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 // Introduce each ingredient into VPlan.
45 for (auto I = VPBB->begin(), E = VPBB->end(); I != E;) {
46 VPRecipeBase *Ingredient = &*I++;
47 // Can only handle VPInstructions.
48 VPInstruction *VPInst = cast<VPInstruction>(Ingredient);
49 Instruction *Inst = cast<Instruction>(VPInst->getUnderlyingValue());
50 if (DeadInstructions.count(Inst)) {
51 VPValue DummyValue;
52 VPInst->replaceAllUsesWith(&DummyValue);
53 Ingredient->eraseFromParent();
54 continue;
55 }
56
57 VPRecipeBase *NewRecipe = nullptr;
58 // Create VPWidenMemoryInstructionRecipe for loads and stores.
59 if (LoadInst *Load = dyn_cast<LoadInst>(Inst))
60 NewRecipe = new VPWidenMemoryInstructionRecipe(
61 *Load, Plan->getOrAddVPValue(getLoadStorePointerOperand(Inst)),
62 nullptr /*Mask*/);
63 else if (StoreInst *Store = dyn_cast<StoreInst>(Inst))
64 NewRecipe = new VPWidenMemoryInstructionRecipe(
65 *Store, Plan->getOrAddVPValue(getLoadStorePointerOperand(Inst)),
66 Plan->getOrAddVPValue(Store->getValueOperand()), nullptr /*Mask*/);
67 else if (PHINode *Phi = dyn_cast<PHINode>(Inst)) {
68 InductionDescriptor II = Inductions.lookup(Phi);
69 if (II.getKind() == InductionDescriptor::IK_IntInduction ||
70 II.getKind() == InductionDescriptor::IK_FpInduction) {
71 VPValue *Start = Plan->getOrAddVPValue(II.getStartValue());
72 NewRecipe = new VPWidenIntOrFpInductionRecipe(Phi, Start);
73 } else
74 NewRecipe = new VPWidenPHIRecipe(Phi);
75 } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Inst)) {
76 NewRecipe = new VPWidenGEPRecipe(
77 GEP, Plan->mapToVPValues(GEP->operands()), OrigLoop);
78 } else
79 NewRecipe =
80 new VPWidenRecipe(*Inst, Plan->mapToVPValues(Inst->operands()));
81
82 NewRecipe->insertBefore(Ingredient);
83 if (NewRecipe->getNumDefinedValues() == 1)
84 VPInst->replaceAllUsesWith(NewRecipe->getVPValue());
85 else
86 assert(NewRecipe->getNumDefinedValues() == 0 &&
87 "Only recpies with zero or one defined values expected");
88 Ingredient->eraseFromParent();
89 }
90 }
91 }
92