r256257 - in /trunk/gcc: ChangeLog tree-ssa-for...

[rsandifo@gcc.gnu.org]

Author: rsandifo
Date: Thu Jan  4 18:04:54 2018
New Revision: 256257

URL: https://gcc.gnu.org/viewcvs?rev=256257&root=gcc&view=rev
Log:
Allow VEC_PERM_EXPR folding to fail

tree-ssa-forwprop.c was asserting that a VEC_PERM_EXPR fold on three
VECTOR_CSTs would always succeed, but it's possible for it to fail
with variable-length vectors.

2017-12-22  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* tree-ssa-forwprop.c (is_combined_permutation_identity): Allow
	the VEC_PERM_EXPR fold to fail.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-ssa-forwprop.c