MipsMCInstLower.cpp revision e33ca9ce1f978b8129972922f1ac0c16eec9e5f1 
1//===-- MipsMCInstLower.cpp - Convert Mips MachineInstr to MCInst ---------===//
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 code to lower Mips MachineInstrs to their corresponding
11// MCInst records.
12//
13//===----------------------------------------------------------------------===//
14
15#include "MipsMCInstLower.h"
16#include "MipsAsmPrinter.h"
17#include "MipsInstrInfo.h"
18#include "MipsMCSymbolRefExpr.h"
19#include "llvm/CodeGen/MachineFunction.h"
20#include "llvm/CodeGen/MachineInstr.h"
21#include "llvm/CodeGen/MachineOperand.h"
22#include "llvm/MC/MCContext.h"
23#include "llvm/MC/MCInst.h"
24#include "llvm/Target/Mangler.h"
25using namespace llvm;
26
27MipsMCInstLower::MipsMCInstLower(Mangler *mang, const MachineFunction &mf,
28                                 MipsAsmPrinter &asmprinter)
29  : Ctx(mf.getContext()), Mang(mang), AsmPrinter(asmprinter) {}
30
31MCOperand MipsMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
32                                              MachineOperandType MOTy,
33                                              unsigned Offset) const {
34  MipsMCSymbolRefExpr::VariantKind Kind;
35  const MCSymbol *Symbol;
36
37  switch(MO.getTargetFlags()) {
38  default:                  assert(0 && "Invalid target flag!");
39  case MipsII::MO_NO_FLAG:  Kind = MipsMCSymbolRefExpr::VK_Mips_None; break;
40  case MipsII::MO_GPREL:    Kind = MipsMCSymbolRefExpr::VK_Mips_GPREL; break;
41  case MipsII::MO_GOT_CALL: Kind = MipsMCSymbolRefExpr::VK_Mips_GOT_CALL; break;
42  case MipsII::MO_GOT:      Kind = MipsMCSymbolRefExpr::VK_Mips_GOT; break;
43  case MipsII::MO_ABS_HI:   Kind = MipsMCSymbolRefExpr::VK_Mips_ABS_HI; break;
44  case MipsII::MO_ABS_LO:   Kind = MipsMCSymbolRefExpr::VK_Mips_ABS_LO; break;
45  case MipsII::MO_TLSGD:    Kind = MipsMCSymbolRefExpr::VK_Mips_TLSGD; break;
46  case MipsII::MO_GOTTPREL: Kind = MipsMCSymbolRefExpr::VK_Mips_GOTTPREL; break;
47  case MipsII::MO_TPREL_HI: Kind = MipsMCSymbolRefExpr::VK_Mips_TPREL_HI; break;
48  case MipsII::MO_TPREL_LO: Kind = MipsMCSymbolRefExpr::VK_Mips_TPREL_LO; break;
49  case MipsII::MO_GPOFF_HI: Kind = MipsMCSymbolRefExpr::VK_Mips_GPOFF_HI; break;
50  case MipsII::MO_GPOFF_LO: Kind = MipsMCSymbolRefExpr::VK_Mips_GPOFF_LO; break;
51  case MipsII::MO_GOT_DISP: Kind = MipsMCSymbolRefExpr::VK_Mips_GOT_DISP; break;
52  case MipsII::MO_GOT_PAGE: Kind = MipsMCSymbolRefExpr::VK_Mips_GOT_PAGE; break;
53  case MipsII::MO_GOT_OFST: Kind = MipsMCSymbolRefExpr::VK_Mips_GOT_OFST; break;
54  }
55
56  switch (MOTy) {
57    case MachineOperand::MO_MachineBasicBlock:
58      Symbol = MO.getMBB()->getSymbol();
59      break;
60
61    case MachineOperand::MO_GlobalAddress:
62      Symbol = Mang->getSymbol(MO.getGlobal());
63      break;
64
65    case MachineOperand::MO_BlockAddress:
66      Symbol = AsmPrinter.GetBlockAddressSymbol(MO.getBlockAddress());
67      break;
68
69    case MachineOperand::MO_ExternalSymbol:
70      Symbol = AsmPrinter.GetExternalSymbolSymbol(MO.getSymbolName());
71      break;
72
73    case MachineOperand::MO_JumpTableIndex:
74      Symbol = AsmPrinter.GetJTISymbol(MO.getIndex());
75      break;
76
77    case MachineOperand::MO_ConstantPoolIndex:
78      Symbol = AsmPrinter.GetCPISymbol(MO.getIndex());
79      if (MO.getOffset())
80        Offset += MO.getOffset();
81      break;
82
83    default:
84      llvm_unreachable("<unknown operand type>");
85  }
86
87  return MCOperand::CreateExpr(MipsMCSymbolRefExpr::Create(Kind, Symbol, Offset,
88                                                           Ctx));
89}
90
91MCOperand MipsMCInstLower::LowerOperand(const MachineOperand& MO) const {
92  MachineOperandType MOTy = MO.getType();
93
94  switch (MOTy) {
95  default:
96    assert(0 && "unknown operand type");
97    break;
98  case MachineOperand::MO_Register:
99    // Ignore all implicit register operands.
100    if (MO.isImplicit()) break;
101    return MCOperand::CreateReg(MO.getReg());
102  case MachineOperand::MO_Immediate:
103    return MCOperand::CreateImm(MO.getImm());
104  case MachineOperand::MO_MachineBasicBlock:
105  case MachineOperand::MO_GlobalAddress:
106  case MachineOperand::MO_ExternalSymbol:
107  case MachineOperand::MO_JumpTableIndex:
108  case MachineOperand::MO_ConstantPoolIndex:
109  case MachineOperand::MO_BlockAddress:
110    return LowerSymbolOperand(MO, MOTy, 0);
111 }
112
113  return MCOperand();
114}
115
116void MipsMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
117  OutMI.setOpcode(MI->getOpcode());
118
119  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
120    const MachineOperand &MO = MI->getOperand(i);
121    MCOperand MCOp = LowerOperand(MO);
122
123    if (MCOp.isValid())
124      OutMI.addOperand(MCOp);
125  }
126}
127