[Bug target/82361] Useless "mov eax, eax" in generated code

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82361

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Sat Sep 30 08:10:15 2017
New Revision: 253317

URL: https://gcc.gnu.org/viewcvs?rev=253317&root=gcc&view=rev
Log:
        PR target/82361
        * config/i386/i386.md
        (TARGET_USE_8BIT_IDIV zext divmodsi4 splitter): New define_split.
        (divmodsi4_zext_1, divmodsi4_zext_2, *divmodsi4_zext_1,
        *divmodsi4_zext_2): New define_insn_and_split.
        (*divmodsi4_noext_zext_1, *divmodsi4_noext_zext_2): New define_insn.
        (TARGET_USE_8BIT_IDIV zext udivmodsi4 splitter): New define_split.
        (udivmodsi4_zext_1, udivmodsi4_zext_2, *udivmodsi4_zext_1,
        *udivmodsi4_zext_2, *udivmodsi4_pow2_zext_1, *udivmodsi4_pow2_zext_2):
        New define_insn_and_split.
        (*udivmodsi4_noext_zext_1, *udivmodsi4_noext_zext_2): New define_insn.
        * config/i386/i386.c (ix86_split_idivmod): Handle operands[0] or
        operands[1] having DImode when mode is SImode.

        * gcc.target/i386/pr82361-1.c: New test.
        * gcc.target/i386/pr82361-2.c: New test.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr82361-1.c
    trunk/gcc/testsuite/gcc.target/i386/pr82361-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/config/i386/i386.md
    trunk/gcc/testsuite/ChangeLog