1//===----- TargetFrameLoweringImpl.cpp - Implement target frame interface --==//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Implements the layout of a stack frame on the target machine.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/CodeGen/MachineFrameInfo.h"
15#include "llvm/CodeGen/MachineFunction.h"
16#include "llvm/Target/TargetFrameLowering.h"
17#include "llvm/Target/TargetMachine.h"
18#include "llvm/Target/TargetRegisterInfo.h"
19
20#include <cstdlib>
21using namespace llvm;
22
23TargetFrameLowering::~TargetFrameLowering() {
24}
25
26/// getFrameIndexOffset - Returns the displacement from the frame register to
27/// the stack frame of the specified index. This is the default implementation
28/// which is overridden for some targets.
29int TargetFrameLowering::getFrameIndexOffset(const MachineFunction &MF,
30                                         int FI) const {
31  const MachineFrameInfo *MFI = MF.getFrameInfo();
32  return MFI->getObjectOffset(FI) + MFI->getStackSize() -
33    getOffsetOfLocalArea() + MFI->getOffsetAdjustment();
34}
35
36int TargetFrameLowering::getFrameIndexReference(const MachineFunction &MF,
37                                             int FI, unsigned &FrameReg) const {
38  const TargetRegisterInfo *RI = MF.getTarget().getRegisterInfo();
39
40  // By default, assume all frame indices are referenced via whatever
41  // getFrameRegister() says. The target can override this if it's doing
42  // something different.
43  FrameReg = RI->getFrameRegister(MF);
44  return getFrameIndexOffset(MF, FI);
45}
46