1 /* Data flow functions for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
27 #include "pointer-set.h"
30 #include "basic-block.h"
34 #include "langhooks.h"
37 #include "tree-pretty-print.h"
38 #include "tree-dump.h"
40 #include "tree-flow.h"
41 #include "tree-inline.h"
42 #include "tree-pass.h"
47 /* Build and maintain data flow information for trees. */
49 /* Counters used to display DFA and SSA statistics. */
57 size_t max_num_phi_args;
63 /* Local functions. */
64 static void collect_dfa_stats (struct dfa_stats_d *);
65 static tree find_vars_r (tree *, int *, void *);
68 /*---------------------------------------------------------------------------
69 Dataflow analysis (DFA) routines
70 ---------------------------------------------------------------------------*/
71 /* Find all the variables referenced in the function. This function
72 builds the global arrays REFERENCED_VARS and CALL_CLOBBERED_VARS.
74 Note that this function does not look for statement operands, it simply
75 determines what variables are referenced in the program and detects
76 various attributes for each variable used by alias analysis and the
80 find_referenced_vars (void)
83 gimple_stmt_iterator si;
87 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
89 gimple stmt = gsi_stmt (si);
90 if (is_gimple_debug (stmt))
92 find_referenced_vars_in (gsi_stmt (si));
95 for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si))
96 find_referenced_vars_in (gsi_stmt (si));
102 struct gimple_opt_pass pass_referenced_vars =
106 "*referenced_vars", /* name */
108 find_referenced_vars, /* execute */
111 0, /* static_pass_number */
112 TV_FIND_REFERENCED_VARS, /* tv_id */
113 PROP_gimple_leh | PROP_cfg, /* properties_required */
114 PROP_referenced_vars, /* properties_provided */
115 0, /* properties_destroyed */
116 TODO_dump_func, /* todo_flags_start */
117 TODO_dump_func /* todo_flags_finish */
122 /*---------------------------------------------------------------------------
124 ---------------------------------------------------------------------------*/
125 /* Create a new annotation for a _DECL node T. */
128 create_var_ann (tree t)
133 gcc_assert (TREE_CODE (t) == VAR_DECL
134 || TREE_CODE (t) == PARM_DECL
135 || TREE_CODE (t) == RESULT_DECL);
137 ann = ggc_alloc_cleared_var_ann_d ();
138 *DECL_VAR_ANN_PTR (t) = ann;
143 /* Renumber all of the gimple stmt uids. */
146 renumber_gimple_stmt_uids (void)
150 set_gimple_stmt_max_uid (cfun, 0);
153 gimple_stmt_iterator bsi;
154 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
156 gimple stmt = gsi_stmt (bsi);
157 gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
162 /* Like renumber_gimple_stmt_uids, but only do work on the basic blocks
163 in BLOCKS, of which there are N_BLOCKS. Also renumbers PHIs. */
166 renumber_gimple_stmt_uids_in_blocks (basic_block *blocks, int n_blocks)
170 set_gimple_stmt_max_uid (cfun, 0);
171 for (i = 0; i < n_blocks; i++)
173 basic_block bb = blocks[i];
174 gimple_stmt_iterator bsi;
175 for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi))
177 gimple stmt = gsi_stmt (bsi);
178 gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
180 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
182 gimple stmt = gsi_stmt (bsi);
183 gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
188 /* Build a temporary. Make sure and register it to be renamed. */
191 make_rename_temp (tree type, const char *prefix)
193 tree t = create_tmp_reg (type, prefix);
195 if (gimple_referenced_vars (cfun))
197 add_referenced_var (t);
198 mark_sym_for_renaming (t);
206 /*---------------------------------------------------------------------------
208 ---------------------------------------------------------------------------*/
209 /* Dump the list of all the referenced variables in the current function to
213 dump_referenced_vars (FILE *file)
216 referenced_var_iterator rvi;
218 fprintf (file, "\nReferenced variables in %s: %u\n\n",
219 get_name (current_function_decl), (unsigned) num_referenced_vars);
221 FOR_EACH_REFERENCED_VAR (var, rvi)
223 fprintf (file, "Variable: ");
224 dump_variable (file, var);
227 fprintf (file, "\n");
231 /* Dump the list of all the referenced variables to stderr. */
234 debug_referenced_vars (void)
236 dump_referenced_vars (stderr);
240 /* Dump variable VAR and its may-aliases to FILE. */
243 dump_variable (FILE *file, tree var)
245 if (TREE_CODE (var) == SSA_NAME)
247 if (POINTER_TYPE_P (TREE_TYPE (var)))
248 dump_points_to_info_for (file, var);
249 var = SSA_NAME_VAR (var);
252 if (var == NULL_TREE)
254 fprintf (file, "<nil>");
258 print_generic_expr (file, var, dump_flags);
260 fprintf (file, ", UID D.%u", (unsigned) DECL_UID (var));
261 if (DECL_PT_UID (var) != DECL_UID (var))
262 fprintf (file, ", PT-UID D.%u", (unsigned) DECL_PT_UID (var));
264 fprintf (file, ", ");
265 print_generic_expr (file, TREE_TYPE (var), dump_flags);
267 if (TREE_ADDRESSABLE (var))
268 fprintf (file, ", is addressable");
270 if (is_global_var (var))
271 fprintf (file, ", is global");
273 if (TREE_THIS_VOLATILE (var))
274 fprintf (file, ", is volatile");
276 if (cfun && gimple_default_def (cfun, var))
278 fprintf (file, ", default def: ");
279 print_generic_expr (file, gimple_default_def (cfun, var), dump_flags);
282 if (DECL_INITIAL (var))
284 fprintf (file, ", initial: ");
285 print_generic_expr (file, DECL_INITIAL (var), dump_flags);
288 fprintf (file, "\n");
292 /* Dump variable VAR and its may-aliases to stderr. */
295 debug_variable (tree var)
297 dump_variable (stderr, var);
301 /* Dump various DFA statistics to FILE. */
304 dump_dfa_stats (FILE *file)
306 struct dfa_stats_d dfa_stats;
308 unsigned long size, total = 0;
309 const char * const fmt_str = "%-30s%-13s%12s\n";
310 const char * const fmt_str_1 = "%-30s%13lu%11lu%c\n";
311 const char * const fmt_str_3 = "%-43s%11lu%c\n";
313 = lang_hooks.decl_printable_name (current_function_decl, 2);
315 collect_dfa_stats (&dfa_stats);
317 fprintf (file, "\nDFA Statistics for %s\n\n", funcname);
319 fprintf (file, "---------------------------------------------------------\n");
320 fprintf (file, fmt_str, "", " Number of ", "Memory");
321 fprintf (file, fmt_str, "", " instances ", "used ");
322 fprintf (file, "---------------------------------------------------------\n");
324 size = num_referenced_vars * sizeof (tree);
326 fprintf (file, fmt_str_1, "Referenced variables", (unsigned long)num_referenced_vars,
327 SCALE (size), LABEL (size));
329 size = dfa_stats.num_var_anns * sizeof (struct var_ann_d);
331 fprintf (file, fmt_str_1, "Variables annotated", dfa_stats.num_var_anns,
332 SCALE (size), LABEL (size));
334 size = dfa_stats.num_uses * sizeof (tree *);
336 fprintf (file, fmt_str_1, "USE operands", dfa_stats.num_uses,
337 SCALE (size), LABEL (size));
339 size = dfa_stats.num_defs * sizeof (tree *);
341 fprintf (file, fmt_str_1, "DEF operands", dfa_stats.num_defs,
342 SCALE (size), LABEL (size));
344 size = dfa_stats.num_vuses * sizeof (tree *);
346 fprintf (file, fmt_str_1, "VUSE operands", dfa_stats.num_vuses,
347 SCALE (size), LABEL (size));
349 size = dfa_stats.num_vdefs * sizeof (tree *);
351 fprintf (file, fmt_str_1, "VDEF operands", dfa_stats.num_vdefs,
352 SCALE (size), LABEL (size));
354 size = dfa_stats.num_phis * sizeof (struct gimple_statement_phi);
356 fprintf (file, fmt_str_1, "PHI nodes", dfa_stats.num_phis,
357 SCALE (size), LABEL (size));
359 size = dfa_stats.num_phi_args * sizeof (struct phi_arg_d);
361 fprintf (file, fmt_str_1, "PHI arguments", dfa_stats.num_phi_args,
362 SCALE (size), LABEL (size));
364 fprintf (file, "---------------------------------------------------------\n");
365 fprintf (file, fmt_str_3, "Total memory used by DFA/SSA data", SCALE (total),
367 fprintf (file, "---------------------------------------------------------\n");
368 fprintf (file, "\n");
370 if (dfa_stats.num_phis)
371 fprintf (file, "Average number of arguments per PHI node: %.1f (max: %ld)\n",
372 (float) dfa_stats.num_phi_args / (float) dfa_stats.num_phis,
373 (long) dfa_stats.max_num_phi_args);
375 fprintf (file, "\n");
379 /* Dump DFA statistics on stderr. */
382 debug_dfa_stats (void)
384 dump_dfa_stats (stderr);
388 /* Collect DFA statistics and store them in the structure pointed to by
392 collect_dfa_stats (struct dfa_stats_d *dfa_stats_p ATTRIBUTE_UNUSED)
395 referenced_var_iterator vi;
398 gcc_assert (dfa_stats_p);
400 memset ((void *)dfa_stats_p, 0, sizeof (struct dfa_stats_d));
402 /* Count all the variable annotations. */
403 FOR_EACH_REFERENCED_VAR (var, vi)
405 dfa_stats_p->num_var_anns++;
407 /* Walk all the statements in the function counting references. */
410 gimple_stmt_iterator si;
412 for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si))
414 gimple phi = gsi_stmt (si);
415 dfa_stats_p->num_phis++;
416 dfa_stats_p->num_phi_args += gimple_phi_num_args (phi);
417 if (gimple_phi_num_args (phi) > dfa_stats_p->max_num_phi_args)
418 dfa_stats_p->max_num_phi_args = gimple_phi_num_args (phi);
421 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
423 gimple stmt = gsi_stmt (si);
424 dfa_stats_p->num_defs += NUM_SSA_OPERANDS (stmt, SSA_OP_DEF);
425 dfa_stats_p->num_uses += NUM_SSA_OPERANDS (stmt, SSA_OP_USE);
426 dfa_stats_p->num_vdefs += gimple_vdef (stmt) ? 1 : 0;
427 dfa_stats_p->num_vuses += gimple_vuse (stmt) ? 1 : 0;
433 /*---------------------------------------------------------------------------
434 Miscellaneous helpers
435 ---------------------------------------------------------------------------*/
436 /* Callback for walk_tree. Used to collect variables referenced in
440 find_vars_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
442 /* If we are reading the lto info back in, we need to rescan the
444 if (TREE_CODE (*tp) == SSA_NAME)
445 add_referenced_var (SSA_NAME_VAR (*tp));
447 /* If T is a regular variable that the optimizers are interested
448 in, add it to the list of variables. */
449 else if (SSA_VAR_P (*tp))
450 add_referenced_var (*tp);
452 /* Type, _DECL and constant nodes have no interesting children.
454 else if (IS_TYPE_OR_DECL_P (*tp) || CONSTANT_CLASS_P (*tp))
460 /* Find referenced variables in STMT. In contrast with
461 find_new_referenced_vars, this function will not mark newly found
462 variables for renaming. */
465 find_referenced_vars_in (gimple stmt)
469 if (gimple_code (stmt) != GIMPLE_PHI)
471 for (i = 0; i < gimple_num_ops (stmt); i++)
472 walk_tree (gimple_op_ptr (stmt, i), find_vars_r, NULL, NULL);
476 walk_tree (gimple_phi_result_ptr (stmt), find_vars_r, NULL, NULL);
478 for (i = 0; i < gimple_phi_num_args (stmt); i++)
480 tree arg = gimple_phi_arg_def (stmt, i);
481 walk_tree (&arg, find_vars_r, NULL, NULL);
487 /* Lookup UID in the referenced_vars hashtable and return the associated
491 referenced_var_lookup (unsigned int uid)
494 struct tree_decl_minimal in;
496 h = (tree) htab_find_with_hash (gimple_referenced_vars (cfun), &in, uid);
497 gcc_assert (h || uid == 0);
501 /* Check if TO is in the referenced_vars hash table and insert it if not.
502 Return true if it required insertion. */
505 referenced_var_check_and_insert (tree to)
508 struct tree_decl_minimal in;
509 unsigned int uid = DECL_UID (to);
512 h = (tree) htab_find_with_hash (gimple_referenced_vars (cfun), &in, uid);
515 /* DECL_UID has already been entered in the table. Verify that it is
516 the same entry as TO. See PR 27793. */
517 gcc_assert (h == to);
521 loc = (tree *) htab_find_slot_with_hash (gimple_referenced_vars (cfun),
527 /* Lookup VAR UID in the default_defs hashtable and return the associated
531 gimple_default_def (struct function *fn, tree var)
533 struct tree_decl_minimal ind;
534 struct tree_ssa_name in;
535 gcc_assert (SSA_VAR_P (var));
537 ind.uid = DECL_UID (var);
538 return (tree) htab_find_with_hash (DEFAULT_DEFS (fn), &in, DECL_UID (var));
541 /* Insert the pair VAR's UID, DEF into the default_defs hashtable. */
544 set_default_def (tree var, tree def)
546 struct tree_decl_minimal ind;
547 struct tree_ssa_name in;
550 gcc_assert (SSA_VAR_P (var));
552 ind.uid = DECL_UID (var);
555 loc = htab_find_slot_with_hash (DEFAULT_DEFS (cfun), &in,
556 DECL_UID (var), INSERT);
558 htab_remove_elt (DEFAULT_DEFS (cfun), *loc);
561 gcc_assert (TREE_CODE (def) == SSA_NAME && SSA_NAME_VAR (def) == var);
562 loc = htab_find_slot_with_hash (DEFAULT_DEFS (cfun), &in,
563 DECL_UID (var), INSERT);
565 /* Default definition might be changed by tail call optimization. */
567 SSA_NAME_IS_DEFAULT_DEF (*(tree *) loc) = false;
570 /* Mark DEF as the default definition for VAR. */
571 SSA_NAME_IS_DEFAULT_DEF (def) = true;
574 /* Add VAR to the list of referenced variables if it isn't already there. */
577 add_referenced_var (tree var)
580 gcc_assert (DECL_P (var));
582 /* Insert VAR into the referenced_vars has table if it isn't present. */
583 if (referenced_var_check_and_insert (var))
585 /* Scan DECL_INITIAL for pointer variables as they may contain
586 address arithmetic referencing the address of other
587 variables. As we are only interested in directly referenced
588 globals or referenced locals restrict this to initializers
589 than can refer to local variables. */
590 if (DECL_INITIAL (var)
591 && DECL_CONTEXT (var) == current_function_decl)
592 walk_tree (&DECL_INITIAL (var), find_vars_r, NULL, 0);
600 /* Remove VAR from the list. */
603 remove_referenced_var (tree var)
606 struct tree_decl_minimal in;
608 unsigned int uid = DECL_UID (var);
610 /* Preserve var_anns of globals. */
611 if (!is_global_var (var)
612 && (v_ann = var_ann (var)))
615 *DECL_VAR_ANN_PTR (var) = NULL;
617 gcc_assert (DECL_P (var));
619 loc = htab_find_slot_with_hash (gimple_referenced_vars (cfun), &in, uid,
621 htab_clear_slot (gimple_referenced_vars (cfun), loc);
625 /* Return the virtual variable associated to the non-scalar variable VAR. */
628 get_virtual_var (tree var)
632 if (TREE_CODE (var) == SSA_NAME)
633 var = SSA_NAME_VAR (var);
635 while (TREE_CODE (var) == REALPART_EXPR || TREE_CODE (var) == IMAGPART_EXPR
636 || handled_component_p (var))
637 var = TREE_OPERAND (var, 0);
639 /* Treating GIMPLE registers as virtual variables makes no sense.
640 Also complain if we couldn't extract a _DECL out of the original
642 gcc_assert (SSA_VAR_P (var));
643 gcc_assert (!is_gimple_reg (var));
648 /* Mark all the naked symbols in STMT for SSA renaming. */
651 mark_symbols_for_renaming (gimple stmt)
658 /* Mark all the operands for renaming. */
659 FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_ALL_OPERANDS)
661 mark_sym_for_renaming (op);
665 /* Find all variables within the gimplified statement that were not
666 previously visible to the function and add them to the referenced
670 find_new_referenced_vars_1 (tree *tp, int *walk_subtrees,
671 void *data ATTRIBUTE_UNUSED)
675 if (TREE_CODE (t) == VAR_DECL && !var_ann (t))
677 add_referenced_var (t);
678 mark_sym_for_renaming (t);
681 if (IS_TYPE_OR_DECL_P (t))
688 /* Find any new referenced variables in STMT. */
691 find_new_referenced_vars (gimple stmt)
693 walk_gimple_op (stmt, find_new_referenced_vars_1, NULL);
697 /* If EXP is a handled component reference for a structure, return the
698 base variable. The access range is delimited by bit positions *POFFSET and
699 *POFFSET + *PMAX_SIZE. The access size is *PSIZE bits. If either
700 *PSIZE or *PMAX_SIZE is -1, they could not be determined. If *PSIZE
701 and *PMAX_SIZE are equal, the access is non-variable. */
704 get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
705 HOST_WIDE_INT *psize,
706 HOST_WIDE_INT *pmax_size)
708 HOST_WIDE_INT bitsize = -1;
709 HOST_WIDE_INT maxsize = -1;
710 tree size_tree = NULL_TREE;
711 HOST_WIDE_INT bit_offset = 0;
712 bool seen_variable_array_ref = false;
714 /* First get the final access size from just the outermost expression. */
715 if (TREE_CODE (exp) == COMPONENT_REF)
716 size_tree = DECL_SIZE (TREE_OPERAND (exp, 1));
717 else if (TREE_CODE (exp) == BIT_FIELD_REF)
718 size_tree = TREE_OPERAND (exp, 1);
719 else if (!VOID_TYPE_P (TREE_TYPE (exp)))
721 enum machine_mode mode = TYPE_MODE (TREE_TYPE (exp));
723 size_tree = TYPE_SIZE (TREE_TYPE (exp));
725 bitsize = GET_MODE_BITSIZE (mode);
727 if (size_tree != NULL_TREE)
729 if (! host_integerp (size_tree, 1))
732 bitsize = TREE_INT_CST_LOW (size_tree);
735 /* Initially, maxsize is the same as the accessed element size.
736 In the following it will only grow (or become -1). */
739 /* Compute cumulative bit-offset for nested component-refs and array-refs,
740 and find the ultimate containing object. */
743 switch (TREE_CODE (exp))
746 bit_offset += TREE_INT_CST_LOW (TREE_OPERAND (exp, 2));
751 tree field = TREE_OPERAND (exp, 1);
752 tree this_offset = component_ref_field_offset (exp);
755 && TREE_CODE (this_offset) == INTEGER_CST
756 && host_integerp (this_offset, 0))
758 HOST_WIDE_INT hthis_offset = TREE_INT_CST_LOW (this_offset);
759 hthis_offset *= BITS_PER_UNIT;
761 += TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field));
762 bit_offset += hthis_offset;
764 /* If we had seen a variable array ref already and we just
765 referenced the last field of a struct or a union member
766 then we have to adjust maxsize by the padding at the end
768 if (seen_variable_array_ref
771 tree stype = TREE_TYPE (TREE_OPERAND (exp, 0));
772 tree next = TREE_CHAIN (field);
773 while (next && TREE_CODE (next) != FIELD_DECL)
774 next = TREE_CHAIN (next);
776 || TREE_CODE (stype) != RECORD_TYPE)
778 tree fsize = DECL_SIZE_UNIT (field);
779 tree ssize = TYPE_SIZE_UNIT (stype);
780 if (host_integerp (fsize, 0)
781 && host_integerp (ssize, 0))
782 maxsize += ((TREE_INT_CST_LOW (ssize)
783 - TREE_INT_CST_LOW (fsize))
784 * BITS_PER_UNIT - hthis_offset);
792 tree csize = TYPE_SIZE (TREE_TYPE (TREE_OPERAND (exp, 0)));
793 /* We need to adjust maxsize to the whole structure bitsize.
794 But we can subtract any constant offset seen so far,
795 because that would get us out of the structure otherwise. */
796 if (maxsize != -1 && csize && host_integerp (csize, 1))
797 maxsize = TREE_INT_CST_LOW (csize) - bit_offset;
805 case ARRAY_RANGE_REF:
807 tree index = TREE_OPERAND (exp, 1);
808 tree low_bound, unit_size;
810 /* If the resulting bit-offset is constant, track it. */
811 if (TREE_CODE (index) == INTEGER_CST
812 && host_integerp (index, 0)
813 && (low_bound = array_ref_low_bound (exp),
814 host_integerp (low_bound, 0))
815 && (unit_size = array_ref_element_size (exp),
816 host_integerp (unit_size, 1)))
818 HOST_WIDE_INT hindex = TREE_INT_CST_LOW (index);
820 hindex -= TREE_INT_CST_LOW (low_bound);
821 hindex *= TREE_INT_CST_LOW (unit_size);
822 hindex *= BITS_PER_UNIT;
823 bit_offset += hindex;
825 /* An array ref with a constant index up in the structure
826 hierarchy will constrain the size of any variable array ref
827 lower in the access hierarchy. */
828 seen_variable_array_ref = false;
832 tree asize = TYPE_SIZE (TREE_TYPE (TREE_OPERAND (exp, 0)));
833 /* We need to adjust maxsize to the whole array bitsize.
834 But we can subtract any constant offset seen so far,
835 because that would get us outside of the array otherwise. */
836 if (maxsize != -1 && asize && host_integerp (asize, 1))
837 maxsize = TREE_INT_CST_LOW (asize) - bit_offset;
841 /* Remember that we have seen an array ref with a variable
843 seen_variable_array_ref = true;
852 bit_offset += bitsize;
855 case VIEW_CONVERT_EXPR:
862 exp = TREE_OPERAND (exp, 0);
866 /* We need to deal with variable arrays ending structures such as
867 struct { int length; int a[1]; } x; x.a[d]
868 struct { struct { int a; int b; } a[1]; } x; x.a[d].a
869 struct { struct { int a[1]; } a[1]; } x; x.a[0][d], x.a[d][0]
870 struct { int len; union { int a[1]; struct X x; } u; } x; x.u.a[d]
871 where we do not know maxsize for variable index accesses to
872 the array. The simplest way to conservatively deal with this
873 is to punt in the case that offset + maxsize reaches the
874 base type boundary. This needs to include possible trailing padding
875 that is there for alignment purposes.
877 That is of course only true if the base object is not a decl. */
881 /* If maxsize is unknown adjust it according to the size of the
884 && host_integerp (DECL_SIZE (exp), 1))
885 maxsize = TREE_INT_CST_LOW (DECL_SIZE (exp)) - bit_offset;
887 else if (seen_variable_array_ref
889 && (!host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1)
890 || (bit_offset + maxsize
891 == (signed) TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp))))))
894 /* ??? Due to negative offsets in ARRAY_REF we can end up with
895 negative bit_offset here. We might want to store a zero offset
897 *poffset = bit_offset;
899 *pmax_size = maxsize;
904 /* Returns true if STMT references an SSA_NAME that has
905 SSA_NAME_OCCURS_IN_ABNORMAL_PHI set, otherwise false. */
908 stmt_references_abnormal_ssa_name (gimple stmt)
913 FOR_EACH_SSA_USE_OPERAND (use_p, stmt, oi, SSA_OP_USE)
915 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (USE_FROM_PTR (use_p)))