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 "MSP430.h"
16 #include "MSP430InstrInfo.h"
17 #include "MSP430MCInstLower.h"
18 #include "MSP430TargetMachine.h"
19 #include "TargetInfo/MSP430TargetInfo.h"
20 #include "llvm/BinaryFormat/ELF.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/IR/Constants.h"
27 #include "llvm/IR/DerivedTypes.h"
28 #include "llvm/IR/Mangler.h"
29 #include "llvm/IR/Module.h"
30 #include "llvm/MC/MCAsmInfo.h"
31 #include "llvm/MC/MCInst.h"
32 #include "llvm/MC/MCSectionELF.h"
33 #include "llvm/MC/MCStreamer.h"
34 #include "llvm/MC/MCSymbol.h"
35 #include "llvm/Support/TargetRegistry.h"
36 #include "llvm/Support/raw_ostream.h"
37 using namespace llvm;
38
39 #define DEBUG_TYPE "asm-printer"
40
41 namespace {
42 class MSP430AsmPrinter : public AsmPrinter {
43 public:
MSP430AsmPrinter(TargetMachine & TM,std::unique_ptr<MCStreamer> Streamer)44 MSP430AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
45 : AsmPrinter(TM, std::move(Streamer)) {}
46
getPassName() const47 StringRef getPassName() const override { return "MSP430 Assembly Printer"; }
48
49 bool runOnMachineFunction(MachineFunction &MF) override;
50
51 void PrintSymbolOperand(const MachineOperand &MO, raw_ostream &O) override;
52 void printOperand(const MachineInstr *MI, int OpNum,
53 raw_ostream &O, const char* Modifier = nullptr);
54 void printSrcMemOperand(const MachineInstr *MI, int OpNum,
55 raw_ostream &O);
56 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
57 const char *ExtraCode, raw_ostream &O) override;
58 bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
59 const char *ExtraCode, raw_ostream &O) override;
60 void emitInstruction(const MachineInstr *MI) override;
61
62 void EmitInterruptVectorSection(MachineFunction &ISR);
63 };
64 } // end of anonymous namespace
65
PrintSymbolOperand(const MachineOperand & MO,raw_ostream & O)66 void MSP430AsmPrinter::PrintSymbolOperand(const MachineOperand &MO,
67 raw_ostream &O) {
68 uint64_t Offset = MO.getOffset();
69 if (Offset)
70 O << '(' << Offset << '+';
71
72 getSymbol(MO.getGlobal())->print(O, MAI);
73
74 if (Offset)
75 O << ')';
76 }
77
printOperand(const MachineInstr * MI,int OpNum,raw_ostream & O,const char * Modifier)78 void MSP430AsmPrinter::printOperand(const MachineInstr *MI, int OpNum,
79 raw_ostream &O, const char *Modifier) {
80 const MachineOperand &MO = MI->getOperand(OpNum);
81 switch (MO.getType()) {
82 default: llvm_unreachable("Not implemented yet!");
83 case MachineOperand::MO_Register:
84 O << MSP430InstPrinter::getRegisterName(MO.getReg());
85 return;
86 case MachineOperand::MO_Immediate:
87 if (!Modifier || strcmp(Modifier, "nohash"))
88 O << '#';
89 O << MO.getImm();
90 return;
91 case MachineOperand::MO_MachineBasicBlock:
92 MO.getMBB()->getSymbol()->print(O, MAI);
93 return;
94 case MachineOperand::MO_GlobalAddress: {
95 // If the global address expression is a part of displacement field with a
96 // register base, we should not emit any prefix symbol here, e.g.
97 // mov.w glb(r1), r2
98 // Otherwise (!) msp430-as will silently miscompile the output :(
99 if (!Modifier || strcmp(Modifier, "nohash"))
100 O << '#';
101 PrintSymbolOperand(MO, O);
102 return;
103 }
104 }
105 }
106
printSrcMemOperand(const MachineInstr * MI,int OpNum,raw_ostream & O)107 void MSP430AsmPrinter::printSrcMemOperand(const MachineInstr *MI, int OpNum,
108 raw_ostream &O) {
109 const MachineOperand &Base = MI->getOperand(OpNum);
110 const MachineOperand &Disp = MI->getOperand(OpNum+1);
111
112 // Print displacement first
113
114 // Imm here is in fact global address - print extra modifier.
115 if (Disp.isImm() && Base.getReg() == MSP430::SR)
116 O << '&';
117 printOperand(MI, OpNum+1, O, "nohash");
118
119 // Print register base field
120 if (Base.getReg() != MSP430::SR && Base.getReg() != MSP430::PC) {
121 O << '(';
122 printOperand(MI, OpNum, O);
123 O << ')';
124 }
125 }
126
127 /// PrintAsmOperand - Print out an operand for an inline asm expression.
128 ///
PrintAsmOperand(const MachineInstr * MI,unsigned OpNo,const char * ExtraCode,raw_ostream & O)129 bool MSP430AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
130 const char *ExtraCode, raw_ostream &O) {
131 // Does this asm operand have a single letter operand modifier?
132 if (ExtraCode && ExtraCode[0])
133 return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
134
135 printOperand(MI, OpNo, O);
136 return false;
137 }
138
PrintAsmMemoryOperand(const MachineInstr * MI,unsigned OpNo,const char * ExtraCode,raw_ostream & O)139 bool MSP430AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
140 unsigned OpNo,
141 const char *ExtraCode,
142 raw_ostream &O) {
143 if (ExtraCode && ExtraCode[0]) {
144 return true; // Unknown modifier.
145 }
146 printSrcMemOperand(MI, OpNo, O);
147 return false;
148 }
149
150 //===----------------------------------------------------------------------===//
emitInstruction(const MachineInstr * MI)151 void MSP430AsmPrinter::emitInstruction(const MachineInstr *MI) {
152 MSP430MCInstLower MCInstLowering(OutContext, *this);
153
154 MCInst TmpInst;
155 MCInstLowering.Lower(MI, TmpInst);
156 EmitToStreamer(*OutStreamer, TmpInst);
157 }
158
EmitInterruptVectorSection(MachineFunction & ISR)159 void MSP430AsmPrinter::EmitInterruptVectorSection(MachineFunction &ISR) {
160 MCSection *Cur = OutStreamer->getCurrentSectionOnly();
161 const auto *F = &ISR.getFunction();
162 if (F->getCallingConv() != CallingConv::MSP430_INTR) {
163 report_fatal_error("Functions with 'interrupt' attribute must have msp430_intrcc CC");
164 }
165 StringRef IVIdx = F->getFnAttribute("interrupt").getValueAsString();
166 MCSection *IV = OutStreamer->getContext().getELFSection(
167 "__interrupt_vector_" + IVIdx,
168 ELF::SHT_PROGBITS, ELF::SHF_ALLOC | ELF::SHF_EXECINSTR);
169 OutStreamer->SwitchSection(IV);
170
171 const MCSymbol *FunctionSymbol = getSymbol(F);
172 OutStreamer->emitSymbolValue(FunctionSymbol, TM.getProgramPointerSize());
173 OutStreamer->SwitchSection(Cur);
174 }
175
runOnMachineFunction(MachineFunction & MF)176 bool MSP430AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
177 // Emit separate section for an interrupt vector if ISR
178 if (MF.getFunction().hasFnAttribute("interrupt")) {
179 EmitInterruptVectorSection(MF);
180 }
181
182 SetupMachineFunction(MF);
183 emitFunctionBody();
184 return false;
185 }
186
187 // Force static initialization.
LLVMInitializeMSP430AsmPrinter()188 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeMSP430AsmPrinter() {
189 RegisterAsmPrinter<MSP430AsmPrinter> X(getTheMSP430Target());
190 }
191