https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112816
--- Comment #10 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:bf418db27c0b48abb8203dd9e08135793cd9ce18 commit r14-6136-gbf418db27c0b48abb8203dd9e08135793cd9ce18 Author: Jakub Jelinek <ja...@redhat.com> Date: Tue Dec 5 09:08:45 2023 +0100 i386: Improve code generation for vector __builtin_signbit (x.x[i]) ? -1 : 0 [PR112816] On the testcase I've recently fixed I've noticed bad code generation, we emit pxor %xmm1, %xmm1 psrld $31, %xmm0 pcmpeqd %xmm1, %xmm0 pcmpeqd %xmm1, %xmm0 or vpxor %xmm1, %xmm1, %xmm1 vpsrld $31, %xmm0, %xmm0 vpcmpeqd %xmm1, %xmm0, %xmm0 vpcmpeqd %xmm1, %xmm0, %xmm2 rather than psrad $31, %xmm2 or vpsrad $31, %xmm1, %xmm2 The following patch fixes that using a combiner splitter. 2023-12-05 Jakub Jelinek <ja...@redhat.com> PR target/112816 * config/i386/sse.md ((eq (eq (lshiftrt x elt_bits-1) 0) 0)): New splitter to turn psrld $31; pcmpeq; pcmpeq into psrad $31. * gcc.target/i386/pr112816.c: New test.
