tree-vrp.c (vrp_int_const_binop): Do not set *overflow_p to true when overflow…

tree-vrp.c (vrp_int_const_binop): Do not set *overflow_p to true when overflow is undefined and we saturated the...

2017-08-17  Richard Biener  <rguenther@suse.de>

	* tree-vrp.c (vrp_int_const_binop): Do not set *overflow_p
	to true when overflow is undefined and we saturated the
	result.

	* gcc.dg/tree-ssa/vrp117.c: New testcase.

From-SVN: r251141

gcc/ChangeLog

+2017-08-17  Richard Biener  <rguenther@suse.de>
+
+	* tree-vrp.c (vrp_int_const_binop): Do not set *overflow_p
+	to true when overflow is undefined and we saturated the
+	result.
+
 2017-08-17  Alan Modra  <amodra@gmail.com>
 
 	PR target/80938

gcc/testsuite/ChangeLog

+2017-08-17  Richard Biener  <rguenther@suse.de>
+
+	* gcc.dg/tree-ssa/vrp117.c: New testcase.
+
 2017-08-16  Uros Bizjak  <ubizjak@gmail.com>
 
 	* c-c++-common/patchable_function_entry-decl.c (dg-final): Adapt

gcc/testsuite/gcc.dg/tree-ssa/vrp117.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-evrp" } */
+
+void link_error (void);
+
+void foo (int i)
+{
+  if (i > __INT_MAX__ - 10)
+    {
+      int j = i * 10;
+      if (j < i)
+	link_error ();
+    }
+}
+
+/* { dg-final { scan-tree-dump-not "link_error" "evrp" } } */

gcc/tree-vrp.c

@@ -1614,6 +1614,8 @@ vrp_int_const_binop (enum tree_code code, tree val1, tree val2,
   signop sign = TYPE_SIGN (TREE_TYPE (val1));
   wide_int res;
 
+  *overflow_p = false;
+
   switch (code)
     {
     case RSHIFT_EXPR:
@@ -1685,8 +1687,6 @@ vrp_int_const_binop (enum tree_code code, tree val1, tree val2,
       gcc_unreachable ();
     }
 
-  *overflow_p = overflow;
-
   if (overflow
       && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1)))
     {
@@ -1730,6 +1730,8 @@ vrp_int_const_binop (enum tree_code code, tree val1, tree val2,
 			      TYPE_SIGN (TREE_TYPE (val1)));
     }
 
+  *overflow_p = overflow;
+
   return res;
 }