diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/opt/alias4.C | 56 | ||||
| -rw-r--r-- | gcc/tree-ssa-alias.c | 7 |
3 files changed, 68 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index b072bab..8044ed5 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2006-06-28 Jason Merrill <jason@redhat.com> + + PR c++/27768 + * tree-ssa-alias.c (compute_flow_insensitive_aliasing): Add + may_aliases already in the tag's annotations to the bitmap. + 2006-06-28 Roger Sayle <roger@eyesopen.com> * genpreds.c (write_predicate_stmts) <IOR>: Add missing break. diff --git a/gcc/testsuite/g++.dg/opt/alias4.C b/gcc/testsuite/g++.dg/opt/alias4.C new file mode 100644 index 0000000..6965b8c --- /dev/null +++ b/gcc/testsuite/g++.dg/opt/alias4.C @@ -0,0 +1,56 @@ +// PR c++/27768 +// Alias grouping was losing some may_aliases, causing us to think +// the store to w.p was dead. + +// { dg-do run } +// { dg-options "-O2" } + +int N = 1; + +struct VA +{ + int *p, *q, *r; + + VA() : p(), q() {} + VA(const VA&) : p(), q() {} + ~VA() { if (p) --N; } +}; + +inline void foo(VA, VA, VA) {} + +struct VB +{ + VA va; + + VB() {} + + VB(const VB&) + { + va.p = new int(va.q - va.p); + va.r = va.p + (va.q - va.p); + foo(va, va, va); + } +}; + +struct VC : VB { char c; }; +struct V : VC {}; + +struct WA +{ + struct X {}; + X **p, **q, **r; + + WA() : p() {} + ~WA() { if (p) --N; } +}; + +struct W : WA {}; + +int main() +{ + { + V v, u(v); + W w; + } + return N; +} diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index 2da4e61..1607c71 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -1162,6 +1162,7 @@ compute_flow_insensitive_aliasing (struct alias_info *ai) struct alias_map_d *p_map = ai->pointers[i]; tree tag = var_ann (p_map->var)->symbol_mem_tag; var_ann_t tag_ann = var_ann (tag); + tree var; /* Call-clobbering information is not finalized yet at this point. */ if (PTR_IS_REF_ALL (p_map->var)) @@ -1170,11 +1171,15 @@ compute_flow_insensitive_aliasing (struct alias_info *ai) p_map->total_alias_vops = 0; p_map->may_aliases = BITMAP_ALLOC (&alias_obstack); + /* Add any pre-existing may_aliases to the bitmap used to represent + TAG's alias set in case we need to group aliases. */ + for (j = 0; VEC_iterate (tree, tag_ann->may_aliases, j, var); ++j) + bitmap_set_bit (p_map->may_aliases, DECL_UID (var)); + for (j = 0; j < ai->num_addressable_vars; j++) { struct alias_map_d *v_map; var_ann_t v_ann; - tree var; bool tag_stored_p, var_stored_p; v_map = ai->addressable_vars[j]; |