llvm-6502/lib/Target/CellSPU/SPUInstrInfo.cpp
2011-10-11 12:55:18 +00:00

454 lines
14 KiB
C++

//===- SPUInstrInfo.cpp - Cell SPU Instruction 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 Cell SPU implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "SPUInstrInfo.h"
#include "SPUInstrBuilder.h"
#include "SPUTargetMachine.h"
#include "SPUHazardRecognizers.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/MC/MCContext.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
#define GET_INSTRINFO_CTOR
#include "SPUGenInstrInfo.inc"
using namespace llvm;
namespace {
//! Predicate for an unconditional branch instruction
inline bool isUncondBranch(const MachineInstr *I) {
unsigned opc = I->getOpcode();
return (opc == SPU::BR
|| opc == SPU::BRA
|| opc == SPU::BI);
}
//! Predicate for a conditional branch instruction
inline bool isCondBranch(const MachineInstr *I) {
unsigned opc = I->getOpcode();
return (opc == SPU::BRNZr32
|| opc == SPU::BRNZv4i32
|| opc == SPU::BRZr32
|| opc == SPU::BRZv4i32
|| opc == SPU::BRHNZr16
|| opc == SPU::BRHNZv8i16
|| opc == SPU::BRHZr16
|| opc == SPU::BRHZv8i16);
}
}
SPUInstrInfo::SPUInstrInfo(SPUTargetMachine &tm)
: SPUGenInstrInfo(SPU::ADJCALLSTACKDOWN, SPU::ADJCALLSTACKUP),
TM(tm),
RI(*TM.getSubtargetImpl(), *this)
{ /* NOP */ }
/// CreateTargetHazardRecognizer - Return the hazard recognizer to use for
/// this target when scheduling the DAG.
ScheduleHazardRecognizer *SPUInstrInfo::CreateTargetHazardRecognizer(
const TargetMachine *TM,
const ScheduleDAG *DAG) const {
const TargetInstrInfo *TII = TM->getInstrInfo();
assert(TII && "No InstrInfo?");
return new SPUHazardRecognizer(*TII);
}
unsigned
SPUInstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
switch (MI->getOpcode()) {
default: break;
case SPU::LQDv16i8:
case SPU::LQDv8i16:
case SPU::LQDv4i32:
case SPU::LQDv4f32:
case SPU::LQDv2f64:
case SPU::LQDr128:
case SPU::LQDr64:
case SPU::LQDr32:
case SPU::LQDr16: {
const MachineOperand MOp1 = MI->getOperand(1);
const MachineOperand MOp2 = MI->getOperand(2);
if (MOp1.isImm() && MOp2.isFI()) {
FrameIndex = MOp2.getIndex();
return MI->getOperand(0).getReg();
}
break;
}
}
return 0;
}
unsigned
SPUInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
switch (MI->getOpcode()) {
default: break;
case SPU::STQDv16i8:
case SPU::STQDv8i16:
case SPU::STQDv4i32:
case SPU::STQDv4f32:
case SPU::STQDv2f64:
case SPU::STQDr128:
case SPU::STQDr64:
case SPU::STQDr32:
case SPU::STQDr16:
case SPU::STQDr8: {
const MachineOperand MOp1 = MI->getOperand(1);
const MachineOperand MOp2 = MI->getOperand(2);
if (MOp1.isImm() && MOp2.isFI()) {
FrameIndex = MOp2.getIndex();
return MI->getOperand(0).getReg();
}
break;
}
}
return 0;
}
void SPUInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I, DebugLoc DL,
unsigned DestReg, unsigned SrcReg,
bool KillSrc) const
{
// We support cross register class moves for our aliases, such as R3 in any
// reg class to any other reg class containing R3. This is required because
// we instruction select bitconvert i64 -> f64 as a noop for example, so our
// types have no specific meaning.
BuildMI(MBB, I, DL, get(SPU::LRr128), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
}
void
SPUInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned SrcReg, bool isKill, int FrameIdx,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const
{
unsigned opc;
bool isValidFrameIdx = (FrameIdx < SPUFrameLowering::maxFrameOffset());
if (RC == SPU::GPRCRegisterClass) {
opc = (isValidFrameIdx ? SPU::STQDr128 : SPU::STQXr128);
} else if (RC == SPU::R64CRegisterClass) {
opc = (isValidFrameIdx ? SPU::STQDr64 : SPU::STQXr64);
} else if (RC == SPU::R64FPRegisterClass) {
opc = (isValidFrameIdx ? SPU::STQDr64 : SPU::STQXr64);
} else if (RC == SPU::R32CRegisterClass) {
opc = (isValidFrameIdx ? SPU::STQDr32 : SPU::STQXr32);
} else if (RC == SPU::R32FPRegisterClass) {
opc = (isValidFrameIdx ? SPU::STQDr32 : SPU::STQXr32);
} else if (RC == SPU::R16CRegisterClass) {
opc = (isValidFrameIdx ? SPU::STQDr16 : SPU::STQXr16);
} else if (RC == SPU::R8CRegisterClass) {
opc = (isValidFrameIdx ? SPU::STQDr8 : SPU::STQXr8);
} else if (RC == SPU::VECREGRegisterClass) {
opc = (isValidFrameIdx) ? SPU::STQDv16i8 : SPU::STQXv16i8;
} else {
llvm_unreachable("Unknown regclass!");
}
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
addFrameReference(BuildMI(MBB, MI, DL, get(opc))
.addReg(SrcReg, getKillRegState(isKill)), FrameIdx);
}
void
SPUInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const
{
unsigned opc;
bool isValidFrameIdx = (FrameIdx < SPUFrameLowering::maxFrameOffset());
if (RC == SPU::GPRCRegisterClass) {
opc = (isValidFrameIdx ? SPU::LQDr128 : SPU::LQXr128);
} else if (RC == SPU::R64CRegisterClass) {
opc = (isValidFrameIdx ? SPU::LQDr64 : SPU::LQXr64);
} else if (RC == SPU::R64FPRegisterClass) {
opc = (isValidFrameIdx ? SPU::LQDr64 : SPU::LQXr64);
} else if (RC == SPU::R32CRegisterClass) {
opc = (isValidFrameIdx ? SPU::LQDr32 : SPU::LQXr32);
} else if (RC == SPU::R32FPRegisterClass) {
opc = (isValidFrameIdx ? SPU::LQDr32 : SPU::LQXr32);
} else if (RC == SPU::R16CRegisterClass) {
opc = (isValidFrameIdx ? SPU::LQDr16 : SPU::LQXr16);
} else if (RC == SPU::R8CRegisterClass) {
opc = (isValidFrameIdx ? SPU::LQDr8 : SPU::LQXr8);
} else if (RC == SPU::VECREGRegisterClass) {
opc = (isValidFrameIdx) ? SPU::LQDv16i8 : SPU::LQXv16i8;
} else {
llvm_unreachable("Unknown regclass in loadRegFromStackSlot!");
}
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
addFrameReference(BuildMI(MBB, MI, DL, get(opc), DestReg), FrameIdx);
}
//! Branch analysis
/*!
\note This code was kiped from PPC. There may be more branch analysis for
CellSPU than what's currently done here.
*/
bool
SPUInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin())
return false;
--I;
while (I->isDebugValue()) {
if (I == MBB.begin())
return false;
--I;
}
if (!isUnpredicatedTerminator(I))
return false;
// Get the last instruction in the block.
MachineInstr *LastInst = I;
// If there is only one terminator instruction, process it.
if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
if (isUncondBranch(LastInst)) {
// Check for jump tables
if (!LastInst->getOperand(0).isMBB())
return true;
TBB = LastInst->getOperand(0).getMBB();
return false;
} else if (isCondBranch(LastInst)) {
// Block ends with fall-through condbranch.
TBB = LastInst->getOperand(1).getMBB();
DEBUG(errs() << "Pushing LastInst: ");
DEBUG(LastInst->dump());
Cond.push_back(MachineOperand::CreateImm(LastInst->getOpcode()));
Cond.push_back(LastInst->getOperand(0));
return false;
}
// Otherwise, don't know what this is.
return true;
}
// Get the instruction before it if it's a terminator.
MachineInstr *SecondLastInst = I;
// If there are three terminators, we don't know what sort of block this is.
if (SecondLastInst && I != MBB.begin() &&
isUnpredicatedTerminator(--I))
return true;
// If the block ends with a conditional and unconditional branch, handle it.
if (isCondBranch(SecondLastInst) && isUncondBranch(LastInst)) {
TBB = SecondLastInst->getOperand(1).getMBB();
DEBUG(errs() << "Pushing SecondLastInst: ");
DEBUG(SecondLastInst->dump());
Cond.push_back(MachineOperand::CreateImm(SecondLastInst->getOpcode()));
Cond.push_back(SecondLastInst->getOperand(0));
FBB = LastInst->getOperand(0).getMBB();
return false;
}
// If the block ends with two unconditional branches, handle it. The second
// one is not executed, so remove it.
if (isUncondBranch(SecondLastInst) && isUncondBranch(LastInst)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
if (AllowModify)
I->eraseFromParent();
return false;
}
// Otherwise, can't handle this.
return true;
}
// search MBB for branch hint labels and branch hit ops
static void removeHBR( MachineBasicBlock &MBB) {
for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end(); ++I){
if (I->getOpcode() == SPU::HBRA ||
I->getOpcode() == SPU::HBR_LABEL){
I=MBB.erase(I);
if (I == MBB.end())
break;
}
}
}
unsigned
SPUInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator I = MBB.end();
removeHBR(MBB);
if (I == MBB.begin())
return 0;
--I;
while (I->isDebugValue()) {
if (I == MBB.begin())
return 0;
--I;
}
if (!isCondBranch(I) && !isUncondBranch(I))
return 0;
// Remove the first branch.
DEBUG(errs() << "Removing branch: ");
DEBUG(I->dump());
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin())
return 1;
--I;
if (!(isCondBranch(I) || isUncondBranch(I)))
return 1;
// Remove the second branch.
DEBUG(errs() << "Removing second branch: ");
DEBUG(I->dump());
I->eraseFromParent();
return 2;
}
/** Find the optimal position for a hint branch instruction in a basic block.
* This should take into account:
* -the branch hint delays
* -congestion of the memory bus
* -dual-issue scheduling (i.e. avoid insertion of nops)
* Current implementation is rather simplistic.
*/
static MachineBasicBlock::iterator findHBRPosition(MachineBasicBlock &MBB)
{
MachineBasicBlock::iterator J = MBB.end();
for( int i=0; i<8; i++) {
if( J == MBB.begin() ) return J;
J--;
}
return J;
}
unsigned
SPUInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond,
DebugLoc DL) const {
// Shouldn't be a fall through.
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 2 || Cond.size() == 0) &&
"SPU branch conditions have two components!");
MachineInstrBuilder MIB;
//TODO: make a more accurate algorithm.
bool haveHBR = MBB.size()>8;
removeHBR(MBB);
MCSymbol *branchLabel = MBB.getParent()->getContext().CreateTempSymbol();
// Add a label just before the branch
if (haveHBR)
MIB = BuildMI(&MBB, DL, get(SPU::HBR_LABEL)).addSym(branchLabel);
// One-way branch.
if (FBB == 0) {
if (Cond.empty()) {
// Unconditional branch
MIB = BuildMI(&MBB, DL, get(SPU::BR));
MIB.addMBB(TBB);
DEBUG(errs() << "Inserted one-way uncond branch: ");
DEBUG((*MIB).dump());
// basic blocks have just one branch so it is safe to add the hint a its
if (haveHBR) {
MIB = BuildMI( MBB, findHBRPosition(MBB), DL, get(SPU::HBRA));
MIB.addSym(branchLabel);
MIB.addMBB(TBB);
}
} else {
// Conditional branch
MIB = BuildMI(&MBB, DL, get(Cond[0].getImm()));
MIB.addReg(Cond[1].getReg()).addMBB(TBB);
if (haveHBR) {
MIB = BuildMI(MBB, findHBRPosition(MBB), DL, get(SPU::HBRA));
MIB.addSym(branchLabel);
MIB.addMBB(TBB);
}
DEBUG(errs() << "Inserted one-way cond branch: ");
DEBUG((*MIB).dump());
}
return 1;
} else {
MIB = BuildMI(&MBB, DL, get(Cond[0].getImm()));
MachineInstrBuilder MIB2 = BuildMI(&MBB, DL, get(SPU::BR));
// Two-way Conditional Branch.
MIB.addReg(Cond[1].getReg()).addMBB(TBB);
MIB2.addMBB(FBB);
if (haveHBR) {
MIB = BuildMI( MBB, findHBRPosition(MBB), DL, get(SPU::HBRA));
MIB.addSym(branchLabel);
MIB.addMBB(FBB);
}
DEBUG(errs() << "Inserted conditional branch: ");
DEBUG((*MIB).dump());
DEBUG(errs() << "part 2: ");
DEBUG((*MIB2).dump());
return 2;
}
}
//! Reverses a branch's condition, returning false on success.
bool
SPUInstrInfo::ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond)
const {
// Pretty brainless way of inverting the condition, but it works, considering
// there are only two conditions...
static struct {
unsigned Opc; //! The incoming opcode
unsigned RevCondOpc; //! The reversed condition opcode
} revconds[] = {
{ SPU::BRNZr32, SPU::BRZr32 },
{ SPU::BRNZv4i32, SPU::BRZv4i32 },
{ SPU::BRZr32, SPU::BRNZr32 },
{ SPU::BRZv4i32, SPU::BRNZv4i32 },
{ SPU::BRHNZr16, SPU::BRHZr16 },
{ SPU::BRHNZv8i16, SPU::BRHZv8i16 },
{ SPU::BRHZr16, SPU::BRHNZr16 },
{ SPU::BRHZv8i16, SPU::BRHNZv8i16 }
};
unsigned Opc = unsigned(Cond[0].getImm());
// Pretty dull mapping between the two conditions that SPU can generate:
for (int i = sizeof(revconds)/sizeof(revconds[0]) - 1; i >= 0; --i) {
if (revconds[i].Opc == Opc) {
Cond[0].setImm(revconds[i].RevCondOpc);
return false;
}
}
return true;
}