Re: [PATCH] MATCH: Make zero_one_valued_p non-recusive fully

[Jakub Jelinek <jakub@redhat.com>]

On Mon, Sep 18, 2023 at 11:04:16AM +0200, Richard Biener via Gcc-patches wrote:
> > Note genmatch should warn (or error out) if this gets detected so I filed PR 111446
> > which I will be looking into next week or the week after so we don't run into
> > this issue again.
> >
> >         PR tree-optimization/111442
> >
> > gcc/ChangeLog:
> >
> >         * match.pd (zero_one_valued_p): Have the bit_and match not be
> >         recusive.

s/recusive/recursive/g
s/recusion/recursion/g

> > diff --git a/gcc/match.pd b/gcc/match.pd
> > index 887665633d4..773c3810f51 100644
> > --- a/gcc/match.pd
> > +++ b/gcc/match.pd
> > @@ -2183,8 +2183,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> >
> >  /* (a&1) is always [0,1] too. This is useful again when
> >     the range is not known. */
> > +/* Note this can't be recusive due to VN handling of equivalents,
> > +   VN and would cause an infinite recusion. */
> >  (match zero_one_valued_p
> > - (bit_and:c@0 @1 zero_one_valued_p))
> > + (bit_and:c@0 @1 integer_onep)
> > + (if (INTEGRAL_TYPE_P (type))))
> >
> >  /* A conversion from an zero_one_valued_p is still a [0,1].
> >     This is useful when the range of a variable is not known */
> > diff --git a/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c b/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c
> > new file mode 100644
> > index 00000000000..5814ee938de
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c
> > @@ -0,0 +1,13 @@
> > +
> > +int *a, b;
> > +int main() {
> > +  int d = 1, e;
> > +  if (d)
> > +    e = a ? 0 % 0 : 0;
> > +  if (d)
> > +    a = &d;
> > +  d = -1;
> > +  b = d & e;
> > +  b = 2 * e ^ 1;
> > +  return 0;
> > +}
> > --
> > 2.31.1
> >

	Jakub