[Bug target/115517] Fix x86 regressions after dropping uses of vcond{,u,eq}_optab

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115517

--- Comment #11 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by hongtao Liu <liuhongt@gcc.gnu.org>:

https://gcc.gnu.org/g:e94e6ee495d95f29355bbc017214228a5e367638

commit r15-1740-ge94e6ee495d95f29355bbc017214228a5e367638
Author: liuhongt <hongtao.liu@intel.com>
Date:   Wed Jun 19 16:05:58 2024 +0800

    Adjust testcase for the regressed testcases after obsolete of vcond{,u,eq}.

    > Richard suggests that we implement the "obvious" transforms like
    > inversion in the middle-end but if for example unsigned compares
    > are not supported the us_minus + eq + negative trick isn't on
    > that list.
    >
    > The main reason to restrict vec_cmp would be to avoid
    > a <= b ? c : d going with an unsupported vec_cmp but instead
    > do a > b ? d : c - the alternative is trying to fix this
    > on the RTL side via combine.  I understand the non-native

    Yes, I have a patch which can fix most regressions via pattern match
    in combine.
    Still there is a situation that is difficult to deal with, mainly the
    optimization w/o sse4.1 . Because pblendvb/blendvps/blendvpd only
    exists under sse4.1, w/o sse4.1, it takes 3
    instructions (pand,pandn,por) to simulate the vcond_mask, and the
    combine matches up to 4 instructions, which makes it currently
    impossible to use the combine to recover those optimizations in the
    vcond{,u,eq}.i.e min/max.

    In the case of sse 4.1 and above, there is basically no regression anymore.

    the regression testcases w/o sse4.1

    FAIL: g++.target/i386/pr100637-1b.C  -std=gnu++14  scan-assembler-times
pcmpeqb 2
    FAIL: g++.target/i386/pr100637-1b.C  -std=gnu++17  scan-assembler-times
pcmpeqb 2
    FAIL: g++.target/i386/pr100637-1b.C  -std=gnu++20  scan-assembler-times
pcmpeqb 2
    FAIL: g++.target/i386/pr100637-1b.C  -std=gnu++98  scan-assembler-times
pcmpeqb 2
    FAIL: g++.target/i386/pr100637-1w.C  -std=gnu++14  scan-assembler-times
pcmpeqw 2
    FAIL: g++.target/i386/pr100637-1w.C  -std=gnu++17  scan-assembler-times
pcmpeqw 2
    FAIL: g++.target/i386/pr100637-1w.C  -std=gnu++20  scan-assembler-times
pcmpeqw 2
    FAIL: g++.target/i386/pr100637-1w.C  -std=gnu++98  scan-assembler-times
pcmpeqw 2
    FAIL: g++.target/i386/pr103861-1.C  -std=gnu++14  scan-assembler-times
pcmpeqb 2
    FAIL: g++.target/i386/pr103861-1.C  -std=gnu++17  scan-assembler-times
pcmpeqb 2
    FAIL: g++.target/i386/pr103861-1.C  -std=gnu++20  scan-assembler-times
pcmpeqb 2
    FAIL: g++.target/i386/pr103861-1.C  -std=gnu++98  scan-assembler-times
pcmpeqb 2
    FAIL: gcc.target/i386/pr88540.c scan-assembler minpd

    gcc/testsuite/ChangeLog:

            PR target/115517
            * g++.target/i386/pr100637-1b.C: Add xfail and -mno-sse4.1.
            * g++.target/i386/pr100637-1w.C: Ditto.
            * g++.target/i386/pr103861-1.C: Ditto.
            * gcc.target/i386/pr88540.c: Ditto.
            * gcc.target/i386/pr103941-2.c: Add -mno-avx512f.
            * g++.target/i386/sse4_1-pr100637-1b.C: New test.
            * g++.target/i386/sse4_1-pr100637-1w.C: New test.
            * g++.target/i386/sse4_1-pr103861-1.C: New test.
            * gcc.target/i386/sse4_1-pr88540.c: New test.