| /* Data flow functions for trees. |
| Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. |
| Contributed by Diego Novillo <dnovillo@redhat.com> |
| |
| 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) |
| any later version. |
| |
| GCC is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING. If not, write to |
| the Free Software Foundation, 51 Franklin Street, Fifth Floor, |
| Boston, MA 02110-1301, USA. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "tm.h" |
| #include "hashtab.h" |
| #include "pointer-set.h" |
| #include "tree.h" |
| #include "rtl.h" |
| #include "tm_p.h" |
| #include "hard-reg-set.h" |
| #include "basic-block.h" |
| #include "output.h" |
| #include "timevar.h" |
| #include "expr.h" |
| #include "ggc.h" |
| #include "langhooks.h" |
| #include "flags.h" |
| #include "function.h" |
| #include "diagnostic.h" |
| #include "tree-dump.h" |
| #include "tree-gimple.h" |
| #include "tree-flow.h" |
| #include "tree-inline.h" |
| #include "tree-pass.h" |
| #include "convert.h" |
| #include "params.h" |
| #include "cgraph.h" |
| |
| /* Build and maintain data flow information for trees. */ |
| |
| /* 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; |
| long num_vuses; |
| long num_v_must_defs; |
| }; |
| |
| |
| /* 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 *); |
| |
| |
| /* Global declarations. */ |
| |
| /* Array of all variables referenced in the function. */ |
| htab_t referenced_vars; |
| |
| /* Default definition for this symbols. If set for symbol, it |
| means that the first reference to this variable in the function is a |
| USE or a VUSE. In those cases, the SSA renamer creates an SSA name |
| for this variable with an empty defining statement. */ |
| htab_t default_defs; |
| |
| |
| /*--------------------------------------------------------------------------- |
| Dataflow analysis (DFA) routines |
| ---------------------------------------------------------------------------*/ |
| /* Find all the variables referenced in the function. This function |
| builds the global arrays REFERENCED_VARS and CALL_CLOBBERED_VARS. |
| |
| Note that this function does not look for statement operands, it simply |
| determines what variables are referenced in the program and detects |
| various attributes for each variable used by alias analysis and the |
| optimizer. */ |
| |
| static unsigned int |
| find_referenced_vars (void) |
| { |
| basic_block bb; |
| block_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, NULL, NULL); |
| } |
| |
| return 0; |
| } |
| |
| struct tree_opt_pass pass_referenced_vars = |
| { |
| NULL, /* name */ |
| NULL, /* gate */ |
| find_referenced_vars, /* execute */ |
| NULL, /* sub */ |
| NULL, /* next */ |
| 0, /* static_pass_number */ |
| TV_FIND_REFERENCED_VARS, /* tv_id */ |
| 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 */ |
| }; |
| |
| |
| /*--------------------------------------------------------------------------- |
| Manage annotations |
| ---------------------------------------------------------------------------*/ |
| /* Create a new annotation for a _DECL node T. */ |
| |
| var_ann_t |
| create_var_ann (tree t) |
| { |
| var_ann_t ann; |
| |
| gcc_assert (t); |
| gcc_assert (DECL_P (t)); |
| gcc_assert (!t->common.ann || t->common.ann->common.type == VAR_ANN); |
| |
| ann = GGC_CNEW (struct var_ann_d); |
| |
| ann->common.type = VAR_ANN; |
| |
| t->common.ann = (tree_ann_t) ann; |
| |
| return ann; |
| } |
| |
| /* Create a new annotation for a FUNCTION_DECL node T. */ |
| |
| function_ann_t |
| create_function_ann (tree t) |
| { |
| function_ann_t ann; |
| |
| gcc_assert (t); |
| gcc_assert (TREE_CODE (t) == FUNCTION_DECL); |
| gcc_assert (!t->common.ann || t->common.ann->common.type == FUNCTION_ANN); |
| |
| ann = ggc_alloc (sizeof (*ann)); |
| memset ((void *) ann, 0, sizeof (*ann)); |
| |
| ann->common.type = FUNCTION_ANN; |
| |
| t->common.ann = (tree_ann_t) ann; |
| |
| return ann; |
| } |
| |
| /* Create a new annotation for a statement node T. */ |
| |
| stmt_ann_t |
| create_stmt_ann (tree t) |
| { |
| stmt_ann_t ann; |
| |
| gcc_assert (is_gimple_stmt (t)); |
| gcc_assert (!t->common.ann || t->common.ann->common.type == STMT_ANN); |
| |
| ann = GGC_CNEW (struct stmt_ann_d); |
| |
| 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; |
| |
| return ann; |
| } |
| |
| /* Create a new annotation for a tree T. */ |
| |
| tree_ann_common_t |
| create_tree_common_ann (tree t) |
| { |
| tree_ann_common_t ann; |
| |
| gcc_assert (t); |
| gcc_assert (!t->common.ann || t->common.ann->common.type == TREE_ANN_COMMON); |
| |
| ann = GGC_CNEW (struct tree_ann_common_d); |
| |
| ann->type = TREE_ANN_COMMON; |
| t->common.ann = (tree_ann_t) ann; |
| |
| return ann; |
| } |
| |
| /* Build a temporary. Make sure and register it to be renamed. */ |
| |
| tree |
| make_rename_temp (tree type, const char *prefix) |
| { |
| tree t = create_tmp_var (type, prefix); |
| |
| if (TREE_CODE (type) == COMPLEX_TYPE) |
| DECL_COMPLEX_GIMPLE_REG_P (t) = 1; |
| |
| if (referenced_vars) |
| { |
| add_referenced_var (t); |
| mark_sym_for_renaming (t); |
| } |
| |
| return t; |
| } |
| |
| |
| |
| /*--------------------------------------------------------------------------- |
| Debugging functions |
| ---------------------------------------------------------------------------*/ |
| /* Dump the list of all the referenced variables in the current function to |
| FILE. */ |
| |
| void |
| dump_referenced_vars (FILE *file) |
| { |
| tree var; |
| referenced_var_iterator rvi; |
| |
| fprintf (file, "\nReferenced variables in %s: %u\n\n", |
| get_name (current_function_decl), (unsigned) num_referenced_vars); |
| |
| FOR_EACH_REFERENCED_VAR (var, rvi) |
| { |
| fprintf (file, "Variable: "); |
| dump_variable (file, var); |
| fprintf (file, "\n"); |
| } |
| } |
| |
| |
| /* Dump the list of all the referenced variables to stderr. */ |
| |
| void |
| debug_referenced_vars (void) |
| { |
| dump_referenced_vars (stderr); |
| } |
| |
| |
| /* 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 |
| dump_variable (FILE *file, tree var) |
| { |
| var_ann_t ann; |
| |
| if (TREE_CODE (var) == SSA_NAME) |
| { |
| if (POINTER_TYPE_P (TREE_TYPE (var))) |
| dump_points_to_info_for (file, var); |
| var = SSA_NAME_VAR (var); |
| } |
| |
| if (var == NULL_TREE) |
| { |
| fprintf (file, "<nil>"); |
| return; |
| } |
| |
| print_generic_expr (file, var, dump_flags); |
| |
| ann = var_ann (var); |
| |
| fprintf (file, ", UID %u", (unsigned) DECL_UID (var)); |
| |
| fprintf (file, ", "); |
| print_generic_expr (file, TREE_TYPE (var), dump_flags); |
| |
| if (ann && ann->symbol_mem_tag) |
| { |
| fprintf (file, ", symbol memory tag: "); |
| print_generic_expr (file, ann->symbol_mem_tag, dump_flags); |
| } |
| |
| if (ann && ann->is_aliased) |
| fprintf (file, ", is aliased"); |
| |
| if (TREE_ADDRESSABLE (var)) |
| fprintf (file, ", is addressable"); |
| |
| if (is_global_var (var)) |
| fprintf (file, ", is global"); |
| |
| if (TREE_THIS_VOLATILE (var)) |
| fprintf (file, ", is volatile"); |
| |
| if (is_call_clobbered (var)) |
| { |
| fprintf (file, ", call clobbered"); |
| if (dump_flags & TDF_DETAILS) |
| { |
| var_ann_t va = var_ann (var); |
| unsigned int escape_mask = va->escape_mask; |
| |
| fprintf (file, " ("); |
| if (escape_mask & ESCAPE_STORED_IN_GLOBAL) |
| fprintf (file, ", stored in global"); |
| if (escape_mask & ESCAPE_TO_ASM) |
| fprintf (file, ", goes through ASM"); |
| if (escape_mask & ESCAPE_TO_CALL) |
| fprintf (file, ", passed to call"); |
| if (escape_mask & ESCAPE_BAD_CAST) |
| fprintf (file, ", bad cast"); |
| if (escape_mask & ESCAPE_TO_RETURN) |
| fprintf (file, ", returned from func"); |
| if (escape_mask & ESCAPE_TO_PURE_CONST) |
| fprintf (file, ", passed to pure/const"); |
| if (escape_mask & ESCAPE_IS_GLOBAL) |
| fprintf (file, ", is global var"); |
| if (escape_mask & ESCAPE_IS_PARM) |
| fprintf (file, ", is incoming pointer"); |
| if (escape_mask & ESCAPE_UNKNOWN) |
| fprintf (file, ", unknown escape"); |
| fprintf (file, " )"); |
| } |
| } |
| |
| if (default_def (var)) |
| { |
| fprintf (file, ", default def: "); |
| print_generic_expr (file, default_def (var), dump_flags); |
| } |
| |
| if (may_aliases (var)) |
| { |
| 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); |
| } |
| |
| fprintf (file, "\n"); |
| } |
| |
| |
| /* Dump variable VAR and its may-aliases to stderr. */ |
| |
| void |
| debug_variable (tree var) |
| { |
| dump_variable (stderr, var); |
| } |
| |
| |
| /* Dump various DFA statistics to FILE. */ |
| |
| void |
| dump_dfa_stats (FILE *file) |
| { |
| struct dfa_stats_d dfa_stats; |
| |
| unsigned long size, total = 0; |
| const char * const fmt_str = "%-30s%-13s%12s\n"; |
| const char * const fmt_str_1 = "%-30s%13lu%11lu%c\n"; |
| const char * const fmt_str_3 = "%-43s%11lu%c\n"; |
| const char *funcname |
| = lang_hooks.decl_printable_name (current_function_decl, 2); |
| |
| collect_dfa_stats (&dfa_stats); |
| |
| fprintf (file, "\nDFA Statistics for %s\n\n", funcname); |
| |
| fprintf (file, "---------------------------------------------------------\n"); |
| fprintf (file, fmt_str, "", " Number of ", "Memory"); |
| fprintf (file, fmt_str, "", " instances ", "used "); |
| fprintf (file, "---------------------------------------------------------\n"); |
| |
| size = num_referenced_vars * sizeof (tree); |
| total += size; |
| 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, |
| SCALE (size), LABEL (size)); |
| |
| size = dfa_stats.num_uses * sizeof (tree *); |
| total += size; |
| fprintf (file, fmt_str_1, "USE operands", dfa_stats.num_uses, |
| SCALE (size), LABEL (size)); |
| |
| size = dfa_stats.num_defs * sizeof (tree *); |
| total += size; |
| fprintf (file, fmt_str_1, "DEF operands", dfa_stats.num_defs, |
| SCALE (size), LABEL (size)); |
| |
| size = dfa_stats.num_vuses * sizeof (tree *); |
| total += size; |
| fprintf (file, fmt_str_1, "VUSE operands", dfa_stats.num_vuses, |
| SCALE (size), LABEL (size)); |
| |
| size = dfa_stats.num_v_may_defs * sizeof (tree *); |
| total += size; |
| fprintf (file, fmt_str_1, "V_MAY_DEF operands", dfa_stats.num_v_may_defs, |
| 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); |
| total += size; |
| fprintf (file, fmt_str_1, "PHI nodes", dfa_stats.num_phis, |
| SCALE (size), LABEL (size)); |
| |
| size = dfa_stats.num_phi_args * sizeof (struct phi_arg_d); |
| total += size; |
| fprintf (file, fmt_str_1, "PHI arguments", dfa_stats.num_phi_args, |
| SCALE (size), LABEL (size)); |
| |
| fprintf (file, "---------------------------------------------------------\n"); |
| fprintf (file, fmt_str_3, "Total memory used by DFA/SSA data", SCALE (total), |
| LABEL (total)); |
| fprintf (file, "---------------------------------------------------------\n"); |
| fprintf (file, "\n"); |
| |
| if (dfa_stats.num_phis) |
| fprintf (file, "Average number of arguments per PHI node: %.1f (max: %d)\n", |
| (float) dfa_stats.num_phi_args / (float) dfa_stats.num_phis, |
| dfa_stats.max_num_phi_args); |
| |
| fprintf (file, "\n"); |
| } |
| |
| |
| /* Dump DFA statistics on stderr. */ |
| |
| void |
| debug_dfa_stats (void) |
| { |
| dump_dfa_stats (stderr); |
| } |
| |
| |
| /* 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) |
| { |
| struct pointer_set_t *pset; |
| basic_block bb; |
| block_stmt_iterator i; |
| |
| 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 NUM_FIXED_BLOCKS, but don't stop at block boundaries. */ |
| pset = pointer_set_create (); |
| |
| for (i = bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS)); |
| !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); |
| |
| FOR_EACH_BB (bb) |
| { |
| tree phi; |
| for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
| { |
| 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); |
| } |
| } |
| } |
| |
| |
| /* 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)) |
| { |
| 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; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| |
| /*--------------------------------------------------------------------------- |
| Miscellaneous helpers |
| ---------------------------------------------------------------------------*/ |
| /* Callback for walk_tree. Used to collect variables referenced in |
| the function. */ |
| |
| static tree |
| find_vars_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) |
| { |
| /* 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); |
| |
| /* Type, _DECL and constant nodes have no interesting children. |
| Ignore them. */ |
| else if (IS_TYPE_OR_DECL_P (*tp) || CONSTANT_CLASS_P (*tp)) |
| *walk_subtrees = 0; |
| |
| return NULL_TREE; |
| } |
| |
| /* 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; |
| in.uid = uid; |
| h = (struct int_tree_map *) htab_find_with_hash (referenced_vars, &in, uid); |
| gcc_assert (h || uid == 0); |
| if (h) |
| return h->to; |
| return NULL_TREE; |
| } |
| |
| /* 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) |
| { |
| struct int_tree_map *h, in; |
| void **loc; |
| unsigned int uid = DECL_UID (to); |
| |
| in.uid = uid; |
| in.to = to; |
| h = (struct int_tree_map *) htab_find_with_hash (referenced_vars, &in, uid); |
| |
| if (h) |
| { |
| /* 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 == to); |
| return false; |
| } |
| |
| h = GGC_NEW (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; |
| return true; |
| } |
| |
| /* Lookup VAR UID in the default_defs hashtable and return the associated |
| variable. */ |
| |
| tree |
| default_def (tree var) |
| { |
| struct int_tree_map *h, in; |
| gcc_assert (SSA_VAR_P (var)); |
| in.uid = DECL_UID (var); |
| h = (struct int_tree_map *) htab_find_with_hash (default_defs, &in, |
| DECL_UID (var)); |
| if (h) |
| return h->to; |
| return NULL_TREE; |
| } |
| |
| /* Insert the pair VAR's UID, DEF into the default_defs hashtable. */ |
| |
| void |
| set_default_def (tree var, tree def) |
| { |
| struct int_tree_map in; |
| struct int_tree_map *h; |
| void **loc; |
| |
| gcc_assert (SSA_VAR_P (var)); |
| in.uid = DECL_UID (var); |
| if (!def && default_def (var)) |
| { |
| loc = htab_find_slot_with_hash (default_defs, &in, DECL_UID (var), INSERT); |
| htab_remove_elt (default_defs, *loc); |
| return; |
| } |
| gcc_assert (TREE_CODE (def) == SSA_NAME); |
| loc = htab_find_slot_with_hash (default_defs, &in, DECL_UID (var), INSERT); |
| /* Default definition might be changed by tail call optimization. */ |
| if (!*loc) |
| { |
| h = GGC_NEW (struct int_tree_map); |
| h->uid = DECL_UID (var); |
| h->to = def; |
| *(struct int_tree_map **) loc = h; |
| } |
| else |
| { |
| h = (struct int_tree_map *) *loc; |
| h->to = def; |
| } |
| } |
| |
| /* Add VAR to the list of referenced variables if it isn't already there. */ |
| |
| void |
| add_referenced_var (tree var) |
| { |
| var_ann_t v_ann; |
| |
| v_ann = get_var_ann (var); |
| 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 found this variable, annotate it with |
| attributes that are intrinsic to the variable. */ |
| |
| /* Tag's don't have DECL_INITIAL. */ |
| if (MTAG_P (var)) |
| return; |
| |
| /* Scan DECL_INITIAL for pointer variables as they may contain |
| address arithmetic referencing the address of other |
| 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 |
| variables because it cannot be propagated by the |
| optimizers. */ |
| && (TREE_CONSTANT (var) || TREE_READONLY (var))) |
| walk_tree (&DECL_INITIAL (var), find_vars_r, NULL, 0); |
| } |
| } |
| |
| |
| /* Return the virtual variable associated to the non-scalar variable VAR. */ |
| |
| tree |
| get_virtual_var (tree var) |
| { |
| STRIP_NOPS (var); |
| |
| if (TREE_CODE (var) == SSA_NAME) |
| var = SSA_NAME_VAR (var); |
| |
| while (TREE_CODE (var) == REALPART_EXPR || TREE_CODE (var) == IMAGPART_EXPR |
| || handled_component_p (var)) |
| var = TREE_OPERAND (var, 0); |
| |
| /* Treating GIMPLE registers as virtual variables makes no sense. |
| Also complain if we couldn't extract a _DECL out of the original |
| expression. */ |
| gcc_assert (SSA_VAR_P (var)); |
| gcc_assert (!is_gimple_reg (var)); |
| |
| return var; |
| } |
| |
| /* 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) |
| { |
| 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; |
| |
| get_stmt_ann (stmt); |
| 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); |
| } |
| |
| /* 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, |
| void *data ATTRIBUTE_UNUSED) |
| { |
| tree t = *tp; |
| |
| if (TREE_CODE (t) == VAR_DECL && !var_ann (t)) |
| { |
| add_referenced_var (t); |
| mark_sym_for_renaming (t); |
| } |
| |
| if (IS_TYPE_OR_DECL_P (t)) |
| *walk_subtrees = 0; |
| |
| return NULL; |
| } |
| |
| void |
| find_new_referenced_vars (tree *stmt_p) |
| { |
| walk_tree (stmt_p, find_new_referenced_vars_1, NULL, NULL); |
| } |
| |
| |
| /* If REF 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 |
| get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset, |
| HOST_WIDE_INT *psize, |
| HOST_WIDE_INT *pmax_size) |
| { |
| HOST_WIDE_INT bitsize = -1; |
| HOST_WIDE_INT maxsize = -1; |
| tree size_tree = NULL_TREE; |
| tree bit_offset = bitsize_zero_node; |
| bool seen_variable_array_ref = false; |
| |
| gcc_assert (!SSA_VAR_P (exp)); |
| |
| /* 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 |
| { |
| 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); |
| } |
| if (size_tree != NULL_TREE) |
| { |
| if (! host_integerp (size_tree, 1)) |
| bitsize = -1; |
| else |
| bitsize = TREE_INT_CST_LOW (size_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 = size_binop (PLUS_EXPR, bit_offset, |
| TREE_OPERAND (exp, 2)); |
| break; |
| |
| case COMPONENT_REF: |
| { |
| tree field = TREE_OPERAND (exp, 1); |
| tree this_offset = component_ref_field_offset (exp); |
| |
| if (this_offset && TREE_CODE (this_offset) == INTEGER_CST) |
| { |
| this_offset = size_binop (MULT_EXPR, |
| fold_convert (bitsizetype, |
| this_offset), |
| bitsize_unit_node); |
| bit_offset = size_binop (PLUS_EXPR, |
| bit_offset, this_offset); |
| bit_offset = size_binop (PLUS_EXPR, bit_offset, |
| DECL_FIELD_BIT_OFFSET (field)); |
| } |
| 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 sofar, |
| because that would get us out of the structure otherwise. */ |
| if (maxsize != -1 |
| && csize && host_integerp (csize, 1)) |
| { |
| maxsize = (TREE_INT_CST_LOW (csize) |
| - TREE_INT_CST_LOW (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 (! integer_zerop (low_bound)) |
| index = fold_build2 (MINUS_EXPR, TREE_TYPE (index), |
| index, low_bound); |
| index = size_binop (MULT_EXPR, |
| fold_convert (sizetype, index), unit_size); |
| if (TREE_CODE (index) == INTEGER_CST) |
| { |
| index = size_binop (MULT_EXPR, |
| fold_convert (bitsizetype, index), |
| bitsize_unit_node); |
| bit_offset = size_binop (PLUS_EXPR, bit_offset, index); |
| |
| /* 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 sofar, |
| because that would get us outside of the array otherwise. */ |
| if (maxsize != -1 |
| && asize && host_integerp (asize, 1)) |
| { |
| maxsize = (TREE_INT_CST_LOW (asize) |
| - TREE_INT_CST_LOW (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 = size_binop (PLUS_EXPR, bit_offset, |
| bitsize_int (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. */ |
| if (seen_variable_array_ref |
| && maxsize != -1 |
| && host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1) |
| && TREE_INT_CST_LOW (bit_offset) + maxsize |
| == 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 = TREE_INT_CST_LOW (bit_offset); |
| *psize = bitsize; |
| *pmax_size = maxsize; |
| |
| return exp; |
| } |