[llvm] [X86] IsElementEquivalent - add handling for ISD::BITCASTS from smaller vector elements (PR #139741)

[Phoebe Wang via llvm-commits]

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@@ -1569,25 +1569,19 @@ define <2 x i64> @mul_v2i64_neg_17_65(<2 x i64> %a0) nounwind {
 }
 
 define <2 x i64> @mul_v2i64_0_1(<2 x i64> %a0) nounwind {
-; X86-SSE2-LABEL: mul_v2i64_0_1:
-; X86-SSE2:       # %bb.0:
-; X86-SSE2-NEXT:    xorpd %xmm1, %xmm1
-; X86-SSE2-NEXT:    movsd {{.*#+}} xmm0 = xmm1[0],xmm0[1]
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phoebewang wrote:

It seems `movsd` is better

https://github.com/llvm/llvm-project/pull/139741