I was notifed I broke proper handling of undefined overflow in
multiplicative ops handling. The following resurrects previous
behavior (and adds a testcase).
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2017-08-17 Richard Biener <rguent...@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.
Index: gcc/tree-vrp.c
===================================================================
--- gcc/tree-vrp.c (revision 251084)
+++ gcc/tree-vrp.c (working copy)
@@ -1614,6 +1614,8 @@ vrp_int_const_binop (enum tree_code code
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
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
TYPE_SIGN (TREE_TYPE (val1)));
}
+ *overflow_p = overflow;
+
return res;
}
Index: gcc/testsuite/gcc.dg/tree-ssa/vrp117.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/vrp117.c (nonexistent)
+++ gcc/testsuite/gcc.dg/tree-ssa/vrp117.c (working copy)
@@ -0,0 +1,16 @@
+/* { 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" } } */
