[Bug target/91719] gcc compiles seq_cst store on x86-64 differently from clang/icc

[uros at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91719

--- Comment #11 from uros at gcc dot gnu.org ---
Author: uros
Date: Mon Sep 16 18:37:28 2019
New Revision: 275754

URL: https://gcc.gnu.org/viewcvs?rev=275754&root=gcc&view=rev
Log:
        PR target/91719
        * config/i386/i386.h (TARGET_USE_XCHG_FOR_ATOMIC_STORE): New macro.
        * config/i386/x86-tune.def (X86_TUNE_USE_XCHG_FOR_ATOMIC_STORE): New.
        * config/i386/sync.md (atomic_store<mode>): emit XCHG for
        TARGET_USE_XCHG_FOR_ATOMIC_STORE.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.h
    trunk/gcc/config/i386/sync.md
    trunk/gcc/config/i386/x86-tune.def