[llvm] [SelectionDAG] Deal with POISON for INSERT_VECTOR_ELT/INSERT_SUBVECTOR (part 1) (PR #143102)

[Björn Pettersson via llvm-commits]

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@@ -4716,6 +4717,7 @@ define void @vec384_i64_widen_to_i128_factor2_broadcast_to_v3i128_factor3(ptr %i
 ; AVX-NEXT:    vmovdqa %xmm3, 32(%rcx)
 ; AVX-NEXT:    vmovdqa %xmm1, 48(%rcx)
 ; AVX-NEXT:    vmovdqa %xmm2, (%rcx)
+; AVX-NEXT:    vzeroupper
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bjope wrote:

They go away again in next patch in the stack https://github.com/llvm/llvm-project/pull/143103/

I tried a local rebase but with this patch alone we still get this regression.

https://github.com/llvm/llvm-project/pull/143102