AArch64MCInstLower.cpp revision 19254c49a8752fe8c6fa648a6eb29f20a1f62c8b 
1//===-- AArch64MCInstLower.cpp - Convert AArch64 MachineInstr to an 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 AArch64 MachineInstrs to their corresponding
11// MCInst records.
12//
13//===----------------------------------------------------------------------===//
14
15#include "AArch64AsmPrinter.h"
16#include "AArch64TargetMachine.h"
17#include "MCTargetDesc/AArch64MCExpr.h"
18#include "Utils/AArch64BaseInfo.h"
19#include "llvm/ADT/SmallString.h"
20#include "llvm/CodeGen/AsmPrinter.h"
21#include "llvm/CodeGen/MachineFunction.h"
22#include "llvm/MC/MCAsmInfo.h"
23#include "llvm/MC/MCContext.h"
24#include "llvm/MC/MCExpr.h"
25#include "llvm/MC/MCInst.h"
26#include "llvm/Target/Mangler.h"
27
28using namespace llvm;
29
30MCOperand
31AArch64AsmPrinter::lowerSymbolOperand(const MachineOperand &MO,
32                                      const MCSymbol *Sym) const {
33  const MCExpr *Expr = 0;
34
35  Expr = MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_None, OutContext);
36
37  switch (MO.getTargetFlags()) {
38  case AArch64II::MO_GOT:
39    Expr = AArch64MCExpr::CreateGOT(Expr, OutContext);
40    break;
41  case AArch64II::MO_GOT_LO12:
42    Expr = AArch64MCExpr::CreateGOTLo12(Expr, OutContext);
43    break;
44  case AArch64II::MO_LO12:
45    Expr = AArch64MCExpr::CreateLo12(Expr, OutContext);
46    break;
47  case AArch64II::MO_DTPREL_G1:
48    Expr = AArch64MCExpr::CreateDTPREL_G1(Expr, OutContext);
49    break;
50  case AArch64II::MO_DTPREL_G0_NC:
51    Expr = AArch64MCExpr::CreateDTPREL_G0_NC(Expr, OutContext);
52    break;
53  case AArch64II::MO_GOTTPREL:
54    Expr = AArch64MCExpr::CreateGOTTPREL(Expr, OutContext);
55    break;
56  case AArch64II::MO_GOTTPREL_LO12:
57    Expr = AArch64MCExpr::CreateGOTTPRELLo12(Expr, OutContext);
58    break;
59  case AArch64II::MO_TLSDESC:
60    Expr = AArch64MCExpr::CreateTLSDesc(Expr, OutContext);
61    break;
62  case AArch64II::MO_TLSDESC_LO12:
63    Expr = AArch64MCExpr::CreateTLSDescLo12(Expr, OutContext);
64    break;
65  case AArch64II::MO_TPREL_G1:
66    Expr = AArch64MCExpr::CreateTPREL_G1(Expr, OutContext);
67    break;
68  case AArch64II::MO_TPREL_G0_NC:
69    Expr = AArch64MCExpr::CreateTPREL_G0_NC(Expr, OutContext);
70    break;
71  case AArch64II::MO_NO_FLAG:
72    // Expr is already correct
73    break;
74  default:
75    llvm_unreachable("Unexpected MachineOperand flag");
76  }
77
78  if (!MO.isJTI() && MO.getOffset())
79    Expr = MCBinaryExpr::CreateAdd(Expr,
80                                   MCConstantExpr::Create(MO.getOffset(),
81                                                          OutContext),
82                                   OutContext);
83
84  return MCOperand::CreateExpr(Expr);
85}
86
87bool AArch64AsmPrinter::lowerOperand(const MachineOperand &MO,
88                                     MCOperand &MCOp) const {
89  switch (MO.getType()) {
90  default: llvm_unreachable("unknown operand type");
91  case MachineOperand::MO_Register:
92    if (MO.isImplicit())
93      return false;
94    assert(!MO.getSubReg() && "Subregs should be eliminated!");
95    MCOp = MCOperand::CreateReg(MO.getReg());
96    break;
97  case MachineOperand::MO_Immediate:
98    MCOp = MCOperand::CreateImm(MO.getImm());
99    break;
100  case MachineOperand::MO_BlockAddress:
101    MCOp = lowerSymbolOperand(MO, GetBlockAddressSymbol(MO.getBlockAddress()));
102    break;
103  case MachineOperand::MO_ExternalSymbol:
104    MCOp = lowerSymbolOperand(MO, GetExternalSymbolSymbol(MO.getSymbolName()));
105    break;
106  case MachineOperand::MO_GlobalAddress:
107    MCOp = lowerSymbolOperand(MO, Mang->getSymbol(MO.getGlobal()));
108    break;
109  case MachineOperand::MO_MachineBasicBlock:
110    MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
111                                   MO.getMBB()->getSymbol(), OutContext));
112    break;
113  case MachineOperand::MO_JumpTableIndex:
114    MCOp = lowerSymbolOperand(MO, GetJTISymbol(MO.getIndex()));
115    break;
116  case MachineOperand::MO_ConstantPoolIndex:
117    MCOp = lowerSymbolOperand(MO, GetCPISymbol(MO.getIndex()));
118    break;
119  case MachineOperand::MO_RegisterMask:
120    // Ignore call clobbers
121    return false;
122
123  }
124
125  return true;
126}
127
128void llvm::LowerAArch64MachineInstrToMCInst(const MachineInstr *MI,
129                                            MCInst &OutMI,
130                                            AArch64AsmPrinter &AP) {
131  OutMI.setOpcode(MI->getOpcode());
132
133  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
134    const MachineOperand &MO = MI->getOperand(i);
135
136    MCOperand MCOp;
137    if (AP.lowerOperand(MO, MCOp))
138      OutMI.addOperand(MCOp);
139  }
140}
141