[clang] [llvm] [InstCombine] Relax singleUse for GEP(p,add(x,constant)) to 2 GEPs (PR #209551)

[Florian Hahn via cfe-commits]

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@@ -133,47 +133,54 @@ define void @vdiv(ptr %x, ptr %y, double %a, i32 %N) #0 {
 ; CHECK-NEXT:    [[TMP30:%.*]] = fmul fast double [[T0]], [[TMP22]]
 ; CHECK-NEXT:    [[ARRAYIDX2:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[X]], i64 [[INDVARS_IV]]
 ; CHECK-NEXT:    store double [[TMP30]], ptr [[ARRAYIDX2]], align 8, !tbaa [[DOUBLE_TBAA3]]
-; CHECK-NEXT:    [[INDVARS_IV_NEXT:%.*]] = add nuw nsw i64 [[INDVARS_IV]], 1
-; CHECK-NEXT:    [[ARRAYIDX_1:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[Y]], i64 [[INDVARS_IV_NEXT]]
+; CHECK-NEXT:    [[TMP44:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[Y]], i64 [[INDVARS_IV]]
+; CHECK-NEXT:    [[ARRAYIDX_1:%.*]] = getelementptr inbounds nuw i8, ptr [[TMP44]], i64 8
 ; CHECK-NEXT:    [[T0_1:%.*]] = load double, ptr [[ARRAYIDX_1]], align 8, !tbaa [[DOUBLE_TBAA3]]
 ; CHECK-NEXT:    [[TMP31:%.*]] = fmul fast double [[T0_1]], [[TMP23]]
-; CHECK-NEXT:    [[ARRAYIDX2_1:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[X]], i64 [[INDVARS_IV_NEXT]]
+; CHECK-NEXT:    [[TMP47:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[X]], i64 [[INDVARS_IV]]
+; CHECK-NEXT:    [[ARRAYIDX2_1:%.*]] = getelementptr inbounds nuw i8, ptr [[TMP47]], i64 8
 ; CHECK-NEXT:    store double [[TMP31]], ptr [[ARRAYIDX2_1]], align 8, !tbaa [[DOUBLE_TBAA3]]
-; CHECK-NEXT:    [[INDVARS_IV_NEXT_1:%.*]] = add nuw nsw i64 [[INDVARS_IV]], 2
-; CHECK-NEXT:    [[ARRAYIDX_2:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[Y]], i64 [[INDVARS_IV_NEXT_1]]
+; CHECK-NEXT:    [[TMP50:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[Y]], i64 [[INDVARS_IV]]
+; CHECK-NEXT:    [[ARRAYIDX_2:%.*]] = getelementptr inbounds nuw i8, ptr [[TMP50]], i64 16
 ; CHECK-NEXT:    [[T0_2:%.*]] = load double, ptr [[ARRAYIDX_2]], align 8, !tbaa [[DOUBLE_TBAA3]]
 ; CHECK-NEXT:    [[TMP32:%.*]] = fmul fast double [[T0_2]], [[TMP24]]
-; CHECK-NEXT:    [[ARRAYIDX2_2:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[X]], i64 [[INDVARS_IV_NEXT_1]]
+; CHECK-NEXT:    [[TMP53:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[X]], i64 [[INDVARS_IV]]
+; CHECK-NEXT:    [[ARRAYIDX2_2:%.*]] = getelementptr inbounds nuw i8, ptr [[TMP53]], i64 16
 ; CHECK-NEXT:    store double [[TMP32]], ptr [[ARRAYIDX2_2]], align 8, !tbaa [[DOUBLE_TBAA3]]
-; CHECK-NEXT:    [[INDVARS_IV_NEXT_2:%.*]] = add nuw nsw i64 [[INDVARS_IV]], 3
-; CHECK-NEXT:    [[ARRAYIDX_3:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[Y]], i64 [[INDVARS_IV_NEXT_2]]
+; CHECK-NEXT:    [[TMP56:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[Y]], i64 [[INDVARS_IV]]
+; CHECK-NEXT:    [[ARRAYIDX_3:%.*]] = getelementptr inbounds nuw i8, ptr [[TMP56]], i64 24
 ; CHECK-NEXT:    [[T0_3:%.*]] = load double, ptr [[ARRAYIDX_3]], align 8, !tbaa [[DOUBLE_TBAA3]]
 ; CHECK-NEXT:    [[TMP33:%.*]] = fmul fast double [[T0_3]], [[TMP25]]
-; CHECK-NEXT:    [[ARRAYIDX2_3:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[X]], i64 [[INDVARS_IV_NEXT_2]]
+; CHECK-NEXT:    [[TMP45:%.*]] = getelementptr inbounds nuw [8 x i8], ptr [[X]], i64 [[INDVARS_IV]]
+; CHECK-NEXT:    [[ARRAYIDX2_3:%.*]] = getelementptr inbounds nuw i8, ptr [[TMP45]], i64 24
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fhahn wrote:

regression?

https://github.com/llvm/llvm-project/pull/209551