329 lines · cpp
1//===-- CSKYAsmPrinter.cpp - CSKY LLVM assembly writer --------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file contains a printer that converts from our internal representation10// of machine-dependent LLVM code to the CSKY assembly language.11//12//===----------------------------------------------------------------------===//13#include "CSKYAsmPrinter.h"14#include "CSKY.h"15#include "CSKYConstantPoolValue.h"16#include "CSKYTargetMachine.h"17#include "MCTargetDesc/CSKYInstPrinter.h"18#include "MCTargetDesc/CSKYMCAsmInfo.h"19#include "MCTargetDesc/CSKYTargetStreamer.h"20#include "TargetInfo/CSKYTargetInfo.h"21#include "llvm/ADT/Statistic.h"22#include "llvm/CodeGen/AsmPrinter.h"23#include "llvm/CodeGen/MachineConstantPool.h"24#include "llvm/CodeGen/MachineFrameInfo.h"25#include "llvm/IR/DataLayout.h"26#include "llvm/MC/MCAsmInfo.h"27#include "llvm/MC/MCContext.h"28#include "llvm/MC/MCInstBuilder.h"29#include "llvm/MC/MCStreamer.h"30#include "llvm/MC/TargetRegistry.h"31 32using namespace llvm;33 34#define DEBUG_TYPE "csky-asm-printer"35 36STATISTIC(CSKYNumInstrsCompressed,37 "Number of C-SKY Compressed instructions emitted");38 39CSKYAsmPrinter::CSKYAsmPrinter(llvm::TargetMachine &TM,40 std::unique_ptr<llvm::MCStreamer> Streamer)41 : AsmPrinter(TM, std::move(Streamer)), MCInstLowering(OutContext, *this) {}42 43bool CSKYAsmPrinter::runOnMachineFunction(MachineFunction &MF) {44 MCP = MF.getConstantPool();45 TII = MF.getSubtarget().getInstrInfo();46 47 // Set the current MCSubtargetInfo to a copy which has the correct48 // feature bits for the current MachineFunction49 MCSubtargetInfo &NewSTI =50 OutStreamer->getContext().getSubtargetCopy(*TM.getMCSubtargetInfo());51 NewSTI.setFeatureBits(MF.getSubtarget().getFeatureBits());52 Subtarget = &NewSTI;53 54 return AsmPrinter::runOnMachineFunction(MF);55}56 57#define GEN_COMPRESS_INSTR58#include "CSKYGenCompressInstEmitter.inc"59void CSKYAsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {60 MCInst CInst;61 bool Res = compressInst(CInst, Inst, *Subtarget);62 if (Res)63 ++CSKYNumInstrsCompressed;64 AsmPrinter::EmitToStreamer(*OutStreamer, Res ? CInst : Inst);65}66 67// Simple pseudo-instructions have their lowering (with expansion to real68// instructions) auto-generated.69#include "CSKYGenMCPseudoLowering.inc"70 71void CSKYAsmPrinter::expandTLSLA(const MachineInstr *MI) {72 DebugLoc DL = MI->getDebugLoc();73 74 MCSymbol *PCLabel = OutContext.getOrCreateSymbol(75 Twine(MAI->getPrivateGlobalPrefix()) + "PC" + Twine(getFunctionNumber()) +76 "_" + Twine(MI->getOperand(3).getImm()));77 78 OutStreamer->emitLabel(PCLabel);79 80 auto Instr = BuildMI(*MF, DL, TII->get(CSKY::LRW32))81 .add(MI->getOperand(0))82 .add(MI->getOperand(2));83 MCInst LRWInst;84 MCInstLowering.Lower(Instr, LRWInst);85 EmitToStreamer(*OutStreamer, LRWInst);86 87 Instr = BuildMI(*MF, DL, TII->get(CSKY::GRS32))88 .add(MI->getOperand(1))89 .addSym(PCLabel);90 MCInst GRSInst;91 MCInstLowering.Lower(Instr, GRSInst);92 EmitToStreamer(*OutStreamer, GRSInst);93 return;94}95 96void CSKYAsmPrinter::emitCustomConstantPool(const MachineInstr *MI) {97 98 // This instruction represents a floating constant pool in the function.99 // The first operand is the ID# for this instruction, the second is the100 // index into the MachineConstantPool that this is, the third is the size101 // in bytes of this constant pool entry.102 // The required alignment is specified on the basic block holding this MI.103 unsigned LabelId = (unsigned)MI->getOperand(0).getImm();104 unsigned CPIdx = (unsigned)MI->getOperand(1).getIndex();105 106 // If this is the first entry of the pool, mark it.107 if (!InConstantPool) {108 OutStreamer->emitValueToAlignment(Align(4));109 InConstantPool = true;110 }111 112 OutStreamer->emitLabel(GetCPISymbol(LabelId));113 114 const MachineConstantPoolEntry &MCPE = MCP->getConstants()[CPIdx];115 if (MCPE.isMachineConstantPoolEntry())116 emitMachineConstantPoolValue(MCPE.Val.MachineCPVal);117 else118 emitGlobalConstant(MF->getDataLayout(), MCPE.Val.ConstVal);119 return;120}121 122void CSKYAsmPrinter::emitFunctionBodyEnd() {123 // Make sure to terminate any constant pools that were at the end124 // of the function.125 if (!InConstantPool)126 return;127 InConstantPool = false;128}129 130void CSKYAsmPrinter::emitStartOfAsmFile(Module &M) {131 if (TM.getTargetTriple().isOSBinFormatELF())132 emitAttributes();133}134 135void CSKYAsmPrinter::emitEndOfAsmFile(Module &M) {136 CSKYTargetStreamer &CTS =137 static_cast<CSKYTargetStreamer &>(*OutStreamer->getTargetStreamer());138 139 if (TM.getTargetTriple().isOSBinFormatELF())140 CTS.finishAttributeSection();141}142 143void CSKYAsmPrinter::emitInstruction(const MachineInstr *MI) {144 CSKY_MC::verifyInstructionPredicates(MI->getOpcode(),145 getSubtargetInfo().getFeatureBits());146 147 // Do any auto-generated pseudo lowerings.148 if (MCInst OutInst; lowerPseudoInstExpansion(MI, OutInst)) {149 EmitToStreamer(*OutStreamer, OutInst);150 return;151 }152 153 // If we just ended a constant pool, mark it as such.154 if (InConstantPool && MI->getOpcode() != CSKY::CONSTPOOL_ENTRY) {155 InConstantPool = false;156 }157 158 if (MI->getOpcode() == CSKY::PseudoTLSLA32)159 return expandTLSLA(MI);160 161 if (MI->getOpcode() == CSKY::CONSTPOOL_ENTRY)162 return emitCustomConstantPool(MI);163 164 MCInst TmpInst;165 MCInstLowering.Lower(MI, TmpInst);166 EmitToStreamer(*OutStreamer, TmpInst);167}168 169// Convert a CSKY-specific constant pool modifier into the associated170// MCSymbolRefExpr variant kind.171static CSKY::Specifier getModifierVariantKind(CSKYCP::CSKYCPModifier Modifier) {172 switch (Modifier) {173 case CSKYCP::NO_MOD:174 return CSKY::S_None;175 case CSKYCP::ADDR:176 return CSKY::S_ADDR;177 case CSKYCP::GOT:178 return CSKY::S_GOT;179 case CSKYCP::GOTOFF:180 return CSKY::S_GOTOFF;181 case CSKYCP::PLT:182 return CSKY::S_PLT;183 case CSKYCP::TLSGD:184 return CSKY::S_TLSGD;185 case CSKYCP::TLSLE:186 return CSKY::S_TLSLE;187 case CSKYCP::TLSIE:188 return CSKY::S_TLSIE;189 }190 llvm_unreachable("Invalid CSKYCPModifier!");191}192 193void CSKYAsmPrinter::emitMachineConstantPoolValue(194 MachineConstantPoolValue *MCPV) {195 int Size = getDataLayout().getTypeAllocSize(MCPV->getType());196 CSKYConstantPoolValue *CCPV = static_cast<CSKYConstantPoolValue *>(MCPV);197 MCSymbol *MCSym;198 199 if (CCPV->isBlockAddress()) {200 const BlockAddress *BA =201 cast<CSKYConstantPoolConstant>(CCPV)->getBlockAddress();202 MCSym = GetBlockAddressSymbol(BA);203 } else if (CCPV->isGlobalValue()) {204 const GlobalValue *GV = cast<CSKYConstantPoolConstant>(CCPV)->getGV();205 MCSym = getSymbol(GV);206 } else if (CCPV->isMachineBasicBlock()) {207 const MachineBasicBlock *MBB = cast<CSKYConstantPoolMBB>(CCPV)->getMBB();208 MCSym = MBB->getSymbol();209 } else if (CCPV->isJT()) {210 signed JTI = cast<CSKYConstantPoolJT>(CCPV)->getJTI();211 MCSym = GetJTISymbol(JTI);212 } else if (CCPV->isConstPool()) {213 const Constant *C = cast<CSKYConstantPoolConstant>(CCPV)->getConstantPool();214 MCSym = GetCPISymbol(MCP->getConstantPoolIndex(C, Align(4)));215 } else {216 assert(CCPV->isExtSymbol() && "unrecognized constant pool value");217 StringRef Sym = cast<CSKYConstantPoolSymbol>(CCPV)->getSymbol();218 MCSym = GetExternalSymbolSymbol(Sym);219 }220 // Create an MCSymbol for the reference.221 const MCExpr *Expr = MCSymbolRefExpr::create(MCSym, OutContext);222 223 if (CCPV->getPCAdjustment()) {224 225 MCSymbol *PCLabel = OutContext.getOrCreateSymbol(226 Twine(MAI->getPrivateGlobalPrefix()) + "PC" +227 Twine(getFunctionNumber()) + "_" + Twine(CCPV->getLabelID()));228 229 const MCExpr *PCRelExpr = MCSymbolRefExpr::create(PCLabel, OutContext);230 if (CCPV->mustAddCurrentAddress()) {231 // We want "(<expr> - .)", but MC doesn't have a concept of the '.'232 // label, so just emit a local label end reference that instead.233 MCSymbol *DotSym = OutContext.createTempSymbol();234 OutStreamer->emitLabel(DotSym);235 const MCExpr *DotExpr = MCSymbolRefExpr::create(DotSym, OutContext);236 PCRelExpr = MCBinaryExpr::createSub(PCRelExpr, DotExpr, OutContext);237 }238 Expr = MCBinaryExpr::createSub(Expr, PCRelExpr, OutContext);239 }240 241 // Create an MCSymbol for the reference.242 Expr = MCSpecifierExpr::create(243 Expr, getModifierVariantKind(CCPV->getModifier()), OutContext);244 245 OutStreamer->emitValue(Expr, Size);246}247 248void CSKYAsmPrinter::emitAttributes() {249 CSKYTargetStreamer &CTS =250 static_cast<CSKYTargetStreamer &>(*OutStreamer->getTargetStreamer());251 252 const Triple &TT = TM.getTargetTriple();253 StringRef CPU = TM.getTargetCPU();254 StringRef FS = TM.getTargetFeatureString();255 const CSKYTargetMachine &CTM = static_cast<const CSKYTargetMachine &>(TM);256 /* TuneCPU doesn't impact emission of ELF attributes, ELF attributes only257 care about arch related features, so we can set TuneCPU as CPU. */258 const CSKYSubtarget STI(TT, CPU, /*TuneCPU=*/CPU, FS, CTM);259 260 CTS.emitTargetAttributes(STI);261}262 263bool CSKYAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,264 const char *ExtraCode, raw_ostream &OS) {265 // First try the generic code, which knows about modifiers like 'c' and 'n'.266 if (!AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, OS))267 return false;268 269 const MachineOperand &MO = MI->getOperand(OpNo);270 if (ExtraCode && ExtraCode[0]) {271 if (ExtraCode[1] != 0)272 return true; // Unknown modifier.273 274 switch (ExtraCode[0]) {275 default:276 return true; // Unknown modifier.277 case 'R':278 if (MO.getType() == MachineOperand::MO_Register) {279 OS << CSKYInstPrinter::getRegisterName(MO.getReg() + 1);280 return false;281 }282 }283 }284 285 switch (MO.getType()) {286 case MachineOperand::MO_Immediate:287 OS << MO.getImm();288 return false;289 case MachineOperand::MO_Register:290 if (MO.getReg() == CSKY::C)291 return false;292 OS << CSKYInstPrinter::getRegisterName(MO.getReg());293 return false;294 case MachineOperand::MO_GlobalAddress:295 PrintSymbolOperand(MO, OS);296 return false;297 case MachineOperand::MO_BlockAddress: {298 MCSymbol *Sym = GetBlockAddressSymbol(MO.getBlockAddress());299 Sym->print(OS, MAI);300 return false;301 }302 default:303 break;304 }305 306 return true;307}308 309bool CSKYAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,310 unsigned OpNo, const char *ExtraCode,311 raw_ostream &OS) {312 if (!ExtraCode) {313 const MachineOperand &MO = MI->getOperand(OpNo);314 // For now, we only support register memory operands in registers and315 // assume there is no addend316 if (!MO.isReg())317 return true;318 319 OS << "(" << CSKYInstPrinter::getRegisterName(MO.getReg()) << ", 0)";320 return false;321 }322 323 return AsmPrinter::PrintAsmMemoryOperand(MI, OpNo, ExtraCode, OS);324}325 326extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeCSKYAsmPrinter() {327 RegisterAsmPrinter<CSKYAsmPrinter> X(getTheCSKYTarget());328}329