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//===- VPlanValue.h - Represent Values in Vectorizer Plan -----------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
/// \file
/// This file contains the declarations of the entities induced by Vectorization
/// Plans, e.g. the instructions the VPlan intends to generate if executed.
/// VPlan models the following entities:
/// VPValue VPUser VPDef
/// | |
/// VPInstruction
/// These are documented in docs/VectorizationPlan.rst.
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/ADT/iterator_range.h"
namespace llvm {
// Forward declarations.
class raw_ostream;
class Value;
class VPDef;
class VPSlotTracker;
class VPUser;
class VPRecipeBase;
class VPWidenMemoryInstructionRecipe;
// This is the base class of the VPlan Def/Use graph, used for modeling the data
// flow into, within and out of the VPlan. VPValues can stand for live-ins
// coming from the input IR, instructions which VPlan will generate if executed
// and live-outs which the VPlan will need to fix accordingly.
class VPValue {
friend class VPBuilder;
friend class VPDef;
friend class VPInstruction;
friend struct VPlanTransforms;
friend class VPBasicBlock;
friend class VPInterleavedAccessInfo;
friend class VPSlotTracker;
friend class VPRecipeBase;
friend class VPWidenMemoryInstructionRecipe;
const unsigned char SubclassID; ///< Subclass identifier (for isa/dyn_cast).
SmallVector<VPUser *, 1> Users;
// Hold the underlying Value, if any, attached to this VPValue.
Value *UnderlyingVal;
/// Pointer to the VPDef that defines this VPValue. If it is nullptr, the
/// VPValue is not defined by any recipe modeled in VPlan.
VPDef *Def;
VPValue(const unsigned char SC, Value *UV = nullptr, VPDef *Def = nullptr);
// DESIGN PRINCIPLE: Access to the underlying IR must be strictly limited to
// the front-end and back-end of VPlan so that the middle-end is as
// independent as possible of the underlying IR. We grant access to the
// underlying IR using friendship. In that way, we should be able to use VPlan
// for multiple underlying IRs (Polly?) by providing a new VPlan front-end,
// back-end and analysis information for the new IR.
// Set \p Val as the underlying Value of this VPValue.
void setUnderlyingValue(Value *Val) {
assert(!UnderlyingVal && "Underlying Value is already set.");
UnderlyingVal = Val;
/// Return the underlying Value attached to this VPValue.
Value *getUnderlyingValue() { return UnderlyingVal; }
const Value *getUnderlyingValue() const { return UnderlyingVal; }
/// An enumeration for keeping track of the concrete subclass of VPValue that
/// are actually instantiated. Values of this enumeration are kept in the
/// SubclassID field of the VPValue objects. They are used for concrete
/// type identification.
enum {
VPValue(Value *UV = nullptr, VPDef *Def = nullptr)
: VPValue(VPValueSC, UV, Def) {}
VPValue(const VPValue &) = delete;
VPValue &operator=(const VPValue &) = delete;
virtual ~VPValue();
/// \return an ID for the concrete type of this object.
/// This is used to implement the classof checks. This should not be used
/// for any other purpose, as the values may change as LLVM evolves.
unsigned getVPValueID() const { return SubclassID; }
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void printAsOperand(raw_ostream &OS, VPSlotTracker &Tracker) const;
void print(raw_ostream &OS, VPSlotTracker &Tracker) const;
/// Dump the value to stderr (for debugging).
void dump() const;
unsigned getNumUsers() const { return Users.size(); }
void addUser(VPUser &User) { Users.push_back(&User); }
/// Remove a single \p User from the list of users.
void removeUser(VPUser &User) {
bool Found = false;
// The same user can be added multiple times, e.g. because the same VPValue
// is used twice by the same VPUser. Remove a single one.
erase_if(Users, [&User, &Found](VPUser *Other) {
if (Found)
return false;
if (Other == &User) {
Found = true;
return true;
return false;
typedef SmallVectorImpl<VPUser *>::iterator user_iterator;
typedef SmallVectorImpl<VPUser *>::const_iterator const_user_iterator;
typedef iterator_range<user_iterator> user_range;
typedef iterator_range<const_user_iterator> const_user_range;
user_iterator user_begin() { return Users.begin(); }
const_user_iterator user_begin() const { return Users.begin(); }
user_iterator user_end() { return Users.end(); }
const_user_iterator user_end() const { return Users.end(); }
user_range users() { return user_range(user_begin(), user_end()); }
const_user_range users() const {
return const_user_range(user_begin(), user_end());
/// Returns true if the value has more than one unique user.
bool hasMoreThanOneUniqueUser() {
if (getNumUsers() == 0)
return false;
// Check if all users match the first user.
auto Current = std::next(user_begin());
while (Current != user_end() && *user_begin() == *Current)
return Current != user_end();
void replaceAllUsesWith(VPValue *New);
VPDef *getDef() { return Def; }
/// Returns the underlying IR value, if this VPValue is defined outside the
/// scope of VPlan. Returns nullptr if the VPValue is defined by a VPDef
/// inside a VPlan.
Value *getLiveInIRValue() {
assert(!getDef() &&
"VPValue is not a live-in; it is defined by a VPDef inside a VPlan");
return getUnderlyingValue();
typedef DenseMap<Value *, VPValue *> Value2VPValueTy;
typedef DenseMap<VPValue *, Value *> VPValue2ValueTy;
raw_ostream &operator<<(raw_ostream &OS, const VPValue &V);
/// This class augments VPValue with operands which provide the inverse def-use
/// edges from VPValue's users to their defs.
class VPUser {
SmallVector<VPValue *, 2> Operands;
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
/// Print the operands to \p O.
void printOperands(raw_ostream &O, VPSlotTracker &SlotTracker) const;
VPUser() {}
VPUser(ArrayRef<VPValue *> Operands) {
for (VPValue *Operand : Operands)
VPUser(std::initializer_list<VPValue *> Operands)
: VPUser(ArrayRef<VPValue *>(Operands)) {}
template <typename IterT> VPUser(iterator_range<IterT> Operands) {
for (VPValue *Operand : Operands)
VPUser(const VPUser &) = delete;
VPUser &operator=(const VPUser &) = delete;
virtual ~VPUser() {
for (VPValue *Op : operands())
void addOperand(VPValue *Operand) {
unsigned getNumOperands() const { return Operands.size(); }
inline VPValue *getOperand(unsigned N) const {
assert(N < Operands.size() && "Operand index out of bounds");
return Operands[N];
void setOperand(unsigned I, VPValue *New) {
Operands[I] = New;
void removeLastOperand() {
VPValue *Op = Operands.pop_back_val();
typedef SmallVectorImpl<VPValue *>::iterator operand_iterator;
typedef SmallVectorImpl<VPValue *>::const_iterator const_operand_iterator;
typedef iterator_range<operand_iterator> operand_range;
typedef iterator_range<const_operand_iterator> const_operand_range;
operand_iterator op_begin() { return Operands.begin(); }
const_operand_iterator op_begin() const { return Operands.begin(); }
operand_iterator op_end() { return Operands.end(); }
const_operand_iterator op_end() const { return Operands.end(); }
operand_range operands() { return operand_range(op_begin(), op_end()); }
const_operand_range operands() const {
return const_operand_range(op_begin(), op_end());
/// Method to support type inquiry through isa, cast, and dyn_cast.
static inline bool classof(const VPDef *Recipe);
/// This class augments a recipe with a set of VPValues defined by the recipe.
/// It allows recipes to define zero, one or multiple VPValues. A VPDef owns
/// the VPValues it defines and is responsible for deleting its defined values.
/// Single-value VPDefs that also inherit from VPValue must make sure to inherit
/// from VPDef before VPValue.
class VPDef {
friend class VPValue;
/// Subclass identifier (for isa/dyn_cast).
const unsigned char SubclassID;
/// The VPValues defined by this VPDef.
TinyPtrVector<VPValue *> DefinedValues;
/// Add \p V as a defined value by this VPDef.
void addDefinedValue(VPValue *V) {
assert(V->getDef() == this &&
"can only add VPValue already linked with this VPDef");
/// Remove \p V from the values defined by this VPDef. \p V must be a defined
/// value of this VPDef.
void removeDefinedValue(VPValue *V) {
assert(V->getDef() == this &&
"can only remove VPValue linked with this VPDef");
assert(is_contained(DefinedValues, V) &&
"VPValue to remove must be in DefinedValues");
erase_value(DefinedValues, V);
V->Def = nullptr;
/// An enumeration for keeping track of the concrete subclass of VPRecipeBase
/// that is actually instantiated. Values of this enumeration are kept in the
/// SubclassID field of the VPRecipeBase objects. They are used for concrete
/// type identification.
using VPRecipeTy = enum {
VPDef(const unsigned char SC) : SubclassID(SC) {}
virtual ~VPDef() {
for (VPValue *D : make_early_inc_range(DefinedValues)) {
assert(D->Def == this &&
"all defined VPValues should point to the containing VPDef");
assert(D->getNumUsers() == 0 &&
"all defined VPValues should have no more users");
D->Def = nullptr;
delete D;
/// Returns the VPValue with index \p I defined by the VPDef.
VPValue *getVPValue(unsigned I = 0) {
assert(DefinedValues[I] && "defined value must be non-null");
return DefinedValues[I];
const VPValue *getVPValue(unsigned I = 0) const {
assert(DefinedValues[I] && "defined value must be non-null");
return DefinedValues[I];
/// Returns an ArrayRef of the values defined by the VPDef.
ArrayRef<VPValue *> definedValues() { return DefinedValues; }
/// Returns an ArrayRef of the values defined by the VPDef.
ArrayRef<VPValue *> definedValues() const { return DefinedValues; }
/// Returns the number of values defined by the VPDef.
unsigned getNumDefinedValues() const { return DefinedValues.size(); }
/// \return an ID for the concrete type of this object.
/// This is used to implement the classof checks. This should not be used
/// for any other purpose, as the values may change as LLVM evolves.
unsigned getVPDefID() const { return SubclassID; }
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
/// Dump the VPDef to stderr (for debugging).
void dump() const;
/// Each concrete VPDef prints itself.
virtual void print(raw_ostream &O, const Twine &Indent,
VPSlotTracker &SlotTracker) const = 0;
class VPlan;
class VPBasicBlock;
class VPRegionBlock;
/// This class can be used to assign consecutive numbers to all VPValues in a
/// VPlan and allows querying the numbering for printing, similar to the
/// ModuleSlotTracker for IR values.
class VPSlotTracker {
DenseMap<const VPValue *, unsigned> Slots;
unsigned NextSlot = 0;
void assignSlots(const VPBlockBase *VPBB);
void assignSlots(const VPRegionBlock *Region);
void assignSlots(const VPBasicBlock *VPBB);
void assignSlot(const VPValue *V);
void assignSlots(const VPlan &Plan);
VPSlotTracker(const VPlan *Plan = nullptr) {
if (Plan)
unsigned getSlot(const VPValue *V) const {
auto I = Slots.find(V);
if (I == Slots.end())
return -1;
return I->second;
} // namespace llvm