[Bug rtl-optimization/115877] [15 Regression] wrong code at -Os (missing zero extension)

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115877

--- Comment #10 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jeff Law <law@gcc.gnu.org>:

https://gcc.gnu.org/g:9d8ef2711dfecd093077aef6123d9e93ea23454e

commit r15-2186-g9d8ef2711dfecd093077aef6123d9e93ea23454e
Author: Jeff Law <jlaw@ventanamicro.com>
Date:   Sun Jul 21 08:41:28 2024 -0600

    [PR rtl-optimization/115877][2/n] Improve liveness computation for constant
initialization

    While debugging pr115877, I noticed we were failing to remove the
destination
    register from LIVENOW bitmap when it was set to a constant value.  ie  (set
    (dest) (const_int)).  This was a trivial oversight in
    safe_for_live_propagation.

    I don't have an example of this affecting code generation, but it certainly
    could.  More importantly, by making LIVENOW more accurate it's easier to
debug
    when LIVENOW differs from expectations.

    As with the prior patch this has been tested as part of a larger patchset
with
    the crosses as well as individually on x86_64.

    Pushing to the trunk,

            PR rtl-optimization/115877
    gcc/
            * ext-dce.cc (safe_for_live_propagation): Handle RTX_CONST_OBJ.