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1 //===-- MSP430MCInstLower.cpp - Convert MSP430 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 MSP430 MachineInstrs to their corresponding
11 // MCInst records.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "MSP430MCInstLower.h"
16 #include "llvm/ADT/SmallString.h"
17 #include "llvm/CodeGen/AsmPrinter.h"
18 #include "llvm/CodeGen/MachineBasicBlock.h"
19 #include "llvm/CodeGen/MachineInstr.h"
20 #include "llvm/IR/DataLayout.h"
21 #include "llvm/IR/Mangler.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/Support/ErrorHandling.h"
27 #include "llvm/Support/raw_ostream.h"
28 #include "llvm/Target/TargetMachine.h"
29 using namespace llvm;
30 
31 MCSymbol *MSP430MCInstLower::
GetGlobalAddressSymbol(const MachineOperand & MO) const32 GetGlobalAddressSymbol(const MachineOperand &MO) const {
33   switch (MO.getTargetFlags()) {
34   default: llvm_unreachable("Unknown target flag on GV operand");
35   case 0: break;
36   }
37 
38   return Printer.getSymbol(MO.getGlobal());
39 }
40 
41 MCSymbol *MSP430MCInstLower::
GetExternalSymbolSymbol(const MachineOperand & MO) const42 GetExternalSymbolSymbol(const MachineOperand &MO) const {
43   switch (MO.getTargetFlags()) {
44   default: llvm_unreachable("Unknown target flag on GV operand");
45   case 0: break;
46   }
47 
48   return Printer.GetExternalSymbolSymbol(MO.getSymbolName());
49 }
50 
51 MCSymbol *MSP430MCInstLower::
GetJumpTableSymbol(const MachineOperand & MO) const52 GetJumpTableSymbol(const MachineOperand &MO) const {
53   const DataLayout &DL = Printer.getDataLayout();
54   SmallString<256> Name;
55   raw_svector_ostream(Name) << DL.getPrivateGlobalPrefix() << "JTI"
56                             << Printer.getFunctionNumber() << '_'
57                             << MO.getIndex();
58 
59   switch (MO.getTargetFlags()) {
60   default: llvm_unreachable("Unknown target flag on GV operand");
61   case 0: break;
62   }
63 
64   // Create a symbol for the name.
65   return Ctx.getOrCreateSymbol(Name);
66 }
67 
68 MCSymbol *MSP430MCInstLower::
GetConstantPoolIndexSymbol(const MachineOperand & MO) const69 GetConstantPoolIndexSymbol(const MachineOperand &MO) const {
70   const DataLayout &DL = Printer.getDataLayout();
71   SmallString<256> Name;
72   raw_svector_ostream(Name) << DL.getPrivateGlobalPrefix() << "CPI"
73                             << Printer.getFunctionNumber() << '_'
74                             << MO.getIndex();
75 
76   switch (MO.getTargetFlags()) {
77   default: llvm_unreachable("Unknown target flag on GV operand");
78   case 0: break;
79   }
80 
81   // Create a symbol for the name.
82   return Ctx.getOrCreateSymbol(Name);
83 }
84 
85 MCSymbol *MSP430MCInstLower::
GetBlockAddressSymbol(const MachineOperand & MO) const86 GetBlockAddressSymbol(const MachineOperand &MO) const {
87   switch (MO.getTargetFlags()) {
88   default: llvm_unreachable("Unknown target flag on GV operand");
89   case 0: break;
90   }
91 
92   return Printer.GetBlockAddressSymbol(MO.getBlockAddress());
93 }
94 
95 MCOperand MSP430MCInstLower::
LowerSymbolOperand(const MachineOperand & MO,MCSymbol * Sym) const96 LowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym) const {
97   // FIXME: We would like an efficient form for this, so we don't have to do a
98   // lot of extra uniquing.
99   const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx);
100 
101   switch (MO.getTargetFlags()) {
102   default: llvm_unreachable("Unknown target flag on GV operand");
103   case 0: break;
104   }
105 
106   if (!MO.isJTI() && MO.getOffset())
107     Expr = MCBinaryExpr::createAdd(Expr,
108                                    MCConstantExpr::create(MO.getOffset(), Ctx),
109                                    Ctx);
110   return MCOperand::createExpr(Expr);
111 }
112 
Lower(const MachineInstr * MI,MCInst & OutMI) const113 void MSP430MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
114   OutMI.setOpcode(MI->getOpcode());
115 
116   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
117     const MachineOperand &MO = MI->getOperand(i);
118 
119     MCOperand MCOp;
120     switch (MO.getType()) {
121     default:
122       MI->dump();
123       llvm_unreachable("unknown operand type");
124     case MachineOperand::MO_Register:
125       // Ignore all implicit register operands.
126       if (MO.isImplicit()) continue;
127       MCOp = MCOperand::createReg(MO.getReg());
128       break;
129     case MachineOperand::MO_Immediate:
130       MCOp = MCOperand::createImm(MO.getImm());
131       break;
132     case MachineOperand::MO_MachineBasicBlock:
133       MCOp = MCOperand::createExpr(MCSymbolRefExpr::create(
134                          MO.getMBB()->getSymbol(), Ctx));
135       break;
136     case MachineOperand::MO_GlobalAddress:
137       MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));
138       break;
139     case MachineOperand::MO_ExternalSymbol:
140       MCOp = LowerSymbolOperand(MO, GetExternalSymbolSymbol(MO));
141       break;
142     case MachineOperand::MO_JumpTableIndex:
143       MCOp = LowerSymbolOperand(MO, GetJumpTableSymbol(MO));
144       break;
145     case MachineOperand::MO_ConstantPoolIndex:
146       MCOp = LowerSymbolOperand(MO, GetConstantPoolIndexSymbol(MO));
147       break;
148     case MachineOperand::MO_BlockAddress:
149       MCOp = LowerSymbolOperand(MO, GetBlockAddressSymbol(MO));
150       break;
151     case MachineOperand::MO_RegisterMask:
152       continue;
153     }
154 
155     OutMI.addOperand(MCOp);
156   }
157 }
158