - REFERENCED_VARS array and annotate it with attributes that are - intrinsic to the variable. */ - if (slot) - *slot = (void *) var; - - referenced_var_insert (DECL_UID (var), var); - - /* Global variables are always call-clobbered. */ - if (is_global_var (var)) - mark_call_clobbered (var); - /* Scan DECL_INITIAL for pointer variables as they may contain address arithmetic referencing the address of other - variables. */ + variables. As we are only interested in directly referenced + globals or referenced locals restrict this to initializers + than can refer to local variables. */ if (DECL_INITIAL (var) - /* Initializers of external variables are not useful to the - optimizers. */ - && !DECL_EXTERNAL (var) - /* It's not necessary to walk the initial value of non-constant - public variables because it cannot be propagated by the - optimizers. */ - && (!TREE_PUBLIC (var) || !TREE_CONSTANT (var))) - walk_tree (&DECL_INITIAL (var), find_vars_r, walk_state, 0); + && DECL_CONTEXT (var) == current_function_decl) + walk_tree (&DECL_INITIAL (var), find_vars_r, NULL, 0); + + return true; + } + + return false; +} + +/* Remove VAR from the list. */ + +void +remove_referenced_var (tree var) +{ + var_ann_t v_ann; + struct tree_decl_minimal in; + void **loc; + unsigned int uid = DECL_UID (var); + + /* Preserve var_anns of globals. */ + if (!is_global_var (var) + && (v_ann = var_ann (var))) + { + ggc_free (v_ann); + var->base.ann = NULL; } + gcc_assert (DECL_P (var)); + in.uid = uid; + loc = htab_find_slot_with_hash (gimple_referenced_vars (cfun), &in, uid, + NO_INSERT); + htab_clear_slot (gimple_referenced_vars (cfun), loc); } @@ -682,86 +651,30 @@ get_virtual_var (tree var) return var; } -/* Add a temporary variable to REFERENCED_VARS. This is similar to - add_referenced_var, but is used by passes that need to add new temps to - the REFERENCED_VARS array after the program has been scanned for - variables. The variable will just receive a new UID and be added - to the REFERENCED_VARS array without checking for duplicates. */ +/* Mark all the naked symbols in STMT for SSA renaming. + + NOTE: This function should only be used for brand new statements. + If the caller is modifying an existing statement, it should use the + combination push_stmt_changes/pop_stmt_changes. */ void -add_referenced_tmp_var (tree var) -{ - add_referenced_var (var, NULL); -} - - -/* Mark all the non-SSA variables found in STMT's operands to be - processed by update_ssa. */ - -void -mark_new_vars_to_rename (tree stmt) +mark_symbols_for_renaming (gimple stmt) { + tree op; ssa_op_iter iter; - tree val; - bitmap vars_in_vops_to_rename; - bool found_exposed_symbol = false; - int v_may_defs_before, v_may_defs_after; - int v_must_defs_before, v_must_defs_after; - - if (TREE_CODE (stmt) == PHI_NODE) - return; - - vars_in_vops_to_rename = BITMAP_ALLOC (NULL); - - /* Before re-scanning the statement for operands, mark the existing - virtual operands to be renamed again. We do this because when new - symbols are exposed, the virtual operands that were here before due to - aliasing will probably be removed by the call to get_stmt_operand. - Therefore, we need to flag them to be renamed beforehand. - - We flag them in a separate bitmap because we don't really want to - rename them if there are not any newly exposed symbols in the - statement operands. */ - v_may_defs_before = NUM_SSA_OPERANDS (stmt, SSA_OP_VMAYDEF); - v_must_defs_before = NUM_SSA_OPERANDS (stmt, SSA_OP_VMUSTDEF); - - FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, - SSA_OP_VMAYDEF | SSA_OP_VUSE | SSA_OP_VMUSTDEF) - { - if (!DECL_P (val)) - val = SSA_NAME_VAR (val); - bitmap_set_bit (vars_in_vops_to_rename, DECL_UID (val)); - } - /* Now force an operand re-scan on the statement and mark any newly - exposed variables. */ update_stmt (stmt); - v_may_defs_after = NUM_SSA_OPERANDS (stmt, SSA_OP_VMAYDEF); - v_must_defs_after = NUM_SSA_OPERANDS (stmt, SSA_OP_VMUSTDEF); - - FOR_EACH_SSA_TREE_OPERAND (val, stmt, iter, SSA_OP_ALL_OPERANDS) - if (DECL_P (val)) - { - found_exposed_symbol = true; - mark_sym_for_renaming (val); - } - - /* If we found any newly exposed symbols, or if there are fewer VDEF - operands in the statement, add the variables we had set in - VARS_IN_VOPS_TO_RENAME to VARS_TO_RENAME. We need to check for - vanishing VDEFs because in those cases, the names that were formerly - generated by this statement are not going to be available anymore. */ - if (found_exposed_symbol - || v_may_defs_before > v_may_defs_after - || v_must_defs_before > v_must_defs_after) - mark_set_for_renaming (vars_in_vops_to_rename); - - BITMAP_FREE (vars_in_vops_to_rename); + /* Mark all the operands for renaming. */ + FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_ALL_OPERANDS) + if (DECL_P (op)) + mark_sym_for_renaming (op); } -/* Find all variables within the gimplified statement that were not previously - visible to the function and add them to the referenced variables list. */ + +/* Find all variables within the gimplified statement that were not + previously visible to the function and add them to the referenced + variables list. */ static tree find_new_referenced_vars_1 (tree *tp, int *walk_subtrees, @@ -771,7 +684,7 @@ find_new_referenced_vars_1 (tree *tp, int *walk_subtrees, if (TREE_CODE (t) == VAR_DECL && !var_ann (t)) { - add_referenced_tmp_var (t); + add_referenced_var (t); mark_sym_for_renaming (t); } @@ -781,52 +694,210 @@ find_new_referenced_vars_1 (tree *tp, int *walk_subtrees, return NULL; } + +/* Find any new referenced variables in STMT. */ + void -find_new_referenced_vars (tree *stmt_p) +find_new_referenced_vars (gimple stmt) { - walk_tree (stmt_p, find_new_referenced_vars_1, NULL, NULL); + walk_gimple_op (stmt, find_new_referenced_vars_1, NULL); } -/* If REF is a COMPONENT_REF for a structure that can have sub-variables, and - we know where REF is accessing, return the variable in REF that has the - sub-variables. If the return value is not NULL, POFFSET will be the - offset, in bits, of REF inside the return value, and PSIZE will be the - size, in bits, of REF inside the return value. */ +/* If EXP is a handled component reference for a structure, return the + base variable. The access range is delimited by bit positions *POFFSET and + *POFFSET + *PMAX_SIZE. The access size is *PSIZE bits. If either + *PSIZE or *PMAX_SIZE is -1, they could not be determined. If *PSIZE + and *PMAX_SIZE are equal, the access is non-variable. */ tree -okay_component_ref_for_subvars (tree ref, unsigned HOST_WIDE_INT *poffset, - unsigned HOST_WIDE_INT *psize) +get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset, + HOST_WIDE_INT *psize, + HOST_WIDE_INT *pmax_size) { - tree result = NULL; - HOST_WIDE_INT bitsize; - HOST_WIDE_INT bitpos; - tree offset; - enum machine_mode mode; - int unsignedp; - int volatilep; - - gcc_assert (!SSA_VAR_P (ref)); - *poffset = 0; - *psize = (unsigned int) -1; - - if (ref_contains_array_ref (ref)) - return result; - ref = get_inner_reference (ref, &bitsize, &bitpos, &offset, &mode, - &unsignedp, &volatilep, false); - if (TREE_CODE (ref) == INDIRECT_REF) - return result; - else if (offset == NULL && bitsize != -1 && SSA_VAR_P (ref)) + HOST_WIDE_INT bitsize = -1; + HOST_WIDE_INT maxsize = -1; + tree size_tree = NULL_TREE; + HOST_WIDE_INT bit_offset = 0; + bool seen_variable_array_ref = false; + bool seen_union = false; + + /* First get the final access size from just the outermost expression. */ + if (TREE_CODE (exp) == COMPONENT_REF) + size_tree = DECL_SIZE (TREE_OPERAND (exp, 1)); + else if (TREE_CODE (exp) == BIT_FIELD_REF) + size_tree = TREE_OPERAND (exp, 1); + else { - *poffset = bitpos; - *psize = bitsize; - if (get_subvars_for_var (ref) != NULL) - return ref; + enum machine_mode mode = TYPE_MODE (TREE_TYPE (exp)); + if (mode == BLKmode) + size_tree = TYPE_SIZE (TREE_TYPE (exp)); + else + bitsize = GET_MODE_BITSIZE (mode); } - else if (SSA_VAR_P (ref)) + if (size_tree != NULL_TREE) { - if (get_subvars_for_var (ref) != NULL) - return ref; + if (! host_integerp (size_tree, 1)) + bitsize = -1; + else + bitsize = TREE_INT_CST_LOW (size_tree); } - return NULL_TREE; + + /* Initially, maxsize is the same as the accessed element size. + In the following it will only grow (or become -1). */ + maxsize = bitsize; + + /* Compute cumulative bit-offset for nested component-refs and array-refs, + and find the ultimate containing object. */ + while (1) + { + switch (TREE_CODE (exp)) + { + case BIT_FIELD_REF: + bit_offset += tree_low_cst (TREE_OPERAND (exp, 2), 0); + break; + + case COMPONENT_REF: + { + tree field = TREE_OPERAND (exp, 1); + tree this_offset = component_ref_field_offset (exp); + + if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == UNION_TYPE) + seen_union = true; + + if (this_offset && TREE_CODE (this_offset) == INTEGER_CST) + { + HOST_WIDE_INT hthis_offset = tree_low_cst (this_offset, 0); + + hthis_offset *= BITS_PER_UNIT; + bit_offset += hthis_offset; + bit_offset += tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 0); + } + else + { + tree csize = TYPE_SIZE (TREE_TYPE (TREE_OPERAND (exp, 0))); + /* We need to adjust maxsize to the whole structure bitsize. + But we can subtract any constant offset seen so far, + because that would get us out of the structure otherwise. */ + if (maxsize != -1 && csize && host_integerp (csize, 1)) + maxsize = TREE_INT_CST_LOW (csize) - bit_offset; + else + maxsize = -1; + } + } + break; + + case ARRAY_REF: + case ARRAY_RANGE_REF: + { + tree index = TREE_OPERAND (exp, 1); + tree low_bound = array_ref_low_bound (exp); + tree unit_size = array_ref_element_size (exp); + + /* If the resulting bit-offset is constant, track it. */ + if (host_integerp (index, 0) + && host_integerp (low_bound, 0) + && host_integerp (unit_size, 1)) + { + HOST_WIDE_INT hindex = tree_low_cst (index, 0); + + hindex -= tree_low_cst (low_bound, 0); + hindex *= tree_low_cst (unit_size, 1); + hindex *= BITS_PER_UNIT; + bit_offset += hindex; + + /* An array ref with a constant index up in the structure + hierarchy will constrain the size of any variable array ref + lower in the access hierarchy. */ + seen_variable_array_ref = false; + } + else + { + tree asize = TYPE_SIZE (TREE_TYPE (TREE_OPERAND (exp, 0))); + /* We need to adjust maxsize to the whole array bitsize. + But we can subtract any constant offset seen so far, + because that would get us outside of the array otherwise. */ + if (maxsize != -1 && asize && host_integerp (asize, 1)) + maxsize = TREE_INT_CST_LOW (asize) - bit_offset; + else + maxsize = -1; + + /* Remember that we have seen an array ref with a variable + index. */ + seen_variable_array_ref = true; + } + } + break; + + case REALPART_EXPR: + break; + + case IMAGPART_EXPR: + bit_offset += bitsize; + break; + + case VIEW_CONVERT_EXPR: + /* ??? We probably should give up here and bail out. */ + break; + + default: + goto done; + } + + exp = TREE_OPERAND (exp, 0); + } + done: + + /* We need to deal with variable arrays ending structures such as + struct { int length; int a[1]; } x; x.a[d] + struct { struct { int a; int b; } a[1]; } x; x.a[d].a + struct { struct { int a[1]; } a[1]; } x; x.a[0][d], x.a[d][0] + where we do not know maxsize for variable index accesses to + the array. The simplest way to conservatively deal with this + is to punt in the case that offset + maxsize reaches the + base type boundary. + + Unfortunately this is difficult to determine reliably when unions are + involved and so we are conservative in such cases. + + FIXME: This approach may be too conservative, we probably want to at least + check that the union is the last field/element at its level or even + propagate the calculated offsets back up the access chain and check + there. */ + + if (seen_variable_array_ref + && (seen_union + || (maxsize != -1 + && host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1) + && bit_offset + maxsize + == (signed) TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp)))))) + maxsize = -1; + + /* ??? Due to negative offsets in ARRAY_REF we can end up with + negative bit_offset here. We might want to store a zero offset + in this case. */ + *poffset = bit_offset; + *psize = bitsize; + *pmax_size = maxsize; + + return exp; +} + +/* Returns true if STMT references an SSA_NAME that has + SSA_NAME_OCCURS_IN_ABNORMAL_PHI set, otherwise false. */ + +bool +stmt_references_abnormal_ssa_name (gimple stmt) +{ + ssa_op_iter oi; + use_operand_p use_p; + + FOR_EACH_SSA_USE_OPERAND (use_p, stmt, oi, SSA_OP_USE) + { + if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (USE_FROM_PTR (use_p))) + return true; + } + + return false; } +