re PR rtl-optimization/50615 (ICE: in distribute_notes, at combine.c:13282 with…

re PR rtl-optimization/50615 (ICE: in distribute_notes, at combine.c:13282 with -O --param max-cse-insns=1)

	PR rtl-optimization/50615
	* combine.c (distribute_notes) <REG_ARGS_SIZE>: Skip if I3 is a no-op.

From-SVN: r180058

gcc/ChangeLog

+2011-10-16  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR rtl-optimization/50615
+	* combine.c (distribute_notes) <REG_ARGS_SIZE>: Skip if I3 is a no-op.
+
 2011-10-16  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/50596

gcc/combine.c

@@ -13274,13 +13274,14 @@ distribute_notes (rtx notes, rtx from_insn, rtx i3, rtx i2, rtx elim_i2,
 	  break;
 
 	case REG_ARGS_SIZE:
-	  {
-	    /* ??? How to distribute between i3-i1.  Assume i3 contains the
-	       entire adjustment.  Assert i3 contains at least some adjust.  */
-	    int old_size, args_size = INTVAL (XEXP (note, 0));
-	    old_size = fixup_args_size_notes (PREV_INSN (i3), i3, args_size);
-	    gcc_assert (old_size != args_size);
-	  }
+	  /* ??? How to distribute between i3-i1.  Assume i3 contains the
+	     entire adjustment.  Assert i3 contains at least some adjust.  */
+	  if (!noop_move_p (i3))
+	    {
+	      int old_size, args_size = INTVAL (XEXP (note, 0));
+	      old_size = fixup_args_size_notes (PREV_INSN (i3), i3, args_size);
+	      gcc_assert (old_size != args_size);
+	    }
 	  break;
 
 	case REG_NORETURN:

gcc/testsuite/ChangeLog

+2011-10-16  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.dg/vla-23.c: New test.
+
 2011-10-16  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/50596

gcc/testsuite/gcc.dg/vla-23.c

+/* PR rtl-optimization/50615 */
+/* Testcase by Zdenek Sojka <zsojka@seznam.cz> */
+
+/* { dg-do compile } */
+/* { dg-options "-O --param max-cse-insns=1" } */
+
+int
+foo (int a)
+{
+  if (!a)
+    return 1;
+
+  {
+    int s[a];
+    return 0;
+  }
+}