From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 12 Jun 2015 11:54:43 +0000 (+0200)
Subject: backport: re PR target/62642 (x86 rdtsc is moved through barrier)
X-Git-Tag: releases/gcc-4.9.3~78
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f310ad015b87353cad60b4a6d6f74e20267a5612;p=thirdparty%2Fgcc.git

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

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

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

From-SVN: r224420
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 971906297dcb..be2c3a9f590c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2015-06-12  Jakub Jelinek  <jakub@redhat.com>
+
+	Backported from mainline
+	2014-12-15  Vladimir Makarov  <vmakarov@redhat.com>
+ 
+	PR target/62642
+	* ira.c (rtx_moveable_p): Prevent UNSPEC_VOLATILE moves.
+
 2015-06-12  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/63608
diff --git a/gcc/ira.c b/gcc/ira.c
index 0c703c514ca0..fb0650e59ecd 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -4434,6 +4434,12 @@ 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;
     }