re PR c++/38256 (ICE with "operator auto")

	PR target/38256
	* config/i386/sync.md (memory_barrier_nosse): New insn
	(memory_barrier): Generate memory_barrier_nosse insn for !TARGET_SSE2.

From-SVN: r142177

gcc/ChangeLog

+2008-11-25  Uros Bizjak  <ubizjak@gmail.com>
+
+	PR target/38256
+	* config/i386/sync.md (memory_barrier_nosse): New insn
+	(memory_barrier): Generate memory_barrier_nosse insn for !TARGET_SSE2.
+
 2008-11-24  Maxim Kuvyrkov  <maxim@codesourcery.com>
 
 	* config/m68k/m68k.md (cmpdi): Use (scratch) instead of pseudo.

gcc/config/i386/sync.md

@@ -36,19 +36,30 @@
 	(unspec:BLK [(match_dup 0)] UNSPEC_MFENCE))]
   ""
 {
+  operands[0] = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (Pmode));
+  MEM_VOLATILE_P (operands[0]) = 1;
+
   if (!TARGET_SSE2)
     {
-      /* Emit a locked no-operation when SSE2 is not available.  */
-      int slot = virtuals_instantiated ? SLOT_TEMP : SLOT_VIRTUAL;
-      rtx temp = assign_386_stack_local (QImode, slot);
-      emit_insn (gen_sync_iorqi (temp, CONST0_RTX (QImode)));
+      emit_insn (gen_memory_barrier_nosse (operands[0]));
       DONE;
     }
-
-  operands[0] = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (Pmode));
-  MEM_VOLATILE_P (operands[0]) = 1;
 })
 
+(define_insn "memory_barrier_nosse"
+  [(set (match_operand:BLK 0 "" "")
+	(unspec:BLK [(match_dup 0)] UNSPEC_MFENCE))
+   (clobber (reg:CC FLAGS_REG))]
+
+  "!TARGET_SSE2"
+{
+  if (TARGET_64BIT)
+    return "lock{%;| }or{q}\t{$0, (%%rsp)|QWORD PTR [rsp], 0}";
+  else
+    return "lock{%;| }or{l}\t{$0, (%%esp)|DWORD PTR [esp], 0}";
+}
+  [(set_attr "memory" "unknown")])
+
 ;; ??? It would be possible to use cmpxchg8b on pentium for DImode
 ;; changes.  It's complicated because the insn uses ecx:ebx as the
 ;; new value; note that the registers are reversed from the order