On Thu, May 20, 2021 at 4:06 PM Richard Biener
<richard.guent...@gmail.com> wrote:
>
> On Thu, May 20, 2021 at 8:54 AM Hongtao Liu <crazy...@gmail.com> wrote:
> >
> > Hi:
> > In folding target-specific builtin, when lhs is NULL, create a
> > temporary variable for it.
> > Bootstrapped and regtested on x86_64-linux-gnu{-m32,}
>
> I would suggest to drop the stmt or leave it unfolded instead.
Will -O0 be able to optimize the builtin away?
Since i've deleted the corresponding expander, there would be an
error if the builtin goes directly to pass_expand.
> Note dropping would mean replacing it with a GIMPLE_NOP
> (gimple_build_nop ()). But creating a new unused LHS certainly
> works as well.
>
> Jakub, any preference?
>
> Richard.
>
> > gcc/ChangeLog:
> > PR target/100660
> > * config/i386/i386.c (ix86_gimple_fold_builtin): Create a tmp
> > variable for lhs when it doesn't exist.
> >
> > gcc/testsuite/ChangeLog:
> > PR target/100660
> > * gcc.target/i386/pr100660.c: New test.
> >
> >
> >
> > --
> > BR,
> > Hongtao
--
BR,
Hongtao
