[Bug rtl-optimization/51447] [4.7 Regression] global register variable definition incorrectly removed as dead code

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51447

--- Comment #22 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Alexandre Oliva <aol...@gcc.gnu.org>:

https://gcc.gnu.org/g:06ef9c119c56568e5f77a5189aa382cb97c95a9e

commit r11-1185-g06ef9c119c56568e5f77a5189aa382cb97c95a9e
Author: Alexandre Oliva <ol...@adacore.com>
Date:   Wed Jun 10 17:56:36 2020 -0300

    [PR51447] restore the global reg var before returning from main

    A runtime system might legitimately hold in rbx a value expected to be
    preserved across the call to main, but its use as a global register
    variable stops main from preserving it.


    for  gcc/testsuite/ChangeLog

            PR rtl-optimization/51447
            * gcc.c-torture/execute/pr51447.c (main): Preserve call-saved
            register.