llvm-6502/lib/Target/MBlaze/MBlazeInstrInfo.cpp
Wesley Peck a70f28ce7d Adding the MicroBlaze backend.
The MicroBlaze is a highly configurable 32-bit soft-microprocessor for
use on Xilinx FPGAs. For more information see:
http://www.xilinx.com/tools/microblaze.htm
http://en.wikipedia.org/wiki/MicroBlaze

The current LLVM MicroBlaze backend generates assembly which can be
compiled using the an appropriate binutils assembler.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96969 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-23 19:15:24 +00:00

223 lines
8.3 KiB
C++

//===- MBlazeInstrInfo.cpp - MBlaze Instruction Information -----*- C++ -*-===//
//
// 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 TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "MBlazeInstrInfo.h"
#include "MBlazeTargetMachine.h"
#include "MBlazeMachineFunction.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/ErrorHandling.h"
#include "MBlazeGenInstrInfo.inc"
using namespace llvm;
MBlazeInstrInfo::MBlazeInstrInfo(MBlazeTargetMachine &tm)
: TargetInstrInfoImpl(MBlazeInsts, array_lengthof(MBlazeInsts)),
TM(tm), RI(*TM.getSubtargetImpl(), *this) {}
static bool isZeroImm(const MachineOperand &op) {
return op.isImm() && op.getImm() == 0;
}
/// Return true if the instruction is a register to register move and
/// leave the source and dest operands in the passed parameters.
bool MBlazeInstrInfo::
isMoveInstr(const MachineInstr &MI, unsigned &SrcReg, unsigned &DstReg,
unsigned &SrcSubIdx, unsigned &DstSubIdx) const {
SrcSubIdx = DstSubIdx = 0; // No sub-registers.
// add $dst, $src, $zero || addu $dst, $zero, $src
// or $dst, $src, $zero || or $dst, $zero, $src
if ((MI.getOpcode() == MBlaze::ADD) || (MI.getOpcode() == MBlaze::OR)) {
if (MI.getOperand(1).isReg() && MI.getOperand(1).getReg() == MBlaze::R0) {
DstReg = MI.getOperand(0).getReg();
SrcReg = MI.getOperand(2).getReg();
return true;
} else if (MI.getOperand(2).isReg() &&
MI.getOperand(2).getReg() == MBlaze::R0) {
DstReg = MI.getOperand(0).getReg();
SrcReg = MI.getOperand(1).getReg();
return true;
}
}
// addi $dst, $src, 0
// ori $dst, $src, 0
if ((MI.getOpcode() == MBlaze::ADDI) || (MI.getOpcode() == MBlaze::ORI)) {
if ((MI.getOperand(1).isReg()) && (isZeroImm(MI.getOperand(2)))) {
DstReg = MI.getOperand(0).getReg();
SrcReg = MI.getOperand(1).getReg();
return true;
}
}
return false;
}
/// isLoadFromStackSlot - If the specified machine instruction is a direct
/// load from a stack slot, return the virtual or physical register number of
/// the destination along with the FrameIndex of the loaded stack slot. If
/// not, return 0. This predicate must return 0 if the instruction has
/// any side effects other than loading from the stack slot.
unsigned MBlazeInstrInfo::
isLoadFromStackSlot(const MachineInstr *MI, int &FrameIndex) const {
if (MI->getOpcode() == MBlaze::LWI) {
if ((MI->getOperand(2).isFI()) && // is a stack slot
(MI->getOperand(1).isImm()) && // the imm is zero
(isZeroImm(MI->getOperand(1)))) {
FrameIndex = MI->getOperand(2).getIndex();
return MI->getOperand(0).getReg();
}
}
return 0;
}
/// isStoreToStackSlot - If the specified machine instruction is a direct
/// store to a stack slot, return the virtual or physical register number of
/// the source reg along with the FrameIndex of the loaded stack slot. If
/// not, return 0. This predicate must return 0 if the instruction has
/// any side effects other than storing to the stack slot.
unsigned MBlazeInstrInfo::
isStoreToStackSlot(const MachineInstr *MI, int &FrameIndex) const {
if (MI->getOpcode() == MBlaze::SWI) {
if ((MI->getOperand(2).isFI()) && // is a stack slot
(MI->getOperand(1).isImm()) && // the imm is zero
(isZeroImm(MI->getOperand(1)))) {
FrameIndex = MI->getOperand(2).getIndex();
return MI->getOperand(0).getReg();
}
}
return 0;
}
/// insertNoop - If data hazard condition is found insert the target nop
/// instruction.
void MBlazeInstrInfo::
insertNoop(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI) const {
DebugLoc DL = DebugLoc::getUnknownLoc();
if (MI != MBB.end()) DL = MI->getDebugLoc();
BuildMI(MBB, MI, DL, get(MBlaze::NOP));
}
bool MBlazeInstrInfo::
copyRegToReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned DestReg, unsigned SrcReg,
const TargetRegisterClass *DestRC,
const TargetRegisterClass *SrcRC) const {
DebugLoc dl = DebugLoc::getUnknownLoc();
llvm::BuildMI(MBB, I, dl, get(MBlaze::ADD), DestReg)
.addReg(SrcReg).addReg(MBlaze::R0);
return true;
}
void MBlazeInstrInfo::
storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned SrcReg, bool isKill, int FI,
const TargetRegisterClass *RC) const {
DebugLoc dl = DebugLoc::getUnknownLoc();
BuildMI(MBB, I, dl, get(MBlaze::SWI)).addReg(SrcReg,getKillRegState(isKill))
.addImm(0).addFrameIndex(FI);
}
void MBlazeInstrInfo::
loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned DestReg, int FI,
const TargetRegisterClass *RC) const {
DebugLoc dl = DebugLoc::getUnknownLoc();
BuildMI(MBB, I, dl, get(MBlaze::LWI), DestReg)
.addImm(0).addFrameIndex(FI);
}
MachineInstr *MBlazeInstrInfo::
foldMemoryOperandImpl(MachineFunction &MF,
MachineInstr* MI,
const SmallVectorImpl<unsigned> &Ops, int FI) const {
if (Ops.size() != 1) return NULL;
MachineInstr *NewMI = NULL;
switch (MI->getOpcode()) {
case MBlaze::OR:
case MBlaze::ADD:
if ((MI->getOperand(0).isReg()) &&
(MI->getOperand(2).isReg()) &&
(MI->getOperand(2).getReg() == MBlaze::R0) &&
(MI->getOperand(1).isReg())) {
if (Ops[0] == 0) { // COPY -> STORE
unsigned SrcReg = MI->getOperand(1).getReg();
bool isKill = MI->getOperand(1).isKill();
bool isUndef = MI->getOperand(1).isUndef();
NewMI = BuildMI(MF, MI->getDebugLoc(), get(MBlaze::SW))
.addReg(SrcReg, getKillRegState(isKill) | getUndefRegState(isUndef))
.addImm(0).addFrameIndex(FI);
} else { // COPY -> LOAD
unsigned DstReg = MI->getOperand(0).getReg();
bool isDead = MI->getOperand(0).isDead();
bool isUndef = MI->getOperand(0).isUndef();
NewMI = BuildMI(MF, MI->getDebugLoc(), get(MBlaze::LW))
.addReg(DstReg, RegState::Define | getDeadRegState(isDead) |
getUndefRegState(isUndef))
.addImm(0).addFrameIndex(FI);
}
}
break;
}
return NewMI;
}
//===----------------------------------------------------------------------===//
// Branch Analysis
//===----------------------------------------------------------------------===//
unsigned MBlazeInstrInfo::
InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond) const {
DebugLoc dl = DebugLoc::getUnknownLoc();
// Can only insert uncond branches so far.
assert(Cond.empty() && !FBB && TBB && "Can only handle uncond branches!");
BuildMI(&MBB, dl, get(MBlaze::BRI)).addMBB(TBB);
return 1;
}
/// getGlobalBaseReg - Return a virtual register initialized with the
/// the global base register value. Output instructions required to
/// initialize the register in the function entry block, if necessary.
///
unsigned MBlazeInstrInfo::getGlobalBaseReg(MachineFunction *MF) const {
MBlazeFunctionInfo *MBlazeFI = MF->getInfo<MBlazeFunctionInfo>();
unsigned GlobalBaseReg = MBlazeFI->getGlobalBaseReg();
if (GlobalBaseReg != 0)
return GlobalBaseReg;
// Insert the set of GlobalBaseReg into the first MBB of the function
MachineBasicBlock &FirstMBB = MF->front();
MachineBasicBlock::iterator MBBI = FirstMBB.begin();
MachineRegisterInfo &RegInfo = MF->getRegInfo();
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
GlobalBaseReg = RegInfo.createVirtualRegister(MBlaze::CPURegsRegisterClass);
bool Ok = TII->copyRegToReg(FirstMBB, MBBI, GlobalBaseReg, MBlaze::R20,
MBlaze::CPURegsRegisterClass,
MBlaze::CPURegsRegisterClass);
assert(Ok && "Couldn't assign to global base register!");
Ok = Ok; // Silence warning when assertions are turned off.
RegInfo.addLiveIn(MBlaze::R20);
MBlazeFI->setGlobalBaseReg(GlobalBaseReg);
return GlobalBaseReg;
}