[Bug tree-optimization/90510] [10 Regression] Unnecessary permutation

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90510

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue May 21 12:01:00 2019
New Revision: 271463

URL: https://gcc.gnu.org/viewcvs?rev=271463&root=gcc&view=rev
Log:
2019-05-21  Richard Biener  <rguent...@suse.de>

        PR middle-end/90510
        * fold-const.c (fold_read_from_vector): New function.
        * fold-const.h (fold_read_from_vector): Declare.
        * match.pd (VEC_PERM_EXPR): Build BIT_INSERT_EXPRs for
        single-element insert permutations.  Canonicalize selector
        further and fix issue with last commit.

        * gcc.target/i386/pr90510.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr90510.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const.c
    trunk/gcc/fold-const.h
    trunk/gcc/match.pd
    trunk/gcc/testsuite/ChangeLog