//===-- ARMFrameLowering.cpp - ARM Frame Information ----------------------===//
//
// 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 ARM implementation of TargetFrameLowering class.
//
//===----------------------------------------------------------------------===//
#include "ARMFrameLowering.h"
#include "ARMBaseInstrInfo.h"
#include "ARMBaseRegisterInfo.h"
#include "ARMMachineFunctionInfo.h"
#include "MCTargetDesc/ARMAddressingModes.h"
#include "llvm/Function.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/CommandLine.h"
using namespace llvm;
static cl::opt<bool>
SpillAlignedNEONRegs("align-neon-spills", cl::Hidden, cl::init(true),
cl::desc("Align ARM NEON spills in prolog and epilog"));
static MachineBasicBlock::iterator
skipAlignedDPRCS2Spills(MachineBasicBlock::iterator MI,
unsigned NumAlignedDPRCS2Regs);
/// 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 ARMFrameLowering::hasFP(const MachineFunction &MF) const {
const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
// iOS requires FP not to be clobbered for backtracing purpose.
if (STI.isTargetIOS())
return true;
const MachineFrameInfo *MFI = MF.getFrameInfo();
// Always eliminate non-leaf frame pointers.
return ((MF.getTarget().Options.DisableFramePointerElim(MF) &&
MFI->hasCalls()) ||
RegInfo->needsStackRealignment(MF) ||
MFI->hasVarSizedObjects() ||
MFI->isFrameAddressTaken());
