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 #include "llvm/Target/TargetSubtargetInfo.h"
30 using namespace llvm;
31 
32 MCSymbol *MSP430MCInstLower::
33 GetGlobalAddressSymbol(const MachineOperand &MO) const {
34   switch (MO.getTargetFlags()) {
35   default: llvm_unreachable("Unknown target flag on GV operand");
36   case 0: break;
37   }
38 
39   return Printer.getSymbol(MO.getGlobal());
40 }
41 
42 MCSymbol *MSP430MCInstLower::
43 GetExternalSymbolSymbol(const MachineOperand &MO) const {
44   switch (MO.getTargetFlags()) {
45   default: llvm_unreachable("Unknown target flag on GV operand");
46   case 0: break;
47   }
48 
49   return Printer.GetExternalSymbolSymbol(MO.getSymbolName());
50 }
51 
52 MCSymbol *MSP430MCInstLower::
53 GetJumpTableSymbol(const MachineOperand &MO) const {
54   const DataLayout *DL = Printer.TM.getSubtargetImpl()->getDataLayout();
55   SmallString<256> Name;
56   raw_svector_ostream(Name) << DL->getPrivateGlobalPrefix() << "JTI"
57                             << Printer.getFunctionNumber() << '_'
58                             << MO.getIndex();
59 
60   switch (MO.getTargetFlags()) {
61   default: llvm_unreachable("Unknown target flag on GV operand");
62   case 0: break;
63   }
64 
65   // Create a symbol for the name.
66   return Ctx.GetOrCreateSymbol(Name.str());
67 }
68 
69 MCSymbol *MSP430MCInstLower::
70 GetConstantPoolIndexSymbol(const MachineOperand &MO) const {
71   const DataLayout *DL = Printer.TM.getSubtargetImpl()->getDataLayout();
72   SmallString<256> Name;
73   raw_svector_ostream(Name) << DL->getPrivateGlobalPrefix() << "CPI"
74                             << Printer.getFunctionNumber() << '_'
75                             << MO.getIndex();
76 
77   switch (MO.getTargetFlags()) {
78   default: llvm_unreachable("Unknown target flag on GV operand");
79   case 0: break;
80   }
81 
82   // Create a symbol for the name.
83   return Ctx.GetOrCreateSymbol(Name.str());
84 }
85 
86 MCSymbol *MSP430MCInstLower::
87 GetBlockAddressSymbol(const MachineOperand &MO) const {
88   switch (MO.getTargetFlags()) {
89   default: llvm_unreachable("Unknown target flag on GV operand");
90   case 0: break;
91   }
92 
93   return Printer.GetBlockAddressSymbol(MO.getBlockAddress());
94 }
95 
96 MCOperand MSP430MCInstLower::
97 LowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym) const {
98   // FIXME: We would like an efficient form for this, so we don't have to do a
99   // lot of extra uniquing.
100   const MCExpr *Expr = MCSymbolRefExpr::Create(Sym, Ctx);
101 
102   switch (MO.getTargetFlags()) {
103   default: llvm_unreachable("Unknown target flag on GV operand");
104   case 0: break;
105   }
106 
107   if (!MO.isJTI() && MO.getOffset())
108     Expr = MCBinaryExpr::CreateAdd(Expr,
109                                    MCConstantExpr::Create(MO.getOffset(), Ctx),
110                                    Ctx);
111   return MCOperand::CreateExpr(Expr);
112 }
113 
114 void MSP430MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
115   OutMI.setOpcode(MI->getOpcode());
116 
117   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
118     const MachineOperand &MO = MI->getOperand(i);
119 
120     MCOperand MCOp;
121     switch (MO.getType()) {
122     default:
123       MI->dump();
124       llvm_unreachable("unknown operand type");
125     case MachineOperand::MO_Register:
126       // Ignore all implicit register operands.
127       if (MO.isImplicit()) continue;
128       MCOp = MCOperand::CreateReg(MO.getReg());
129       break;
130     case MachineOperand::MO_Immediate:
131       MCOp = MCOperand::CreateImm(MO.getImm());
132       break;
133     case MachineOperand::MO_MachineBasicBlock:
134       MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
135                          MO.getMBB()->getSymbol(), Ctx));
136       break;
137     case MachineOperand::MO_GlobalAddress:
138       MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));
139       break;
140     case MachineOperand::MO_ExternalSymbol:
141       MCOp = LowerSymbolOperand(MO, GetExternalSymbolSymbol(MO));
142       break;
143     case MachineOperand::MO_JumpTableIndex:
144       MCOp = LowerSymbolOperand(MO, GetJumpTableSymbol(MO));
145       break;
146     case MachineOperand::MO_ConstantPoolIndex:
147       MCOp = LowerSymbolOperand(MO, GetConstantPoolIndexSymbol(MO));
148       break;
149     case MachineOperand::MO_BlockAddress:
150       MCOp = LowerSymbolOperand(MO, GetBlockAddressSymbol(MO));
151       break;
152     case MachineOperand::MO_RegisterMask:
153       continue;
154     }
155 
156     OutMI.addOperand(MCOp);
157   }
158 }
159