Avoid is_constant calls in vectorizable_bswap
The "new" VEC_PERM_EXPR handling makes it easy to support bswap
for variable-length vectors.
2018-08-24 Richard Sandiford <richard.sandiford@arm.com>
gcc/
* tree-vect-stmts.c (vectorizable_bswap): Handle variable-length
vectors.
gcc/testsuite/
* gcc.target/aarch64/sve/bswap_1.c: New test.
* gcc.target/aarch64/sve/bswap_2.c: Likewise.
* gcc.target/aarch64/sve/bswap_3.c: Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@263833 138bc75d-0d04-0410-961f-82ee72b054a4