[llvm] Introducing a new ISD::POISON SDNode to represent the poison value in the IR. (PR #125883)

[Craig Topper via llvm-commits]

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@@ -5,9 +5,10 @@ define dso_local void @foo() #1 {
 ; CHECK-LABEL: foo:
 ; CHECK:       # %bb.0: # %newFuncRoot
 ; CHECK-NEXT:    vpmovzxbd {{.*#+}} ymm0 = mem[0],zero,zero,zero,mem[1],zero,zero,zero,mem[2],zero,zero,zero,mem[3],zero,zero,zero,mem[4],zero,zero,zero,mem[5],zero,zero,zero,mem[6],zero,zero,zero,mem[7],zero,zero,zero
-; CHECK-NEXT:    vpbroadcastd {{.*#+}} ymm1 = [64,64,64,64,64,64,64,64]
-; CHECK-NEXT:    vpdpwssd {{\.?LCPI[0-9]+_[0-9]+}}(%rip){1to8}, %ymm0, %ymm1
-; CHECK-NEXT:    vpsrld $7, %ymm1, %ymm0
+; CHECK-NEXT:    vpbroadcastd {{.*#+}} ymm1 = [18,0,18,0,18,0,18,0,18,0,18,0,18,0,18,0]
+; CHECK-NEXT:    vpmaddwd        %ymm1, %ymm0, %ymm0
+; CHECK-NEXT:    vpaddd {{\.?LCPI[0-9]+_[0-9]+}}(%rip){1to8}, %ymm0, %ymm0
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topperc wrote:

What happened here?

https://github.com/llvm/llvm-project/pull/125883