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Diffstat (limited to 'contrib/llvm-project/llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp')
| -rw-r--r-- | contrib/llvm-project/llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp | 413 |
1 files changed, 413 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp b/contrib/llvm-project/llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp new file mode 100644 index 000000000000..99d229c9b74e --- /dev/null +++ b/contrib/llvm-project/llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp @@ -0,0 +1,413 @@ +//===- 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 "AMDGPUAsmPrinter.h" +#include "AMDGPUSubtarget.h" +#include "AMDGPUTargetMachine.h" +#include "MCTargetDesc/AMDGPUInstPrinter.h" +#include "MCTargetDesc/AMDGPUMCTargetDesc.h" +#include "R600AsmPrinter.h" +#include "SIInstrInfo.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; + +namespace { + +class AMDGPUMCInstLower { + MCContext &Ctx; + const TargetSubtargetInfo &ST; + const AsmPrinter &AP; + + const MCExpr *getLongBranchBlockExpr(const MachineBasicBlock &SrcBB, + const MachineOperand &MO) const; + +public: + AMDGPUMCInstLower(MCContext &ctx, const TargetSubtargetInfo &ST, + const AsmPrinter &AP); + + bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp) const; + + /// Lower a MachineInstr to an MCInst + void lower(const MachineInstr *MI, MCInst &OutMI) const; + +}; + +class R600MCInstLower : public AMDGPUMCInstLower { +public: + R600MCInstLower(MCContext &ctx, const R600Subtarget &ST, + const AsmPrinter &AP); + + /// Lower a MachineInstr to an MCInst + void lower(const MachineInstr *MI, MCInst &OutMI) const; +}; + + +} // End anonymous namespace + +#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; + } +} + +const MCExpr *AMDGPUMCInstLower::getLongBranchBlockExpr( + const MachineBasicBlock &SrcBB, + const MachineOperand &MO) const { + const MCExpr *DestBBSym + = MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx); + const MCExpr *SrcBBSym = MCSymbolRefExpr::create(SrcBB.getSymbol(), Ctx); + + // FIXME: The first half of this assert should be removed. This should + // probably be PC relative instead of using the source block symbol, and + // therefore the indirect branch expansion should use a bundle. + assert( + skipDebugInstructionsForward(SrcBB.begin(), SrcBB.end())->getOpcode() == + AMDGPU::S_GETPC_B64 && + ST.getInstrInfo()->get(AMDGPU::S_GETPC_B64).Size == 4); + + // s_getpc_b64 returns the address of next instruction. + const MCConstantExpr *One = MCConstantExpr::create(4, Ctx); + SrcBBSym = MCBinaryExpr::createAdd(SrcBBSym, One, Ctx); + + if (MO.getTargetFlags() == SIInstrInfo::MO_LONG_BRANCH_FORWARD) + return MCBinaryExpr::createSub(DestBBSym, SrcBBSym, Ctx); + + assert(MO.getTargetFlags() == SIInstrInfo::MO_LONG_BRANCH_BACKWARD); + return MCBinaryExpr::createSub(SrcBBSym, DestBBSym, Ctx); +} + +bool AMDGPUMCInstLower::lowerOperand(const MachineOperand &MO, + MCOperand &MCOp) const { + switch (MO.getType()) { + default: + llvm_unreachable("unknown operand type"); + 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: { + if (MO.getTargetFlags() != 0) { + MCOp = MCOperand::createExpr( + getLongBranchBlockExpr(*MO.getParent()->getParent(), MO)); + } else { + 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; + } +} + +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); +} + +static const MCExpr *lowerAddrSpaceCast(const TargetMachine &TM, + const Constant *CV, + MCContext &OutContext) { + // TargetMachine does not support llvm-style cast. Use C++-style cast. + // This is safe since TM is always of type AMDGPUTargetMachine or its + // derived class. + auto &AT = static_cast<const AMDGPUTargetMachine&>(TM); + auto *CE = dyn_cast<ConstantExpr>(CV); + + // Lower null pointers in private and local address space. + // Clang generates addrspacecast for null pointers in private and local + // address space, which needs to be lowered. + if (CE && CE->getOpcode() == Instruction::AddrSpaceCast) { + auto Op = CE->getOperand(0); + auto SrcAddr = Op->getType()->getPointerAddressSpace(); + if (Op->isNullValue() && AT.getNullPointerValue(SrcAddr) == 0) { + auto DstAddr = CE->getType()->getPointerAddressSpace(); + return MCConstantExpr::create(AT.getNullPointerValue(DstAddr), + OutContext); + } + } + return nullptr; +} + +const MCExpr *AMDGPUAsmPrinter::lowerConstant(const Constant *CV) { + if (const MCExpr *E = lowerAddrSpaceCast(TM, CV, OutContext)) + return E; + return AsmPrinter::lowerConstant(CV); +} + +void AMDGPUAsmPrinter::emitInstruction(const MachineInstr *MI) { + 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 SI_MASK_BRANCH/SI_RETURN_TO_EPILOG encoded. They are + // placeholder terminator instructions and should only be printed as + // comments. + if (MI->getOpcode() == AMDGPU::SI_MASK_BRANCH) { + if (isVerbose()) { + SmallVector<char, 16> BBStr; + raw_svector_ostream Str(BBStr); + + const MachineBasicBlock *MBB = MI->getOperand(0).getMBB(); + const MCSymbolRefExpr *Expr + = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext); + Expr->print(Str, MAI); + OutStreamer->emitRawComment(Twine(" mask branch ") + BBStr); + } + + return; + } + + 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::SI_MASKED_UNREACHABLE) { + if (isVerbose()) + OutStreamer->emitRawComment(" divergent unreachable"); + return; + } + + MCInst TmpInst; + MCInstLowering.lower(MI, TmpInst); + EmitToStreamer(*OutStreamer, TmpInst); + +#ifdef EXPENSIVE_CHECKS + // Sanity-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. + if (!MI->isPseudo() && STI.isCPUStringValid(STI.getCPU())) { + SmallVector<MCFixup, 4> Fixups; + SmallVector<char, 16> CodeBytes; + raw_svector_ostream CodeStream(CodeBytes); + + std::unique_ptr<MCCodeEmitter> InstEmitter(createSIMCCodeEmitter( + *STI.getInstrInfo(), *OutContext.getRegisterInfo(), 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()); + } + } +} + +R600MCInstLower::R600MCInstLower(MCContext &Ctx, const R600Subtarget &ST, + const AsmPrinter &AP) : + AMDGPUMCInstLower(Ctx, ST, AP) { } + +void R600MCInstLower::lower(const MachineInstr *MI, MCInst &OutMI) const { + OutMI.setOpcode(MI->getOpcode()); + for (const MachineOperand &MO : MI->explicit_operands()) { + MCOperand MCOp; + lowerOperand(MO, MCOp); + OutMI.addOperand(MCOp); + } +} + +void R600AsmPrinter::emitInstruction(const MachineInstr *MI) { + const R600Subtarget &STI = MF->getSubtarget<R600Subtarget>(); + R600MCInstLower 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 { + MCInst TmpInst; + MCInstLowering.lower(MI, TmpInst); + EmitToStreamer(*OutStreamer, TmpInst); + } +} + +const MCExpr *R600AsmPrinter::lowerConstant(const Constant *CV) { + if (const MCExpr *E = lowerAddrSpaceCast(TM, CV, OutContext)) + return E; + return AsmPrinter::lowerConstant(CV); +} |