1 //===-- MSP430AsmPrinter.cpp - MSP430 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 MSP430 assembly language. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "MCTargetDesc/MSP430InstPrinter.h" 15 #include "MSP430MCInstLower.h" 16 #include "MSP430TargetMachine.h" 17 #include "TargetInfo/MSP430TargetInfo.h" 18 #include "llvm/BinaryFormat/ELF.h" 19 #include "llvm/CodeGen/AsmPrinter.h" 20 #include "llvm/CodeGen/MachineConstantPool.h" 21 #include "llvm/CodeGen/MachineInstr.h" 22 #include "llvm/CodeGen/MachineModuleInfo.h" 23 #include "llvm/IR/Mangler.h" 24 #include "llvm/MC/MCAsmInfo.h" 25 #include "llvm/MC/MCInst.h" 26 #include "llvm/MC/MCSectionELF.h" 27 #include "llvm/MC/MCStreamer.h" 28 #include "llvm/MC/MCSymbol.h" 29 #include "llvm/MC/TargetRegistry.h" 30 #include "llvm/Support/raw_ostream.h" 31 using namespace llvm; 32 33 #define DEBUG_TYPE "asm-printer" 34 35 namespace { 36 class MSP430AsmPrinter : public AsmPrinter { 37 public: 38 MSP430AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer) 39 : AsmPrinter(TM, std::move(Streamer)) {} 40 41 StringRef getPassName() const override { return "MSP430 Assembly Printer"; } 42 43 bool runOnMachineFunction(MachineFunction &MF) override; 44 45 void PrintSymbolOperand(const MachineOperand &MO, raw_ostream &O) override; 46 void printOperand(const MachineInstr *MI, int OpNum, 47 raw_ostream &O, const char* Modifier = nullptr); 48 void printSrcMemOperand(const MachineInstr *MI, int OpNum, 49 raw_ostream &O); 50 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, 51 const char *ExtraCode, raw_ostream &O) override; 52 bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo, 53 const char *ExtraCode, raw_ostream &O) override; 54 void emitInstruction(const MachineInstr *MI) override; 55 56 void EmitInterruptVectorSection(MachineFunction &ISR); 57 }; 58 } // end of anonymous namespace 59 60 void MSP430AsmPrinter::PrintSymbolOperand(const MachineOperand &MO, 61 raw_ostream &O) { 62 uint64_t Offset = MO.getOffset(); 63 if (Offset) 64 O << '(' << Offset << '+'; 65 66 getSymbol(MO.getGlobal())->print(O, MAI); 67 68 if (Offset) 69 O << ')'; 70 } 71 72 void MSP430AsmPrinter::printOperand(const MachineInstr *MI, int OpNum, 73 raw_ostream &O, const char *Modifier) { 74 const MachineOperand &MO = MI->getOperand(OpNum); 75 switch (MO.getType()) { 76 default: llvm_unreachable("Not implemented yet!"); 77 case MachineOperand::MO_Register: 78 O << MSP430InstPrinter::getRegisterName(MO.getReg()); 79 return; 80 case MachineOperand::MO_Immediate: 81 if (!Modifier || strcmp(Modifier, "nohash")) 82 O << '#'; 83 O << MO.getImm(); 84 return; 85 case MachineOperand::MO_MachineBasicBlock: 86 MO.getMBB()->getSymbol()->print(O, MAI); 87 return; 88 case MachineOperand::MO_GlobalAddress: { 89 // If the global address expression is a part of displacement field with a 90 // register base, we should not emit any prefix symbol here, e.g. 91 // mov.w glb(r1), r2 92 // Otherwise (!) msp430-as will silently miscompile the output :( 93 if (!Modifier || strcmp(Modifier, "nohash")) 94 O << '#'; 95 PrintSymbolOperand(MO, O); 96 return; 97 } 98 } 99 } 100 101 void MSP430AsmPrinter::printSrcMemOperand(const MachineInstr *MI, int OpNum, 102 raw_ostream &O) { 103 const MachineOperand &Base = MI->getOperand(OpNum); 104 const MachineOperand &Disp = MI->getOperand(OpNum+1); 105 106 // Print displacement first 107 108 // Imm here is in fact global address - print extra modifier. 109 if (Disp.isImm() && Base.getReg() == MSP430::SR) 110 O << '&'; 111 printOperand(MI, OpNum+1, O, "nohash"); 112 113 // Print register base field 114 if (Base.getReg() != MSP430::SR && Base.getReg() != MSP430::PC) { 115 O << '('; 116 printOperand(MI, OpNum, O); 117 O << ')'; 118 } 119 } 120 121 /// PrintAsmOperand - Print out an operand for an inline asm expression. 122 /// 123 bool MSP430AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, 124 const char *ExtraCode, raw_ostream &O) { 125 // Does this asm operand have a single letter operand modifier? 126 if (ExtraCode && ExtraCode[0]) 127 return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O); 128 129 printOperand(MI, OpNo, O); 130 return false; 131 } 132 133 bool MSP430AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, 134 unsigned OpNo, 135 const char *ExtraCode, 136 raw_ostream &O) { 137 if (ExtraCode && ExtraCode[0]) { 138 return true; // Unknown modifier. 139 } 140 printSrcMemOperand(MI, OpNo, O); 141 return false; 142 } 143 144 //===----------------------------------------------------------------------===// 145 void MSP430AsmPrinter::emitInstruction(const MachineInstr *MI) { 146 MSP430_MC::verifyInstructionPredicates(MI->getOpcode(), 147 getSubtargetInfo().getFeatureBits()); 148 149 MSP430MCInstLower MCInstLowering(OutContext, *this); 150 151 MCInst TmpInst; 152 MCInstLowering.Lower(MI, TmpInst); 153 EmitToStreamer(*OutStreamer, TmpInst); 154 } 155 156 void MSP430AsmPrinter::EmitInterruptVectorSection(MachineFunction &ISR) { 157 MCSection *Cur = OutStreamer->getCurrentSectionOnly(); 158 const auto *F = &ISR.getFunction(); 159 if (F->getCallingConv() != CallingConv::MSP430_INTR) { 160 report_fatal_error("Functions with 'interrupt' attribute must have msp430_intrcc CC"); 161 } 162 StringRef IVIdx = F->getFnAttribute("interrupt").getValueAsString(); 163 MCSection *IV = OutStreamer->getContext().getELFSection( 164 "__interrupt_vector_" + IVIdx, 165 ELF::SHT_PROGBITS, ELF::SHF_ALLOC | ELF::SHF_EXECINSTR); 166 OutStreamer->switchSection(IV); 167 168 const MCSymbol *FunctionSymbol = getSymbol(F); 169 OutStreamer->emitSymbolValue(FunctionSymbol, TM.getProgramPointerSize()); 170 OutStreamer->switchSection(Cur); 171 } 172 173 bool MSP430AsmPrinter::runOnMachineFunction(MachineFunction &MF) { 174 // Emit separate section for an interrupt vector if ISR 175 if (MF.getFunction().hasFnAttribute("interrupt")) { 176 EmitInterruptVectorSection(MF); 177 } 178 179 SetupMachineFunction(MF); 180 emitFunctionBody(); 181 return false; 182 } 183 184 // Force static initialization. 185 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeMSP430AsmPrinter() { 186 RegisterAsmPrinter<MSP430AsmPrinter> X(getTheMSP430Target()); 187 } 188