[llvm] [X86] LowervXi8MulWithUNPCK - remove special case constant folding handling (PR #163567)

[Phoebe Wang via llvm-commits]

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@@ -665,14 +665,12 @@ define <16 x i8> @combine_vec_udiv_nonuniform4(<16 x i8> %x) {
 ;
 ; XOP-LABEL: combine_vec_udiv_nonuniform4:
 ; XOP:       # %bb.0:
-; XOP-NEXT:    movl $171, %eax
+; XOP-NEXT:    movl $249, %eax
 ; XOP-NEXT:    vmovd %eax, %xmm1
 ; XOP-NEXT:    vpmovzxbw {{.*#+}} xmm2 = xmm0[0],zero,xmm0[1],zero,xmm0[2],zero,xmm0[3],zero,xmm0[4],zero,xmm0[5],zero,xmm0[6],zero,xmm0[7],zero
-; XOP-NEXT:    vpmullw %xmm1, %xmm2, %xmm1
-; XOP-NEXT:    vpsrlw $8, %xmm1, %xmm1
-; XOP-NEXT:    movl $249, %eax
-; XOP-NEXT:    vmovd %eax, %xmm2
-; XOP-NEXT:    vpshlb %xmm2, %xmm1, %xmm1
+; XOP-NEXT:    vpmullw {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm2, %xmm2
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phoebewang wrote:

Thanks for checking! Yeah, unless we have a precise register model. We don't know which is the best in different scenarios. I see the rest are NFC, so I'll +1 for the change.

https://github.com/llvm/llvm-project/pull/163567