llvm-6502/include/llvm/IR/Instruction.h
Chandler Carruth 36b699f2b1 [C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
   detail
2) Change it to actually be a *Use* iterator rather than a *User*
   iterator.
3) Add an adaptor which is a User iterator that always looks through the
   Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
   they wanted a use_iterator (and to explicitly dig out the User when
   needed), or a user_iterator which makes the Use itself totally
   opaque.

Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.

The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.

However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203364 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-09 03:16:01 +00:00

486 lines
18 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_IR_INSTRUCTION_H
#define LLVM_IR_INSTRUCTION_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/ilist_node.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/User.h"
namespace llvm {
class FastMathFlags;
class LLVMContext;
class MDNode;
template<typename ValueSubClass, typename ItemParentClass>
class SymbolTableListTraits;
class Instruction : public User, public ilist_node<Instruction> {
void operator=(const Instruction &) LLVM_DELETED_FUNCTION;
Instruction(const Instruction &) LLVM_DELETED_FUNCTION;
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();
/// user_back - Specialize the methods defined in Value, as we know that an
/// instruction can only be used by other instructions.
Instruction *user_back() { return cast<Instruction>(*user_begin());}
const Instruction *user_back() const { return cast<Instruction>(*user_begin());}
inline const BasicBlock *getParent() const { return Parent; }
inline BasicBlock *getParent() { return Parent; }
const DataLayout *getDataLayout() const;
/// 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);
/// \brief Drop unknown metadata.
/// Passes are required to drop metadata they don't understand. This is a
/// convenience method for passes to do so.
void dropUnknownMetadata(ArrayRef<unsigned> KnownIDs);
void dropUnknownMetadata() {
return dropUnknownMetadata(ArrayRef<unsigned>());
}
void dropUnknownMetadata(unsigned ID1) {
return dropUnknownMetadata(makeArrayRef(ID1));
}
void dropUnknownMetadata(unsigned ID1, unsigned ID2) {
unsigned IDs[] = {ID1, ID2};
return dropUnknownMetadata(IDs);
}
/// 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; }
/// Set or clear the unsafe-algebra flag on this instruction, which must be an
/// operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasUnsafeAlgebra(bool B);
/// Set or clear the no-nans flag on this instruction, which must be an
/// operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasNoNaNs(bool B);
/// Set or clear the no-infs flag on this instruction, which must be an
/// operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasNoInfs(bool B);
/// Set or clear the no-signed-zeros flag on this instruction, which must be
/// an operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasNoSignedZeros(bool B);
/// Set or clear the allow-reciprocal flag on this instruction, which must be
/// an operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasAllowReciprocal(bool B);
/// Convenience function for setting all the fast-math flags on this
/// instruction, which must be an operator which supports these flags. See
/// LangRef.html for the meaning of these flats.
void setFastMathFlags(FastMathFlags FMF);
/// Determine whether the unsafe-algebra flag is set.
bool hasUnsafeAlgebra() const;
/// Determine whether the no-NaNs flag is set.
bool hasNoNaNs() const;
/// Determine whether the no-infs flag is set.
bool hasNoInfs() const;
/// Determine whether the no-signed-zeros flag is set.
bool hasNoSignedZeros() const;
/// Determine whether the allow-reciprocal flag is set.
bool hasAllowReciprocal() const;
/// Convenience function for getting all the fast-math flags, which must be an
/// operator which supports these flags. See LangRef.html for the meaning of
/// these flats.
FastMathFlags getFastMathFlags() const;
/// Copy I's fast-math flags
void copyFastMathFlags(const Instruction *I);
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;
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);
/// isIdempotent - Return true if the instruction is idempotent:
///
/// Idempotent operators satisfy: x op x === x
///
/// In LLVM, the And and Or operators are idempotent.
///
bool isIdempotent() const { return isIdempotent(getOpcode()); }
static bool isIdempotent(unsigned op);
/// isNilpotent - Return true if the instruction is nilpotent:
///
/// Nilpotent operators satisfy: x op x === Id,
///
/// where Id is the identity for the operator, i.e. a constant such that
/// x op Id === x and Id op x === x for all x.
///
/// In LLVM, the Xor operator is nilpotent.
///
bool isNilpotent() const { return isNilpotent(getOpcode()); }
static bool isNilpotent(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;
/// mayReturn - Return true if this is a function that may return.
/// this is true for all normal instructions. The only exception
/// is functions that are marked with the 'noreturn' attribute.
///
bool mayReturn() 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() || !mayReturn();
}
/// 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;
/// When checking for operation equivalence (using isSameOperationAs) it is
/// sometimes useful to ignore certain attributes.
enum OperationEquivalenceFlags {
/// Check for equivalence ignoring load/store alignment.
CompareIgnoringAlignment = 1<<0,
/// Check for equivalence treating a type and a vector of that type
/// as equivalent.
CompareUsingScalarTypes = 1<<1
};
/// 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, unsigned flags = 0) 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 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/IR/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/IR/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/IR/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/IR/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/IR/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