[Bug tree-optimization/123109] `a >> (bits-1) != 0` is not optimized to `a < 0` by match

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123109

--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Pengxuan Zheng <pzh...@gcc.gnu.org>:

https://gcc.gnu.org/g:8d5eb4f6c1f248340f12adbe76882c3615343e8b

commit r16-6753-g8d5eb4f6c1f248340f12adbe76882c3615343e8b
Author: Pengxuan Zheng <pengxuan.zh...@oss.qualcomm.com>
Date:   Fri Jan 9 10:49:45 2026 -0800

    match: (X >> C) NE/EQ 0 -> X LT/GE 0 [PR123109]

    Implement (X >> C) NE/EQ 0 -> X LT/GE 0 in match.pd instead of
fold-const.cc.

    Bootstrapped and tested on x86_64 and aarch64.

            PR tree-optimization/123109

    gcc/ChangeLog:

            * fold-const.cc (fold_binary_loc): Remove (X >> C) NE/EQ 0 -> X
LT/GE 0
            folding.
            * match.pd (`(X >> C) NE/EQ 0 -> X LT/GE 0`): New pattern.

    gcc/testsuite/ChangeLog:

            * gcc.dg/tree-ssa/vrp99.c: Update test.
            * gcc.dg/pr123109.c: New test.

    Signed-off-by: Pengxuan Zheng <pengxuan.zh...@oss.qualcomm.com>