re PR tree-optimization/28230 (-O2 -fwrapv miscompiles gcc, binutils, gzip.)

2006-10-11  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/28230
	* tree-vrp.c (vrp_int_const_binop): Move flag_wrapv handling
	to the correct place.

	* gcc.dg/torture/pr28230.c: New testcase.

From-SVN: r117637

gcc/ChangeLog

 2006-10-11  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/28230
+	* tree-vrp.c (vrp_int_const_binop): Move flag_wrapv handling
+	to the correct place.
+
+2006-10-11  Richard Guenther  <rguenther@suse.de>
+
 	PR inline-asm/29119
 	* gimplify.c (gimplify_asm_expr): Mark the gimplified lvalue
 	addressable.

gcc/testsuite/ChangeLog

 2006-10-11  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/28230
+	* gcc.dg/torture/pr28230.c: New testcase.
+
+2006-10-11  Richard Guenther  <rguenther@suse.de>
+
 	PR inline-asm/29119
 	* gcc.dg/torture/pr29119.c: New testcase.
 

gcc/testsuite/gcc.dg/torture/pr28230.c

+/* { dg-do run } */
+/* { dg-options "-fwrapv" } */
+
+void foo( unsigned long long bb, unsigned short tn, unsigned e, unsigned* w );
+void foo( unsigned long long bb, unsigned short tn, unsigned e, unsigned* w )
+{
+        unsigned n = tn + bb;
+        do {
+                e = (e > n) ? e : *w;
+                n -= (e > n) ? n : e;
+                if (*w)
+                        *w = 0;
+        } while ( n );
+}
+int main()
+{
+        unsigned w = 0;
+        foo( 0, 0, 0, &w );
+        return 0;
+}

gcc/tree-vrp.c

@@ -1235,14 +1235,12 @@ vrp_int_const_binop (enum tree_code code, tree val1, tree val2)
 {
   tree res;
 
-  if (flag_wrapv)
-    return int_const_binop (code, val1, val2, 0);
+  res = int_const_binop (code, val1, val2, 0);
 
   /* If we are not using wrapping arithmetic, operate symbolically
      on -INF and +INF.  */
-  res = int_const_binop (code, val1, val2, 0);
-
-  if (TYPE_UNSIGNED (TREE_TYPE (val1)))
+  if (TYPE_UNSIGNED (TREE_TYPE (val1))
+      || flag_wrapv)
     {
       int checkz = compare_values (res, val1);
       bool overflow = false;