From 17d2c090a10e1ff15d78e4e139f7df7c39a54d4e Mon Sep 17 00:00:00 2001 From: Richard Guenther Date: Wed, 23 Apr 2008 14:08:25 +0000 Subject: [PATCH] re PR tree-optimization/27799 (adding unused char field inhibits optimization) 2008-04-23 Richard Guenther PR tree-optimization/27799 PR tree-optimization/32921 PR tree-optimization/32624 * tree-ssa-structalias.c (merge_smts_into): Only merge the SMTs aliases and the tag itself into the solution. * tree-ssa-alias.c (compute_flow_sensitive_aliasing): Do not merge the points-to solution back into the SMT aliases. (may_alias_p): Use alias_set_subset_of instead of aliases_conflict_p. A pointer which points to memory with alias set zero may access any variable. * gcc.dg/tree-ssa/pr27799.c: New testcase. * gcc.dg/tree-ssa/20030807-7.c: Remove xfail, scan vrp dump. From-SVN: r134598 --- gcc/ChangeLog | 13 +++++++++++ gcc/testsuite/ChangeLog | 8 +++++++ gcc/testsuite/gcc.dg/tree-ssa/20030807-7.c | 9 ++++---- gcc/testsuite/gcc.dg/tree-ssa/pr27799.c | 26 +++++++++++++++++++++ gcc/tree-ssa-alias.c | 27 +++++++++++----------- gcc/tree-ssa-structalias.c | 16 +------------ 6 files changed, 65 insertions(+), 34 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr27799.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a774a43341a..4fdb84928c5 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,16 @@ +2008-04-23 Richard Guenther + + PR tree-optimization/27799 + PR tree-optimization/32921 + PR tree-optimization/32624 + * tree-ssa-structalias.c (merge_smts_into): Only merge the + SMTs aliases and the tag itself into the solution. + * tree-ssa-alias.c (compute_flow_sensitive_aliasing): Do not + merge the points-to solution back into the SMT aliases. + (may_alias_p): Use alias_set_subset_of instead of + aliases_conflict_p. A pointer which points to + memory with alias set zero may access any variable. + 2008-04-23 Richard Guenther * alias.c (alias_set_subset_of): Correctly handle asking diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index d5828e87085..82b6042f877 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,11 @@ +2008-04-23 Richard Guenther + + PR tree-optimization/27799 + PR tree-optimization/32921 + PR tree-optimization/32624 + * gcc.dg/tree-ssa/pr27799.c: New testcase. + * gcc.dg/tree-ssa/20030807-7.c: Remove xfail, scan vrp dump. + 2008-04-23 Richard Guenther PR middle-end/36021 diff --git a/gcc/testsuite/gcc.dg/tree-ssa/20030807-7.c b/gcc/testsuite/gcc.dg/tree-ssa/20030807-7.c index 253c27ac4f7..f9f5fb798ef 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/20030807-7.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/20030807-7.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O2 -fdump-tree-dom3" } */ +/* { dg-options "-O2 -fdump-tree-vrp1" } */ extern void abort (void); @@ -32,7 +32,6 @@ simplify_condition (cond_p) c_simplify_stmt (&decl); } -/* There should be exactly one IF conditional. TBAA is not able to - determine that 'decl' and 'cond' can't alias. */ -/* { dg-final { scan-tree-dump-times "if " 1 "dom3" { xfail *-*-* } } } */ -/* { dg-final { cleanup-tree-dump "dom3" } } */ +/* There should be exactly one IF conditional. */ +/* { dg-final { scan-tree-dump-times "if " 1 "vrp1" } } */ +/* { dg-final { cleanup-tree-dump "vrp1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr27799.c b/gcc/testsuite/gcc.dg/tree-ssa/pr27799.c new file mode 100644 index 00000000000..de09a40e08b --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr27799.c @@ -0,0 +1,26 @@ +/* { dg-do link } */ +/* { dg-options "-O2" } */ + +struct X { double m; int x; }; +struct Y { int y; short d; }; +struct YY { int y; short d; char c; }; + +extern void link_error (void); + +int foo(struct X *x, struct Y *y) +{ + x->x = 0; + y->y = 1; + if (x->x != 0) + link_error (); +} + +int foo_no(struct X *x, struct YY *y) +{ + x->x = 0; + y->y = 1; + if (x->x != 0) + link_error (); +} + +int main() {} diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index eb57010bdda..ecc827ab9e9 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -2354,7 +2354,6 @@ compute_flow_sensitive_aliasing (struct alias_info *ai) for (i = 0; VEC_iterate (tree, ai->processed_ptrs, i, ptr); i++) { struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr); - tree tag = symbol_mem_tag (SSA_NAME_VAR (ptr)); /* Set up aliasing information for PTR's name memory tag (if it has one). Note that only pointers that have been dereferenced will @@ -2362,18 +2361,7 @@ compute_flow_sensitive_aliasing (struct alias_info *ai) if (pi->name_mem_tag && pi->pt_vars) { if (!bitmap_empty_p (pi->pt_vars)) - { - union_alias_set_into (pi->name_mem_tag, pi->pt_vars); - union_alias_set_into (tag, pi->pt_vars); - bitmap_clear_bit (MTAG_ALIASES (tag), DECL_UID (tag)); - - /* It may be the case that this the tag uid was the only - bit we had set in the aliases list, and in this case, - we don't want to keep an empty bitmap, as this - asserts in tree-ssa-operands.c . */ - if (bitmap_empty_p (MTAG_ALIASES (tag))) - BITMAP_FREE (MTAG_ALIASES (tag)); - } + union_alias_set_into (pi->name_mem_tag, pi->pt_vars); } } timevar_pop (TV_FLOW_SENSITIVE); @@ -2860,8 +2848,19 @@ may_alias_p (tree ptr, alias_set_type mem_alias_set, { alias_stats.tbaa_queries++; + /* If the pointed to memory has alias set zero or the pointer + is ref-all, the MEM can alias VAR. */ + if (mem_alias_set == 0 + || PTR_IS_REF_ALL (ptr)) + { + alias_stats.alias_mayalias++; + alias_stats.tbaa_resolved++; + return true; + } + /* If the alias sets don't conflict then MEM cannot alias VAR. */ - if (!alias_sets_conflict_p (mem_alias_set, var_alias_set)) + if (mem_alias_set != var_alias_set + && !alias_set_subset_of (mem_alias_set, var_alias_set)) { alias_stats.alias_noalias++; alias_stats.tbaa_resolved++; diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c index 5323a2ba976..9a8afb70a2b 100644 --- a/gcc/tree-ssa-structalias.c +++ b/gcc/tree-ssa-structalias.c @@ -4861,8 +4861,6 @@ set_used_smts (void) static void merge_smts_into (tree p, bitmap solution) { - unsigned int i; - bitmap_iterator bi; tree smt; bitmap aliases; tree var = p; @@ -4873,20 +4871,8 @@ merge_smts_into (tree p, bitmap solution) smt = var_ann (var)->symbol_mem_tag; if (smt) { - alias_set_type smtset = get_alias_set (TREE_TYPE (smt)); - - /* Need to set the SMT subsets first before this - will work properly. */ + /* The smt itself isn't included in its aliases. */ bitmap_set_bit (solution, DECL_UID (smt)); - EXECUTE_IF_SET_IN_BITMAP (used_smts, 0, i, bi) - { - tree newsmt = referenced_var (i); - tree newsmttype = TREE_TYPE (newsmt); - - if (alias_set_subset_of (get_alias_set (newsmttype), - smtset)) - bitmap_set_bit (solution, i); - } aliases = MTAG_ALIASES (smt); if (aliases) -- 2.30.2