[VPlan] Add vp_depth_first_deep (NFC)

[fhahn]

Summary

Similar to vp_depth_first_shallow (D140512) add vp_depth_first_deep to
make existing code clearer and more compact.

[Ayal]

Thanks for adding, looks good to me, ship it!

[fhahn]

Update block wrapper to use Deep naming as well.

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

while (!Worklist.empty()) {
         if (VPRecipeBase *OpDef = operand->getDefiningRecipe())
           Worklist.push_back(OpDef);
     }
   });
 
   // Traverse all the recipes in the VPlan and collect the poison-generating
   // recipes in the backward slice starting at the address of a VPWidenRecipe or
   // VPInterleaveRecipe.
-  auto Iter = depth_first(
-      VPBlockRecursiveTraversalWrapper<VPBlockBase *>(State.Plan->getEntry()));
+  auto Iter = vp_depth_first_deep(State.Plan->getEntry());
   for (VPBasicBlock *VPBB : VPBlockUtils::blocksOnly<VPBasicBlock>(Iter)) {
     for (VPRecipeBase &Recipe : *VPBB) {
       if (auto *WidenRec = dyn_cast<VPWidenMemoryInstructionRecipe>(&Recipe)) {
         Instruction &UnderlyingInstr = WidenRec->getIngredient();
         VPRecipeBase *AddrDef = WidenRec->getAddr()->getDefiningRecipe();
         if (AddrDef && WidenRec->isConsecutive() &&
             Legal->blockNeedsPredication(UnderlyingInstr.getParent()))
           collectPoisonGeneratingInstrsInBackwardSlice(AddrDef);
while (!Worklist.empty()) {
       // need to iterate.
       Changed = true;
     }
   } while (Changed);
 }
 
 void InnerLoopVectorizer::fixNonInductionPHIs(VPlan &Plan,
                                               VPTransformState &State) {
-  auto Iter = depth_first(
-      VPBlockRecursiveTraversalWrapper<VPBlockBase *>(Plan.getEntry()));
+  auto Iter = vp_depth_first_deep(Plan.getEntry());
   for (VPBasicBlock *VPBB : VPBlockUtils::blocksOnly<VPBasicBlock>(Iter)) {
     for (VPRecipeBase &P : VPBB->phis()) {
       VPWidenPHIRecipe *VPPhi = dyn_cast<VPWidenPHIRecipe>(&P);
       if (!VPPhi)
         continue;
       PHINode *NewPhi = cast<PHINode>(State.get(VPPhi, 0));
       // Make sure the builder has a valid insert point.
       Builder.SetInsertPoint(NewPhi);

llvm/lib/Transforms/Vectorize/VPlanCFG.h

 }
 inline iterator_range<
     df_iterator<VPBlockNonRecursiveTraversalWrapper<const VPBlockBase *>>>
 vp_depth_first_shallow(const VPBlockBase *G) {
   return depth_first(
       VPBlockNonRecursiveTraversalWrapper<const VPBlockBase *>(G));
 }
 
+/// Returns an iterator range to traverse the graph starting at \p G in
+/// depth-first order while traversing through region blocks.
+inline iterator_range<
+    df_iterator<VPBlockRecursiveTraversalWrapper<VPBlockBase *>>>
+vp_depth_first_deep(VPBlockBase *G) {
+  return depth_first(VPBlockRecursiveTraversalWrapper<VPBlockBase *>(G));
+}
+inline iterator_range<
+    df_iterator<VPBlockRecursiveTraversalWrapper<const VPBlockBase *>>>
+vp_depth_first_deep(const VPBlockBase *G) {
+  return depth_first(VPBlockRecursiveTraversalWrapper<const VPBlockBase *>(G));
+}
+
 } // namespace llvm
 
 #endif // LLVM_TRANSFORMS_VECTORIZE_VPLANCFG_H

llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

for (VPRecipeBase &Ingredient :
       for (auto *Def : NewRecipe->definedValues()) {
         Plan->addVPValue(Inst, Def);
       }
     }
   }
 }
 
 bool VPlanTransforms::sinkScalarOperands(VPlan &Plan) {
-  auto Iter = depth_first(
-      VPBlockRecursiveTraversalWrapper<VPBlockBase *>(Plan.getEntry()));
+  auto Iter = vp_depth_first_deep(Plan.getEntry());
   bool Changed = false;
   // First, collect the operands of all predicated replicate recipes as seeds
   // for sinking.
   SetVector<std::pair<VPBasicBlock *, VPRecipeBase *>> WorkList;
   for (VPBasicBlock *VPBB : VPBlockUtils::blocksOnly<VPBasicBlock>(Iter)) {
     for (auto &Recipe : *VPBB) {
       auto *RepR = dyn_cast<VPReplicateRecipe>(&Recipe);
       if (!RepR || !RepR->isPredicated())

 
 bool VPlanTransforms::mergeReplicateRegionsIntoSuccessors(VPlan &Plan) {
   SetVector<VPRegionBlock *> DeletedRegions;
 
   // Collect replicate regions followed by an empty block, followed by another
   // replicate region with matching masks to process front. This is to avoid
   // iterator invalidation issues while merging regions.
   SmallVector<VPRegionBlock *, 8> WorkList;
-  for (VPRegionBlock *Region1 :
-       VPBlockUtils::blocksOnly<VPRegionBlock>(depth_first(
-           VPBlockRecursiveTraversalWrapper<VPBlockBase *>(Plan.getEntry())))) {
+  for (VPRegionBlock *Region1 : VPBlockUtils::blocksOnly<VPRegionBlock>(
+           vp_depth_first_deep(Plan.getEntry()))) {
     if (!Region1->isReplicator())
       continue;
     auto *MiddleBasicBlock =
         dyn_cast_or_null<VPBasicBlock>(Region1->getSingleSuccessor());
     if (!MiddleBasicBlock || !MiddleBasicBlock->empty())
       continue;
 
     auto *Region2 =
bool VPlanTransforms::mergeReplicateRegionsIntoSuccessors(VPlan &Plan) {
 
   for (VPRegionBlock *ToDelete : DeletedRegions)
     delete ToDelete;
   return !DeletedRegions.empty();
 }
 
 bool VPlanTransforms::mergeBlocksIntoPredecessors(VPlan &Plan) {
   SmallVector<VPBasicBlock *> WorkList;
-  for (VPBasicBlock *VPBB : VPBlockUtils::blocksOnly<VPBasicBlock>(depth_first(
-           VPBlockRecursiveTraversalWrapper<VPBlockBase *>(Plan.getEntry())))) {
+  for (VPBasicBlock *VPBB : VPBlockUtils::blocksOnly<VPBasicBlock>(
+           vp_depth_first_deep(Plan.getEntry()))) {
     auto *PredVPBB =
         dyn_cast_or_null<VPBasicBlock>(VPBB->getSinglePredecessor());
     if (PredVPBB && PredVPBB->getNumSuccessors() == 1)
       WorkList.push_back(VPBB);
   }
 
   for (VPBasicBlock *VPBB : WorkList) {
     VPBasicBlock *PredVPBB = cast<VPBasicBlock>(VPBB->getSinglePredecessor());

llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp

for (const VPRecipeBase &R : *VPBB) {
     }
   }
   return true;
 }
 
 bool VPlanVerifier::verifyPlanIsValid(const VPlan &Plan) {
   DenseMap<const VPBlockBase *, unsigned> BlockNumbering;
   unsigned Cnt = 0;
-  auto Iter = depth_first(
-      VPBlockRecursiveTraversalWrapper<const VPBlockBase *>(Plan.getEntry()));
+  auto Iter = vp_depth_first_deep(Plan.getEntry());
   for (const VPBlockBase *VPB : Iter) {
     BlockNumbering[VPB] = Cnt++;
     auto *VPBB = dyn_cast<VPBasicBlock>(VPB);
     if (!VPBB)
       continue;
     if (!verifyVPBasicBlock(VPBB, BlockNumbering))
       return false;
   }
if (!LastInst || (LastInst->getOpcode() != VPInstruction::BranchOnCount &&
                     LastInst->getOpcode() != VPInstruction::BranchOnCond)) {
     errs() << "VPlan vector loop exit must end with BranchOnCount or "
               "BranchOnCond VPInstruction\n";
     return false;
   }
 
   for (const VPRegionBlock *Region :
        VPBlockUtils::blocksOnly<const VPRegionBlock>(
-           depth_first(VPBlockRecursiveTraversalWrapper<const VPBlockBase *>(
-               Plan.getEntry())))) {
+           vp_depth_first_deep(Plan.getEntry()))) {
     if (Region->getEntry()->getNumPredecessors() != 0) {
       errs() << "region entry block has predecessors\n";
       return false;
     }
     if (Region->getExiting()->getNumSuccessors() != 0) {
       errs() << "region exiting block has successors\n";
       return false;
     }