[Bug tree-optimization/94683] ICE in forwprop when folding to a VEC_PERM_EXPR

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94683

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Sandiford <rsandifo@gcc.gnu.org>:

https://gcc.gnu.org/g:85353e24ca90282e1d3620682841f524de20475c

commit r10-7851-g85353e24ca90282e1d3620682841f524de20475c
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Tue Apr 21 16:11:07 2020 +0100

    forwprop: Fix ICE when building a VEC_PERM_EXPR [PR94683]

    The type compatibility handling in simplify_vector_constructor is
    based on the number of elements and on element type compatibility,
    but that's no longer enough to ensure that two vector types are
    compatible.  This patch uses a VIEW_CONVERT_EXPR if the permutation
    type and result type are distinct.

    2020-04-21  Richard Sandiford  <richard.sandiford@arm.com>

    gcc/
            PR tree-optimization/94683
            * tree-ssa-forwprop.c (simplify_vector_constructor): Use a
            VIEW_CONVERT_EXPR to handle mixtures of similarly-structured
            but distinct vector types.

    gcc/testsuite/
            PR tree-optimization/94683
            * gcc.target/aarch64/sve/acle/general/pr94683.c: New test.