[Bug middle-end/78103] Failure to optimize with __builtin_clzl

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78103

--- Comment #24 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by H.J. Lu <h...@gcc.gnu.org>:

https://gcc.gnu.org/g:6f0c43e97825ee54e3779afbedcd0def12443001

commit r12-2656-g6f0c43e97825ee54e3779afbedcd0def12443001
Author: H.J. Lu <hjl.to...@gmail.com>
Date:   Sun Aug 1 09:55:33 2021 -0700

    i386: Improve SImode constant - __builtin_clzll for -mno-lzcnt

    Add a zero_extend patten for bsr_rex64_1 and use it to split SImode
    constant - __builtin_clzll to avoid unncessary zero_extend.

    gcc/

            PR target/78103
            * config/i386/i386.md (bsr_rex64_1_zext): New.
            (combine splitter for constant - clzll): Replace gen_bsr_rex64_1
            with gen_bsr_rex64_1_zext.

    gcc/testsuite/

            PR target/78103
            * gcc.target/i386/pr78103-2.c: Also scan incl.
            * gcc.target/i386/pr78103-3.c: Scan leal|addl|incl for x32.  Also
            scan incq.