Address review comments

- Move `setStepValue` to `VPWidenInductionRecipe`
- Make `simplifyBranchConditionForVFAndUF` a static, non-member function
- Update a lit test

Author: hazzlim

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -1726,6 +1726,9 @@ class VPWidenInductionRecipe : public VPHeaderPHIRecipe {
   VPValue *getStepValue() { return getOperand(1); }
   const VPValue *getStepValue() const { return getOperand(1); }
 
+  /// Update the step value of the recipe.
+  void setStepValue(VPValue *V) { setOperand(1, V); }
+
   PHINode *getPHINode() const { return cast<PHINode>(getUnderlyingValue()); }
 
   /// Returns the induction descriptor for the recipe.
@@ -1800,9 +1803,6 @@ class VPWidenIntOrFpInductionRecipe : public VPWidenInductionRecipe {
              VPSlotTracker &SlotTracker) const override;
 #endif
 
-  /// Update the step value of the recipe.
-  void setStepValue(VPValue *V) { setOperand(1, V); }
-
   VPValue *getVFValue() { return getOperand(2); }
   const VPValue *getVFValue() const { return getOperand(2); }
 

llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

@@ -1079,9 +1079,11 @@ static bool optimizeVectorInductionWidthForTCAndVFUF(VPlan &Plan,
   return MadeChange;
 }
 
-bool VPlanTransforms::simplifyBranchConditionForVFAndUF(
-    VPlan &Plan, ElementCount BestVF, unsigned BestUF,
-    PredicatedScalarEvolution &PSE) {
+/// Try to simplify the branch condition of \p Plan. This may restrict the
+/// resulting plan to \p BestVF and \p BestUF.
+static bool simplifyBranchConditionForVFAndUF(VPlan &Plan, ElementCount BestVF,
+                                              unsigned BestUF,
+                                              PredicatedScalarEvolution &PSE) {
   VPRegionBlock *VectorRegion = Plan.getVectorLoopRegion();
   VPBasicBlock *ExitingVPBB = VectorRegion->getExitingBasicBlock();
   auto *Term = &ExitingVPBB->back();
@@ -1131,7 +1133,7 @@ bool VPlanTransforms::simplifyBranchConditionForVFAndUF(
 
     VPBlockUtils::connectBlocks(Preheader, Header);
     VPBlockUtils::connectBlocks(ExitingVPBB, Exit);
-    simplifyRecipes(Plan, *CanIVTy);
+    VPlanTransforms::simplifyRecipes(Plan, *CanIVTy);
   } else {
     // The vector region contains header phis for which we cannot remove the
     // loop region yet.

llvm/lib/Transforms/Vectorize/VPlanTransforms.h

@@ -97,13 +97,6 @@ struct VPlanTransforms {
                                  unsigned BestUF,
                                  PredicatedScalarEvolution &PSE);
 
-  /// Try to simplify the branch condition of \p Plan. This may restrict the
-  /// resulting plan to \p BestVF and \p BestUF.
-  static bool simplifyBranchConditionForVFAndUF(VPlan &Plan,
-                                                ElementCount BestVF,
-                                                unsigned BestUF,
-                                                PredicatedScalarEvolution &PSE);
-
   /// Apply VPlan-to-VPlan optimizations to \p Plan, including induction recipe
   /// optimizations, dead recipe removal, replicate region optimizations and
   /// block merging.

llvm/test/Transforms/LoopVectorize/AArch64/transform-narrow-interleave-to-widen-memory-remove-loop-region.ll

@@ -51,8 +51,8 @@ define void @load_store_interleave_group_tc_2(ptr noalias %data) {
 ; VF4-NEXT:    br label %[[VECTOR_BODY:.*]]
 ; VF4:       [[VECTOR_BODY]]:
 ; VF4-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[PRED_STORE_CONTINUE6:.*]] ]
-; VF4-NEXT:    [[VEC_IND:%.*]] = phi <4 x i64> [ <i64 0, i64 1, i64 2, i64 3>, %[[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], %[[PRED_STORE_CONTINUE6]] ]
-; VF4-NEXT:    [[TMP0:%.*]] = icmp ule <4 x i64> [[VEC_IND]], splat (i64 1)
+; VF4-NEXT:    [[VEC_IND:%.*]] = phi <4 x i8> [ <i8 0, i8 1, i8 2, i8 3>, %[[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], %[[PRED_STORE_CONTINUE6]] ]
+; VF4-NEXT:    [[TMP0:%.*]] = icmp ule <4 x i8> [[VEC_IND]], splat (i8 1)
 ; VF4-NEXT:    [[TMP1:%.*]] = extractelement <4 x i1> [[TMP0]], i32 0
 ; VF4-NEXT:    br i1 [[TMP1]], label %[[PRED_STORE_IF:.*]], label %[[PRED_STORE_CONTINUE:.*]]
 ; VF4:       [[PRED_STORE_IF]]:
@@ -109,7 +109,7 @@ define void @load_store_interleave_group_tc_2(ptr noalias %data) {
 ; VF4-NEXT:    store i64 [[TMP32]], ptr [[TMP31]], align 8
 ; VF4-NEXT:    br label %[[PRED_STORE_CONTINUE6]]
 ; VF4:       [[PRED_STORE_CONTINUE6]]:
-; VF4-NEXT:    [[VEC_IND_NEXT]] = add <4 x i64> [[VEC_IND]], splat (i64 4)
+; VF4-NEXT:    [[VEC_IND_NEXT]] = add <4 x i8> [[VEC_IND]], splat (i8 4)
 ; VF4-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
 ; VF4-NEXT:    br i1 true, label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
 ; VF4:       [[MIDDLE_BLOCK]]: