path: root/lib/Target/X86/X86FrameLowering.cpp

//=======- X86FrameLowering.cpp - X86 Frame Information --------*- 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 X86 implementation of TargetFrameLowering class.
//
//===----------------------------------------------------------------------===//

#include "X86FrameLowering.h"
#include "X86InstrBuilder.h"
#include "X86InstrInfo.h"
#include "X86MachineFunctionInfo.h"
#include "X86TargetMachine.h"
#include "llvm/Function.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/ADT/SmallSet.h"

using namespace llvm;

// FIXME: completely move here.
extern cl::opt<bool> ForceStackAlign;

bool X86FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
  return !MF.getFrameInfo()->hasVarSizedObjects();
}

/// hasFP - Return true if the specified function should have a dedicated frame
/// pointer register.  This is true if the function has variable sized allocas
/// or if frame pointer elimination is disabled.
bool X86FrameLowering::hasFP(const MachineFunction &MF) const {
  const MachineFrameInfo *MFI = MF.getFrameInfo();
  const MachineModuleInfo &MMI = MF.getMMI();
  const TargetRegisterInfo *RI = TM.getRegisterInfo();

  return (DisableFramePointerElim(MF) ||
          RI->needsStackRealignment(MF) ||
          MFI->hasVarSizedObjects() ||
          MFI->isFrameAddressTaken() ||
          MF.getInfo<X86MachineFunctionInfo>()->getForceFramePointer() ||
          MMI.callsUnwindInit());
}

static unsigned getSUBriOpcode(unsigned is64Bit, int64_t Imm) {
  if (is64Bit) {
    if (isInt<8>(Imm))
      return X86::SUB64ri8;
    return X86::SUB64ri32;
  } else {
    if (isInt<8>(Imm))
      return X86::SUB32ri8;
    return X86::SUB32ri;
  }
}

static unsigned getADDriOpcode(unsigned is64Bit, int64_t Imm) {
  if (is64Bit) {
    if (isInt<8>(Imm))
      return X86::ADD64ri8;
    return X86::ADD64ri32;
  } else {
    if (isInt<8>(Imm))
      return X86::ADD32ri8;
    return X86::ADD32ri;
  <