ira: volatile asm's are not moveable (PR82602)

A volatile asm statement can not be moved (relative to other volatile
asm, etc.), but IRA would do it nevertheless.  This patch fixes it.


	PR rtl-optimization/82602
	* ira.c (rtx_moveable_p): Return false for volatile asm.

From-SVN: r253869

gcc/ChangeLog

+2017-10-18  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR rtl-optimization/82602
+	* ira.c (rtx_moveable_p): Return false for volatile asm.
+
 2017-10-18  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR target/82580

gcc/ira.c

@@ -4400,6 +4400,12 @@ rtx_moveable_p (rtx *loc, enum op_type type)
 	 for a reason.  */
       return false;
 
+    case ASM_OPERANDS:
+      /* The same is true for volatile asm: it has unknown side effects, it
+         cannot be moved at will.  */
+      if (MEM_VOLATILE_P (x))
+	return false;
+
     default:
       break;
     }