Check whether a vector of QIs can store all indices
The patch to remove the vec_perm_const optab checked whether replacing
a constant permute with a variable permute is safe, or whether it might
truncate the indices. This patch adds a corresponding check for whether
variable permutes can be lowered to QImode-based permutes.
2018-01-02 Richard Sandiford <richard.sandiford@linaro.org>
gcc/
* optabs-query.c (can_vec_perm_var_p): Check whether lowering
to qimode could truncate the indices.
* optabs.c (expand_vec_perm_var): Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@256094 138bc75d-0d04-0410-961f-82ee72b054a4