llvm-6502/lib/Target/Mips/Mips16RegisterInfo.cpp
2015-03-12 05:43:57 +00:00

152 lines
4.9 KiB
C++

//===-- Mips16RegisterInfo.cpp - MIPS16 Register 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 MIPS16 implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#include "Mips16RegisterInfo.h"
#include "Mips.h"
#include "Mips16InstrInfo.h"
#include "MipsAnalyzeImmediate.h"
#include "MipsInstrInfo.h"
#include "MipsMachineFunction.h"
#include "MipsSubtarget.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Type.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
#define DEBUG_TYPE "mips16-registerinfo"
Mips16RegisterInfo::Mips16RegisterInfo() : MipsRegisterInfo() {}
bool Mips16RegisterInfo::requiresRegisterScavenging
(const MachineFunction &MF) const {
return false;
}
bool Mips16RegisterInfo::requiresFrameIndexScavenging
(const MachineFunction &MF) const {
return false;
}
bool Mips16RegisterInfo::useFPForScavengingIndex
(const MachineFunction &MF) const {
return false;
}
bool Mips16RegisterInfo::saveScavengerRegister
(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
MachineBasicBlock::iterator &UseMI,
const TargetRegisterClass *RC,
unsigned Reg) const {
DebugLoc DL;
const TargetInstrInfo &TII = *MBB.getParent()->getSubtarget().getInstrInfo();
TII.copyPhysReg(MBB, I, DL, Mips::T0, Reg, true);
TII.copyPhysReg(MBB, UseMI, DL, Reg, Mips::T0, true);
return true;
}
const TargetRegisterClass *
Mips16RegisterInfo::intRegClass(unsigned Size) const {
assert(Size == 4);
return &Mips::CPU16RegsRegClass;
}
void Mips16RegisterInfo::eliminateFI(MachineBasicBlock::iterator II,
unsigned OpNo, int FrameIndex,
uint64_t StackSize,
int64_t SPOffset) const {
MachineInstr &MI = *II;
MachineFunction &MF = *MI.getParent()->getParent();
MachineFrameInfo *MFI = MF.getFrameInfo();
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
int MinCSFI = 0;
int MaxCSFI = -1;
if (CSI.size()) {
MinCSFI = CSI[0].getFrameIdx();
MaxCSFI = CSI[CSI.size() - 1].getFrameIdx();
}
// The following stack frame objects are always
// referenced relative to $sp:
// 1. Outgoing arguments.
// 2. Pointer to dynamically allocated stack space.
// 3. Locations for callee-saved registers.
// Everything else is referenced relative to whatever register
// getFrameRegister() returns.
unsigned FrameReg;
if (FrameIndex >= MinCSFI && FrameIndex <= MaxCSFI)
FrameReg = Mips::SP;
else {
const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
if (TFI->hasFP(MF)) {
FrameReg = Mips::S0;
}
else {
if ((MI.getNumOperands()> OpNo+2) && MI.getOperand(OpNo+2).isReg())
FrameReg = MI.getOperand(OpNo+2).getReg();
else
FrameReg = Mips::SP;
}
}
// Calculate final offset.
// - There is no need to change the offset if the frame object
// is one of the
// following: an outgoing argument, pointer to a dynamically allocated
// stack space or a $gp restore location,
// - If the frame object is any of the following,
// its offset must be adjusted
// by adding the size of the stack:
// incoming argument, callee-saved register location or local variable.
int64_t Offset;
bool IsKill = false;
Offset = SPOffset + (int64_t)StackSize;
Offset += MI.getOperand(OpNo + 1).getImm();
DEBUG(errs() << "Offset : " << Offset << "\n" << "<--------->\n");
if (!MI.isDebugValue() &&
!Mips16InstrInfo::validImmediate(MI.getOpcode(), FrameReg, Offset)) {
MachineBasicBlock &MBB = *MI.getParent();
DebugLoc DL = II->getDebugLoc();
unsigned NewImm;
const Mips16InstrInfo &TII =
*static_cast<const Mips16InstrInfo *>(MF.getSubtarget().getInstrInfo());
FrameReg = TII.loadImmediate(FrameReg, Offset, MBB, II, DL, NewImm);
Offset = SignExtend64<16>(NewImm);
IsKill = true;
}
MI.getOperand(OpNo).ChangeToRegister(FrameReg, false, false, IsKill);
MI.getOperand(OpNo + 1).ChangeToImmediate(Offset);
}