On Tue, May 2, 2023 at 5:24 AM Richard Biener via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > On Sun, Apr 30, 2023 at 11:13 PM Andrew Pinski via Gcc-patches > <gcc-patches@gcc.gnu.org> wrote: > > > > This ports the clrsb builtin part of builtin_zero_pattern > > to match.pd. A simple pattern to port. > > > > OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. > > > > gcc/ChangeLog: > > > > * match.pd (a != 0 ? CLRSB(a) : CST -> CLRSB(a)): New > > pattern. > > --- > > gcc/match.pd | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/gcc/match.pd b/gcc/match.pd > > index 0e782cde71d..bf918ba70ce 100644 > > --- a/gcc/match.pd > > +++ b/gcc/match.pd > > @@ -7787,6 +7787,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > > (cond (ne @0 integer_zerop@1) (func@4 (convert? @2)) integer_zerop@3) > > @4)) > > > > +/* a != 0 ? FUN(a) : CST -> Fun(a) for some CLRSB builtins > > + where CST is precision-1. */ > > +(for func (CLRSB) > > + (simplify > > + (cond (ne @0 integer_zerop@1) (func@5 (convert?@4 @2)) INTEGER_CST@3) > > As you don't seem to use @2 why not match (func@5 @4) only?
Thanks for catching this, @2 should really have been @0, otherwise we get the wrong answer in general. I fixed the other patterns I just added for this same issue too. This is what I committed instead: /* a != 0 ? FUN(a) : CST -> Fun(a) for some CLRSB builtins where CST is precision-1. */ (for func (CLRSB) (simplify (cond (ne @0 integer_zerop@1) (func@4 (convert?@3 @0)) INTEGER_CST@2) (if (wi::to_widest (@2) == TYPE_PRECISION (TREE_TYPE (@3)) - 1) @4))) Thanks, Andrew > > Otherwise LGTM. > > > + (if (wi::to_widest (@3) == TYPE_PRECISION (TREE_TYPE (@4)) - 1) > > + @5))) > > + > > #if GIMPLE > > /* a != 0 ? CLZ(a) : CST -> .CLZ(a) where CST is the result of the > > internal function for 0. */ > > (for func (CLZ) > > -- > > 2.31.1 > >
