[llvm] [LV] Create in-loop sub reductions (PR #147026)

[Sam Tebbs via llvm-commits]

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@@ -636,15 +636,16 @@ define i32 @reduction_sub_lhs(ptr noalias nocapture %A) {
 ; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
 ; CHECK:       vector.body:
 ; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT:    [[VEC_PHI:%.*]] = phi <4 x i32> [ zeroinitializer, [[VECTOR_PH]] ], [ [[TMP1:%.*]], [[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[VEC_PHI:%.*]] = phi i32 [ 0, [[VECTOR_PH]] ], [ [[TMP3:%.*]], [[VECTOR_BODY]] ]
 ; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds i32, ptr [[A:%.*]], i64 [[INDEX]]
 ; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <4 x i32>, ptr [[TMP0]], align 4
-; CHECK-NEXT:    [[TMP1]] = sub <4 x i32> [[VEC_PHI]], [[WIDE_LOAD]]
+; CHECK-NEXT:    [[TMP4:%.*]] = sub nsw <4 x i32> zeroinitializer, [[WIDE_LOAD]]
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SamTebbs33 wrote:

I believe it's coming from `CurrentLinkI` in https://github.com/llvm/llvm-project/pull/147026/files#diff-da321d454a7246f8ae276bf1db2782bf26b5210b8133cb59e4d7fd45d0905decR9151 .

https://github.com/llvm/llvm-project/pull/147026