[Bug c++/107358] [13 Regression] i686-linux: Since r13-3290-g98e341130f8798 code fails to build libjxl-0/7.0 (vector float code)

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107358

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:65e3274e363cb2c6bfe6b5e648916eb7696f7e2f

commit r13-3461-g65e3274e363cb2c6bfe6b5e648916eb7696f7e2f
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Mon Oct 24 17:53:16 2022 +0200

    c, c++: Fix up excess precision handling of scalar_to_vector conversion
[PR107358]

    As mentioned earlier in the C++ excess precision support mail, the
following
    testcase is broken with excess precision both in C and C++ (though just in
C++
    it was triggered in real-world code).
    scalar_to_vector is called in both FEs after the excess precision
promotions
    (or stripping of EXCESS_PRECISION_EXPR), so we can then get invalid
    diagnostics that say float vector + float involves truncation (on ia32
    from long double to float).

    The following patch fixes that by calling scalar_to_vector on the operands
    before the excess precision promotions, let scalar_to_vector just do the
    diagnostics (it does e.g. fold_for_warn so it will fold
    EXCESS_PRECISION_EXPR around REAL_CST to constants etc.) but will then
    do the actual conversions using the excess precision promoted operands
    (so say if we have vector double + (float + float) we don't actually do
    vector double + (float) ((long double) float + (long double) float)
    but
    vector double + (double) ((long double) float + (long double) float)

    2022-10-24  Jakub Jelinek  <jakub@redhat.com>

            PR c++/107358
    gcc/c/
            * c-typeck.cc (build_binary_op): Pass operands before excess
precision
            promotions to scalar_to_vector call.
    gcc/cp/
            * typeck.cc (cp_build_binary_op): Pass operands before excess
precision
            promotions to scalar_to_vector call.
    gcc/testsuite/
            * c-c++-common/pr107358.c: New test.
            * g++.dg/cpp1y/pr68180.C: Remove -fexcess-precision=fast from
            dg-options.