llvm-6502/include/llvm/Instruction.h
Dan Gohman f451cb870e Fix "the the" and similar typos.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95781 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-10 16:03:48 +00:00

362 lines
14 KiB
C++

//===-- llvm/Instruction.h - Instruction class definition -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the declaration of the Instruction class, which is the
// base class for all of the LLVM instructions.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_INSTRUCTION_H
#define LLVM_INSTRUCTION_H
#include "llvm/User.h"
#include "llvm/ADT/ilist_node.h"
namespace llvm {
class LLVMContext;
class MDNode;
template<typename ValueSubClass, typename ItemParentClass>
class SymbolTableListTraits;
class Instruction : public User, public ilist_node<Instruction> {
void operator=(const Instruction &); // Do not implement
Instruction(const Instruction &); // Do not implement
BasicBlock *Parent;
enum {
/// HasMetadataBit - This is a bit stored in the SubClassData field which
/// indicates whether this instruction has metadata attached to it or not.
HasMetadataBit = 1 << 15
};
public:
// Out of line virtual method, so the vtable, etc has a home.
~Instruction();
/// use_back - Specialize the methods defined in Value, as we know that an
/// instruction can only be used by other instructions.
Instruction *use_back() { return cast<Instruction>(*use_begin());}
const Instruction *use_back() const { return cast<Instruction>(*use_begin());}
inline const BasicBlock *getParent() const { return Parent; }
inline BasicBlock *getParent() { return Parent; }
/// removeFromParent - This method unlinks 'this' from the containing basic
/// block, but does not delete it.
///
void removeFromParent();
/// eraseFromParent - This method unlinks 'this' from the containing basic
/// block and deletes it.
///
void eraseFromParent();
/// insertBefore - Insert an unlinked instructions into a basic block
/// immediately before the specified instruction.
void insertBefore(Instruction *InsertPos);
/// insertAfter - Insert an unlinked instructions into a basic block
/// immediately after the specified instruction.
void insertAfter(Instruction *InsertPos);
/// moveBefore - Unlink this instruction from its current basic block and
/// insert it into the basic block that MovePos lives in, right before
/// MovePos.
void moveBefore(Instruction *MovePos);
//===--------------------------------------------------------------------===//
// Subclass classification.
//===--------------------------------------------------------------------===//
/// getOpcode() returns a member of one of the enums like Instruction::Add.
unsigned getOpcode() const { return getValueID() - InstructionVal; }
const char *getOpcodeName() const { return getOpcodeName(getOpcode()); }
bool isTerminator() const { return isTerminator(getOpcode()); }
bool isBinaryOp() const { return isBinaryOp(getOpcode()); }
bool isShift() { return isShift(getOpcode()); }
bool isCast() const { return isCast(getOpcode()); }
static const char* getOpcodeName(unsigned OpCode);
static inline bool isTerminator(unsigned OpCode) {
return OpCode >= TermOpsBegin && OpCode < TermOpsEnd;
}
static inline bool isBinaryOp(unsigned Opcode) {
return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd;
}
/// @brief Determine if the Opcode is one of the shift instructions.
static inline bool isShift(unsigned Opcode) {
return Opcode >= Shl && Opcode <= AShr;
}
/// isLogicalShift - Return true if this is a logical shift left or a logical
/// shift right.
inline bool isLogicalShift() const {
return getOpcode() == Shl || getOpcode() == LShr;
}
/// isArithmeticShift - Return true if this is an arithmetic shift right.
inline bool isArithmeticShift() const {
return getOpcode() == AShr;
}
/// @brief Determine if the OpCode is one of the CastInst instructions.
static inline bool isCast(unsigned OpCode) {
return OpCode >= CastOpsBegin && OpCode < CastOpsEnd;
}
//===--------------------------------------------------------------------===//
// Metadata manipulation.
//===--------------------------------------------------------------------===//
/// hasMetadata() - Return true if this instruction has any metadata attached
/// to it.
bool hasMetadata() const {
return (getSubclassDataFromValue() & HasMetadataBit) != 0;
}
/// getMetadata - Get the metadata of given kind attached to this Instruction.
/// If the metadata is not found then return null.
MDNode *getMetadata(unsigned KindID) const {
if (!hasMetadata()) return 0;
return getMetadataImpl(KindID);
}
/// getMetadata - Get the metadata of given kind attached to this Instruction.
/// If the metadata is not found then return null.
MDNode *getMetadata(const char *Kind) const {
if (!hasMetadata()) return 0;
return getMetadataImpl(Kind);
}
/// getAllMetadata - Get all metadata attached to this Instruction. The first
/// element of each pair returned is the KindID, the second element is the
/// metadata value. This list is returned sorted by the KindID.
void getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode*> > &MDs)const{
if (hasMetadata())
getAllMetadataImpl(MDs);
}
/// setMetadata - Set the metadata of the specified kind to the specified
/// node. This updates/replaces metadata if already present, or removes it if
/// Node is null.
void setMetadata(unsigned KindID, MDNode *Node);
void setMetadata(const char *Kind, MDNode *Node);
private:
// These are all implemented in Metadata.cpp.
MDNode *getMetadataImpl(unsigned KindID) const;
MDNode *getMetadataImpl(const char *Kind) const;
void getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned,MDNode*> > &)const;
void removeAllMetadata();
public:
//===--------------------------------------------------------------------===//
// Predicates and helper methods.
//===--------------------------------------------------------------------===//
/// isAssociative - Return true if the instruction is associative:
///
/// Associative operators satisfy: x op (y op z) === (x op y) op z
///
/// In LLVM, the Add, Mul, And, Or, and Xor operators are associative, when
/// not applied to floating point types.
///
bool isAssociative() const { return isAssociative(getOpcode(), getType()); }
static bool isAssociative(unsigned op, const Type *Ty);
/// isCommutative - Return true if the instruction is commutative:
///
/// Commutative operators satisfy: (x op y) === (y op x)
///
/// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
/// applied to any type.
///
bool isCommutative() const { return isCommutative(getOpcode()); }
static bool isCommutative(unsigned op);
/// mayWriteToMemory - Return true if this instruction may modify memory.
///
bool mayWriteToMemory() const;
/// mayReadFromMemory - Return true if this instruction may read memory.
///
bool mayReadFromMemory() const;
/// mayThrow - Return true if this instruction may throw an exception.
///
bool mayThrow() const;
/// mayHaveSideEffects - Return true if the instruction may have side effects.
///
/// Note that this does not consider malloc and alloca to have side
/// effects because the newly allocated memory is completely invisible to
/// instructions which don't used the returned value. For cases where this
/// matters, isSafeToSpeculativelyExecute may be more appropriate.
bool mayHaveSideEffects() const {
return mayWriteToMemory() || mayThrow();
}
/// isSafeToSpeculativelyExecute - Return true if the instruction does not
/// have any effects besides calculating the result and does not have
/// undefined behavior.
///
/// This method never returns true for an instruction that returns true for
/// mayHaveSideEffects; however, this method also does some other checks in
/// addition. It checks for undefined behavior, like dividing by zero or
/// loading from an invalid pointer (but not for undefined results, like a
/// shift with a shift amount larger than the width of the result). It checks
/// for malloc and alloca because speculatively executing them might cause a
/// memory leak. It also returns false for instructions related to control
/// flow, specifically terminators and PHI nodes.
///
/// This method only looks at the instruction itself and its operands, so if
/// this method returns true, it is safe to move the instruction as long as
/// the correct dominance relationships for the operands and users hold.
/// However, this method can return true for instructions that read memory;
/// for such instructions, moving them may change the resulting value.
bool isSafeToSpeculativelyExecute() const;
/// clone() - Create a copy of 'this' instruction that is identical in all
/// ways except the following:
/// * The instruction has no parent
/// * The instruction has no name
///
Instruction *clone() const;
/// isIdenticalTo - Return true if the specified instruction is exactly
/// identical to the current one. This means that all operands match and any
/// extra information (e.g. load is volatile) agree.
bool isIdenticalTo(const Instruction *I) const;
/// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
/// ignores the SubclassOptionalData flags, which specify conditions
/// under which the instruction's result is undefined.
bool isIdenticalToWhenDefined(const Instruction *I) const;
/// This function determines if the specified instruction executes the same
/// operation as the current one. This means that the opcodes, type, operand
/// types and any other factors affecting the operation must be the same. This
/// is similar to isIdenticalTo except the operands themselves don't have to
/// be identical.
/// @returns true if the specified instruction is the same operation as
/// the current one.
/// @brief Determine if one instruction is the same operation as another.
bool isSameOperationAs(const Instruction *I) const;
/// isUsedOutsideOfBlock - Return true if there are any uses of this
/// instruction in blocks other than the specified block. Note that PHI nodes
/// are considered to evaluate their operands in the corresponding predecessor
/// block.
bool isUsedOutsideOfBlock(const BasicBlock *BB) const;
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const Instruction *) { return true; }
static inline bool classof(const Value *V) {
return V->getValueID() >= Value::InstructionVal;
}
//----------------------------------------------------------------------
// Exported enumerations.
//
enum TermOps { // These terminate basic blocks
#define FIRST_TERM_INST(N) TermOpsBegin = N,
#define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N,
#define LAST_TERM_INST(N) TermOpsEnd = N+1
#include "llvm/Instruction.def"
};
enum BinaryOps {
#define FIRST_BINARY_INST(N) BinaryOpsBegin = N,
#define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N,
#define LAST_BINARY_INST(N) BinaryOpsEnd = N+1
#include "llvm/Instruction.def"
};
enum MemoryOps {
#define FIRST_MEMORY_INST(N) MemoryOpsBegin = N,
#define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N,
#define LAST_MEMORY_INST(N) MemoryOpsEnd = N+1
#include "llvm/Instruction.def"
};
enum CastOps {
#define FIRST_CAST_INST(N) CastOpsBegin = N,
#define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N,
#define LAST_CAST_INST(N) CastOpsEnd = N+1
#include "llvm/Instruction.def"
};
enum OtherOps {
#define FIRST_OTHER_INST(N) OtherOpsBegin = N,
#define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N,
#define LAST_OTHER_INST(N) OtherOpsEnd = N+1
#include "llvm/Instruction.def"
};
private:
// Shadow Value::setValueSubclassData with a private forwarding method so that
// subclasses cannot accidentally use it.
void setValueSubclassData(unsigned short D) {
Value::setValueSubclassData(D);
}
unsigned short getSubclassDataFromValue() const {
return Value::getSubclassDataFromValue();
}
void setHasMetadata(bool V) {
setValueSubclassData((getSubclassDataFromValue() & ~HasMetadataBit) |
(V ? HasMetadataBit : 0));
}
friend class SymbolTableListTraits<Instruction, BasicBlock>;
void setParent(BasicBlock *P);
protected:
// Instruction subclasses can stick up to 15 bits of stuff into the
// SubclassData field of instruction with these members.
// Verify that only the low 15 bits are used.
void setInstructionSubclassData(unsigned short D) {
assert((D & HasMetadataBit) == 0 && "Out of range value put into field");
setValueSubclassData((getSubclassDataFromValue() & HasMetadataBit) | D);
}
unsigned getSubclassDataFromInstruction() const {
return getSubclassDataFromValue() & ~HasMetadataBit;
}
Instruction(const Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
Instruction *InsertBefore = 0);
Instruction(const Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
BasicBlock *InsertAtEnd);
virtual Instruction *clone_impl() const = 0;
};
// Instruction* is only 4-byte aligned.
template<>
class PointerLikeTypeTraits<Instruction*> {
typedef Instruction* PT;
public:
static inline void *getAsVoidPointer(PT P) { return P; }
static inline PT getFromVoidPointer(void *P) {
return static_cast<PT>(P);
}
enum { NumLowBitsAvailable = 2 };
};
} // End llvm namespace
#endif