MSP430AsmPrinter.cpp revision 4b64e8a9e13ba782da2034e1dee52f077bdb759c 
1//===-- MSP430AsmPrinter.cpp - MSP430 LLVM assembly writer ----------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains a printer that converts from our internal representation
11// of machine-dependent LLVM code to the MSP430 assembly language.
12//
13//===----------------------------------------------------------------------===//
14
15#define DEBUG_TYPE "asm-printer"
16#include "MSP430.h"
17#include "MSP430InstrInfo.h"
18#include "MSP430MCInstLower.h"
19#include "MSP430TargetMachine.h"
20#include "InstPrinter/MSP430InstPrinter.h"
21#include "llvm/Constants.h"
22#include "llvm/DerivedTypes.h"
23#include "llvm/Module.h"
24#include "llvm/Assembly/Writer.h"
25#include "llvm/CodeGen/AsmPrinter.h"
26#include "llvm/CodeGen/MachineModuleInfo.h"
27#include "llvm/CodeGen/MachineFunctionPass.h"
28#include "llvm/CodeGen/MachineConstantPool.h"
29#include "llvm/CodeGen/MachineInstr.h"
30#include "llvm/MC/MCAsmInfo.h"
31#include "llvm/MC/MCInst.h"
32#include "llvm/MC/MCStreamer.h"
33#include "llvm/MC/MCSymbol.h"
34#include "llvm/Target/Mangler.h"
35#include "llvm/Target/TargetData.h"
36#include "llvm/Target/TargetLoweringObjectFile.h"
37#include "llvm/Target/TargetRegistry.h"
38#include "llvm/Support/raw_ostream.h"
39using namespace llvm;
40
41namespace {
42  class MSP430AsmPrinter : public AsmPrinter {
43  public:
44    MSP430AsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
45      : AsmPrinter(TM, Streamer) {}
46
47    virtual const char *getPassName() const {
48      return "MSP430 Assembly Printer";
49    }
50
51    void printOperand(const MachineInstr *MI, int OpNum,
52                      raw_ostream &O, const char* Modifier = 0);
53    void printSrcMemOperand(const MachineInstr *MI, int OpNum,
54                            raw_ostream &O);
55    bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
56                         unsigned AsmVariant, const char *ExtraCode,
57                         raw_ostream &O);
58    bool PrintAsmMemoryOperand(const MachineInstr *MI,
59                               unsigned OpNo, unsigned AsmVariant,
60                               const char *ExtraCode, raw_ostream &O);
61    void EmitInstruction(const MachineInstr *MI);
62  };
63} // end of anonymous namespace
64
65
66void MSP430AsmPrinter::printOperand(const MachineInstr *MI, int OpNum,
67                                    raw_ostream &O, const char *Modifier) {
68  const MachineOperand &MO = MI->getOperand(OpNum);
69  switch (MO.getType()) {
70  default: assert(0 && "Not implemented yet!");
71  case MachineOperand::MO_Register:
72    O << MSP430InstPrinter::getRegisterName(MO.getReg());
73    return;
74  case MachineOperand::MO_Immediate:
75    if (!Modifier || strcmp(Modifier, "nohash"))
76      O << '#';
77    O << MO.getImm();
78    return;
79  case MachineOperand::MO_MachineBasicBlock:
80    O << *MO.getMBB()->getSymbol();
81    return;
82  case MachineOperand::MO_GlobalAddress: {
83    bool isMemOp  = Modifier && !strcmp(Modifier, "mem");
84    uint64_t Offset = MO.getOffset();
85
86    // If the global address expression is a part of displacement field with a
87    // register base, we should not emit any prefix symbol here, e.g.
88    //   mov.w &foo, r1
89    // vs
90    //   mov.w glb(r1), r2
91    // Otherwise (!) msp430-as will silently miscompile the output :(
92    if (!Modifier || strcmp(Modifier, "nohash"))
93      O << (isMemOp ? '&' : '#');
94    if (Offset)
95      O << '(' << Offset << '+';
96
97    O << *Mang->getSymbol(MO.getGlobal());
98
99    if (Offset)
100      O << ')';
101
102    return;
103  }
104  case MachineOperand::MO_ExternalSymbol: {
105    bool isMemOp  = Modifier && !strcmp(Modifier, "mem");
106    O << (isMemOp ? '&' : '#');
107    O << MAI->getGlobalPrefix() << MO.getSymbolName();
108    return;
109  }
110  }
111}
112
113void MSP430AsmPrinter::printSrcMemOperand(const MachineInstr *MI, int OpNum,
114                                          raw_ostream &O) {
115  const MachineOperand &Base = MI->getOperand(OpNum);
116  const MachineOperand &Disp = MI->getOperand(OpNum+1);
117
118  // Print displacement first
119
120  // Imm here is in fact global address - print extra modifier.
121  if (Disp.isImm() && !Base.getReg())
122    O << '&';
123  printOperand(MI, OpNum+1, O, "nohash");
124
125  // Print register base field
126  if (Base.getReg()) {
127    O << '(';
128    printOperand(MI, OpNum, O);
129    O << ')';
130  }
131}
132
133/// PrintAsmOperand - Print out an operand for an inline asm expression.
134///
135bool MSP430AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
136                                       unsigned AsmVariant,
137                                       const char *ExtraCode, raw_ostream &O) {
138  // Does this asm operand have a single letter operand modifier?
139  if (ExtraCode && ExtraCode[0])
140    return true; // Unknown modifier.
141
142  printOperand(MI, OpNo, O);
143  return false;
144}
145
146bool MSP430AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
147                                             unsigned OpNo, unsigned AsmVariant,
148                                             const char *ExtraCode,
149                                             raw_ostream &O) {
150  if (ExtraCode && ExtraCode[0]) {
151    return true; // Unknown modifier.
152  }
153  printSrcMemOperand(MI, OpNo, O);
154  return false;
155}
156
157//===----------------------------------------------------------------------===//
158void MSP430AsmPrinter::EmitInstruction(const MachineInstr *MI) {
159  MSP430MCInstLower MCInstLowering(OutContext, *Mang, *this);
160
161  MCInst TmpInst;
162  MCInstLowering.Lower(MI, TmpInst);
163  OutStreamer.EmitInstruction(TmpInst);
164}
165
166// Force static initialization.
167extern "C" void LLVMInitializeMSP430AsmPrinter() {
168  RegisterAsmPrinter<MSP430AsmPrinter> X(TheMSP430Target);
169}
170