emit-rtl.c (emit_label_before): Do not allow the same label to be emitted twice.

	* emit-rtl.c (emit_label_before): Do not allow the same label
	to be emitted twice.
	(emit_label_after): Likewise.
	(emit_label): Likewise.

From-SVN: r189521

gcc/ChangeLog

 2012-07-16  Steven Bosscher  <steven@gcc.gnu.org>
 
+	* emit-rtl.c (emit_label_before): Do not allow the same label
+        to be emitted twice.
+	(emit_label_after): Likewise.
+	(emit_label): Likewise.
+
 	* flags.h (TYPE_OVERFLOW_WRAPS, TYPE_OVERFLOW_UNDEFINED,
 	TYPE_OVERFLOW_TRAPS, POINTER_TYPE_OVERFLOW_UNDEFINED): Move to tree.h.
 	* tree.h (TYPE_OVERFLOW_WRAPS, TYPE_OVERFLOW_UNDEFINED,

gcc/emit-rtl.c

@@ -4220,14 +4220,9 @@ emit_barrier_before (rtx before)
 rtx
 emit_label_before (rtx label, rtx before)
 {
-  /* This can be called twice for the same label as a result of the
-     confusion that follows a syntax error!  So make it harmless.  */
-  if (INSN_UID (label) == 0)
-    {
-      INSN_UID (label) = cur_insn_uid++;
-      add_insn_before (label, before, NULL);
-    }
-
+  gcc_checking_assert (INSN_UID (label) == 0);
+  INSN_UID (label) = cur_insn_uid++;
+  add_insn_before (label, before, NULL);
   return label;
 }
 
@@ -4386,15 +4381,9 @@ emit_barrier_after (rtx after)
 rtx
 emit_label_after (rtx label, rtx after)
 {
-  /* This can be called twice for the same label
-     as a result of the confusion that follows a syntax error!
-     So make it harmless.  */
-  if (INSN_UID (label) == 0)
-    {
-      INSN_UID (label) = cur_insn_uid++;
-      add_insn_after (label, after, NULL);
-    }
-
+  gcc_checking_assert (INSN_UID (label) == 0);
+  INSN_UID (label) = cur_insn_uid++;
+  add_insn_after (label, after, NULL);
   return label;
 }
 
@@ -4810,14 +4799,9 @@ emit_call_insn (rtx x)
 rtx
 emit_label (rtx label)
 {
-  /* This can be called twice for the same label
-     as a result of the confusion that follows a syntax error!
-     So make it harmless.  */
-  if (INSN_UID (label) == 0)
-    {
-      INSN_UID (label) = cur_insn_uid++;
-      add_insn (label);
-    }
+  gcc_checking_assert (INSN_UID (label) == 0);
+  INSN_UID (label) = cur_insn_uid++;
+  add_insn (label);
   return label;
 }