|  | //===- AMDGPUMCInstLower.cpp - Lower AMDGPU MachineInstr to an MCInst -----===// | 
|  | // | 
|  | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | 
|  | // See https://llvm.org/LICENSE.txt for license information. | 
|  | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  | // | 
|  | /// \file | 
|  | /// Code to lower AMDGPU MachineInstrs to their corresponding MCInst. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  | // | 
|  |  | 
|  | #include "AMDGPUMCInstLower.h" | 
|  | #include "AMDGPUAsmPrinter.h" | 
|  | #include "AMDGPUMachineFunction.h" | 
|  | #include "AMDGPUTargetMachine.h" | 
|  | #include "MCTargetDesc/AMDGPUInstPrinter.h" | 
|  | #include "MCTargetDesc/AMDGPUMCTargetDesc.h" | 
|  | #include "llvm/CodeGen/MachineBasicBlock.h" | 
|  | #include "llvm/CodeGen/MachineInstr.h" | 
|  | #include "llvm/IR/Constants.h" | 
|  | #include "llvm/IR/Function.h" | 
|  | #include "llvm/IR/GlobalVariable.h" | 
|  | #include "llvm/MC/MCCodeEmitter.h" | 
|  | #include "llvm/MC/MCContext.h" | 
|  | #include "llvm/MC/MCExpr.h" | 
|  | #include "llvm/MC/MCInst.h" | 
|  | #include "llvm/MC/MCObjectStreamer.h" | 
|  | #include "llvm/MC/MCStreamer.h" | 
|  | #include "llvm/Support/ErrorHandling.h" | 
|  | #include "llvm/Support/Format.h" | 
|  | #include <algorithm> | 
|  |  | 
|  | using namespace llvm; | 
|  |  | 
|  | #include "AMDGPUGenMCPseudoLowering.inc" | 
|  |  | 
|  | AMDGPUMCInstLower::AMDGPUMCInstLower(MCContext &ctx, | 
|  | const TargetSubtargetInfo &st, | 
|  | const AsmPrinter &ap): | 
|  | Ctx(ctx), ST(st), AP(ap) { } | 
|  |  | 
|  | static MCSymbolRefExpr::VariantKind getVariantKind(unsigned MOFlags) { | 
|  | switch (MOFlags) { | 
|  | default: | 
|  | return MCSymbolRefExpr::VK_None; | 
|  | case SIInstrInfo::MO_GOTPCREL: | 
|  | return MCSymbolRefExpr::VK_GOTPCREL; | 
|  | case SIInstrInfo::MO_GOTPCREL32_LO: | 
|  | return MCSymbolRefExpr::VK_AMDGPU_GOTPCREL32_LO; | 
|  | case SIInstrInfo::MO_GOTPCREL32_HI: | 
|  | return MCSymbolRefExpr::VK_AMDGPU_GOTPCREL32_HI; | 
|  | case SIInstrInfo::MO_REL32_LO: | 
|  | return MCSymbolRefExpr::VK_AMDGPU_REL32_LO; | 
|  | case SIInstrInfo::MO_REL32_HI: | 
|  | return MCSymbolRefExpr::VK_AMDGPU_REL32_HI; | 
|  | case SIInstrInfo::MO_ABS32_LO: | 
|  | return MCSymbolRefExpr::VK_AMDGPU_ABS32_LO; | 
|  | case SIInstrInfo::MO_ABS32_HI: | 
|  | return MCSymbolRefExpr::VK_AMDGPU_ABS32_HI; | 
|  | } | 
|  | } | 
|  |  | 
|  | bool AMDGPUMCInstLower::lowerOperand(const MachineOperand &MO, | 
|  | MCOperand &MCOp) const { | 
|  | switch (MO.getType()) { | 
|  | default: | 
|  | break; | 
|  | case MachineOperand::MO_Immediate: | 
|  | MCOp = MCOperand::createImm(MO.getImm()); | 
|  | return true; | 
|  | case MachineOperand::MO_Register: | 
|  | MCOp = MCOperand::createReg(AMDGPU::getMCReg(MO.getReg(), ST)); | 
|  | return true; | 
|  | case MachineOperand::MO_MachineBasicBlock: | 
|  | MCOp = MCOperand::createExpr( | 
|  | MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx)); | 
|  | return true; | 
|  | case MachineOperand::MO_GlobalAddress: { | 
|  | const GlobalValue *GV = MO.getGlobal(); | 
|  | SmallString<128> SymbolName; | 
|  | AP.getNameWithPrefix(SymbolName, GV); | 
|  | MCSymbol *Sym = Ctx.getOrCreateSymbol(SymbolName); | 
|  | const MCExpr *Expr = | 
|  | MCSymbolRefExpr::create(Sym, getVariantKind(MO.getTargetFlags()),Ctx); | 
|  | int64_t Offset = MO.getOffset(); | 
|  | if (Offset != 0) { | 
|  | Expr = MCBinaryExpr::createAdd(Expr, | 
|  | MCConstantExpr::create(Offset, Ctx), Ctx); | 
|  | } | 
|  | MCOp = MCOperand::createExpr(Expr); | 
|  | return true; | 
|  | } | 
|  | case MachineOperand::MO_ExternalSymbol: { | 
|  | MCSymbol *Sym = Ctx.getOrCreateSymbol(StringRef(MO.getSymbolName())); | 
|  | Sym->setExternal(true); | 
|  | const MCSymbolRefExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx); | 
|  | MCOp = MCOperand::createExpr(Expr); | 
|  | return true; | 
|  | } | 
|  | case MachineOperand::MO_RegisterMask: | 
|  | // Regmasks are like implicit defs. | 
|  | return false; | 
|  | case MachineOperand::MO_MCSymbol: | 
|  | if (MO.getTargetFlags() == SIInstrInfo::MO_FAR_BRANCH_OFFSET) { | 
|  | MCSymbol *Sym = MO.getMCSymbol(); | 
|  | MCOp = MCOperand::createExpr(Sym->getVariableValue()); | 
|  | return true; | 
|  | } | 
|  | break; | 
|  | } | 
|  | llvm_unreachable("unknown operand type"); | 
|  | } | 
|  |  | 
|  | void AMDGPUMCInstLower::lower(const MachineInstr *MI, MCInst &OutMI) const { | 
|  | unsigned Opcode = MI->getOpcode(); | 
|  | const auto *TII = static_cast<const SIInstrInfo*>(ST.getInstrInfo()); | 
|  |  | 
|  | // FIXME: Should be able to handle this with emitPseudoExpansionLowering. We | 
|  | // need to select it to the subtarget specific version, and there's no way to | 
|  | // do that with a single pseudo source operation. | 
|  | if (Opcode == AMDGPU::S_SETPC_B64_return) | 
|  | Opcode = AMDGPU::S_SETPC_B64; | 
|  | else if (Opcode == AMDGPU::SI_CALL) { | 
|  | // SI_CALL is just S_SWAPPC_B64 with an additional operand to track the | 
|  | // called function (which we need to remove here). | 
|  | OutMI.setOpcode(TII->pseudoToMCOpcode(AMDGPU::S_SWAPPC_B64)); | 
|  | MCOperand Dest, Src; | 
|  | lowerOperand(MI->getOperand(0), Dest); | 
|  | lowerOperand(MI->getOperand(1), Src); | 
|  | OutMI.addOperand(Dest); | 
|  | OutMI.addOperand(Src); | 
|  | return; | 
|  | } else if (Opcode == AMDGPU::SI_TCRETURN) { | 
|  | // TODO: How to use branch immediate and avoid register+add? | 
|  | Opcode = AMDGPU::S_SETPC_B64; | 
|  | } | 
|  |  | 
|  | int MCOpcode = TII->pseudoToMCOpcode(Opcode); | 
|  | if (MCOpcode == -1) { | 
|  | LLVMContext &C = MI->getParent()->getParent()->getFunction().getContext(); | 
|  | C.emitError("AMDGPUMCInstLower::lower - Pseudo instruction doesn't have " | 
|  | "a target-specific version: " + Twine(MI->getOpcode())); | 
|  | } | 
|  |  | 
|  | OutMI.setOpcode(MCOpcode); | 
|  |  | 
|  | for (const MachineOperand &MO : MI->explicit_operands()) { | 
|  | MCOperand MCOp; | 
|  | lowerOperand(MO, MCOp); | 
|  | OutMI.addOperand(MCOp); | 
|  | } | 
|  |  | 
|  | int FIIdx = AMDGPU::getNamedOperandIdx(MCOpcode, AMDGPU::OpName::fi); | 
|  | if (FIIdx >= (int)OutMI.getNumOperands()) | 
|  | OutMI.addOperand(MCOperand::createImm(0)); | 
|  | } | 
|  |  | 
|  | bool AMDGPUAsmPrinter::lowerOperand(const MachineOperand &MO, | 
|  | MCOperand &MCOp) const { | 
|  | const GCNSubtarget &STI = MF->getSubtarget<GCNSubtarget>(); | 
|  | AMDGPUMCInstLower MCInstLowering(OutContext, STI, *this); | 
|  | return MCInstLowering.lowerOperand(MO, MCOp); | 
|  | } | 
|  |  | 
|  | const MCExpr *AMDGPUAsmPrinter::lowerConstant(const Constant *CV) { | 
|  |  | 
|  | // Intercept LDS variables with known addresses | 
|  | if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(CV)) { | 
|  | if (AMDGPUMachineFunction::isKnownAddressLDSGlobal(*GV)) { | 
|  | unsigned offset = | 
|  | AMDGPUMachineFunction::calculateKnownAddressOfLDSGlobal(*GV); | 
|  | Constant *C = ConstantInt::get(CV->getContext(), APInt(32, offset)); | 
|  | return AsmPrinter::lowerConstant(C); | 
|  | } | 
|  | } | 
|  |  | 
|  | if (const MCExpr *E = lowerAddrSpaceCast(TM, CV, OutContext)) | 
|  | return E; | 
|  | return AsmPrinter::lowerConstant(CV); | 
|  | } | 
|  |  | 
|  | void AMDGPUAsmPrinter::emitInstruction(const MachineInstr *MI) { | 
|  | // FIXME: Enable feature predicate checks once all the test pass. | 
|  | // AMDGPU_MC::verifyInstructionPredicates(MI->getOpcode(), | 
|  | //                                        getSubtargetInfo().getFeatureBits()); | 
|  |  | 
|  | if (emitPseudoExpansionLowering(*OutStreamer, MI)) | 
|  | return; | 
|  |  | 
|  | const GCNSubtarget &STI = MF->getSubtarget<GCNSubtarget>(); | 
|  | AMDGPUMCInstLower MCInstLowering(OutContext, STI, *this); | 
|  |  | 
|  | StringRef Err; | 
|  | if (!STI.getInstrInfo()->verifyInstruction(*MI, Err)) { | 
|  | LLVMContext &C = MI->getParent()->getParent()->getFunction().getContext(); | 
|  | C.emitError("Illegal instruction detected: " + Err); | 
|  | MI->print(errs()); | 
|  | } | 
|  |  | 
|  | if (MI->isBundle()) { | 
|  | const MachineBasicBlock *MBB = MI->getParent(); | 
|  | MachineBasicBlock::const_instr_iterator I = ++MI->getIterator(); | 
|  | while (I != MBB->instr_end() && I->isInsideBundle()) { | 
|  | emitInstruction(&*I); | 
|  | ++I; | 
|  | } | 
|  | } else { | 
|  | // We don't want these pseudo instructions encoded. They are | 
|  | // placeholder terminator instructions and should only be printed as | 
|  | // comments. | 
|  | if (MI->getOpcode() == AMDGPU::SI_RETURN_TO_EPILOG) { | 
|  | if (isVerbose()) | 
|  | OutStreamer->emitRawComment(" return to shader part epilog"); | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (MI->getOpcode() == AMDGPU::WAVE_BARRIER) { | 
|  | if (isVerbose()) | 
|  | OutStreamer->emitRawComment(" wave barrier"); | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (MI->getOpcode() == AMDGPU::SCHED_BARRIER) { | 
|  | if (isVerbose()) { | 
|  | std::string HexString; | 
|  | raw_string_ostream HexStream(HexString); | 
|  | HexStream << format_hex(MI->getOperand(0).getImm(), 10, true); | 
|  | OutStreamer->emitRawComment(" sched_barrier mask(" + HexString + ")"); | 
|  | } | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (MI->getOpcode() == AMDGPU::SCHED_GROUP_BARRIER) { | 
|  | if (isVerbose()) { | 
|  | std::string HexString; | 
|  | raw_string_ostream HexStream(HexString); | 
|  | HexStream << format_hex(MI->getOperand(0).getImm(), 10, true); | 
|  | OutStreamer->emitRawComment( | 
|  | " sched_group_barrier mask(" + HexString + ") size(" + | 
|  | Twine(MI->getOperand(1).getImm()) + ") SyncID(" + | 
|  | Twine(MI->getOperand(2).getImm()) + ")"); | 
|  | } | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (MI->getOpcode() == AMDGPU::IGLP_OPT) { | 
|  | if (isVerbose()) { | 
|  | std::string HexString; | 
|  | raw_string_ostream HexStream(HexString); | 
|  | HexStream << format_hex(MI->getOperand(0).getImm(), 10, true); | 
|  | OutStreamer->emitRawComment(" iglp_opt mask(" + HexString + ")"); | 
|  | } | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (MI->getOpcode() == AMDGPU::SI_MASKED_UNREACHABLE) { | 
|  | if (isVerbose()) | 
|  | OutStreamer->emitRawComment(" divergent unreachable"); | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (MI->isMetaInstruction()) { | 
|  | if (isVerbose()) | 
|  | OutStreamer->emitRawComment(" meta instruction"); | 
|  | return; | 
|  | } | 
|  |  | 
|  | MCInst TmpInst; | 
|  | MCInstLowering.lower(MI, TmpInst); | 
|  | EmitToStreamer(*OutStreamer, TmpInst); | 
|  |  | 
|  | #ifdef EXPENSIVE_CHECKS | 
|  | // Check getInstSizeInBytes on explicitly specified CPUs (it cannot | 
|  | // work correctly for the generic CPU). | 
|  | // | 
|  | // The isPseudo check really shouldn't be here, but unfortunately there are | 
|  | // some negative lit tests that depend on being able to continue through | 
|  | // here even when pseudo instructions haven't been lowered. | 
|  | // | 
|  | // We also overestimate branch sizes with the offset bug. | 
|  | if (!MI->isPseudo() && STI.isCPUStringValid(STI.getCPU()) && | 
|  | (!STI.hasOffset3fBug() || !MI->isBranch())) { | 
|  | SmallVector<MCFixup, 4> Fixups; | 
|  | SmallVector<char, 16> CodeBytes; | 
|  | raw_svector_ostream CodeStream(CodeBytes); | 
|  |  | 
|  | std::unique_ptr<MCCodeEmitter> InstEmitter(createSIMCCodeEmitter( | 
|  | *STI.getInstrInfo(), OutContext)); | 
|  | InstEmitter->encodeInstruction(TmpInst, CodeStream, Fixups, STI); | 
|  |  | 
|  | assert(CodeBytes.size() == STI.getInstrInfo()->getInstSizeInBytes(*MI)); | 
|  | } | 
|  | #endif | 
|  |  | 
|  | if (DumpCodeInstEmitter) { | 
|  | // Disassemble instruction/operands to text | 
|  | DisasmLines.resize(DisasmLines.size() + 1); | 
|  | std::string &DisasmLine = DisasmLines.back(); | 
|  | raw_string_ostream DisasmStream(DisasmLine); | 
|  |  | 
|  | AMDGPUInstPrinter InstPrinter(*TM.getMCAsmInfo(), *STI.getInstrInfo(), | 
|  | *STI.getRegisterInfo()); | 
|  | InstPrinter.printInst(&TmpInst, 0, StringRef(), STI, DisasmStream); | 
|  |  | 
|  | // Disassemble instruction/operands to hex representation. | 
|  | SmallVector<MCFixup, 4> Fixups; | 
|  | SmallVector<char, 16> CodeBytes; | 
|  | raw_svector_ostream CodeStream(CodeBytes); | 
|  |  | 
|  | DumpCodeInstEmitter->encodeInstruction( | 
|  | TmpInst, CodeStream, Fixups, MF->getSubtarget<MCSubtargetInfo>()); | 
|  | HexLines.resize(HexLines.size() + 1); | 
|  | std::string &HexLine = HexLines.back(); | 
|  | raw_string_ostream HexStream(HexLine); | 
|  |  | 
|  | for (size_t i = 0; i < CodeBytes.size(); i += 4) { | 
|  | unsigned int CodeDWord = *(unsigned int *)&CodeBytes[i]; | 
|  | HexStream << format("%s%08X", (i > 0 ? " " : ""), CodeDWord); | 
|  | } | 
|  |  | 
|  | DisasmStream.flush(); | 
|  | DisasmLineMaxLen = std::max(DisasmLineMaxLen, DisasmLine.size()); | 
|  | } | 
|  | } | 
|  | } |