[Bug target/87537] Redundant vmovaps

[hjl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87537

--- Comment #2 from hjl at gcc dot gnu.org <hjl at gcc dot gnu.org> ---
Author: hjl
Date: Thu Oct 18 08:18:42 2018
New Revision: 265260

URL: https://gcc.gnu.org/viewcvs?rev=265260&root=gcc&view=rev
Log:
Simplify subreg of vec_merge of vec_duplicate

We can simplify

  (subreg (vec_merge (vec_duplicate X)
                     (vector)
                     (const_int ((1 << N) | M)))
          (N * sizeof (X)))

to X when mode of X is the same as of mode of subreg.

gcc/

        PR target/87537
        * simplify-rtx.c (simplify_subreg): Simplify subreg of vec_merge
        of vec_duplicate.
        (test_vector_ops_duplicate): Add test for a scalar subreg of a
        VEC_MERGE of a VEC_DUPLICATE.

gcc/testsuite/

        PR target/87537
        * gcc.target/i386/pr87537-1.c: New test.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr87537-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/simplify-rtx.c
    trunk/gcc/testsuite/ChangeLog