[Bug tree-optimization/123153] [16 regression] gcc/tree-vect-loop-manip.cc:1979: -Wliteral-conversion

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123153

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Victor Do Nascimento
<victorldn@gcc.gnu.org>:

https://gcc.gnu.org/g:24bf392581ea6d931afc1e97d90d6a2d6bdaa183

commit r16-6243-g24bf392581ea6d931afc1e97d90d6a2d6bdaa183
Author: Victor Do Nascimento <victor.donascimento@arm.com>
Date:   Wed Dec 17 14:43:41 2025 +0000

    Fix profile_probability constructor arg [PR123153]

    Given that profile probability is computed as an unsigned integer
    value in the [0, max_probability = (uint32_t) 1 << (n_bits - 2)]
    range (as opposed to a [0, 1] float), 50/50 likeihoods are encoded as
    `even()', mapping to `max_probability / 2'.

    The previous use of 0.5 for an even probability was, as a consequence
    of the implicit `double' -> `uint32_t' conversion, silently set to 0 by
    GCC when not using the `-Wconversion' flag.

    We therefore replace the erroneous `probability (0.5, GUESSED)'
    initialization with its correct `profile_probability::even ()'
    counterpart.

    gcc/ChangeLog:

            PR tree-optimization/123153
            * tree-vect-loop-manip.cc
            (slpeel_tree_duplicate_loop_to_edge_cfg): use
            profile_probability::even () for even likelihood.