re PR middle-end/30338 (infinite loop in maybe_canonicalize_comparison)

2006-12-31  Richard Guenther  <rguenther@suse.de>

	PR middle-end/30338
	* fold-const.c (fold_binary): Fix type-mismatch in folding
	of -1 - A to ~A.

	* gcc.c-torture/compile/pr30338.c: New testcase.

From-SVN: r120297

gcc/ChangeLog

+2006-12-31  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/30338
+	* fold-const.c (fold_binary): Fix type-mismatch in folding
+	of -1 - A to ~A.
+
 2006-12-30  Kazu Hirata  <kazu@codesourcery.com>
 
 	* tree-inline.c: Fix a comment typo.

gcc/fold-const.c

@@ -9009,7 +9009,7 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
       /* Convert -1 - A to ~A.  */
       if (INTEGRAL_TYPE_P (type)
 	  && integer_all_onesp (arg0))
-	return fold_build1 (BIT_NOT_EXPR, type, arg1);
+	return fold_build1 (BIT_NOT_EXPR, type, op1);
 
       if (! FLOAT_TYPE_P (type))
 	{

gcc/testsuite/ChangeLog

+2006-12-31  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/30338
+	* gcc.c-torture/compile/pr30338.c: New testcase.
+
 2006-12-31  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/27900

gcc/testsuite/gcc.c-torture/compile/pr30338.c

+/* We used to do folding with mismatched types which caused us to
+   infinitely loop in comparison foldings.  */
+
+extern char *grub_scratch_mem;
+int testload_func (char *arg, int flags)
+{
+  int i;
+  for (i = 0; i < 0x10ac0; i++)
+    if (*((unsigned char *) ((0x200000 + i + (int) grub_scratch_mem)))
+        != *((unsigned char *) ((0x300000 + i + (int) grub_scratch_mem))))
+      return 0;
+  return 1;
+}
+