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/Compiler.h"
31 #include "llvm/Support/raw_ostream.h"
32 using namespace llvm;
33
34 #define DEBUG_TYPE "asm-printer"
35
36 namespace {
37 class MSP430AsmPrinter : public AsmPrinter {
38 public:
MSP430AsmPrinter(TargetMachine & TM,std::unique_ptr<MCStreamer> Streamer)39 MSP430AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
40 : AsmPrinter(TM, std::move(Streamer), ID) {}
41
getPassName() const42 StringRef getPassName() const override { return "MSP430 Assembly Printer"; }
43
44 bool runOnMachineFunction(MachineFunction &MF) override;
45
46 void PrintSymbolOperand(const MachineOperand &MO, raw_ostream &O) override;
47 void printOperand(const MachineInstr *MI, int OpNum, raw_ostream &O,
48 bool PrefixHash = true);
49 void printSrcMemOperand(const MachineInstr *MI, int OpNum,
50 raw_ostream &O);
51 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
52 const char *ExtraCode, raw_ostream &O) override;
53 bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
54 const char *ExtraCode, raw_ostream &O) override;
55 void emitInstruction(const MachineInstr *MI) override;
56
57 void EmitInterruptVectorSection(MachineFunction &ISR);
58
59 static char ID;
60 };
61 } // end of anonymous namespace
62
PrintSymbolOperand(const MachineOperand & MO,raw_ostream & O)63 void MSP430AsmPrinter::PrintSymbolOperand(const MachineOperand &MO,
64 raw_ostream &O) {
65 uint64_t Offset = MO.getOffset();
66 if (Offset)
67 O << '(' << Offset << '+';
68
69 getSymbol(MO.getGlobal())->print(O, MAI);
70
71 if (Offset)
72 O << ')';
73 }
74
printOperand(const MachineInstr * MI,int OpNum,raw_ostream & O,bool PrefixHash)75 void MSP430AsmPrinter::printOperand(const MachineInstr *MI, int OpNum,
76 raw_ostream &O, bool PrefixHash) {
77 const MachineOperand &MO = MI->getOperand(OpNum);
78 switch (MO.getType()) {
79 default: llvm_unreachable("Not implemented yet!");
80 case MachineOperand::MO_Register:
81 O << MSP430InstPrinter::getRegisterName(MO.getReg());
82 return;
83 case MachineOperand::MO_Immediate:
84 if (PrefixHash)
85 O << '#';
86 O << MO.getImm();
87 return;
88 case MachineOperand::MO_MachineBasicBlock:
89 MO.getMBB()->getSymbol()->print(O, MAI);
90 return;
91 case MachineOperand::MO_GlobalAddress: {
92 // If the global address expression is a part of displacement field with a
93 // register base, we should not emit any prefix symbol here, e.g.
94 // mov.w glb(r1), r2
95 // Otherwise (!) msp430-as will silently miscompile the output :(
96 if (PrefixHash)
97 O << '#';
98 PrintSymbolOperand(MO, O);
99 return;
100 }
101 }
102 }
103
printSrcMemOperand(const MachineInstr * MI,int OpNum,raw_ostream & O)104 void MSP430AsmPrinter::printSrcMemOperand(const MachineInstr *MI, int OpNum,
105 raw_ostream &O) {
106 const MachineOperand &Base = MI->getOperand(OpNum);
107 const MachineOperand &Disp = MI->getOperand(OpNum+1);
108
109 // Print displacement first
110
111 // Imm here is in fact global address - print extra modifier.
112 if (Disp.isImm() && Base.getReg() == MSP430::SR)
113 O << '&';
114 printOperand(MI, OpNum + 1, O, /*PrefixHash=*/false);
115
116 // Print register base field
117 if (Base.getReg() != MSP430::SR && Base.getReg() != MSP430::PC) {
118 O << '(';
119 printOperand(MI, OpNum, O);
120 O << ')';
121 }
122 }
123
124 /// PrintAsmOperand - Print out an operand for an inline asm expression.
125 ///
PrintAsmOperand(const MachineInstr * MI,unsigned OpNo,const char * ExtraCode,raw_ostream & O)126 bool MSP430AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
127 const char *ExtraCode, raw_ostream &O) {
128 // Does this asm operand have a single letter operand modifier?
129 if (ExtraCode && ExtraCode[0])
130 return AsmPrinter::PrintAsmOperand(MI, OpNo, ExtraCode, O);
131
132 printOperand(MI, OpNo, O);
133 return false;
134 }
135
PrintAsmMemoryOperand(const MachineInstr * MI,unsigned OpNo,const char * ExtraCode,raw_ostream & O)136 bool MSP430AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
137 unsigned OpNo,
138 const char *ExtraCode,
139 raw_ostream &O) {
140 if (ExtraCode && ExtraCode[0]) {
141 return true; // Unknown modifier.
142 }
143 printSrcMemOperand(MI, OpNo, O);
144 return false;
145 }
146
147 //===----------------------------------------------------------------------===//
emitInstruction(const MachineInstr * MI)148 void MSP430AsmPrinter::emitInstruction(const MachineInstr *MI) {
149 MSP430_MC::verifyInstructionPredicates(MI->getOpcode(),
150 getSubtargetInfo().getFeatureBits());
151
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 char MSP430AsmPrinter::ID = 0;
188
189 INITIALIZE_PASS(MSP430AsmPrinter, "msp430-asm-printer",
190 "MSP430 Assembly Printer", false, false)
191
192 // Force static initialization.
193 extern "C" LLVM_ABI LLVM_EXTERNAL_VISIBILITY void
LLVMInitializeMSP430AsmPrinter()194 LLVMInitializeMSP430AsmPrinter() {
195 RegisterAsmPrinter<MSP430AsmPrinter> X(getTheMSP430Target());
196 }
197