https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101021
Uroš Bizjak <ubizjak at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed| |2021-06-11 Ever confirmed|0 |1 Assignee|unassigned at gcc dot gnu.org |ubizjak at gmail dot com Status|UNCONFIRMED |ASSIGNED --- Comment #1 from Uroš Bizjak <ubizjak at gmail dot com> --- Created attachment 50982 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50982&action=edit Proposed patch Effectively one liner patch with: + /* Try to avoid variable permutation instruction. */ + if (canonicalize_vector_int_perm (d, &nd) && expand_vec_perm_1 (&nd)) + return false; in a strategic place. Survives: GCC_TEST_RUN_EXPENSIVE=1 make check-gcc RUNTESTFLAGS='--target_board=unix/-mavx dg-torture.exp=vshuf*.c'