[Bug tree-optimization/122848] `zero_extend<a> & sign_extend<a>` is not optimized to `zero_extend<a>` for the gimple level

"cvs-commit at gcc dot gnu.org via Gcc-bugs" <[email protected]> Thu, 30 Jul 2026 10:45:47 +0000

Newsgroups	gmane.comp.gcc.bugs
Message-ID	<[email protected]/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122848

--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Eikansh Gupta <[email protected]>:

https://gcc.gnu.org/g:ece564fdaa15a0da008cedd881afcd3f0f4dbd5a

commit r17-2824-gece564fdaa15a0da008cedd881afcd3f0f4dbd5a
Author: Eikansh Gupta <[email protected]>
Date:   Wed Jun 3 15:46:29 2026 +0530

    MATCH: Simplify zero/sign extension bit operations [PR122848]

    Fold bitwise operations involving zero and sign extensions from the same
    low-precision value.  The AND case folds to the zero extension, and the
    OR case folds to the sign extension.

            PR tree-optimization/122848

    gcc/ChangeLog:

            * match.pd (zero_extend & sign_extend -> zero_extend): New pattern.
            (zero_extend | sign_extend -> sign_extend): Likewise.

    gcc/testsuite/ChangeLog:

            * gcc.dg/tree-ssa/pr122848.c: New test.

    Signed-off-by: Eikansh Gupta <[email protected]>