path: root/lib/VMCore/Instructions.cpp

//===-- Instructions.cpp - Implement the LLVM instructions ----------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements all of the non-inline methods for the LLVM instruction
// classes.
//
//===----------------------------------------------------------------------===//

#include "llvm/BasicBlock.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/Instructions.h"
#include "llvm/Support/CallSite.h"
using namespace llvm;

unsigned CallSite::getCallingConv() const {
  if (CallInst *CI = dyn_cast<CallInst>(I))
    return CI->getCallingConv();
  else
    return cast<InvokeInst>(I)->getCallingConv();
}
void CallSite::setCallingConv(unsigned CC) {
  if (CallInst *CI = dyn_cast<CallInst>(I))
    CI->setCallingConv(CC);
  else
    cast<InvokeInst>(I)->setCallingConv(CC);
}


//===----------------------------------------------------------------------===//
//                            TerminatorInst Class
//===----------------------------------------------------------------------===//

TerminatorInst::TerminatorInst(Instruction::TermOps iType,
                               Use *Ops, unsigned NumOps, Instruction *IB)
  : Instruction(Type::VoidTy, iType, Ops, NumOps, "", IB) {
}

TerminatorInst::TerminatorInst(Instruction::TermOps iType,
                               Use *Ops, unsigned NumOps, BasicBlock *IAE)
  : Instruction(Type::VoidTy, iType, Ops, NumOps, "", IAE) {
}



//===----------------------------------------------------------------------===//
//                               PHINode Class
//===----------------------------------------------------------------------===//

PHINode::PHINode(const PHINode &PN)
  : Instruction(PN.getType(), Instruction::PHI,
                new Use[PN.getNumOperands()], PN.getNumOperands()),
    ReservedSpace(PN.getNumOperands()) {
  Use *OL = OperandList;
  for (unsigned i = 0, e = PN.getNumOperands(); i != e; i+=2) {
    OL[i].init(PN.getOperand(i), this);
    OL[i+1].init(PN.getOperand(i+1), this);
  }
}

PHINode::~PHINode() {
  delete [] OperandList;
}

// removeIncomingValue - Remove an incoming value.  This is useful if a
// predecessor basic block is deleted.
Value *PHINode::removeIncomingValue(unsigned Idx, bool DeletePHIIfEmpty) {
  unsigned NumOps = getNumOperands();
  Use *OL = OperandList;
  assert(Idx*2 < NumOps && "BB not in PHI node!");
  Value *Removed = OL[Idx*2];

  // Move everything after this operand down.
  //
  // FIXME: we could just swap with the end of the list, then erase.  However,
  // client might not expect this to happen.  The code as it is thrashes the
  // use/def lists, which is kinda lame.
  for (unsigned i = (Idx+1)*2; i != NumOps; i += 2) {
    OL[i-2] = OL[i];
    OL[i-2+1] = OL[i+1];
  }

  // Nuke the last value.
  OL[NumOps-2].set(0);
  OL[NumOps-2+1].set(0);
  NumOperands = NumOps-2;

  // If the PHI node is dead, because it has zero entries, nuke it now.
  if (NumOps == 2 && DeletePHIIfEmpty) {
    // If anyone is using this PHI, make them use a dummy value instead...
    replaceAllUsesWith(UndefValue::get(getType()));
    eraseFromParent();
  }
  return Removed;
}

/// resizeOperands - resize operands - This adjusts the length of the operands
/// list accord