As PR47283 shows we still have issues with debug insns and the alias
oracle. This patch makes us give conservative answers for
refs_may_alias_p_1 like we do in the other oracle entires (where
I noticed a bug, fixed with this patch). I'll keep the assert
for checking-enabled builds as we probably want to fix the issues
nevertheless.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2011-03-03 Richard Guenther <rguent...@suse.de>
PR middle-end/47283
* tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Make code
match comment.
(refs_may_alias_p_1): For release branches return true if
we are confused by our input.
Index: gcc/tree-ssa-alias.c
===================================================================
*** gcc/tree-ssa-alias.c (revision 170594)
--- gcc/tree-ssa-alias.c (working copy)
*************** ptr_deref_may_alias_decl_p (tree ptr, tr
*** 178,184 ****
|| (TREE_CODE (decl) != VAR_DECL
&& TREE_CODE (decl) != PARM_DECL
&& TREE_CODE (decl) != RESULT_DECL))
! return false;
/* Disregard pointer offsetting. */
if (TREE_CODE (ptr) == POINTER_PLUS_EXPR)
--- 178,184 ----
|| (TREE_CODE (decl) != VAR_DECL
&& TREE_CODE (decl) != PARM_DECL
&& TREE_CODE (decl) != RESULT_DECL))
! return true;
/* Disregard pointer offsetting. */
if (TREE_CODE (ptr) == POINTER_PLUS_EXPR)
*************** refs_may_alias_p_1 (ao_ref *ref1, ao_ref
*** 1080,1086 ****
--- 1080,1091 ----
ao_ref_alias_set (ref2), -1,
tbaa_p);
+ /* We really do not want to end up here, but returning true is safe. */
+ #ifdef ENABLE_CHECKING
gcc_unreachable ();
+ #else
+ return true;
+ #endif
}
bool
