1 //===-- RISCVAsmPrinter.cpp - RISCV 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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file contains a printer that converts from our internal representation 10 // of machine-dependent LLVM code to the RISCV assembly language. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "MCTargetDesc/RISCVInstPrinter.h" 15 #include "MCTargetDesc/RISCVMCExpr.h" 16 #include "MCTargetDesc/RISCVTargetStreamer.h" 17 #include "RISCV.h" 18 #include "RISCVTargetMachine.h" 19 #include "TargetInfo/RISCVTargetInfo.h" 20 #include "llvm/ADT/Statistic.h" 21 #include "llvm/CodeGen/AsmPrinter.h" 22 #include "llvm/CodeGen/MachineConstantPool.h" 23 #include "llvm/CodeGen/MachineFunctionPass.h" 24 #include "llvm/CodeGen/MachineInstr.h" 25 #include "llvm/CodeGen/MachineModuleInfo.h" 26 #include "llvm/MC/MCAsmInfo.h" 27 #include "llvm/MC/MCInst.h" 28 #include "llvm/MC/MCStreamer.h" 29 #include "llvm/MC/MCSymbol.h" 30 #include "llvm/MC/TargetRegistry.h" 31 #include "llvm/Support/raw_ostream.h" 32 using namespace llvm; 33 34 #define DEBUG_TYPE "asm-printer" 35 36 STATISTIC(RISCVNumInstrsCompressed, 37 "Number of RISC-V Compressed instructions emitted"); 38 39 namespace { 40 class RISCVAsmPrinter : public AsmPrinter { 41 const MCSubtargetInfo *MCSTI; 42 const RISCVSubtarget *STI; 43 44 public: 45 explicit RISCVAsmPrinter(TargetMachine &TM, 46 std::unique_ptr<MCStreamer> Streamer) 47 : AsmPrinter(TM, std::move(Streamer)), MCSTI(TM.getMCSubtargetInfo()) {} 48 49 StringRef getPassName() const override { return "RISCV Assembly Printer"; } 50 51 bool runOnMachineFunction(MachineFunction &MF) override; 52 53 void emitInstruction(const MachineInstr *MI) override; 54 55 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, 56 const char *ExtraCode, raw_ostream &OS) override; 57 bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo, 58 const char *ExtraCode, raw_ostream &OS) override; 59 60 void EmitToStreamer(MCStreamer &S, const MCInst &Inst); 61 bool emitPseudoExpansionLowering(MCStreamer &OutStreamer, 62 const MachineInstr *MI); 63 64 // Wrapper needed for tblgenned pseudo lowering. 65 bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp) const { 66 return lowerRISCVMachineOperandToMCOperand(MO, MCOp, *this); 67 } 68 69 void emitStartOfAsmFile(Module &M) override; 70 void emitEndOfAsmFile(Module &M) override; 71 72 void emitFunctionEntryLabel() override; 73 74 private: 75 void emitAttributes(); 76 }; 77 } 78 79 #define GEN_COMPRESS_INSTR 80 #include "RISCVGenCompressInstEmitter.inc" 81 void RISCVAsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) { 82 MCInst CInst; 83 bool Res = compressInst(CInst, Inst, *STI, OutStreamer->getContext()); 84 if (Res) 85 ++RISCVNumInstrsCompressed; 86 AsmPrinter::EmitToStreamer(*OutStreamer, Res ? CInst : Inst); 87 } 88 89 // Simple pseudo-instructions have their lowering (with expansion to real 90 // instructions) auto-generated. 91 #include "RISCVGenMCPseudoLowering.inc" 92 93 void RISCVAsmPrinter::emitInstruction(const MachineInstr *MI) { 94 // Do any auto-generated pseudo lowerings. 95 if (emitPseudoExpansionLowering(*OutStreamer, MI)) 96 return; 97 98 MCInst TmpInst; 99 if (!lowerRISCVMachineInstrToMCInst(MI, TmpInst, *this)) 100 EmitToStreamer(*OutStreamer, TmpInst); 101 } 102 103 bool RISCVAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, 104 const char *ExtraCode, raw_ostream &OS) { 105 // First try the generic code, which knows about modifiers like 'c' and 'n'. 106 if (!AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, OS)) 107 return false; 108 109 const MachineOperand &MO = MI->getOperand(OpNo); 110 if (ExtraCode && ExtraCode[0]) { 111 if (ExtraCode[1] != 0) 112 return true; // Unknown modifier. 113 114 switch (ExtraCode[0]) { 115 default: 116 return true; // Unknown modifier. 117 case 'z': // Print zero register if zero, regular printing otherwise. 118 if (MO.isImm() && MO.getImm() == 0) { 119 OS << RISCVInstPrinter::getRegisterName(RISCV::X0); 120 return false; 121 } 122 break; 123 case 'i': // Literal 'i' if operand is not a register. 124 if (!MO.isReg()) 125 OS << 'i'; 126 return false; 127 } 128 } 129 130 switch (MO.getType()) { 131 case MachineOperand::MO_Immediate: 132 OS << MO.getImm(); 133 return false; 134 case MachineOperand::MO_Register: 135 OS << RISCVInstPrinter::getRegisterName(MO.getReg()); 136 return false; 137 case MachineOperand::MO_GlobalAddress: 138 PrintSymbolOperand(MO, OS); 139 return false; 140 case MachineOperand::MO_BlockAddress: { 141 MCSymbol *Sym = GetBlockAddressSymbol(MO.getBlockAddress()); 142 Sym->print(OS, MAI); 143 return false; 144 } 145 default: 146 break; 147 } 148 149 return true; 150 } 151 152 bool RISCVAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, 153 unsigned OpNo, 154 const char *ExtraCode, 155 raw_ostream &OS) { 156 if (!ExtraCode) { 157 const MachineOperand &MO = MI->getOperand(OpNo); 158 // For now, we only support register memory operands in registers and 159 // assume there is no addend 160 if (!MO.isReg()) 161 return true; 162 163 OS << "0(" << RISCVInstPrinter::getRegisterName(MO.getReg()) << ")"; 164 return false; 165 } 166 167 return AsmPrinter::PrintAsmMemoryOperand(MI, OpNo, ExtraCode, OS); 168 } 169 170 bool RISCVAsmPrinter::runOnMachineFunction(MachineFunction &MF) { 171 // Set the current MCSubtargetInfo to a copy which has the correct 172 // feature bits for the current MachineFunction 173 MCSubtargetInfo &NewSTI = 174 OutStreamer->getContext().getSubtargetCopy(*TM.getMCSubtargetInfo()); 175 NewSTI.setFeatureBits(MF.getSubtarget().getFeatureBits()); 176 MCSTI = &NewSTI; 177 STI = &MF.getSubtarget<RISCVSubtarget>(); 178 179 SetupMachineFunction(MF); 180 emitFunctionBody(); 181 return false; 182 } 183 184 void RISCVAsmPrinter::emitStartOfAsmFile(Module &M) { 185 if (TM.getTargetTriple().isOSBinFormatELF()) 186 emitAttributes(); 187 } 188 189 void RISCVAsmPrinter::emitEndOfAsmFile(Module &M) { 190 RISCVTargetStreamer &RTS = 191 static_cast<RISCVTargetStreamer &>(*OutStreamer->getTargetStreamer()); 192 193 if (TM.getTargetTriple().isOSBinFormatELF()) 194 RTS.finishAttributeSection(); 195 } 196 197 void RISCVAsmPrinter::emitAttributes() { 198 RISCVTargetStreamer &RTS = 199 static_cast<RISCVTargetStreamer &>(*OutStreamer->getTargetStreamer()); 200 RTS.emitTargetAttributes(*MCSTI); 201 } 202 203 void RISCVAsmPrinter::emitFunctionEntryLabel() { 204 AsmPrinter::emitFunctionEntryLabel(); 205 RISCVTargetStreamer &RTS = 206 static_cast<RISCVTargetStreamer &>(*OutStreamer->getTargetStreamer()); 207 RTS.setTargetABI(STI->getTargetABI()); 208 } 209 210 // Force static initialization. 211 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeRISCVAsmPrinter() { 212 RegisterAsmPrinter<RISCVAsmPrinter> X(getTheRISCV32Target()); 213 RegisterAsmPrinter<RISCVAsmPrinter> Y(getTheRISCV64Target()); 214 } 215