lib/Target/MSP430/MSP430MCInstLower.cpp

   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/CodeGen/AsmPrinter.h"
  17 #include "llvm/CodeGen/MachineBasicBlock.h"
  18 #include "llvm/CodeGen/MachineInstr.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/Target/Mangler.h"
  24 #include "llvm/Support/raw_ostream.h"
  25 #include "llvm/Support/ErrorHandling.h"
  26 #include "llvm/ADT/SmallString.h"
  27 using namespace llvm;
  28
  29 MCSymbol *MSP430MCInstLower::
  30 GetGlobalAddressSymbol(const MachineOperand &MO) const {
  31   switch (MO.getTargetFlags()) {
  32   default: llvm_unreachable("Unknown target flag on GV operand");
  33   case 0: break;
  34   }
  35
  36   return Printer.Mang->getSymbol(MO.getGlobal());
  37 }
  38
  39 MCSymbol *MSP430MCInstLower::
  40 GetExternalSymbolSymbol(const MachineOperand &MO) const {
  41   switch (MO.getTargetFlags()) {
  42   default: assert(0 && "Unknown target flag on GV operand");
  43   case 0: break;
  44   }
  45
  46   return Printer.GetExternalSymbolSymbol(MO.getSymbolName());
  47 }
  48
  49 MCSymbol *MSP430MCInstLower::
  50 GetJumpTableSymbol(const MachineOperand &MO) const {
  51   SmallString<256> Name;
  52   raw_svector_ostream(Name) << Printer.MAI->getPrivateGlobalPrefix() << "JTI"
  53                             << Printer.getFunctionNumber() << '_'
  54                             << MO.getIndex();
  55
  56   switch (MO.getTargetFlags()) {
  57   default: llvm_unreachable("Unknown target flag on GV operand");
  58   case 0: break;
  59   }
  60
  61   // Create a symbol for the name.
  62   return Ctx.GetOrCreateSymbol(Name.str());
  63 }
  64
  65 MCSymbol *MSP430MCInstLower::
  66 GetConstantPoolIndexSymbol(const MachineOperand &MO) const {
  67   SmallString<256> Name;
  68   raw_svector_ostream(Name) << Printer.MAI->getPrivateGlobalPrefix() << "CPI"
  69                             << Printer.getFunctionNumber() << '_'
  70                             << MO.getIndex();
  71
  72   switch (MO.getTargetFlags()) {
  73   default: llvm_unreachable("Unknown target flag on GV operand");
  74   case 0: break;
  75   }
  76
  77   // Create a symbol for the name.
  78   return Ctx.GetOrCreateSymbol(Name.str());
  79 }
  80
  81 MCSymbol *MSP430MCInstLower::
  82 GetBlockAddressSymbol(const MachineOperand &MO) const {
  83   switch (MO.getTargetFlags()) {
  84   default: assert(0 && "Unknown target flag on GV operand");
  85   case 0: break;
  86   }
  87
  88   return Printer.GetBlockAddressSymbol(MO.getBlockAddress());
  89 }
  90
  91 MCOperand MSP430MCInstLower::
  92 LowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym) const {
  93   // FIXME: We would like an efficient form for this, so we don't have to do a
  94   // lot of extra uniquing.
  95   const MCExpr *Expr = MCSymbolRefExpr::Create(Sym, Ctx);
  96
  97   switch (MO.getTargetFlags()) {
  98   default: llvm_unreachable("Unknown target flag on GV operand");
  99   case 0: break;
 100   }
 101
 102   if (!MO.isJTI() && MO.getOffset())
 103     Expr = MCBinaryExpr::CreateAdd(Expr,
 104                                    MCConstantExpr::Create(MO.getOffset(), Ctx),
 105                                    Ctx);
 106   return MCOperand::CreateExpr(Expr);
 107 }
 108
 109 void MSP430MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
 110   OutMI.setOpcode(MI->getOpcode());
 111
 112   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
 113     const MachineOperand &MO = MI->getOperand(i);
 114
 115     MCOperand MCOp;
 116     switch (MO.getType()) {
 117     default:
 118       MI->dump();
 119       assert(0 && "unknown operand type");
 120     case MachineOperand::MO_Register:
 121       // Ignore all implicit register operands.
 122       if (MO.isImplicit()) continue;
 123       MCOp = MCOperand::CreateReg(MO.getReg());
 124       break;
 125     case MachineOperand::MO_Immediate:
 126       MCOp = MCOperand::CreateImm(MO.getImm());
 127       break;
 128     case MachineOperand::MO_MachineBasicBlock:
 129       MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
 130                          MO.getMBB()->getSymbol(), Ctx));
 131       break;
 132     case MachineOperand::MO_GlobalAddress:
 133       MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));
 134       break;
 135     case MachineOperand::MO_ExternalSymbol:
 136       MCOp = LowerSymbolOperand(MO, GetExternalSymbolSymbol(MO));
 137       break;
 138     case MachineOperand::MO_JumpTableIndex:
 139       MCOp = LowerSymbolOperand(MO, GetJumpTableSymbol(MO));
 140       break;
 141     case MachineOperand::MO_ConstantPoolIndex:
 142       MCOp = LowerSymbolOperand(MO, GetConstantPoolIndexSymbol(MO));
 143       break;
 144     case MachineOperand::MO_BlockAddress:
 145       MCOp = LowerSymbolOperand(MO, GetBlockAddressSymbol(MO));
 146     }
 147
 148     OutMI.addOperand(MCOp);
 149   }
 150 }