[llvm] [NFC] get rid of `undef` in avx512vl-intrinsics.ll test (PR #143641)

[Craig Topper via llvm-commits]

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@@ -884,12 +884,13 @@ define <4 x float> @test_mm512_maskz_max_ps_128(<4 x float> %a0, <4 x float> %a1
 ; X64-NEXT:    retq # encoding: [0xc3]
   %1 = call <4 x float> @llvm.x86.sse.max.ps(<4 x float> %a0, <4 x float> %a1)
   %2 = bitcast i8 %mask to <8 x i1>
-  %extract = shufflevector <8 x i1> %2, <8 x i1> undef, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
-  %3 = select <4 x i1> %extract, <4 x float> %1, <4 x float> zeroinitializer
-  ret <4 x float> %3
+  %3 = bitcast i8 %mask to <8 x i1>
+  %extract = shufflevector <8 x i1> %2, <8 x i1> %3, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
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topperc wrote:

Yes. If the mask indices don't reference the second operand, then the canonical form is to use `poison` for that operand.

https://github.com/llvm/llvm-project/pull/143641