http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55845
Uros Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |bonzini at gnu dot org
--- Comment #9 from Uros Bizjak <ubizjak at gmail dot com> 2013-01-06 13:23:54
UTC ---
It is try_head_merge_bb that moves unspec_volatile to the wrong place. However,
the core of the problem lies in can_move_insns_accross, which does not
special-case unspec_volatiles.
The untested df-problems.c patch that fixes the failing testcase:
--cut here--
Index: df-problems.c
===================================================================
--- df-problems.c (revision 194945)
+++ df-problems.c (working copy)
@@ -3916,6 +3916,10 @@ can_move_insns_across (rtx from, rtx to, rtx acros
break;
if (NONDEBUG_INSN_P (insn))
{
+ /* Do not move unspec_volatile insns. */
+ if (GET_CODE (PATTERN (insn)) == UNSPEC_VOLATILE)
+ break;
+
if (may_trap_or_fault_p (PATTERN (insn))
&& (trapping_insns_in_across || other_branch_live != NULL))
break;
--cut here--
Adding Paolo B. to CC.
