The following patch fixes PR56005. The details are on
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56005
2013-01-16 Vladimir Makarov <vmaka...@redhat.com>
PR rtl-optimization/56005
* sched-deps.c (sched_analyze_2): Check deps->readonly for adding
pending reads for prefetch.
The patch was successfully bootstrapped and tested on x86-64.
Committed as rev 195247.
Index: sched-deps.c
===================================================================
--- sched-deps.c (revision 195244)
+++ sched-deps.c (working copy)
@@ -2719,8 +2719,9 @@ sched_analyze_2 (struct deps_desc *deps,
to generate accurate dependencies for prefetch insns as
prefetch has only the start address but it is better to have
something than nothing. */
- add_insn_mem_dependence (deps, true, insn,
- gen_rtx_MEM (Pmode, XEXP (PATTERN (insn), 0)));
+ if (!deps->readonly)
+ add_insn_mem_dependence (deps, true, insn,
+ gen_rtx_MEM (Pmode, XEXP (PATTERN (insn), 0)));
break;
case UNSPEC_VOLATILE:
