[Bug tree-optimization/116101] [14/15 Regression] isel duplicates comparisons even at -O0

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116101

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Andrew Pinski <pinskia@gcc.gnu.org>:

https://gcc.gnu.org/g:9fe53beacfc5c01e24690dc70d7599db084cc8b4

commit r15-2343-g9fe53beacfc5c01e24690dc70d7599db084cc8b4
Author: Andrew Pinski <quic_apinski@quicinc.com>
Date:   Thu Jul 25 17:43:07 2024 -0700

    isel: Don't duplicate comparisons for -O0 nor -fno-tree-ter [PR116101]

    While doing cleanups on this code I noticed that we do the duplicate
    of comparisons at -O0. For C and C++ code this makes no difference as
    the gimplifier never produces COND_EXPR. But it could make a difference
    for other front-ends.
    Oh and for -fno-tree-ter, duplicating the comparison is just a waste
    as it is never used for expand.

    I also decided to add a few testcases so this is checked in the future.
    Even added one for the duplication itself.

    Bootstrapped and tested on x86_64-linux-gnu with no regressions.

            PR tree-optimization/116101

    gcc/ChangeLog:

            * gimple-isel.cc (maybe_duplicate_comparison): Don't
            do anything for -O0 or -fno-tree-ter.

    gcc/testsuite/ChangeLog:

            * gcc.dg/tree-ssa/dup_compare_cond-1.c: New test.
            * gcc.dg/tree-ssa/dup_compare_cond-2.c: New test.
            * gcc.dg/tree-ssa/dup_compare_cond-3.c: New test.

    Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>