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"
37using namespace llvm;
38
39#define DEBUG_TYPE "asm-printer"
40
41namespace {
42  class MSP430AsmPrinter : public AsmPrinter {
43  public:
44    MSP430AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
45        : AsmPrinter(TM, std::move(Streamer)) {}
46
47    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
66void 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
78void 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
107void 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///
129bool 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
139bool 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//===----------------------------------------------------------------------===//
151void 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
159void 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
176bool 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.
188extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeMSP430AsmPrinter() {
189  RegisterAsmPrinter<MSP430AsmPrinter> X(getTheMSP430Target());
190}
191