[llvm] [VPlan] Optimize resume values of IVs together with other exit values. (PR #174239)

[Florian Hahn via llvm-commits]

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@@ -57,16 +57,16 @@ define i32 @recurrence_1(ptr nocapture readonly %a, ptr nocapture %b, i32 %n) {
 ; CHECK-VF4UF1:       [[MIDDLE_BLOCK]]:
 ; CHECK-VF4UF1-NEXT:    [[TMP25:%.*]] = call i32 @llvm.vscale.i32()
 ; CHECK-VF4UF1-NEXT:    [[TMP26:%.*]] = mul nuw i32 [[TMP25]], 4
-; CHECK-VF4UF1-NEXT:    [[TMP27:%.*]] = sub i32 [[TMP26]], 1
+; CHECK-VF4UF1-NEXT:    [[TMP27:%.*]] = sub i32 [[TMP26]], 2
 ; CHECK-VF4UF1-NEXT:    [[VECTOR_RECUR_EXTRACT_FOR_PHI:%.*]] = extractelement <vscale x 4 x i32> [[WIDE_LOAD]], i32 [[TMP27]]
 ; CHECK-VF4UF1-NEXT:    [[TMP28:%.*]] = call i32 @llvm.vscale.i32()
 ; CHECK-VF4UF1-NEXT:    [[TMP29:%.*]] = mul nuw i32 [[TMP28]], 4
-; CHECK-VF4UF1-NEXT:    [[TMP30:%.*]] = sub i32 [[TMP29]], 2
+; CHECK-VF4UF1-NEXT:    [[TMP30:%.*]] = sub i32 [[TMP29]], 1
 ; CHECK-VF4UF1-NEXT:    [[VECTOR_RECUR_EXTRACT:%.*]] = extractelement <vscale x 4 x i32> [[WIDE_LOAD]], i32 [[TMP30]]
 ; CHECK-VF4UF1-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[TMP2]], [[N_VEC]]
 ; CHECK-VF4UF1-NEXT:    br i1 [[CMP_N]], [[FOR_EXIT:label %.*]], label %[[SCALAR_PH]]
 ; CHECK-VF4UF1:       [[SCALAR_PH]]:
-; CHECK-VF4UF1-NEXT:    [[SCALAR_RECUR_INIT:%.*]] = phi i32 [ [[VECTOR_RECUR_EXTRACT_FOR_PHI]], %[[MIDDLE_BLOCK]] ], [ [[PRE_LOAD]], %[[FOR_PREHEADER]] ], [ [[PRE_LOAD]], %[[VECTOR_MEMCHECK]] ]
+; CHECK-VF4UF1-NEXT:    [[SCALAR_RECUR_INIT:%.*]] = phi i32 [ [[VECTOR_RECUR_EXTRACT]], %[[MIDDLE_BLOCK]] ], [ [[PRE_LOAD]], %[[FOR_PREHEADER]] ], [ [[PRE_LOAD]], %[[VECTOR_MEMCHECK]] ]
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fhahn wrote:

Yes, the script tries to minimize the changes. here the extracts got re-ordered, but the names not updated. Should be fixed manually.

https://github.com/llvm/llvm-project/pull/174239