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//===-- MBlazeRegisterInfo.cpp - MBlaze 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 MBlaze implementation of the TargetRegisterInfo
// class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mblaze-frame-info"
#include "MBlazeRegisterInfo.h"
#include "MBlaze.h"
#include "MBlazeMachineFunction.h"
#include "MBlazeSubtarget.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/ValueTypes.h"
#include "llvm/Constants.h"
#include "llvm/Function.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"
#include "llvm/Type.h"
#define GET_REGINFO_TARGET_DESC
#include "MBlazeGenRegisterInfo.inc"
using namespace llvm;
MBlazeRegisterInfo::
MBlazeRegisterInfo(const MBlazeSubtarget &ST, const TargetInstrInfo &tii)
: MBlazeGenRegisterInfo(MBlaze::R15), Subtarget(ST), TII(tii) {}
unsigned MBlazeRegisterInfo::getPICCallReg() {
return MBlaze::R20;
}
//===----------------------------------------------------------------------===//
// Callee Saved Registers methods
//===----------------------------------------------------------------------===//
/// MBlaze Callee Saved Registers
const uint16_t* MBlazeRegisterInfo::
getCalleeSavedRegs(const MachineFunction *MF) const {
// MBlaze callee-save register range is R20 - R31
static const uint16_t CalleeSavedRegs[] = {
MBlaze::R20, MBlaze::R21, MBlaze::R22, MBlaze::R23,
MBlaze::R24, MBlaze::R25, MBlaze::R26, MBlaze::R27,
MBlaze::R28, MBlaze::R29, MBlaze::R30, MBlaze::R31,
0
};
return CalleeSavedRegs;
}
BitVector MBlazeRegisterInfo::
getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
Reserved.set(MBlaze::R0);
Reserved.set(MBlaze::R1);
Reserved.set(MBlaze::R2);
Reserved.set(MBlaze::R13);
Reserved.set(MBlaze::R14);
Reserved.set(MBlaze::R15);
Reserved.set(MBlaze::R16);
Reserved.set(MBlaze::R17);
Reserved.set(MBlaze::R18);
Reserved.set(MBlaze::R19);
return Reserved;
}
// This function eliminate ADJCALLSTACKDOWN/ADJCALLSTACKUP pseudo instructions
void MBlazeRegisterInfo::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
if (!TFI->hasReservedCallFrame(MF)) {
// If we have a frame pointer, turn the adjcallstackup instruction into a
// 'addi r1, r1, -<amt>' and the adjcallstackdown instruction into
// 'addi r1, r1, <amt>'
MachineInstr *Old = I;
int Amount = Old->getOperand(0).getImm() + 4;
if (Amount != 0) {
// We need to keep the stack aligned properly. To do this, we round the
// amount of space needed for the outgoing arguments up to the next
// alignment boundary.
unsigned Align = TFI->getStackAlignment();
Amount = (Amount+Align-1)/Align*Align;
MachineInstr *New;
if (Old->getOpcode() == MBlaze::ADJCALLSTACKDOWN) {
New = BuildMI(MF,Old->getDebugLoc(),TII.get(MBlaze::ADDIK),MBlaze::R1)
.addReg(MBlaze::R1).addImm(-Amount);
} else {
assert(Old->getOpcode() == MBlaze::ADJCALLSTACKUP);
New = BuildMI(MF,Old->getDebugLoc(),TII.get(MBlaze::ADDIK),MBlaze::R1)
.addReg(MBlaze::R1).addImm(Amount);
}
// Replace the pseudo instruction with a new instruction...
MBB.insert(I, New);
}
}
// Simply discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions.
MBB.erase(I);
}
// FrameIndex represent objects inside a abstract stack.
// We must replace FrameIndex with an stack/frame pointer
// direct reference.
void MBlazeRegisterInfo::
eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
RegScavenger *RS) const {
MachineInstr &MI = *II;
MachineFunction &MF = *MI.getParent()->getParent();
MachineFrameInfo *MFI = MF.getFrameInfo();
unsigned i = 0;
while (!MI.getOperand(i).isFI()) {
++i;
assert(i < MI.getNumOperands() &&
"Instr doesn't have FrameIndex operand!");
}
unsigned oi = i == 2 ? 1 : 2;
DEBUG(dbgs() << "\nFunction : " << MF.getName() << "\n";
dbgs() << "<--------->\n" << MI);
int FrameIndex = MI.getOperand(i).getIndex();
int stackSize = MFI->getStackSize();
int spOffset = MFI->getObjectOffset(FrameIndex);
DEBUG(MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
dbgs() << "FrameIndex : " << FrameIndex << "\n"
<< "spOffset : " << spOffset << "\n"
<< "stackSize : " << stackSize << "\n"
<< "isFixed : " << MFI->isFixedObjectIndex(FrameIndex) << "\n"
<< "isLiveIn : " << MBlazeFI->isLiveIn(FrameIndex) << "\n"
<< "isSpill : " << MFI->isSpillSlotObjectIndex(FrameIndex)
<< "\n" );
// as explained on LowerFormalArguments, detect negative offsets
// and adjust SPOffsets considering the final stack size.
int Offset = (spOffset < 0) ? (stackSize - spOffset) : spOffset;
Offset += MI.getOperand(oi).getImm();
DEBUG(dbgs() << "Offset : " << Offset << "\n" << "<--------->\n");
MI.getOperand(oi).ChangeToImmediate(Offset);
MI.getOperand(i).ChangeToRegister(getFrameRegister(MF), false);
}
void MBlazeRegisterInfo::
processFunctionBeforeFrameFinalized(MachineFunction &MF) const {
// Set the stack offset where GP must be saved/loaded from.
MachineFrameInfo *MFI = MF.getFrameInfo();
MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
if (MBlazeFI->needGPSaveRestore())
MFI->setObjectOffset(MBlazeFI->getGPFI(), MBlazeFI->getGPStackOffset());
}
unsigned MBlazeRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
return TFI->hasFP(MF) ? MBlaze::R19 : MBlaze::R1;
}
unsigned MBlazeRegisterInfo::getEHExceptionRegister() const {
llvm_unreachable("What is the exception register");
}
unsigned MBlazeRegisterInfo::getEHHandlerRegister() const {
llvm_unreachable("What is the exception handler register");
}
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