[PATCH 2/2 V4] Add plusminus-with-convert pattern (PR 94234)

[Richard Biener]

On Tue, Sep 15, 2020 at 2:25 PM Feng Xue OS <fxue@os.amperecomputing.com> wrote:
>
> >> Add a rule (T)(A) +- (T)(B) -> (T)(A +- B), which works only when (A +- B)
> >> could be folded to a simple value. By this rule, a plusminus-mult-with-convert
> >> expression could be handed over to the rule (A * C) +- (B * C) -> (A +- B).
> >
> >Please use INTEGRAL_TYPE_P () instead of TREE_CODE == INTEGER_TYPE
> >in all three cases.  It's enough to check for INTEGRAL_TYPE_P on one operand,
> >the types_match will take care of the other.
>
> I would have considered using INTEGRAL_TYPE_P(), but if inner type is bool or
> enum, can we do plus/minus operation on that?

Yes, the distinction doesn't really exist for the middle-end - they
are just integer
types with certain precision and signedness.

Richard.

> Feng
>
> >
> >OK with those changes.
> >
> >Thanks,
> >Richard.
> >
> >
> > Bootstrapped/regtested on x86_64-linux and aarch64-linux.
> >
> > Feng
> > ---
> > 2020-09-15  Feng Xue  <fxue@os.amperecomputing.com>
> >
> > gcc/
> >         PR tree-optimization/94234
> >         * match.pd (T)(A) +- (T)(B) -> (T)(A +- B): New simplification.
> >
> > gcc/testsuite/
> >         PR tree-optimization/94234
> >         * gcc.dg/pr94234-3.c: New test.