//===-- MachineCodeForInstruction.cpp -------------------------------------===//
//
//   Representation of the sequence of machine instructions created
//   for a single VM instruction.  Additionally records information
//   about hidden and implicit values used by the machine instructions:
//   about hidden values used by the machine instructions:
// 
//   "Temporary values" are intermediate values used in the machine
//   instruction sequence, but not in the VM instruction
//   Note that such values should be treated as pure SSA values with
//   no interpretation of their operands (i.e., as a TmpInstruction
//   object which actually represents such a value).
// 
//   (2) "Implicit uses" are values used in the VM instruction but not in
//       the machine instruction sequence
// 
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/MachineCodeForInstruction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/InstrSelection.h"

static AnnotationID MCFI_AID(
             AnnotationManager::getID("CodeGen::MachineCodeForInstruction"));

static Annotation *CreateMCFI(AnnotationID AID, const Annotable *, void *) {
  assert(AID == MCFI_AID);
  return new MachineCodeForInstruction();  // Invoke constructor!
}

// Register the annotation with the annotation factory
static struct Initializer {
  Initializer() {
    AnnotationManager::registerAnnotationFactory(MCFI_AID, &CreateMCFI);
  }
} RegisterAID;


MachineCodeForInstruction&
MachineCodeForInstruction::get(const Instruction *I){
  return *(MachineCodeForInstruction*)I->getOrCreateAnnotation(MCFI_AID);
}


void
MachineCodeForInstruction::destroy(const Instruction *I) {
  I->deleteAnnotation(MCFI_AID);
}


void
MachineCodeForInstruction::dropAllReferences()
{
  for (unsigned i=0, N=tempVec.size(); i < N; i++)
    cast<TmpInstruction>(tempVec[i])->dropAllReferences();
}


MachineCodeForInstruction::MachineCodeForInstruction()
  : Annotation(MCFI_AID)
{}


MachineCodeForInstruction::~MachineCodeForInstruction()
{
  // Let go of all uses in temp. instructions
  dropAllReferences();
  
  // Free the Value objects created to hold intermediate values
  for (unsigned i=0, N=tempVec.size(); i < N; i++)
    delete tempVec[i];
  
  // Free the MachineInstr objects allocated, if any.
  for (unsigned i=0, N = size(); i < N; i++)
    delete (*this)[i];
}