[Bug tree-optimization/114203] [13 Regression] Miscompilation: A possible miscompilation in GCC 13 and 14 with option -Os

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114203

--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Richard Biener
<rgue...@gcc.gnu.org>:

https://gcc.gnu.org/g:a729b1227bc8c84cd91a3b8c9c9d11bc43d415de

commit r13-8482-ga729b1227bc8c84cd91a3b8c9c9d11bc43d415de
Author: Richard Biener <rguent...@suse.de>
Date:   Mon Mar 4 10:38:31 2024 +0100

    tree-optimization/114203 - wrong CLZ niter computation

    For precision less than int we apply the adjustment to make it defined
    at zero after the adjustment to make it compute CLZ rather than CTZ.
    That's wrong.

            PR tree-optimization/114203
            * tree-ssa-loop-niter.cc (build_cltz_expr): Apply CTZ->CLZ
            adjustment before making the result defined at zero.

            * gcc.dg/torture/pr114203.c: New testcase.

    (cherry picked from commit cde50296a19b109909089b91d532d2c8455f5f10)