lib/Target/PowerPC/PPCMCInstLower.cpp

   1 //===-- PPCMCInstLower.cpp - Convert PPC 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 PPC MachineInstrs to their corresponding
  11 // MCInst records.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "MCTargetDesc/PPCMCExpr.h"
  16 #include "PPC.h"
  17 #include "PPCSubtarget.h"
  18 #include "llvm/ADT/SmallString.h"
  19 #include "llvm/ADT/Twine.h"
  20 #include "llvm/CodeGen/AsmPrinter.h"
  21 #include "llvm/CodeGen/MachineFunction.h"
  22 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
  23 #include "llvm/CodeGen/TargetLowering.h"
  24 #include "llvm/CodeGen/TargetLoweringObjectFile.h"
  25 #include "llvm/IR/DataLayout.h"
  26 #include "llvm/IR/GlobalValue.h"
  27 #include "llvm/IR/Mangler.h"
  28 #include "llvm/MC/MCAsmInfo.h"
  29 #include "llvm/MC/MCExpr.h"
  30 #include "llvm/MC/MCInst.h"
  31 using namespace llvm;
  32
  33 static MachineModuleInfoMachO &getMachOMMI(AsmPrinter &AP) {
  34   return AP.MMI->getObjFileInfo<MachineModuleInfoMachO>();
  35 }
  36
  37 static MCSymbol *GetSymbolFromOperand(const MachineOperand &MO,
  38                                       AsmPrinter &AP) {
  39   const TargetMachine &TM = AP.TM;
  40   Mangler &Mang = TM.getObjFileLowering()->getMangler();
  41   const DataLayout &DL = AP.getDataLayout();
  42   MCContext &Ctx = AP.OutContext;
  43
  44   SmallString<128> Name;
  45   StringRef Suffix;
  46   if (MO.getTargetFlags() & PPCII::MO_NLP_FLAG)
  47     Suffix = "$non_lazy_ptr";
  48
  49   if (!Suffix.empty())
  50     Name += DL.getPrivateGlobalPrefix();
  51
  52   if (!MO.isGlobal()) {
  53     assert(MO.isSymbol() && "Isn't a symbol reference");
  54     Mangler::getNameWithPrefix(Name, MO.getSymbolName(), DL);
  55   } else {
  56     const GlobalValue *GV = MO.getGlobal();
  57     TM.getNameWithPrefix(Name, GV, Mang);
  58   }
  59
  60   Name += Suffix;
  61   MCSymbol *Sym = Ctx.getOrCreateSymbol(Name);
  62
  63   // If the symbol reference is actually to a non_lazy_ptr, not to the symbol,
  64   // then add the suffix.
  65   if (MO.getTargetFlags() & PPCII::MO_NLP_FLAG) {
  66     MachineModuleInfoMachO &MachO = getMachOMMI(AP);
  67
  68     MachineModuleInfoImpl::StubValueTy &StubSym = MachO.getGVStubEntry(Sym);
  69
  70     if (!StubSym.getPointer()) {
  71       assert(MO.isGlobal() && "Extern symbol not handled yet");
  72       StubSym = MachineModuleInfoImpl::
  73                    StubValueTy(AP.getSymbol(MO.getGlobal()),
  74                                !MO.getGlobal()->hasInternalLinkage());
  75     }
  76     return Sym;
  77   }
  78
  79   return Sym;
  80 }
  81
  82 static MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol,
  83                               AsmPrinter &Printer, bool isDarwin) {
  84   MCContext &Ctx = Printer.OutContext;
  85   MCSymbolRefExpr::VariantKind RefKind = MCSymbolRefExpr::VK_None;
  86
  87   unsigned access = MO.getTargetFlags() & PPCII::MO_ACCESS_MASK;
  88
  89   switch (access) {
  90     case PPCII::MO_TPREL_LO:
  91       RefKind = MCSymbolRefExpr::VK_PPC_TPREL_LO;
  92       break;
  93     case PPCII::MO_TPREL_HA:
  94       RefKind = MCSymbolRefExpr::VK_PPC_TPREL_HA;
  95       break;
  96     case PPCII::MO_DTPREL_LO:
  97       RefKind = MCSymbolRefExpr::VK_PPC_DTPREL_LO;
  98       break;
  99     case PPCII::MO_TLSLD_LO:
 100       RefKind = MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO;
 101       break;
 102     case PPCII::MO_TOC_LO:
 103       RefKind = MCSymbolRefExpr::VK_PPC_TOC_LO;
 104       break;
 105     case PPCII::MO_TLS:
 106       RefKind = MCSymbolRefExpr::VK_PPC_TLS;
 107       break;
 108   }
 109
 110   if (MO.getTargetFlags() == PPCII::MO_PLT)
 111     RefKind = MCSymbolRefExpr::VK_PLT;
 112
 113   const MCExpr *Expr = MCSymbolRefExpr::create(Symbol, RefKind, Ctx);
 114
 115   if (!MO.isJTI() && MO.getOffset())
 116     Expr = MCBinaryExpr::createAdd(Expr,
 117                                    MCConstantExpr::create(MO.getOffset(), Ctx),
 118                                    Ctx);
 119
 120   // Subtract off the PIC base if required.
 121   if (MO.getTargetFlags() & PPCII::MO_PIC_FLAG) {
 122     const MachineFunction *MF = MO.getParent()->getParent()->getParent();
 123
 124     const MCExpr *PB = MCSymbolRefExpr::create(MF->getPICBaseSymbol(), Ctx);
 125     Expr = MCBinaryExpr::createSub(Expr, PB, Ctx);
 126   }
 127
 128   // Add ha16() / lo16() markers if required.
 129   switch (access) {
 130     case PPCII::MO_LO:
 131       Expr = PPCMCExpr::createLo(Expr, isDarwin, Ctx);
 132       break;
 133     case PPCII::MO_HA:
 134       Expr = PPCMCExpr::createHa(Expr, isDarwin, Ctx);
 135       break;
 136   }
 137
 138   return MCOperand::createExpr(Expr);
 139 }
 140
 141 void llvm::LowerPPCMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
 142                                         AsmPrinter &AP, bool isDarwin) {
 143   OutMI.setOpcode(MI->getOpcode());
 144
 145   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
 146     MCOperand MCOp;
 147     if (LowerPPCMachineOperandToMCOperand(MI->getOperand(i), MCOp, AP,
 148                                           isDarwin))
 149       OutMI.addOperand(MCOp);
 150   }
 151 }
 152
 153 bool llvm::LowerPPCMachineOperandToMCOperand(const MachineOperand &MO,
 154                                              MCOperand &OutMO, AsmPrinter &AP,
 155                                              bool isDarwin) {
 156   switch (MO.getType()) {
 157   default:
 158     llvm_unreachable("unknown operand type");
 159   case MachineOperand::MO_Register:
 160     assert(!MO.getSubReg() && "Subregs should be eliminated!");
 161     assert(MO.getReg() > PPC::NoRegister &&
 162            MO.getReg() < PPC::NUM_TARGET_REGS &&
 163            "Invalid register for this target!");
 164     OutMO = MCOperand::createReg(MO.getReg());
 165     return true;
 166   case MachineOperand::MO_Immediate:
 167     OutMO = MCOperand::createImm(MO.getImm());
 168     return true;
 169   case MachineOperand::MO_MachineBasicBlock:
 170     OutMO = MCOperand::createExpr(
 171         MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), AP.OutContext));
 172     return true;
 173   case MachineOperand::MO_GlobalAddress:
 174   case MachineOperand::MO_ExternalSymbol:
 175     OutMO = GetSymbolRef(MO, GetSymbolFromOperand(MO, AP), AP, isDarwin);
 176     return true;
 177   case MachineOperand::MO_JumpTableIndex:
 178     OutMO = GetSymbolRef(MO, AP.GetJTISymbol(MO.getIndex()), AP, isDarwin);
 179     return true;
 180   case MachineOperand::MO_ConstantPoolIndex:
 181     OutMO = GetSymbolRef(MO, AP.GetCPISymbol(MO.getIndex()), AP, isDarwin);
 182     return true;
 183   case MachineOperand::MO_BlockAddress:
 184     OutMO = GetSymbolRef(MO, AP.GetBlockAddressSymbol(MO.getBlockAddress()), AP,
 185                          isDarwin);
 186     return true;
 187   case MachineOperand::MO_RegisterMask:
 188     return false;
 189   }
 190 }