Hi, this patch makes SRA create all scheduled replacements declarations before starting the modification pass over the function. Because we now create more replacements when generating debug info than when we do not, this is the only way we can be sure the declarations (even those that eventually happen in non-debug statements) are created in the same order in -g and -g0, their UIDs have the same order and thus do not cause inadvertent code generation differences later. And we also call create_tmp_var the same number of times which was causing one of the PR 56294 problems in the first place. There is still at least one outstanding issue, I'll update the bug shortly with what I know so far about it.
I chucked out some dumping from analyze_access_subtree because newly called create_access_replacement dumps basically the same thing. Bootstrapped and tested on x86_64-linux, fixes an -fdebug-compare regression. OK for trunk? Thanks, Martin 2013-02-25 Martin Jambor <mjam...@suse.cz> PR tree-optimization/56294 * tree-sra.c (analyze_access_subtree): Create replacement declarations. Adjust dumping. (get_access_replacement): Do not call create_access_replacement. Assert a replacement exists. (get_repl_default_def_ssa_name): Create the replacement declaration itself. testsuite/ * g++.dg/debug/pr56294.C: New test. Index: src/gcc/tree-sra.c =================================================================== --- src.orig/gcc/tree-sra.c +++ src/gcc/tree-sra.c @@ -2000,8 +2000,7 @@ create_access_replacement (struct access static inline tree get_access_replacement (struct access *access) { - if (!access->replacement_decl) - access->replacement_decl = create_access_replacement (access); + gcc_checking_assert (access->replacement_decl); return access->replacement_decl; } @@ -2157,7 +2156,6 @@ analyze_access_subtree (struct access *r || ((root->grp_scalar_read || root->grp_assignment_read) && (root->grp_scalar_write || root->grp_assignment_write)))) { - bool new_integer_type; /* Always create access replacements that cover the whole access. For integral types this means the precision has to match. Avoid assumptions based on the integral type kind, too. */ @@ -2176,22 +2174,19 @@ analyze_access_subtree (struct access *r root->expr = build_ref_for_offset (UNKNOWN_LOCATION, root->base, root->offset, root->type, NULL, false); - new_integer_type = true; - } - else - new_integer_type = false; - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Marking "); - print_generic_expr (dump_file, root->base, 0); - fprintf (dump_file, " offset: %u, size: %u ", - (unsigned) root->offset, (unsigned) root->size); - fprintf (dump_file, " to be replaced%s.\n", - new_integer_type ? " with an integer": ""); + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Changing the type of a replacement for "); + print_generic_expr (dump_file, root->base, 0); + fprintf (dump_file, " offset: %u, size: %u ", + (unsigned) root->offset, (unsigned) root->size); + fprintf (dump_file, " to an integer.\n"); + } } root->grp_to_be_replaced = 1; + root->replacement_decl = create_access_replacement (root); sth_created = true; hole = false; } @@ -2209,15 +2204,7 @@ analyze_access_subtree (struct access *r if (MAY_HAVE_DEBUG_STMTS) { root->grp_to_be_debug_replaced = 1; - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Marking "); - print_generic_expr (dump_file, root->base, 0); - fprintf (dump_file, " offset: %u, size: %u ", - (unsigned) root->offset, (unsigned) root->size); - fprintf (dump_file, " to be replaced with debug " - "statements.\n"); - } + root->replacement_decl = create_access_replacement (root); } } @@ -2973,7 +2960,11 @@ sra_modify_constructor_assign (gimple *s static tree get_repl_default_def_ssa_name (struct access *racc) { - return get_or_create_ssa_default_def (cfun, get_access_replacement (racc)); + gcc_checking_assert (!racc->grp_to_be_replaced && + !racc->grp_to_be_debug_replaced); + if (!racc->replacement_decl) + racc->replacement_decl = create_access_replacement (racc); + return get_or_create_ssa_default_def (cfun, racc->replacement_decl); } /* Return true if REF has a COMPONENT_REF with a bit-field field declaration Index: src/gcc/testsuite/g++.dg/debug/pr56294.C =================================================================== --- /dev/null +++ src/gcc/testsuite/g++.dg/debug/pr56294.C @@ -0,0 +1,30 @@ +// { dg-do compile } +// { dg-options "-fno-ipa-sra -fcompare-debug" } + +struct comp_cost { int cost; unsigned complexity; }; +struct cost_pair { struct iv_cand *cand; }; +struct iv_use { unsigned n_map_members; cost_pair *cost_map; }; +struct iv_cand { unsigned id; }; + +unsigned gu; + +void +bar (comp_cost, comp_cost) +{ +} + +void +foo (iv_use *use, iv_cand *cand) +{ + unsigned i, s = cand->id & (use->n_map_members - 1); + for (i = 0; i < s; i++) + if (use->cost_map[i].cand) + goto found; +found: + use->cost_map[i].cand = cand; + comp_cost elim_cost, express_cost, bound_cost; + bar (elim_cost, express_cost); + gu = express_cost.complexity; +} + +