1 //===-- ARMMCInstLower.cpp - Convert ARM 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 ARM MachineInstrs to their corresponding
11 // MCInst records.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "ARM.h"
16 #include "ARMAsmPrinter.h"
17 #include "MCTargetDesc/ARMMCExpr.h"
18 #include "llvm/CodeGen/MachineBasicBlock.h"
19 #include "llvm/IR/Constants.h"
20 #include "llvm/MC/MCExpr.h"
21 #include "llvm/MC/MCInst.h"
22 #include "llvm/Target/Mangler.h"
23 using namespace llvm;
24
25
GetSymbolRef(const MachineOperand & MO,const MCSymbol * Symbol)26 MCOperand ARMAsmPrinter::GetSymbolRef(const MachineOperand &MO,
27 const MCSymbol *Symbol) {
28 const MCExpr *Expr;
29 switch (MO.getTargetFlags()) {
30 default: {
31 Expr = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_None,
32 OutContext);
33 switch (MO.getTargetFlags()) {
34 default: llvm_unreachable("Unknown target flag on symbol operand");
35 case 0:
36 break;
37 case ARMII::MO_LO16:
38 Expr = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_None,
39 OutContext);
40 Expr = ARMMCExpr::CreateLower16(Expr, OutContext);
41 break;
42 case ARMII::MO_HI16:
43 Expr = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_None,
44 OutContext);
45 Expr = ARMMCExpr::CreateUpper16(Expr, OutContext);
46 break;
47 }
48 break;
49 }
50
51 case ARMII::MO_PLT:
52 Expr = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_PLT,
53 OutContext);
54 break;
55 }
56
57 if (!MO.isJTI() && MO.getOffset())
58 Expr = MCBinaryExpr::CreateAdd(Expr,
59 MCConstantExpr::Create(MO.getOffset(),
60 OutContext),
61 OutContext);
62 return MCOperand::CreateExpr(Expr);
63
64 }
65
lowerOperand(const MachineOperand & MO,MCOperand & MCOp)66 bool ARMAsmPrinter::lowerOperand(const MachineOperand &MO,
67 MCOperand &MCOp) {
68 switch (MO.getType()) {
69 default: llvm_unreachable("unknown operand type");
70 case MachineOperand::MO_Register:
71 // Ignore all non-CPSR implicit register operands.
72 if (MO.isImplicit() && MO.getReg() != ARM::CPSR)
73 return false;
74 assert(!MO.getSubReg() && "Subregs should be eliminated!");
75 MCOp = MCOperand::CreateReg(MO.getReg());
76 break;
77 case MachineOperand::MO_Immediate:
78 MCOp = MCOperand::CreateImm(MO.getImm());
79 break;
80 case MachineOperand::MO_MachineBasicBlock:
81 MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
82 MO.getMBB()->getSymbol(), OutContext));
83 break;
84 case MachineOperand::MO_GlobalAddress:
85 MCOp = GetSymbolRef(MO, Mang->getSymbol(MO.getGlobal()));
86 break;
87 case MachineOperand::MO_ExternalSymbol:
88 MCOp = GetSymbolRef(MO,
89 GetExternalSymbolSymbol(MO.getSymbolName()));
90 break;
91 case MachineOperand::MO_JumpTableIndex:
92 MCOp = GetSymbolRef(MO, GetJTISymbol(MO.getIndex()));
93 break;
94 case MachineOperand::MO_ConstantPoolIndex:
95 MCOp = GetSymbolRef(MO, GetCPISymbol(MO.getIndex()));
96 break;
97 case MachineOperand::MO_BlockAddress:
98 MCOp = GetSymbolRef(MO, GetBlockAddressSymbol(MO.getBlockAddress()));
99 break;
100 case MachineOperand::MO_FPImmediate: {
101 APFloat Val = MO.getFPImm()->getValueAPF();
102 bool ignored;
103 Val.convert(APFloat::IEEEdouble, APFloat::rmTowardZero, &ignored);
104 MCOp = MCOperand::CreateFPImm(Val.convertToDouble());
105 break;
106 }
107 case MachineOperand::MO_RegisterMask:
108 // Ignore call clobbers.
109 return false;
110 }
111 return true;
112 }
113
LowerARMMachineInstrToMCInst(const MachineInstr * MI,MCInst & OutMI,ARMAsmPrinter & AP)114 void llvm::LowerARMMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
115 ARMAsmPrinter &AP) {
116 OutMI.setOpcode(MI->getOpcode());
117
118 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
119 const MachineOperand &MO = MI->getOperand(i);
120
121 MCOperand MCOp;
122 if (AP.lowerOperand(MO, MCOp))
123 OutMI.addOperand(MCOp);
124 }
125 }
126