re PR target/48126 (arm_output_sync_loop: misplaced memory barrier)

gcc/
2011-10-14  David Alan Gilbert  <david.gilbert@linaro.org>

	PR target/48126
	* config/arm/arm.c (arm_output_sync_loop): Move label before barrier.

From-SVN: r179980

gcc/ChangeLog

 2011-10-14  David Alan Gilbert  <david.gilbert@linaro.org>
 
+	PR target/48126
+	* config/arm/arm.c (arm_output_sync_loop): Move label before barrier.
+
+2011-10-14  David Alan Gilbert  <david.gilbert@linaro.org>
+
 	* config/arm/arm.h (TARGET_HAVE_DMB_MCR): MCR Not available in Thumb1.
 
 2011-10-14  Paolo Carlini  <paolo.carlini@oracle.com>

gcc/config/arm/arm.c

@@ -24217,8 +24217,11 @@ arm_output_sync_loop (emit_f emit,
 	}
     }
 
-  arm_process_output_memory_barrier (emit, NULL);
+  /* Note: label is before barrier so that in cmp failure case we still get
+     a barrier to stop subsequent loads floating upwards past the ldrex
+     PR target/48126.  */
   arm_output_asm_insn (emit, 1, operands, "%sLSYB%%=:", LOCAL_LABEL_PREFIX);
+  arm_process_output_memory_barrier (emit, NULL);
 }
 
 static rtx