https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113871
--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Uros Bizjak <u...@gcc.gnu.org>: https://gcc.gnu.org/g:2c2f57e4158924467afbf4c2fd3938e507287dab commit r14-8989-g2c2f57e4158924467afbf4c2fd3938e507287dab Author: Uros Bizjak <ubiz...@gmail.com> Date: Wed Feb 14 20:41:42 2024 +0100 i386: psrlq is not used for PERM<a,{0},1,2,3,4> [PR113871] Introduce vec_shl_<mode> and vec_shr_<mode> expanders to improve '*a = __builtin_shufflevector(*a, (vect64){0}, 1, 2, 3, 4);' and '*a = __builtin_shufflevector((vect64){0}, *a, 3, 4, 5, 6);' shuffles. The generated code improves from: movzwl 6(%rdi), %eax movzwl 4(%rdi), %edx salq $16, %rax orq %rdx, %rax movzwl 2(%rdi), %edx salq $16, %rax orq %rdx, %rax movq %rax, (%rdi) to: movq (%rdi), %xmm0 psrlq $16, %xmm0 movq %xmm0, (%rdi) and to: movq (%rdi), %xmm0 psllq $16, %xmm0 movq %xmm0, (%rdi) in the second case. The patch handles 32-bit vectors as well and improves generated code from: movd (%rdi), %xmm0 pxor %xmm1, %xmm1 punpcklwd %xmm1, %xmm0 pshuflw $230, %xmm0, %xmm0 movd %xmm0, (%rdi) to: movd (%rdi), %xmm0 psrld $16, %xmm0 movd %xmm0, (%rdi) and to: movd (%rdi), %xmm0 pslld $16, %xmm0 movd %xmm0, (%rdi) PR target/113871 gcc/ChangeLog: * config/i386/mmx.md (V248FI): New mode iterator. (V24FI_32): DItto. (vec_shl_<V248FI:mode>): New expander. (vec_shl_<V24FI_32:mode>): Ditto. (vec_shr_<V248FI:mode>): Ditto. (vec_shr_<V24FI_32:mode>): Ditto. * config/i386/sse.md (vec_shl_<V_128:mode>): Simplify expander. (vec_shr_<V248FI:mode>): Ditto. gcc/testsuite/ChangeLog: * gcc.target/i386/pr113871-1a.c: New test. * gcc.target/i386/pr113871-1b.c: New test. * gcc.target/i386/pr113871-2a.c: New test. * gcc.target/i386/pr113871-2b.c: New test. * gcc.target/i386/pr113871-3a.c: New test. * gcc.target/i386/pr113871-3b.c: New test. * gcc.target/i386/pr113871-4a.c: New test.