re PR target/62642 (x86 rdtsc is moved through barrier)

2014-12-15  Vladimir Makarov  <vmakarov@redhat.com>

	PR target/62642
	* ira.c (rtx_moveable_p): Prevent UNSPEC_VOLATILE moves.

From-SVN: r218761

1 files changed, 6 insertions, 0 deletions

diff --git a/gcc/ira.c b/gcc/ira.c
index e610d35..f08aa23 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -4358,6 +4358,12 @@ rtx_moveable_p (rtx *loc, enum op_type type)
     case CLOBBER:
       return rtx_moveable_p (&SET_DEST (x), OP_OUT);
 
+    case UNSPEC_VOLATILE:
+      /* It is a bad idea to consider insns with with such rtl
+	 as moveable ones.  The insn scheduler also considers them as barrier
+	 for a reason.  */
+      return false;
+
     default:
       break;
     }