[Bug tree-optimization/94920] Failure to optimize abs pattern from arithmetic with selected operands based on comparisons with 0

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94920

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Sam Feifer <sfei...@gcc.gnu.org>:

https://gcc.gnu.org/g:633e9920589ddfaf2d6da1c24ce99b18a2638db4

commit r13-1785-g633e9920589ddfaf2d6da1c24ce99b18a2638db4
Author: Sam Feifer <sfei...@redhat.com>
Date:   Thu Jul 21 16:31:41 2022 -0400

    match.pd: Add new abs pattern [PR94920]

    This patch is intended to fix a missed optimization in match.pd. It
optimizes (x >= 0 ? x : 0) + (x <= 0 ? -x : 0) to just abs(x). Additionally,
the pattern (x <= 0 ? -x : 0) now gets optimized to max(-x, 0), which helps
with the other simplification rule.

    Tests are also included to be added to the testsuite.

    Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?

            PR tree-optimization/94920

    gcc/ChangeLog:

            * match.pd (x >= 0 ? x : 0) + (x <= 0 ? -x : 0): New
simplification.
                       (x <= 0 ? -x : 0): New simplification.

    gcc/testsuite/ChangeLog:

            * g++.dg/pr94920-1.C: New test.
            * g++.dg/pr94920.C: New test.
            * gcc.dg/pr94920-2.c: New test.