[llvm] [DAG] SimplifyDemandedBits - use ComputeKnownBits instead of getValidShiftAmountConstant to check for constant shift amounts. (PR #92412)

[Phoebe Wang via llvm-commits]

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@@ -3176,7 +3176,8 @@ define <2 x i64> @test_128_i64_x_2_18446744065119617024_mask_ashr_32(<2 x i64> %
 ;
 ; X86-AVX2-LABEL: test_128_i64_x_2_18446744065119617024_mask_ashr_32:
 ; X86-AVX2:       # %bb.0:
-; X86-AVX2-NEXT:    vpand {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0, %xmm0
+; X86-AVX2-NEXT:    vpbroadcastd {{.*#+}} xmm1 = [4294967294,4294967294,4294967294,4294967294]
+; X86-AVX2-NEXT:    vpand %xmm1, %xmm0, %xmm0
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phoebewang wrote:

Looks we only recognize it on 32-bits?

https://github.com/llvm/llvm-project/pull/92412