re PR c/43661 (ice in fold_comparison, at fold-const.c:9579)

2010-04-06  Richard Guenther  <rguenther@suse.de>

	PR middle-end/43661
	* fold-const.c (fold_comparison): Handle X * 0 CMP 0.

	* gcc.c-torture/compile/pr43661.c: New testcase.

From-SVN: r157984

gcc/ChangeLog

+2010-04-06  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/43661
+	* fold-const.c (fold_comparison): Handle X * 0 CMP 0.
+
 2010-04-05  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
 
 	* doc/invoke.texi (Optimize Options): Document that LTO

gcc/fold-const.c

@@ -9576,7 +9576,9 @@ fold_comparison (location_t loc, enum tree_code code, tree type,
       tree variable1 = TREE_OPERAND (arg0, 0);
       enum tree_code cmp_code = code;
 
-      gcc_assert (!integer_zerop (const1));
+      /* Handle unfolded multiplication by zero.  */
+      if (integer_zerop (const1))
+	return fold_build2_loc (loc, cmp_code, type, const1, const2);
 
       fold_overflow_warning (("assuming signed overflow does not occur when "
 			      "eliminating multiplication in comparison "

gcc/testsuite/ChangeLog

+2010-04-06  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/43661
+	* gcc.c-torture/compile/pr43661.c: New testcase.
+
 2010-04-06  Jakub Jelinek  <jakub@redhat.com>
 
 	* gcc.target/s390/stackcheck1.c: Add dg-warning.

gcc/testsuite/gcc.c-torture/compile/pr43661.c

+int
+func (int x)
+{
+  return 0 ? (unsigned short) (0 ? : 1 * (signed char) (x ^ x) >= 0) : 1;
+}