llvm-6502/include/llvm/Instruction.h
Dan Gohman f042660197 Move Instruction::isSafeToSpeculativelyExecute out of VMCore and
into Analysis as a standalone function, since there's no need for
it to be in VMCore. Also, update it to use isKnownNonZero and
other goodies available in Analysis, making it more precise,
enabling more aggressive optimization.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146610 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-14 23:49:11 +00:00

378 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"
#include "llvm/Support/DebugLoc.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;
DebugLoc DbgLoc; // 'dbg' Metadata cache.
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 !DbgLoc.isUnknown() || hasMetadataHashEntry();
}
/// hasMetadataOtherThanDebugLoc - Return true if this instruction has
/// metadata attached to it other than a debug location.
bool hasMetadataOtherThanDebugLoc() const {
return hasMetadataHashEntry();
}
/// 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(StringRef 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);
}
/// getAllMetadataOtherThanDebugLoc - This does the same thing as
/// getAllMetadata, except that it filters out the debug location.
void getAllMetadataOtherThanDebugLoc(SmallVectorImpl<std::pair<unsigned,
MDNode*> > &MDs) const {
if (hasMetadataOtherThanDebugLoc())
getAllMetadataOtherThanDebugLocImpl(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(StringRef Kind, MDNode *Node);
/// setDebugLoc - Set the debug location information for this instruction.
void setDebugLoc(const DebugLoc &Loc) { DbgLoc = Loc; }
/// getDebugLoc - Return the debug location for this node as a DebugLoc.
const DebugLoc &getDebugLoc() const { return DbgLoc; }
private:
/// hasMetadataHashEntry - Return true if we have an entry in the on-the-side
/// metadata hash.
bool hasMetadataHashEntry() const {
return (getSubclassDataFromValue() & HasMetadataBit) != 0;
}
// These are all implemented in Metadata.cpp.
MDNode *getMetadataImpl(unsigned KindID) const;
MDNode *getMetadataImpl(StringRef Kind) const;
void getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned,MDNode*> > &)const;
void getAllMetadataOtherThanDebugLocImpl(SmallVectorImpl<std::pair<unsigned,
MDNode*> > &) const;
void clearMetadataHashEntries();
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.
///
bool isAssociative() const { return isAssociative(getOpcode()); }
static bool isAssociative(unsigned op);
/// 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;
/// mayReadOrWriteMemory - Return true if this instruction may read or
/// write memory.
///
bool mayReadOrWriteMemory() const {
return mayReadFromMemory() || mayWriteToMemory();
}
/// 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();
}
/// 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 setHasMetadataHashEntry(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(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
Instruction *InsertBefore = 0);
Instruction(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