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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::
     32 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::
     42 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::
     52 GetJumpTableSymbol(const MachineOperand &MO) const {
     53   const DataLayout *DL = Printer.TM.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.str());
     66 }
     67 
     68 MCSymbol *MSP430MCInstLower::
     69 GetConstantPoolIndexSymbol(const MachineOperand &MO) const {
     70   const DataLayout *DL = Printer.TM.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.str());
     83 }
     84 
     85 MCSymbol *MSP430MCInstLower::
     86 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::
     96 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 
    113 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