[llvm] [LV] Only require a scalar epilogue for interleave groups actually widened as interleave accesses (PR #213904)

[Mel Chen via llvm-commits]

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@@ -218,14 +218,14 @@ define i64 @test_pr62954_scalar_epilogue_required(ptr %A, ptr noalias %B, ptr %C
 ; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
 ; CHECK-NEXT:    [[VEC_IND:%.*]] = phi <2 x i64> [ <i64 1, i64 3>, [[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], [[VECTOR_BODY]] ]
 ; CHECK-NEXT:    [[STEP_ADD:%.*]] = add nuw nsw <2 x i64> [[VEC_IND]], splat (i64 4)
+; CHECK-NEXT:    [[TMP0:%.*]] = sub nsw <2 x i64> zeroinitializer, [[STEP_ADD]]
+; CHECK-NEXT:    [[TMP2:%.*]] = extractelement <2 x i64> [[TMP0]], i64 1
+; CHECK-NEXT:    store i64 [[TMP2]], ptr [[GEP]], align 8
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Mel-Chen wrote:

https://github.com/llvm/llvm-project/pull/217238

https://github.com/llvm/llvm-project/pull/213904