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 "ARMMCInstLower.h"
16 //#include "llvm/CodeGen/MachineModuleInfoImpls.h"
17 #include "llvm/CodeGen/AsmPrinter.h"
18 #include "llvm/CodeGen/MachineBasicBlock.h"
19 #include "llvm/MC/MCAsmInfo.h"
20 #include "llvm/MC/MCContext.h"
21 #include "llvm/MC/MCExpr.h"
22 #include "llvm/MC/MCInst.h"
23 //#include "llvm/MC/MCStreamer.h"
24 #include "llvm/Target/Mangler.h"
25 #include "llvm/Support/raw_ostream.h"
26 #include "llvm/ADT/SmallString.h"
27 using namespace llvm;
28 
29 
30 #if 0
31 const ARMSubtarget &ARMMCInstLower::getSubtarget() const {
32   return AsmPrinter.getSubtarget();
33 }
34 
35 MachineModuleInfoMachO &ARMMCInstLower::getMachOMMI() const {
36   assert(getSubtarget().isTargetDarwin() &&"Can only get MachO info on darwin");
37   return AsmPrinter.MMI->getObjFileInfo<MachineModuleInfoMachO>();
38 }
39 #endif
40 
41 MCSymbol *ARMMCInstLower::
42 GetGlobalAddressSymbol(const MachineOperand &MO) const {
43   // FIXME: HANDLE PLT references how??
44   switch (MO.getTargetFlags()) {
45   default: assert(0 && "Unknown target flag on GV operand");
46   case 0: break;
47   }
48 
49   return Printer.Mang->getSymbol(MO.getGlobal());
50 }
51 
52 MCSymbol *ARMMCInstLower::
53 GetExternalSymbolSymbol(const MachineOperand &MO) const {
54   // FIXME: HANDLE PLT references how??
55   switch (MO.getTargetFlags()) {
56   default: assert(0 && "Unknown target flag on GV operand");
57   case 0: break;
58   }
59 
60   return Printer.GetExternalSymbolSymbol(MO.getSymbolName());
61 }
62 
63 
64 
65 MCSymbol *ARMMCInstLower::
66 GetJumpTableSymbol(const MachineOperand &MO) const {
67   SmallString<256> Name;
68   raw_svector_ostream(Name) << Printer.MAI->getPrivateGlobalPrefix() << "JTI"
69     << Printer.getFunctionNumber() << '_' << MO.getIndex();
70 
71 #if 0
72   switch (MO.getTargetFlags()) {
73     default: llvm_unreachable("Unknown target flag on GV operand");
74   }
75 #endif
76 
77   // Create a symbol for the name.
78   return Ctx.GetOrCreateSymbol(Name.str());
79 }
80 
81 MCSymbol *ARMMCInstLower::
82 GetConstantPoolIndexSymbol(const MachineOperand &MO) const {
83   SmallString<256> Name;
84   raw_svector_ostream(Name) << Printer.MAI->getPrivateGlobalPrefix() << "CPI"
85     << Printer.getFunctionNumber() << '_' << MO.getIndex();
86 
87 #if 0
88   switch (MO.getTargetFlags()) {
89   default: llvm_unreachable("Unknown target flag on GV operand");
90   }
91 #endif
92 
93   // Create a symbol for the name.
94   return Ctx.GetOrCreateSymbol(Name.str());
95 }
96 
97 MCOperand ARMMCInstLower::
98 LowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym) const {
99   // FIXME: We would like an efficient form for this, so we don't have to do a
100   // lot of extra uniquing.
101   const MCExpr *Expr = MCSymbolRefExpr::Create(Sym, Ctx);
102 
103 #if 0
104   switch (MO.getTargetFlags()) {
105   default: llvm_unreachable("Unknown target flag on GV operand");
106   }
107 #endif
108 
109   if (!MO.isJTI() && MO.getOffset())
110     Expr = MCBinaryExpr::CreateAdd(Expr,
111                                    MCConstantExpr::Create(MO.getOffset(), Ctx),
112                                    Ctx);
113   return MCOperand::CreateExpr(Expr);
114 }
115 
116 
117 void ARMMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
118   OutMI.setOpcode(MI->getOpcode());
119 
120   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
121     const MachineOperand &MO = MI->getOperand(i);
122 
123     MCOperand MCOp;
124     switch (MO.getType()) {
125     default:
126       MI->dump();
127       assert(0 && "unknown operand type");
128     case MachineOperand::MO_Register:
129       // Ignore all implicit register operands.
130       if (MO.isImplicit()) continue;
131       assert(!MO.getSubReg() && "Subregs should be eliminated!");
132       MCOp = MCOperand::CreateReg(MO.getReg());
133       break;
134     case MachineOperand::MO_Immediate:
135       MCOp = MCOperand::CreateImm(MO.getImm());
136       break;
137     case MachineOperand::MO_MachineBasicBlock:
138       MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
139                        MO.getMBB()->getSymbol(), Ctx));
140       break;
141     case MachineOperand::MO_GlobalAddress:
142       MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));
143       break;
144     case MachineOperand::MO_ExternalSymbol:
145       MCOp = LowerSymbolOperand(MO, GetExternalSymbolSymbol(MO));
146       break;
147     case MachineOperand::MO_JumpTableIndex:
148       MCOp = LowerSymbolOperand(MO, GetJumpTableSymbol(MO));
149       break;
150     case MachineOperand::MO_ConstantPoolIndex:
151       MCOp = LowerSymbolOperand(MO, GetConstantPoolIndexSymbol(MO));
152       break;
153     case MachineOperand::MO_BlockAddress:
154       MCOp = LowerSymbolOperand(MO, Printer.GetBlockAddressSymbol(
155                                               MO.getBlockAddress()));
156       break;
157     }
158 
159     OutMI.addOperand(MCOp);
160   }
161 
162 }
163