//===-- llvm/Operator.h - Operator utility subclass -------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines various classes for working with Instructions and
// ConstantExprs.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_OPERATOR_H
#define LLVM_IR_OPERATOR_H
#include "llvm/ADT/MapVector.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/FMF.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/Casting.h"
#include <cstddef>
#include <optional>
namespace llvm {
/// This is a utility class that provides an abstraction for the common
/// functionality between Instructions and ConstantExprs.
class Operator : public User {
public:
// The Operator class is intended to be used as a utility, and is never itself
// instantiated.
Operator() = delete;
~Operator() = delete;
void *operator new(size_t s) = delete;
/// Return the opcode for this Instruction or ConstantExpr.
unsigned getOpcode() const {
if (const Instruction *I = dyn_cast<Instruction>(this))
return I->getOpcode();
return cast<ConstantExpr>(this)->getOpcode();
}
/// If V is an Instruction or ConstantExpr, return its opcode.
/// Otherwise return UserOp1.
static unsigned getOpcode(const Value *V) {
if (const Instruction *I = dyn_cast<Instruction>(V))
return I->getOpcode();
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
return CE->getOpcode();
return Instruction::UserOp1;
}
static bool classof(const Instruction *) { return true; }
static bool classof(const ConstantExpr *) { return true; }
static bool classof(const Value *V) {
return isa<Instruction>(V) || isa<ConstantExpr>(V);
}
/// Return true if this operator has flags which may cause this operator
/// to evaluate to poison despite having non-poison inputs.
bool hasPoisonGeneratingFlags() const;
/// Return true if this operator has poison-generating flags or metadata.
/// The latter is only possible for instructions.
bool hasPoisonGeneratingFlagsOrMetadata() const;
};
/// Utility class for integer operators which may exhibit overflow - Add, Sub,
/// Mul, and Shl. It does not include SDiv, despite that operator having the
/// potential for overflow.
class OverflowingBinaryOperator : public Operator {
public:
enum {
AnyWrap = 0,
NoUnsignedWrap = (1 << 0),
NoSignedWrap = (1 << 1)
};
private:
friend class Instruction;
friend class ConstantExpr;
void setHasNoUnsignedWrap(bool B) {
SubclassOptionalData =
(SubclassOptionalData & ~NoUnsignedWrap) | (B * NoUnsignedWrap);
}
void setHasNoSignedWrap(bool B) {
SubclassOptionalData =
(SubclassOptionalData & ~NoSignedWrap) | (B * NoSignedWrap);
}
public:
/// Test whether this operation is known to never
/// undergo unsigned overflow, aka the nuw property.
bool hasNoUnsignedWrap() const {
return SubclassOptionalData & NoUnsignedWrap;
}
/// Test whether this operation is known to never
/// undergo signed overflow, aka the nsw property.
bool hasNoSignedWrap() const {
return (SubclassOptionalData & NoSignedWrap) != 0;
}
static bool classof(const Instruction *I) {
return I->getOpcode() == Instruction::Add ||
I->getOpcode() == Instruction::Sub ||
I->getOpcode() == Instruction::Mul ||
I->getOpcode() == Instruction::Shl;
}
static bool classof(const ConstantExpr *CE) {
return CE->getOpcode() == Instruction::Add ||
CE->getOpcode() == Instruction::Sub ||
CE->getOpcode() == Instruction::Mul ||
CE->getOpcode() == Instruction::Shl;
}
static bool classof(const Value *V) {
return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
(isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
}
};
/// A udiv or sdiv instruction, which can be marked as "exact",
/// indicating that no bits are destroyed.
class PossiblyExactOperator : public Operator {
public:
enum {
IsExact = (1 << 0)
};
private:
friend class Instruction;
friend class ConstantExpr;
void setIsExact(bool B) {
SubclassOptionalData = (SubclassOptionalData & ~IsExact) | (B * IsExact);
}
public:
/// Test whether this division is known to be exact, with zero remainder.
bool isExact() const {
return SubclassOptionalData & IsExact;
}
static bool isPossiblyExactOpcode(unsigned OpC) {
return OpC == Instruction::SDiv ||
OpC == Instruction::UDiv ||
OpC == Instruction::AShr ||
OpC == Instruction::LShr;
}
static bool classof(const ConstantExpr *CE) {
return isPossiblyExactOpcode(CE->getOpcode());
}
static bool classof(const Instruction *I) {
return isPossiblyExactOpcode(I->getOpcode());
}
static bool classof(const Value *V) {
return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
(isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
}
};
/// Utility class for floating point operations which can have
/// information about relaxed accuracy requirements attached to them.
class FPMathOperator : public Operator {
private:
friend class Instruction;
/// 'Fast' means all bits are set.
void setFast(bool B) {
setHasAllowReassoc(B);
setHasNoNaNs(B);
setHasNoInfs(B);
setHasNoSignedZeros(B);
setHasAllowReciprocal(B);
setHasAllowContract(B);
setHasApproxFunc(B);
}
void setHasAllowReassoc(bool B) {
SubclassOptionalData =
(SubclassOptionalData & ~FastMathFlags::AllowReassoc) |
(B * FastMathFlags::AllowReassoc);
}
void setHasNoNaNs(bool B) {
SubclassOptionalData =
(SubclassOptionalData & ~FastMathFlags::NoNaNs) |
(B * FastMathFlags::NoNaNs);
}
void setHasNoInfs(bool B) {
SubclassOptionalData =
(SubclassOptionalData & ~FastMathFlags::NoInfs) |
(B * FastMathFlags::NoInfs);
}
void setHasNoSignedZeros(bool B) {
SubclassOptionalData =
(SubclassOptionalData & ~FastMathFlags::NoSignedZeros) |
(B * FastMathFlags::NoSignedZeros);
}
void setHasAllowReciprocal(bool B) {
SubclassOptionalData =
(SubclassOptionalData & ~FastMathFlags::AllowReciprocal) |
(B * FastMathFlags::AllowReciprocal);
}
void setHasAllowContract(bool B) {
SubclassOptionalData =
(SubclassOptionalData & ~FastMathFlags::AllowContract) |
(B * FastMathFlags::AllowContract);
}
void setHasApproxFunc(bool B) {
SubclassOptionalData =
(SubclassOptionalData & ~FastMathFlags::ApproxFunc) |
(B * FastMathFlags::ApproxFunc);
}
/// Convenience function for setting multiple fast-math flags.
/// FMF is a mask of the bits to set.
void setFastMathFlags(FastMathFlags FMF) {
SubclassOptionalData |= FMF.Flags;
}
/// Convenience function for copying all fast-math flags.
/// All values in FMF are transferred to this operator.
void copyFastMathFlags(FastMathFlags FMF) {
SubclassOptionalData = FMF.Flags;
}
public:
/// Test if this operation allows all non-strict floating-point transforms.
bool isFast() const {
return ((SubclassOptionalData & FastMathFlags::AllowReassoc) != 0 &&
(SubclassOptionalData & FastMathFlags::NoNaNs) != 0 &&
(SubclassOptionalData & FastMathFlags::NoInfs) != 0 &&
(SubclassOptionalData & FastMathFlags::NoSignedZeros) != 0 &&
(SubclassOptionalData & FastMathFlags::AllowReciprocal) != 0 &&
(SubclassOptionalData & FastMathFlags::AllowContract) != 0 &&
(SubclassOptionalData & FastMathFlags::ApproxFunc) != 0);
}
/// Test if this operation may be simplified with reassociative transforms.
bool hasAllowReassoc() const {
return (SubclassOptionalData & FastMathFlags::AllowReassoc) != 0;
}
/// Test if this operation's arguments and results are assumed not-NaN.
bool hasNoNaNs() const {
return (SubclassOptionalData & FastMathFlags::NoNaNs) != 0;
}
/// Test if this operation's arguments and results are assumed not-infinite.
bool hasNoInfs() const {
return (SubclassOptionalData & FastMathFlags::NoInfs) != 0;
}
/// Test if this operation can ignore the sign of zero.
bool hasNoSignedZeros() const {
return (SubclassOptionalData & FastMathFlags::NoSignedZeros) != 0;
}
/// Test if this operation can use reciprocal multiply instead of division.
bool hasAllowReciprocal() const {
return (SubclassOptionalData & FastMathFlags::AllowReciprocal) != 0;
}
/// Test if this operation can be floating-point contracted (FMA).
bool hasAllowContract() const {
return (SubclassOptionalData & FastMathFlags::AllowContract) != 0;
}
/// Test if this operation allows approximations of math library functions or
/// intrinsics.
bool hasApproxFunc() const {
return (SubclassOptionalData & FastMathFlags::ApproxFunc) != 0;
}
/// Convenience function for getting all the fast-math flags
FastMathFlags getFastMathFlags() const {
return FastMathFlags(SubclassOptionalData);
}
/// Get the maximum error permitted by this operation in ULPs. An accuracy of
/// 0.0 means that the operation should be performed with the default
/// precision.
float getFPAccuracy() const;
static bool classof(const Value *V) {
unsigned Opcode;
if (auto *I = dyn_cast<Instruction>(V))
Opcode = I->getOpcode();
else if (auto *CE = dyn_cast<ConstantExpr>(V))
Opcode = CE->getOpcode();
else
return false;
switch (Opcode) {
case Instruction::FNeg:
case Instruction::FAdd:
case Instruction::FSub:
case Instruction::FMul:
case Instruction::FDiv:
case Instruction::FRem:
// FIXME: To clean up and correct the semantics of fast-math-flags, FCmp
// should not be treated as a math op, but the other opcodes should.
// This would make things consistent with Select/PHI (FP value type
// determines whether they are math ops and, therefore, capable of
// having fast-math-flags).
case Instruction::FCmp:
return true;
case Instruction::PHI:
case Instruction::Select:
case Instruction::Call: {
Type *Ty = V->getType();
while (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty))
Ty = ArrTy->getElementType();
return Ty->isFPOrFPVectorTy();
}
default:
return false;
}
}
};
/// A helper template for defining operators for individual opcodes.
template<typename SuperClass, unsigned Opc>
class ConcreteOperator : public SuperClass {
public:
static bool classof(const Instruction *I) {
return I->getOpcode() == Opc;
}
static bool classof(const ConstantExpr *CE) {
return CE->getOpcode() == Opc;
}
static bool classof(const Value *V) {
return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
(isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
}
};
class AddOperator
: public ConcreteOperator<OverflowingBinaryOperator, Instruction::Add> {
};
class SubOperator
: public ConcreteOperator<OverflowingBinaryOperator, Instruction::Sub> {
};
class MulOperator
: public ConcreteOperator<OverflowingBinaryOperator, Instruction::Mul> {
};
class ShlOperator
: public ConcreteOperator<OverflowingBinaryOperator, Instruction::Shl> {
};
class SDivOperator
: public ConcreteOperator<PossiblyExactOperator, Instruction::SDiv> {
};
class UDivOperator
: public ConcreteOperator<PossiblyExactOperator, Instruction::UDiv> {
};
class AShrOperator
: public ConcreteOperator<PossiblyExactOperator, Instruction::AShr> {
};
class LShrOperator
: public ConcreteOperator<PossiblyExactOperator, Instruction::LShr> {
};
class ZExtOperator : public ConcreteOperator<Operator, Instruction::ZExt> {};
class GEPOperator
: public ConcreteOperator<Operator, Instruction::GetElementPtr> {
friend class GetElementPtrInst;
friend class ConstantExpr;
enum {
IsInBounds = (1 << 0),
// InRangeIndex: bits 1-6
};
void setIsInBounds(bool B) {
SubclassOptionalData =
(SubclassOptionalData & ~IsInBounds) | (B * IsInBounds);
}
public:
/// Test whether this is an inbounds GEP, as defined by LangRef.html.
bool isInBounds() const {
return SubclassOptionalData & IsInBounds;
}
/// Returns the offset of the index with an inrange attachment, or
/// std::nullopt if none.
std::optional<unsigned> getInRangeIndex() const {
if (SubclassOptionalData >> 1 == 0)
return std::nullopt;
return (SubclassOptionalData >> 1) - 1;
}
inline op_iterator idx_begin() { return op_begin()+1; }
inline const_op_iterator idx_begin() const { return op_begin()+1; }
inline op_iterator idx_end() { return op_end(); }
inline const_op_iterator idx_end() const { return op_end(); }
inline iterator_range<op_iterator> indices() {
return make_range(idx_begin(), idx_end());
}
inline iterator_range<const_op_iterator> indices() const {
return make_range(idx_begin(), idx_end());
}
Value *getPointerOperand() {
return getOperand(0);
}
const Value *getPointerOperand() const {
return getOperand(0);
}
static unsigned getPointerOperandIndex() {
return 0U; // get index for modifying correct operand
}
/// Method to return the pointer operand as a PointerType.
Type *getPointerOperandType() const {
return getPointerOperand()->getType();
}
Type *getSourceElementType() const;
Type *getResultElementType() const;
/// Method to return the address space of the pointer operand.
unsigned getPointerAddressSpace() const {
return getPointerOperandType()->getPointerAddressSpace();
}
unsigned getNumIndices() const { // Note: always non-negative
return getNumOperands() - 1;
}
bool hasIndices() const {
return getNumOperands() > 1;
}
/// Return true if all of the indices of this GEP are zeros.
/// If so, the result pointer and the first operand have the same
/// value, just potentially different types.
bool hasAllZeroIndices() const {
for (const_op_iterator I = idx_begin(), E = idx_end(); I != E; ++I) {
if (ConstantInt *C = dyn_cast<ConstantInt>(I))
if (C->isZero())
continue;
return false;
}
return true;
}
/// Return true if all of the indices of this GEP are constant integers.
/// If so, the result pointer and the first operand have
/// a constant offset between them.
bool hasAllConstantIndices() const {
for (const_op_iterator I = idx_begin(), E = idx_end(); I != E; ++I) {
if (!isa<ConstantInt>(I))
return false;
}
return true;
}
unsigned countNonConstantIndices() const {
return count_if(indices(), [](const Use& use) {
return !isa<ConstantInt>(*use);
});
}
/// Compute the maximum alignment that this GEP is garranteed to preserve.
Align getMaxPreservedAlignment(const DataLayout &DL) const;
/// Accumulate the constant address offset of this GEP if possible.
///
/// This routine accepts an APInt into which it will try to accumulate the
/// constant offset of this GEP.
///
/// If \p ExternalAnalysis is provided it will be used to calculate a offset
/// when a operand of GEP is not constant.
/// For example, for a value \p ExternalAnalysis might try to calculate a
/// lower bound. If \p ExternalAnalysis is successful, it should return true.
///
/// If the \p ExternalAnalysis returns false or the value returned by \p
/// ExternalAnalysis results in a overflow/underflow, this routine returns
/// false and the value of the offset APInt is undefined (it is *not*
/// preserved!).
///
/// The APInt passed into this routine must be at exactly as wide as the
/// IntPtr type for the address space of the base GEP pointer.
bool accumulateConstantOffset(
const DataLayout &DL, APInt &Offset,
function_ref<bool(Value &, APInt &)> ExternalAnalysis = nullptr) const;
static bool accumulateConstantOffset(
Type *SourceType, ArrayRef<const Value *> Index, const DataLayout &DL,
APInt &Offset,
function_ref<bool(Value &, APInt &)> ExternalAnalysis = nullptr);
/// Collect the offset of this GEP as a map of Values to their associated
/// APInt multipliers, as well as a total Constant Offset.
bool collectOffset(const DataLayout &DL, unsigned BitWidth,
MapVector<Value *, APInt> &VariableOffsets,
APInt &ConstantOffset) const;
};
class PtrToIntOperator
: public ConcreteOperator<Operator, Instruction::PtrToInt> {
friend class PtrToInt;
friend class ConstantExpr;
public:
Value *getPointerOperand() {
return getOperand(0);
}
const Value *getPointerOperand() const {
return getOperand(0);
}
static unsigned getPointerOperandIndex() {
return 0U; // get index for modifying correct operand
}
/// Method to return the pointer operand as a PointerType.
Type *getPointerOperandType() const {
return getPointerOperand()->getType();
}
/// Method to return the address space of the pointer operand.
unsigned getPointerAddressSpace() const {
return cast<PointerType>(getPointerOperandType())->getAddressSpace();
}
};
class BitCastOperator
: public ConcreteOperator<Operator, Instruction::BitCast> {
friend class BitCastInst;
friend class ConstantExpr;
public:
Type *getSrcTy() const {
return getOperand(0)->getType();
}
Type *getDestTy() const {
return getType();
}
};
class AddrSpaceCastOperator
: public ConcreteOperator<Operator, Instruction::AddrSpaceCast> {
friend class AddrSpaceCastInst;
friend class ConstantExpr;
public:
Value *getPointerOperand() { return getOperand(0); }
const Value *getPointerOperand() const { return getOperand(0); }
unsigned getSrcAddressSpace() const {
return getPointerOperand()->getType()->getPointerAddressSpace();
}
unsigned getDestAddressSpace() const {
return getType()->getPointerAddressSpace();
}
};
} // end namespace llvm
#endif // LLVM_IR_OPERATOR_H