[llvm] RegisterPressure: Remove dead defs correctly (PR #222627)

[Matt Arsenault via llvm-commits]

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@@ -253,44 +253,50 @@ define <8 x i64> @test_divv_8i64(<8 x i64> %a, <8 x i64> %b) nounwind {
 ; NODQ-NEXT:    vpextrq $1, %xmm3, %rcx
 ; NODQ-NEXT:    xorl %edx, %edx
 ; NODQ-NEXT:    divq %rcx
-; NODQ-NEXT:    vmovq %rax, %xmm4
+; NODQ-NEXT:    movq %rax, %rcx
 ; NODQ-NEXT:    vmovq %xmm2, %rax
-; NODQ-NEXT:    vmovq %xmm3, %rcx
+; NODQ-NEXT:    vmovq %xmm3, %rsi
 ; NODQ-NEXT:    xorl %edx, %edx
-; NODQ-NEXT:    divq %rcx
-; NODQ-NEXT:    vmovq %rax, %xmm2
-; NODQ-NEXT:    vpunpcklqdq {{.*#+}} xmm2 = xmm2[0],xmm4[0]
-; NODQ-NEXT:    vextracti32x4 $2, %zmm0, %xmm3
-; NODQ-NEXT:    vpextrq $1, %xmm3, %rax
-; NODQ-NEXT:    vextracti32x4 $2, %zmm1, %xmm4
-; NODQ-NEXT:    vpextrq $1, %xmm4, %rcx
+; NODQ-NEXT:    divq %rsi
+; NODQ-NEXT:    movq %rax, %rsi
+; NODQ-NEXT:    vextracti32x4 $2, %zmm0, %xmm2
+; NODQ-NEXT:    vpextrq $1, %xmm2, %rax
+; NODQ-NEXT:    vextracti32x4 $2, %zmm1, %xmm3
+; NODQ-NEXT:    vpextrq $1, %xmm3, %rdi
 ; NODQ-NEXT:    xorl %edx, %edx
-; NODQ-NEXT:    divq %rcx
-; NODQ-NEXT:    vmovq %rax, %xmm5
-; NODQ-NEXT:    vmovq %xmm3, %rax
-; NODQ-NEXT:    vmovq %xmm4, %rcx
+; NODQ-NEXT:    divq %rdi
+; NODQ-NEXT:    movq %rax, %rdi
+; NODQ-NEXT:    vmovq %xmm2, %rax
+; NODQ-NEXT:    vmovq %xmm3, %r8
 ; NODQ-NEXT:    xorl %edx, %edx
-; NODQ-NEXT:    divq %rcx
-; NODQ-NEXT:    vmovq %rax, %xmm3
-; NODQ-NEXT:    vpunpcklqdq {{.*#+}} xmm3 = xmm3[0],xmm5[0]
-; NODQ-NEXT:    vinserti128 $1, %xmm2, %ymm3, %ymm2
-; NODQ-NEXT:    vextracti128 $1, %ymm0, %xmm3
-; NODQ-NEXT:    vpextrq $1, %xmm3, %rax
-; NODQ-NEXT:    vextracti128 $1, %ymm1, %xmm4
-; NODQ-NEXT:    vpextrq $1, %xmm4, %rcx
+; NODQ-NEXT:    divq %r8
+; NODQ-NEXT:    movq %rax, %r8
+; NODQ-NEXT:    vextracti128 $1, %ymm0, %xmm2
+; NODQ-NEXT:    vpextrq $1, %xmm2, %rax
+; NODQ-NEXT:    vextracti128 $1, %ymm1, %xmm3
+; NODQ-NEXT:    vpextrq $1, %xmm3, %r9
 ; NODQ-NEXT:    xorl %edx, %edx
-; NODQ-NEXT:    divq %rcx
-; NODQ-NEXT:    vmovq %rax, %xmm5
-; NODQ-NEXT:    vmovq %xmm3, %rax
-; NODQ-NEXT:    vmovq %xmm4, %rcx
+; NODQ-NEXT:    divq %r9
+; NODQ-NEXT:    movq %rax, %r9
+; NODQ-NEXT:    vmovq %xmm2, %rax
+; NODQ-NEXT:    vmovq %xmm3, %r10
 ; NODQ-NEXT:    xorl %edx, %edx
-; NODQ-NEXT:    divq %rcx
-; NODQ-NEXT:    vmovq %rax, %xmm3
-; NODQ-NEXT:    vpunpcklqdq {{.*#+}} xmm3 = xmm3[0],xmm5[0]
+; NODQ-NEXT:    divq %r10
+; NODQ-NEXT:    movq %rax, %r10
 ; NODQ-NEXT:    vpextrq $1, %xmm0, %rax
-; NODQ-NEXT:    vpextrq $1, %xmm1, %rcx
+; NODQ-NEXT:    vpextrq $1, %xmm1, %r11
 ; NODQ-NEXT:    xorl %edx, %edx
-; NODQ-NEXT:    divq %rcx
+; NODQ-NEXT:    divq %r11
+; NODQ-NEXT:    vmovq %rcx, %xmm2
+; NODQ-NEXT:    vmovq %rsi, %xmm3
+; NODQ-NEXT:    vmovq %rdi, %xmm4
+; NODQ-NEXT:    vmovq %r8, %xmm5
+; NODQ-NEXT:    vpunpcklqdq {{.*#+}} xmm2 = xmm3[0],xmm2[0]
+; NODQ-NEXT:    vmovq %r9, %xmm3
+; NODQ-NEXT:    vpunpcklqdq {{.*#+}} xmm4 = xmm5[0],xmm4[0]
+; NODQ-NEXT:    vinserti128 $1, %xmm2, %ymm4, %ymm2
+; NODQ-NEXT:    vmovq %r10, %xmm4
+; NODQ-NEXT:    vpunpcklqdq {{.*#+}} xmm3 = xmm4[0],xmm3[0]
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arsenm wrote:

Don't know but I really don't want to get bogged down yakshaving a regression in one random test. I've been stuck on this assert way too many times before 

I also have the patches ready to finally delete LiveVariables, this is the main issue blocking that 

https://github.com/llvm/llvm-project/pull/222627