llvm-6502/lib/Target/R600/R600ControlFlowFinalizer.cpp

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//===-- R600ControlFlowFinalizer.cpp - Finalize Control Flow Inst----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// \file
/// This pass compute turns all control flow pseudo instructions into native one
/// computing their address on the fly ; it also sets STACK_SIZE info.
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "r600cf"
#include "llvm/Support/Debug.h"
#include "AMDGPU.h"
#include "R600Defines.h"
#include "R600InstrInfo.h"
#include "R600MachineFunctionInfo.h"
#include "R600RegisterInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
class R600ControlFlowFinalizer : public MachineFunctionPass {
private:
typedef std::pair<MachineInstr *, std::vector<MachineInstr *> > ClauseFile;
enum ControlFlowInstruction {
CF_TC,
CF_VC,
CF_CALL_FS,
CF_WHILE_LOOP,
CF_END_LOOP,
CF_LOOP_BREAK,
CF_LOOP_CONTINUE,
CF_JUMP,
CF_ELSE,
CF_POP,
CF_END
};
static char ID;
const R600InstrInfo *TII;
const R600RegisterInfo *TRI;
unsigned MaxFetchInst;
const AMDGPUSubtarget &ST;
bool IsTrivialInst(MachineInstr *MI) const {
switch (MI->getOpcode()) {
case AMDGPU::KILL:
case AMDGPU::RETURN:
return true;
default:
return false;
}
}
const MCInstrDesc &getHWInstrDesc(ControlFlowInstruction CFI) const {
unsigned Opcode = 0;
bool isEg = (ST.getGeneration() >= AMDGPUSubtarget::EVERGREEN);
switch (CFI) {
case CF_TC:
Opcode = isEg ? AMDGPU::CF_TC_EG : AMDGPU::CF_TC_R600;
break;
case CF_VC:
Opcode = isEg ? AMDGPU::CF_VC_EG : AMDGPU::CF_VC_R600;
break;
case CF_CALL_FS:
Opcode = isEg ? AMDGPU::CF_CALL_FS_EG : AMDGPU::CF_CALL_FS_R600;
break;
case CF_WHILE_LOOP:
Opcode = isEg ? AMDGPU::WHILE_LOOP_EG : AMDGPU::WHILE_LOOP_R600;
break;
case CF_END_LOOP:
Opcode = isEg ? AMDGPU::END_LOOP_EG : AMDGPU::END_LOOP_R600;
break;
case CF_LOOP_BREAK:
Opcode = isEg ? AMDGPU::LOOP_BREAK_EG : AMDGPU::LOOP_BREAK_R600;
break;
case CF_LOOP_CONTINUE:
Opcode = isEg ? AMDGPU::CF_CONTINUE_EG : AMDGPU::CF_CONTINUE_R600;
break;
case CF_JUMP:
Opcode = isEg ? AMDGPU::CF_JUMP_EG : AMDGPU::CF_JUMP_R600;
break;
case CF_ELSE:
Opcode = isEg ? AMDGPU::CF_ELSE_EG : AMDGPU::CF_ELSE_R600;
break;
case CF_POP:
Opcode = isEg ? AMDGPU::POP_EG : AMDGPU::POP_R600;
break;
case CF_END:
if (ST.hasCaymanISA()) {
Opcode = AMDGPU::CF_END_CM;
break;
}
Opcode = isEg ? AMDGPU::CF_END_EG : AMDGPU::CF_END_R600;
break;
}
assert (Opcode && "No opcode selected");
return TII->get(Opcode);
}
bool isCompatibleWithClause(const MachineInstr *MI,
std::set<unsigned> &DstRegs) const {
unsigned DstMI, SrcMI;
for (MachineInstr::const_mop_iterator I = MI->operands_begin(),
E = MI->operands_end(); I != E; ++I) {
const MachineOperand &MO = *I;
if (!MO.isReg())
continue;
if (MO.isDef()) {
unsigned Reg = MO.getReg();
if (AMDGPU::R600_Reg128RegClass.contains(Reg))
DstMI = Reg;
else
DstMI = TRI->getMatchingSuperReg(Reg,
TRI->getSubRegFromChannel(TRI->getHWRegChan(Reg)),
&AMDGPU::R600_Reg128RegClass);
}
if (MO.isUse()) {
unsigned Reg = MO.getReg();
if (AMDGPU::R600_Reg128RegClass.contains(Reg))
SrcMI = Reg;
else
SrcMI = TRI->getMatchingSuperReg(Reg,
TRI->getSubRegFromChannel(TRI->getHWRegChan(Reg)),
&AMDGPU::R600_Reg128RegClass);
}
}
if ((DstRegs.find(SrcMI) == DstRegs.end())) {
DstRegs.insert(DstMI);
return true;
} else
return false;
}
ClauseFile
MakeFetchClause(MachineBasicBlock &MBB, MachineBasicBlock::iterator &I)
const {
MachineBasicBlock::iterator ClauseHead = I;
std::vector<MachineInstr *> ClauseContent;
unsigned AluInstCount = 0;
bool IsTex = TII->usesTextureCache(ClauseHead);
std::set<unsigned> DstRegs;
for (MachineBasicBlock::iterator E = MBB.end(); I != E; ++I) {
if (IsTrivialInst(I))
continue;
if (AluInstCount >= MaxFetchInst)
break;
if ((IsTex && !TII->usesTextureCache(I)) ||
(!IsTex && !TII->usesVertexCache(I)))
break;
if (!isCompatibleWithClause(I, DstRegs))
break;
AluInstCount ++;
ClauseContent.push_back(I);
}
MachineInstr *MIb = BuildMI(MBB, ClauseHead, MBB.findDebugLoc(ClauseHead),
getHWInstrDesc(IsTex?CF_TC:CF_VC))
.addImm(0) // ADDR
.addImm(AluInstCount - 1); // COUNT
return ClauseFile(MIb, ClauseContent);
}
void getLiteral(MachineInstr *MI, std::vector<int64_t> &Lits) const {
static const unsigned LiteralRegs[] = {
AMDGPU::ALU_LITERAL_X,
AMDGPU::ALU_LITERAL_Y,
AMDGPU::ALU_LITERAL_Z,
AMDGPU::ALU_LITERAL_W
};
const SmallVector<std::pair<MachineOperand *, int64_t>, 3 > Srcs =
TII->getSrcs(MI);
for (unsigned i = 0, e = Srcs.size(); i < e; ++i) {
if (Srcs[i].first->getReg() != AMDGPU::ALU_LITERAL_X)
continue;
int64_t Imm = Srcs[i].second;
std::vector<int64_t>::iterator It =
std::find(Lits.begin(), Lits.end(), Imm);
if (It != Lits.end()) {
unsigned Index = It - Lits.begin();
Srcs[i].first->setReg(LiteralRegs[Index]);
} else {
assert(Lits.size() < 4 && "Too many literals in Instruction Group");
Srcs[i].first->setReg(LiteralRegs[Lits.size()]);
Lits.push_back(Imm);
}
}
}
MachineBasicBlock::iterator insertLiterals(
MachineBasicBlock::iterator InsertPos,
const std::vector<unsigned> &Literals) const {
MachineBasicBlock *MBB = InsertPos->getParent();
for (unsigned i = 0, e = Literals.size(); i < e; i+=2) {
unsigned LiteralPair0 = Literals[i];
unsigned LiteralPair1 = (i + 1 < e)?Literals[i + 1]:0;
InsertPos = BuildMI(MBB, InsertPos->getDebugLoc(),
TII->get(AMDGPU::LITERALS))
.addImm(LiteralPair0)
.addImm(LiteralPair1);
}
return InsertPos;
}
ClauseFile
MakeALUClause(MachineBasicBlock &MBB, MachineBasicBlock::iterator &I)
const {
MachineBasicBlock::iterator ClauseHead = I;
std::vector<MachineInstr *> ClauseContent;
I++;
for (MachineBasicBlock::instr_iterator E = MBB.instr_end(); I != E;) {
if (IsTrivialInst(I)) {
++I;
continue;
}
if (!I->isBundle() && !TII->isALUInstr(I->getOpcode()))
break;
std::vector<int64_t> Literals;
if (I->isBundle()) {
MachineInstr *DeleteMI = I;
MachineBasicBlock::instr_iterator BI = I.getInstrIterator();
while (++BI != E && BI->isBundledWithPred()) {
BI->unbundleFromPred();
for (unsigned i = 0, e = BI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = BI->getOperand(i);
if (MO.isReg() && MO.isInternalRead())
MO.setIsInternalRead(false);
}
getLiteral(BI, Literals);
ClauseContent.push_back(BI);
}
I = BI;
DeleteMI->eraseFromParent();
} else {
getLiteral(I, Literals);
ClauseContent.push_back(I);
I++;
}
for (unsigned i = 0, e = Literals.size(); i < e; i+=2) {
unsigned literal0 = Literals[i];
unsigned literal2 = (i + 1 < e)?Literals[i + 1]:0;
MachineInstr *MILit = BuildMI(MBB, I, I->getDebugLoc(),
TII->get(AMDGPU::LITERALS))
.addImm(literal0)
.addImm(literal2);
ClauseContent.push_back(MILit);
}
}
assert(ClauseContent.size() < 128 && "ALU clause is too big");
ClauseHead->getOperand(7).setImm(ClauseContent.size() - 1);
return ClauseFile(ClauseHead, ClauseContent);
}
void
EmitFetchClause(MachineBasicBlock::iterator InsertPos, ClauseFile &Clause,
unsigned &CfCount) {
CounterPropagateAddr(Clause.first, CfCount);
MachineBasicBlock *BB = Clause.first->getParent();
BuildMI(BB, InsertPos->getDebugLoc(), TII->get(AMDGPU::FETCH_CLAUSE))
.addImm(CfCount);
for (unsigned i = 0, e = Clause.second.size(); i < e; ++i) {
BB->splice(InsertPos, BB, Clause.second[i]);
}
CfCount += 2 * Clause.second.size();
}
void
EmitALUClause(MachineBasicBlock::iterator InsertPos, ClauseFile &Clause,
unsigned &CfCount) {
Clause.first->getOperand(0).setImm(0);
CounterPropagateAddr(Clause.first, CfCount);
MachineBasicBlock *BB = Clause.first->getParent();
BuildMI(BB, InsertPos->getDebugLoc(), TII->get(AMDGPU::ALU_CLAUSE))
.addImm(CfCount);
for (unsigned i = 0, e = Clause.second.size(); i < e; ++i) {
BB->splice(InsertPos, BB, Clause.second[i]);
}
CfCount += Clause.second.size();
}
void CounterPropagateAddr(MachineInstr *MI, unsigned Addr) const {
MI->getOperand(0).setImm(Addr + MI->getOperand(0).getImm());
}
void CounterPropagateAddr(std::set<MachineInstr *> MIs, unsigned Addr)
const {
for (std::set<MachineInstr *>::iterator It = MIs.begin(), E = MIs.end();
It != E; ++It) {
MachineInstr *MI = *It;
CounterPropagateAddr(MI, Addr);
}
}
unsigned getHWStackSize(unsigned StackSubEntry, bool hasPush) const {
switch (ST.getGeneration()) {
case AMDGPUSubtarget::R600:
case AMDGPUSubtarget::R700:
if (hasPush)
StackSubEntry += 2;
break;
case AMDGPUSubtarget::EVERGREEN:
if (hasPush)
StackSubEntry ++;
case AMDGPUSubtarget::NORTHERN_ISLANDS:
StackSubEntry += 2;
break;
default: llvm_unreachable("Not a VLIW4/VLIW5 GPU");
}
return (StackSubEntry + 3)/4; // Need ceil value of StackSubEntry/4
}
public:
R600ControlFlowFinalizer(TargetMachine &tm) : MachineFunctionPass(ID),
TII (0), TRI(0),
ST(tm.getSubtarget<AMDGPUSubtarget>()) {
const AMDGPUSubtarget &ST = tm.getSubtarget<AMDGPUSubtarget>();
MaxFetchInst = ST.getTexVTXClauseSize();
}
virtual bool runOnMachineFunction(MachineFunction &MF) {
TII=static_cast<const R600InstrInfo *>(MF.getTarget().getInstrInfo());
TRI=static_cast<const R600RegisterInfo *>(MF.getTarget().getRegisterInfo());
unsigned MaxStack = 0;
unsigned CurrentStack = 0;
unsigned CurrentLoopDepth = 0;
bool HasPush = false;
for (MachineFunction::iterator MB = MF.begin(), ME = MF.end(); MB != ME;
++MB) {
MachineBasicBlock &MBB = *MB;
unsigned CfCount = 0;
std::vector<std::pair<unsigned, std::set<MachineInstr *> > > LoopStack;
std::vector<MachineInstr * > IfThenElseStack;
R600MachineFunctionInfo *MFI = MF.getInfo<R600MachineFunctionInfo>();
if (MFI->ShaderType == 1) {
BuildMI(MBB, MBB.begin(), MBB.findDebugLoc(MBB.begin()),
getHWInstrDesc(CF_CALL_FS));
CfCount++;
MaxStack = 1;
}
std::vector<ClauseFile> FetchClauses, AluClauses;
std::vector<MachineInstr *> LastAlu(1);
std::vector<MachineInstr *> ToPopAfter;
for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end();
I != E;) {
if (TII->usesTextureCache(I) || TII->usesVertexCache(I)) {
DEBUG(dbgs() << CfCount << ":"; I->dump(););
FetchClauses.push_back(MakeFetchClause(MBB, I));
CfCount++;
continue;
}
MachineBasicBlock::iterator MI = I;
if (MI->getOpcode() != AMDGPU::ENDIF)
LastAlu.back() = 0;
if (MI->getOpcode() == AMDGPU::CF_ALU)
LastAlu.back() = MI;
I++;
switch (MI->getOpcode()) {
case AMDGPU::CF_ALU_PUSH_BEFORE:
CurrentStack++;
MaxStack = std::max(MaxStack, CurrentStack);
HasPush = true;
if (ST.hasCaymanISA() && CurrentLoopDepth > 1) {
BuildMI(MBB, MI, MBB.findDebugLoc(MI), TII->get(AMDGPU::CF_PUSH_CM))
.addImm(CfCount + 1)
.addImm(1);
MI->setDesc(TII->get(AMDGPU::CF_ALU));
CfCount++;
}
case AMDGPU::CF_ALU:
I = MI;
AluClauses.push_back(MakeALUClause(MBB, I));
DEBUG(dbgs() << CfCount << ":"; MI->dump(););
CfCount++;
break;
case AMDGPU::WHILELOOP: {
CurrentStack+=4;
CurrentLoopDepth++;
MaxStack = std::max(MaxStack, CurrentStack);
MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
getHWInstrDesc(CF_WHILE_LOOP))
.addImm(1);
std::pair<unsigned, std::set<MachineInstr *> > Pair(CfCount,
std::set<MachineInstr *>());
Pair.second.insert(MIb);
LoopStack.push_back(Pair);
MI->eraseFromParent();
CfCount++;
break;
}
case AMDGPU::ENDLOOP: {
CurrentStack-=4;
CurrentLoopDepth--;
std::pair<unsigned, std::set<MachineInstr *> > Pair =
LoopStack.back();
LoopStack.pop_back();
CounterPropagateAddr(Pair.second, CfCount);
BuildMI(MBB, MI, MBB.findDebugLoc(MI), getHWInstrDesc(CF_END_LOOP))
.addImm(Pair.first + 1);
MI->eraseFromParent();
CfCount++;
break;
}
case AMDGPU::IF_PREDICATE_SET: {
LastAlu.push_back(0);
MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
getHWInstrDesc(CF_JUMP))
.addImm(0)
.addImm(0);
IfThenElseStack.push_back(MIb);
DEBUG(dbgs() << CfCount << ":"; MIb->dump(););
MI->eraseFromParent();
CfCount++;
break;
}
case AMDGPU::ELSE: {
MachineInstr * JumpInst = IfThenElseStack.back();
IfThenElseStack.pop_back();
CounterPropagateAddr(JumpInst, CfCount);
MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
getHWInstrDesc(CF_ELSE))
.addImm(0)
.addImm(0);
DEBUG(dbgs() << CfCount << ":"; MIb->dump(););
IfThenElseStack.push_back(MIb);
MI->eraseFromParent();
CfCount++;
break;
}
case AMDGPU::ENDIF: {
CurrentStack--;
if (LastAlu.back()) {
ToPopAfter.push_back(LastAlu.back());
} else {
MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
getHWInstrDesc(CF_POP))
.addImm(CfCount + 1)
.addImm(1);
(void)MIb;
DEBUG(dbgs() << CfCount << ":"; MIb->dump(););
CfCount++;
}
MachineInstr *IfOrElseInst = IfThenElseStack.back();
IfThenElseStack.pop_back();
CounterPropagateAddr(IfOrElseInst, CfCount);
IfOrElseInst->getOperand(1).setImm(1);
LastAlu.pop_back();
MI->eraseFromParent();
break;
}
case AMDGPU::BREAK: {
CfCount ++;
MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
getHWInstrDesc(CF_LOOP_BREAK))
.addImm(0);
LoopStack.back().second.insert(MIb);
MI->eraseFromParent();
break;
}
case AMDGPU::CONTINUE: {
MachineInstr *MIb = BuildMI(MBB, MI, MBB.findDebugLoc(MI),
getHWInstrDesc(CF_LOOP_CONTINUE))
.addImm(0);
LoopStack.back().second.insert(MIb);
MI->eraseFromParent();
CfCount++;
break;
}
case AMDGPU::RETURN: {
BuildMI(MBB, MI, MBB.findDebugLoc(MI), getHWInstrDesc(CF_END));
CfCount++;
MI->eraseFromParent();
if (CfCount % 2) {
BuildMI(MBB, I, MBB.findDebugLoc(MI), TII->get(AMDGPU::PAD));
CfCount++;
}
for (unsigned i = 0, e = FetchClauses.size(); i < e; i++)
EmitFetchClause(I, FetchClauses[i], CfCount);
for (unsigned i = 0, e = AluClauses.size(); i < e; i++)
EmitALUClause(I, AluClauses[i], CfCount);
}
default:
if (TII->isExport(MI->getOpcode())) {
DEBUG(dbgs() << CfCount << ":"; MI->dump(););
CfCount++;
}
break;
}
}
for (unsigned i = 0, e = ToPopAfter.size(); i < e; ++i) {
MachineInstr *Alu = ToPopAfter[i];
BuildMI(MBB, Alu, MBB.findDebugLoc((MachineBasicBlock::iterator)Alu),
TII->get(AMDGPU::CF_ALU_POP_AFTER))
.addImm(Alu->getOperand(0).getImm())
.addImm(Alu->getOperand(1).getImm())
.addImm(Alu->getOperand(2).getImm())
.addImm(Alu->getOperand(3).getImm())
.addImm(Alu->getOperand(4).getImm())
.addImm(Alu->getOperand(5).getImm())
.addImm(Alu->getOperand(6).getImm())
.addImm(Alu->getOperand(7).getImm())
.addImm(Alu->getOperand(8).getImm());
Alu->eraseFromParent();
}
MFI->StackSize = getHWStackSize(MaxStack, HasPush);
}
return false;
}
const char *getPassName() const {
return "R600 Control Flow Finalizer Pass";
}
};
char R600ControlFlowFinalizer::ID = 0;
} // end anonymous namespace
llvm::FunctionPass *llvm::createR600ControlFlowFinalizer(TargetMachine &TM) {
return new R600ControlFlowFinalizer(TM);
}