[llvm] [X86] Try Folding icmp of v8i32 -> fcmp of v8f32 on AVX (PR #82290)

[Simon Pilgrim via llvm-commits]

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@@ -861,6 +861,9 @@ define <8 x i32> @v8i32(<8 x i32> %x, <8 x i32> %y) nounwind {
 ; AVX1-NEXT:    vpcmpgtd %xmm2, %xmm3, %xmm3
 ; AVX1-NEXT:    vpcmpgtd %xmm4, %xmm0, %xmm0
 ; AVX1-NEXT:    vinsertf128 $1, %xmm3, %ymm0, %ymm0
+; AVX1-NEXT:    vcvtdq2ps %ymm1, %ymm1
+; AVX1-NEXT:    vpxor %xmm3, %xmm3, %xmm3
+; AVX1-NEXT:    vcmpltps %ymm3, %ymm1, %ymm1
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RKSimon wrote:

My guess is the PCMPGT handling in computeKnownBitsForTargetNode was managing to constant fold - but for some reason it never succeeded earlier?

https://github.com/llvm/llvm-project/pull/82290