[Bug target/82260] [x86] Unnecessary use of 8-bit registers with -Os. slightly slower and larger code

jakub at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Thu Sep 21 07:28:00 GMT 2017


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82260

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Thu Sep 21 07:27:54 2017
New Revision: 253050

URL: https://gcc.gnu.org/viewcvs?rev=253050&root=gcc&view=rev
Log:
        PR target/82260
        * config/i386/i386.md (*movqi_internal): Replace (=q,q) alternative
        with (=Q,Q), (=R,R) and (=r,r) alternatives, only enable the
        latter two for 64-bit, renumber alternatives, for -Os imov (=q,n)
        alternative always use QI mode, for -Os imov (=R,R) alternative
        always use SI mode, for imov (=Q,Q) or (=r,r) alternatives
        ignore -Os.

        * gcc.target/i386/pr82260-1.c: New test.
        * gcc.target/i386/pr82260-2.c: New test.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr82260-1.c
    trunk/gcc/testsuite/gcc.target/i386/pr82260-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.md
    trunk/gcc/testsuite/ChangeLog


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