https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104610
--- Comment #10 from Hongtao.liu <crazylht at gmail dot com> --- (In reply to H.J. Lu from comment #9) > ix86_gen_scratch_sse_rtx was added to prevent combine from changing > store of vector registers with constant value to store of constant > value. You can change ix86_gen_scratch_sse_rtx to return a pseudo > register and watch the regressions in GCC testsuite. If we can fix > these regressions, ix86_gen_scratch_sse_rtx isn't needed. it regresses, i'm thinking of add a peephole2 to split mov mem to mov + movd + shufd which can prevent regression for pr100865, and for vzeroupper, i don't have a good way to avoid those regressions. gcc.target/i386/pr100865-11b.c scan-assembler-times vmovdqa64[\\t ]%xmm[0-9]+, 16 gcc.target/i386/pr100865-12b.c scan-assembler-times vmovdqa64[\\t ]%xmm[0-9]+, 16 gcc.target/i386/pr100865-8a.c scan-assembler-times (?:vpbroadcastd|vpshufd)[\\t ]+[^\n]*, %xmm[0-9]+ 1 gcc.target/i386/pr100865-8b.c scan-assembler-times vmovdqa64[\\t ]%xmm[0-9]+, 16 gcc.target/i386/pr100865-8c.c scan-assembler-times vpshufd[\\t ]+[^\n]*, %xmm[0-9]+ 1 gcc.target/i386/pr100865-9b.c scan-assembler-times vmovdqa64[\\t ]%xmm[0-9]+, 16 gcc.target/i386/pr100865-9c.c scan-assembler-times vpshufd[\\t ]+[^\n]*, %xmm[0-9]+ 1 gcc.target/i386/pr82941-1.c scan-assembler-not vzeroupper gcc.target/i386/pr82942-1.c scan-assembler-not vzeroupper gcc.target/i386/pr82990-1.c scan-assembler-not vzeroupper gcc.target/i386/pr82990-3.c scan-assembler-not vzeroupper gcc.target/i386/pr82990-5.c scan-assembler-not vzeroupper