This fixes PR54634, data-ref analysis does not properly model
"reads of global memory" done by pure functions. So just give
up.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2012-09-20 Richard Guenther <rguent...@suse.de>
PR tree-optimization/54634
* tree-data-ref.c (get_references_in_stmt): For now give
up for pure functions.
Index: gcc/tree-data-ref.c
===================================================================
--- gcc/tree-data-ref.c (revision 191561)
+++ gcc/tree-data-ref.c (working copy)
@@ -4307,10 +4307,10 @@ get_references_in_stmt (gimple stmt, VEC
*references = NULL;
/* ASM_EXPR and CALL_EXPR may embed arbitrary side effects.
- Calls have side-effects, except those to const or pure
- functions. */
+ As we cannot model data-references to not spelled out
+ accesses give up if they may occur. */
if ((stmt_code == GIMPLE_CALL
- && !(gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE)))
+ && !(gimple_call_flags (stmt) & ECF_CONST))
|| (stmt_code == GIMPLE_ASM
&& (gimple_asm_volatile_p (stmt) || gimple_vuse (stmt))))
clobbers_memory = true;
