On Wed, Apr 20, 2016 at 12:54:12PM +0200, Richard Biener wrote:
> On Wed, Apr 20, 2016 at 12:37 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> > On Wed, Apr 20, 2016 at 11:04:08AM +0200, Richard Biener wrote:
> >> > --- gcc/tree-if-conv.c
> >> > +++ gcc/tree-if-conv.c
> >> > @@ -262,6 +262,16 @@ ifc_temp_var (tree type, tree expr,
> >> > gimple_stmt_iterator *gsi)
> >> > return new_name;
> >> > }
> >> >
> >> > +/* Return true when COND is a false predicate. */
> >> > +
> >> > +static inline bool
> >> > +is_false_predicate (tree cond)
> >> > +{
> >> > + return (cond == NULL_TREE
> >> > + || cond == boolean_false_node
> >> > + || integer_zerop (cond));
> >> > +}
> >> > +
> >
> > Is it really a good idea to return true even for cond == NULL_TREE?
> > I mean it is then very confusing, because both is_true_predicate and
> > is_false_predicate are true in that case.
>
> Ah, indeed. NULL_TREE is true, not false.
I can fix it up with the following.
Bootstrap/regtest pending on x86_64-linux, ok for trunk and 6 if it passes?
2016-04-20 Marek Polacek <pola...@redhat.com>
* tree-if-conv.c (is_false_predicate): For NULL_TREE return false
rather than true.
diff --git gcc/tree-if-conv.c gcc/tree-if-conv.c
index a9fbab9..72e808e 100644
--- gcc/tree-if-conv.c
+++ gcc/tree-if-conv.c
@@ -267,9 +267,9 @@ ifc_temp_var (tree type, tree expr, gimple_stmt_iterator
*gsi)
static inline bool
is_false_predicate (tree cond)
{
- return (cond == NULL_TREE
- || cond == boolean_false_node
- || integer_zerop (cond));
+ return (cond != NULL_TREE
+ && (cond == boolean_false_node
+ || integer_zerop (cond)));
}
/* Return true when COND is a true predicate. */
Marek
