src/llvm/lib/CodeGen/TargetFrameLoweringImpl.cpp

   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/TargetRegisterInfo.h"
  18 #include "llvm/Target/TargetSubtargetInfo.h"
  19 #include <cstdlib>
  20 using namespace llvm;
  21
  22 TargetFrameLowering::~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.
  28 int 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
  35 int TargetFrameLowering::getFrameIndexReference(const MachineFunction &MF,
  36                                              int FI, unsigned &FrameReg) const {
  37   const TargetRegisterInfo *RI = MF.getSubtarget().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 }