combine.c (distribute_notes): Avoid adding REG_LABEL notes to JUMP_INSNs with JUMP_LABEL.

	* combine.c (distribute_notes): Avoid adding REG_LABEL notes
	to JUMP_INSNs with JUMP_LABEL.

	* gcc.c-torture/execute/20011219-1.c: New test.

From-SVN: r48198

gcc/ChangeLog

+2001-12-20  Jakub Jelinek  <jakub@redhat.com>
+
+	* combine.c (distribute_notes): Avoid adding REG_LABEL notes
+	to JUMP_INSNs with JUMP_LABEL.
+
 2001-12-19  Aldy Hernandez  <aldyh@redhat.com>
 
         * doc/install.texi: Add documentation for --enable-altivec.

gcc/combine.c

@@ -12129,6 +12129,25 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1)
 	      else
 		place = i2;
 	    }
+
+	  /* Don't attach REG_LABEL note to a JUMP_INSN which has
+	     JUMP_LABEL already.  Instead, decrement LABEL_NUSES.  */
+	  if (place && GET_CODE (place) == JUMP_INSN && JUMP_LABEL (place))
+	    {
+	      if (JUMP_LABEL (place) != XEXP (note, 0))
+		abort ();
+	      if (GET_CODE (JUMP_LABEL (place)) == CODE_LABEL)
+		LABEL_NUSES (JUMP_LABEL (place))--;
+	      place = 0;
+	    }
+	  if (place2 && GET_CODE (place2) == JUMP_INSN && JUMP_LABEL (place2))
+	    {
+	      if (JUMP_LABEL (place2) != XEXP (note, 0))
+		abort ();
+	      if (GET_CODE (JUMP_LABEL (place2)) == CODE_LABEL)
+		LABEL_NUSES (JUMP_LABEL (place2))--;
+	      place2 = 0;
+	    }
 	  break;
 
 	case REG_NONNEG:

gcc/testsuite/ChangeLog

+2001-12-20  Jakub Jelinek  <jakub@redhat.com>
+
+	* gcc.c-torture/execute/20011219-1.c: New test.
+
 2001-12-19  David Billinghurst <David.Billinghurst@riotinto.com>
 
 	* gcc.dg/special/ecos.exp:  wkali-1.c unsupported if

gcc/testsuite/gcc.c-torture/execute/20011219-1.c

+/* This testcase failed on IA-32 at -O and above, because combine attached
+   a REG_LABEL note to jump instruction already using JUMP_LABEL.  */
+
+extern void abort (void);
+extern void exit (int);
+
+enum X { A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q };
+
+void
+bar (const char *x, int y, const char *z)
+{
+}
+
+long
+foo (enum X x, const void *y)
+{
+  long a;
+
+  switch (x)
+    {
+    case K:
+      a = *(long *)y;
+      break;
+    case L:
+      a = *(long *)y;
+      break;
+    case M:
+      a = *(long *)y;
+      break;
+    case N:
+      a = *(long *)y;
+      break;
+    case O:
+      a = *(long *)y;
+      break;
+    default:
+      bar ("foo", 1, "bar");
+    }
+  return a;
+}
+
+int
+main ()
+{
+  int i = 24;
+  if (foo (N, &i) != 24)
+    abort ();
+  exit (0);
+}