1 //===-- VPlanTransforms.cpp - Utility VPlan to VPlan transforms -----------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// This file implements a set of utility VPlan to VPlan transformations.
11 ///
12 //===----------------------------------------------------------------------===//
13
14 #include "VPlanTransforms.h"
15 #include "llvm/ADT/PostOrderIterator.h"
16
17 using namespace llvm;
18
VPInstructionsToVPRecipes(Loop * OrigLoop,VPlanPtr & Plan,LoopVectorizationLegality::InductionList * Inductions,SmallPtrSetImpl<Instruction * > & DeadInstructions)19 void VPlanTransforms::VPInstructionsToVPRecipes(
20 Loop *OrigLoop, VPlanPtr &Plan,
21 LoopVectorizationLegality::InductionList *Inductions,
22 SmallPtrSetImpl<Instruction *> &DeadInstructions) {
23
24 auto *TopRegion = cast<VPRegionBlock>(Plan->getEntry());
25 ReversePostOrderTraversal<VPBlockBase *> RPOT(TopRegion->getEntry());
26
27 // Condition bit VPValues get deleted during transformation to VPRecipes.
28 // Create new VPValues and save away as condition bits. These will be deleted
29 // after finalizing the vector IR basic blocks.
30 for (VPBlockBase *Base : RPOT) {
31 VPBasicBlock *VPBB = Base->getEntryBasicBlock();
32 if (auto *CondBit = VPBB->getCondBit()) {
33 auto *NCondBit = new VPValue(CondBit->getUnderlyingValue());
34 VPBB->setCondBit(NCondBit);
35 Plan->addCBV(NCondBit);
36 }
37 }
38 for (VPBlockBase *Base : RPOT) {
39 // Do not widen instructions in pre-header and exit blocks.
40 if (Base->getNumPredecessors() == 0 || Base->getNumSuccessors() == 0)
41 continue;
42
43 VPBasicBlock *VPBB = Base->getEntryBasicBlock();
44 VPRecipeBase *LastRecipe = nullptr;
45 // Introduce each ingredient into VPlan.
46 for (auto I = VPBB->begin(), E = VPBB->end(); I != E;) {
47 VPRecipeBase *Ingredient = &*I++;
48 // Can only handle VPInstructions.
49 VPInstruction *VPInst = cast<VPInstruction>(Ingredient);
50 Instruction *Inst = cast<Instruction>(VPInst->getUnderlyingValue());
51 if (DeadInstructions.count(Inst)) {
52 Ingredient->eraseFromParent();
53 continue;
54 }
55
56 VPRecipeBase *NewRecipe = nullptr;
57 // Create VPWidenMemoryInstructionRecipe for loads and stores.
58 if (isa<LoadInst>(Inst) || isa<StoreInst>(Inst))
59 NewRecipe = new VPWidenMemoryInstructionRecipe(
60 *Inst, Plan->getOrAddVPValue(getLoadStorePointerOperand(Inst)),
61 nullptr /*Mask*/);
62 else if (PHINode *Phi = dyn_cast<PHINode>(Inst)) {
63 InductionDescriptor II = Inductions->lookup(Phi);
64 if (II.getKind() == InductionDescriptor::IK_IntInduction ||
65 II.getKind() == InductionDescriptor::IK_FpInduction) {
66 NewRecipe = new VPWidenIntOrFpInductionRecipe(Phi);
67 } else
68 NewRecipe = new VPWidenPHIRecipe(Phi);
69 } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Inst)) {
70 NewRecipe = new VPWidenGEPRecipe(GEP, OrigLoop);
71 } else {
72 // If the last recipe is a VPWidenRecipe, add Inst to it instead of
73 // creating a new recipe.
74 if (VPWidenRecipe *WidenRecipe =
75 dyn_cast_or_null<VPWidenRecipe>(LastRecipe)) {
76 WidenRecipe->appendInstruction(Inst);
77 Ingredient->eraseFromParent();
78 continue;
79 }
80 NewRecipe = new VPWidenRecipe(Inst);
81 }
82
83 NewRecipe->insertBefore(Ingredient);
84 LastRecipe = NewRecipe;
85 Ingredient->eraseFromParent();
86 }
87 }
88 }
89