[Bug target/82418] Division on a constant is suboptimal because of not using imul instruction

[amonakov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82418

--- Comment #8 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
Author: amonakov
Date: Fri Aug 10 10:13:37 2018
New Revision: 263467

URL: https://gcc.gnu.org/viewcvs?rev=263467&root=gcc&view=rev
Log:
i386: do not use SImode mul-highpart on 64-bit (PR 82418)

        PR target/82418
        * config/i386/i386.md (<s>mul<mode>3_highpart): Use DWIH mode iterator
        instead of SWI48.

testsuite/
        * gcc.target/i386/pr82418.c: New test.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr82418.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.md
    trunk/gcc/testsuite/ChangeLog