[Bug target/97147] GCC uses vhaddpd which is bad for latency

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97147

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by hongtao Liu <liuho...@gcc.gnu.org>:

https://gcc.gnu.org/g:97d51c1764554fcef05fe94ee6445f5d2252bcff

commit r12-2981-g97d51c1764554fcef05fe94ee6445f5d2252bcff
Author: liuhongt <hongtao....@intel.com>
Date:   Tue Aug 17 13:11:26 2021 +0800

    Add x86 tune to enable v2df vector reduction by paddpd.

    The tune is disabled by default.

    gcc/ChangeLog:

            PR target/97147
            * config/i386/i386.h (TARGET_V2DF_REDUCTION_PREFER_HADDPD):
            New macro.
            * config/i386/sse.md (*sse3_haddv2df3_low): Add
            TARGET_V2DF_REDUCTION_PREFER_HADDPD.
            (*sse3_hsubv2df3_low): Ditto.
            * config/i386/x86-tune.def
            (X86_TUNE_V2DF_REDUCTION_PREFER_HADDPD): New tune.

    gcc/testsuite/ChangeLog:

            PR target/97147
            * gcc.target/i386/pr54400.c: Adjust testcase.
            * gcc.target/i386/pr94147.c: New test.