[Bug tree-optimization/105049] ICE: in build_vector_from_val, at tree.cc:2119 with -O -fno-tree-forwprop

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105049

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:0b0fc52b0412cc1608f4f0edb8a0ab2495619c4e

commit r12-7813-g0b0fc52b0412cc1608f4f0edb8a0ab2495619c4e
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Mar 25 08:43:45 2022 +0100

    middle-end/105049 - fix uniform_vector_p and vector CTOR gimplification

    We have

      return VIEW_CONVERT_EXPR<U>( VEC_PERM_EXPR < {<<< Unknown tree:
compound_literal_expr
            V D.1984 = { 0 }; >>>, { 0 }} , {<<< Unknown tree:
compound_literal_expr
            V D.1985 = { 0 }; >>>, { 0 }} , { 0, 0 } >  & {(short int)
SAVE_EXPR <c>, (short int) SAVE_EXPR <c>});

    where we gimplify the init CTORs to

      _1 = {{ 0 }, { 0 }};
      _2 = {{ 0 }, { 0 }};

    instead of to vector constants.  That later runs into a bug in
    uniform_vector_p which doesn't handle CTORs of vector elements
    correctly.

    The following adjusts uniform_vector_p to handle CTORs of vector
    elements.

    2022-03-25  Richard Biener  <rguenther@suse.de>

            PR middle-end/105049
            * tree.cc (uniform_vector_p): Recurse for VECTOR_CST or
            CONSTRUCTOR first elements.

            * gcc.dg/pr105049.c: New testcase.