llvm-mirror/lib/VMCore/iBranch.cpp

//===-- iBranch.cpp - Implement the Branch instruction -----------*- C++ -*--=//
//
// This file implements the 'br' instruction, which can represent either a 
// conditional or unconditional branch.
//
//===----------------------------------------------------------------------===//

#include "llvm/iTerminators.h"
#include "llvm/BasicBlock.h"
#ifndef NDEBUG
#include "llvm/Type.h"       // Only used for assertions...
#include "llvm/Assembly/Writer.h"
#endif

BranchInst::BranchInst(BasicBlock *True, BasicBlock *False, Value *Cond) 
  : TerminatorInst(Instruction::Br) {
  assert(True != 0 && "True branch destination may not be null!!!");
  Operands.reserve(False ? 3 : 1);
  Operands.push_back(Use(True, this));
  if (False) {
    Operands.push_back(Use(False, this));
    Operands.push_back(Use(Cond, this));
  }

  assert(!!False == !!Cond &&
	 "Either both cond and false or neither can be specified!");

#ifndef NDEBUG
  if (Cond != 0 && Cond->getType() != Type::BoolTy)
    cerr << "Bad Condition: " << Cond << endl;
#endif
  assert((Cond == 0 || Cond->getType() == Type::BoolTy) && 
         "May only branch on boolean predicates!!!!");
}

BranchInst::BranchInst(const BranchInst &BI) : TerminatorInst(Instruction::Br) {
  Operands.reserve(BI.Operands.size());
  Operands.push_back(Use(BI.Operands[0], this));
  if (BI.Operands.size() != 1) {
    assert(BI.Operands.size() == 3 && "BR can have 1 or 3 operands!");
    Operands.push_back(Use(BI.Operands[1], this));
    Operands.push_back(Use(BI.Operands[2], this));
  }
}