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/Target/TargetFrameLowering.h"
15#include "llvm/CodeGen/MachineFrameInfo.h"
16#include "llvm/CodeGen/MachineFunction.h"
17#include "llvm/Target/TargetMachine.h"
18#include "llvm/Target/TargetRegisterInfo.h"
19#include <cstdlib>
20using namespace llvm;
21
22TargetFrameLowering::~TargetFrameLowering() {
23}
24
25/// getFrameIndexOffset - Returns the displacement from the frame register to
26/// the stack frame of the specified index. This is the default implementation
27/// which is overridden for some targets.
28int TargetFrameLowering::getFrameIndexOffset(const MachineFunction &MF,
29                                         int FI) const {
30  const MachineFrameInfo *MFI = MF.getFrameInfo();
31  return MFI->getObjectOffset(FI) + MFI->getStackSize() -
32    getOffsetOfLocalArea() + MFI->getOffsetAdjustment();
33}
34
35int TargetFrameLowering::getFrameIndexReference(const MachineFunction &MF,
36                                             int FI, unsigned &FrameReg) const {
37  const TargetRegisterInfo *RI = MF.getTarget().getRegisterInfo();
38
39  // By default, assume all frame indices are referenced via whatever
40  // getFrameRegister() says. The target can override this if it's doing
41  // something different.
42  FrameReg = RI->getFrameRegister(MF);
43  return getFrameIndexOffset(MF, FI);
44}
45