re PR middle-end/18921 (wrong code with operator "?")

	PR middle-end/18921
	* fold-const.c (fold_unwidened_comparison): Use omit_one_operand
	instead of constant_boolean_node as arg0 may have side-effects.

	* gcc.dg/pr18921-1.c: New test case.

From-SVN: r92030

gcc/ChangeLog

+2004-12-11  Roger Sayle  <roger@eyesopen.com>
+
+	PR middle-end/18921
+	* fold-const.c (fold_unwidened_comparison): Use omit_one_operand
+	instead of constant_boolean_node as arg0 may have side-effects.
+
 2004-12-10  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
 
 	* pa-host.c (pa_gt_pch_use_address): Use lseek and read to copy PCH

gcc/fold-const.c

@@ -6023,27 +6023,27 @@ fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
     {
     case EQ_EXPR:
       if (above || below)
-	return constant_boolean_node (false, type);
+	return omit_one_operand (type, integer_zero_node, arg0);
       break;
 
     case NE_EXPR:
       if (above || below)
-	return constant_boolean_node (true, type);
+	return omit_one_operand (type, integer_one_node, arg0);
       break;
 
     case LT_EXPR:
     case LE_EXPR:
       if (above)
-	return constant_boolean_node (true, type);
+	return omit_one_operand (type, integer_one_node, arg0);
       else if (below)
-	return constant_boolean_node (false, type);;
+	return omit_one_operand (type, integer_zero_node, arg0);
 
     case GT_EXPR:
     case GE_EXPR:
       if (above)
-	return constant_boolean_node (false, type);
+	return omit_one_operand (type, integer_zero_node, arg0);
       else if (below)
-	return constant_boolean_node (true, type);;
+	return omit_one_operand (type, integer_one_node, arg0);
 
     default:
       break;

gcc/testsuite/ChangeLog

+2004-12-11  Roger Sayle  <roger@eyesopen.com>
+
+	PR middle-end/18921
+	* gcc.dg/pr18921-1.c: New test case.
+
 2004-12-11  Tobias Schlueter  <tobias.schlueter@physik.uni-muenchen.de>
 
 	PR fortran/17175

gcc/testsuite/gcc.dg/pr18921-1.c

+/* PR middle-end/18921 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+extern void abort (void);
+
+int foo (int k)
+{
+  unsigned char j = 0;
+  (k ? 0 : j++) == -1;
+  return j;
+}
+
+int main ()
+{
+  if (!foo (0))
+    abort ();
+  return 0;
+}
+