https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82139
--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> --- (In reply to Andrew Pinski from comment #1) > It is worse on the trunk: > .L2: > movdqu (%rdi), %xmm1 > movdqu (%rdi), %xmm0 > addq $16, %rdi > paddd %xmm3, %xmm1 > paddd %xmm2, %xmm0 > blendpd $2, %xmm0, %xmm1 > movups %xmm1, -16(%rdi) > cmpq %rdi, %rax > jne .L2 > > Why two loads from %rdi here? > This is done during RA as far as I can tell. It looks like generic cost model should be updated. w/ -O2 -msse4 -mno-avx -mtune=skylake looks optimal movdqu (%rdi), %xmm0 movdqa %xmm3, %xmm1 paddd %xmm0, %xmm1 paddd %xmm2, %xmm0 blendpd $2, %xmm0, %xmm1 movups %xmm1, (%rdi) addq $16, %rdi cmpq %rdi, %rax jne .L2
