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//===-- llvm/iPHINode.h - PHI instruction definition -------------*- C++ -*--=//
//
// This file defines the PHINode class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IPHINODE_H
#define LLVM_IPHINODE_H
#include "llvm/Instruction.h"
class BasicBlock;
//===----------------------------------------------------------------------===//
// PHINode Class
//===----------------------------------------------------------------------===//
// PHINode - The PHINode class is used to represent the magical mystical PHI
// node, that can not exist in nature, but can be synthesized in a computer
// scientist's overactive imagination.
//
class PHINode : public Instruction {
PHINode(const PHINode &PN);
public:
PHINode(const Type *Ty, const std::string &Name = "",
Instruction *InsertBefore = 0)
: Instruction(Ty, Instruction::PHINode, Name, InsertBefore) {
}
virtual Instruction *clone() const { return new PHINode(*this); }
/// getNumIncomingValues - Return the number of incoming edges the PHI node
/// has
unsigned getNumIncomingValues() const { return Operands.size()/2; }
/// getIncomingValue - Return incoming value #x
Value *getIncomingValue(unsigned i) const {
assert(i*2 < Operands.size() && "Invalid value number!");
return Operands[i*2];
}
void setIncomingValue(unsigned i, Value *V) {
assert(i*2 < Operands.size() && "Invalid value number!");
Operands[i*2] = V;
}
inline unsigned getOperandNumForIncomingValue(unsigned i) {
return i*2;
}
/// getIncomingBlock - Return incoming basic block #x
BasicBlock *getIncomingBlock(unsigned i) const {
assert(i*2+1 < Operands.size() && "Invalid value number!");
return (BasicBlock*)Operands[i*2+1].get();
}
void setIncomingBlock(unsigned i, BasicBlock *BB) {
assert(i*2+1 < Operands.size() && "Invalid value number!");
Operands[i*2+1] = (Value*)BB;
}
unsigned getOperandNumForIncomingBlock(unsigned i) {
return i*2+1;
}
/// addIncoming - Add an incoming value to the end of the PHI list
void addIncoming(Value *D, BasicBlock *BB) {
assert(getType() == D->getType() &&
"All operands to PHI node must be the same type as the PHI node!");
Operands.push_back(Use(D, this));
Operands.push_back(Use((Value*)BB, this));
}
/// removeIncomingValue - Remove an incoming value. This is useful if a
/// predecessor basic block is deleted. The value removed is returned.
///
/// If the last incoming value for a PHI node is removed (and DeletePHIIfEmpty
/// is true), the PHI node is destroyed and any uses of it are replaced with
/// dummy values. The only time there should be zero incoming values to a PHI
/// node is when the block is dead, so this strategy is sound.
///
Value *removeIncomingValue(unsigned Idx, bool DeletePHIIfEmpty = true);
Value *removeIncomingValue(const BasicBlock *BB, bool DeletePHIIfEmpty =true){
int Idx = getBasicBlockIndex(BB);
assert(Idx >= 0 && "Invalid basic block argument to remove!");
return removeIncomingValue(Idx, DeletePHIIfEmpty);
}
/// getBasicBlockIndex - Return the first index of the specified basic
/// block in the value list for this PHI. Returns -1 if no instance.
///
int getBasicBlockIndex(const BasicBlock *BB) const {
for (unsigned i = 0; i < Operands.size()/2; ++i)
if (getIncomingBlock(i) == BB) return i;
return -1;
}
Value *getIncomingValueForBlock(const BasicBlock *BB) const {
return getIncomingValue(getBasicBlockIndex(BB));
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const PHINode *) { return true; }
static inline bool classof(const Instruction *I) {
return I->getOpcode() == Instruction::PHINode;
}
static inline bool classof(const Value *V) {
return isa<Instruction>(V) && classof(cast<Instruction>(V));
}
};
#endif
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