Home | History | Annotate | Download | only in XCore 
      1 //===-- XCoreAsmPrinter.cpp - XCore LLVM assembly writer ------------------===//
      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 a printer that converts from our internal representation
     11 // of machine-dependent LLVM code to the XAS-format XCore assembly language.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #define DEBUG_TYPE "asm-printer"
     16 #include "XCore.h"
     17 #include "XCoreInstrInfo.h"
     18 #include "XCoreSubtarget.h"
     19 #include "XCoreTargetMachine.h"
     20 #include "llvm/Constants.h"
     21 #include "llvm/DerivedTypes.h"
     22 #include "llvm/Module.h"
     23 #include "llvm/Analysis/DebugInfo.h"
     24 #include "llvm/CodeGen/AsmPrinter.h"
     25 #include "llvm/CodeGen/MachineModuleInfo.h"
     26 #include "llvm/CodeGen/MachineFunctionPass.h"
     27 #include "llvm/CodeGen/MachineConstantPool.h"
     28 #include "llvm/CodeGen/MachineInstr.h"
     29 #include "llvm/CodeGen/MachineJumpTableInfo.h"
     30 #include "llvm/MC/MCAsmInfo.h"
     31 #include "llvm/MC/MCStreamer.h"
     32 #include "llvm/MC/MCSymbol.h"
     33 #include "llvm/Target/Mangler.h"
     34 #include "llvm/Target/TargetData.h"
     35 #include "llvm/Target/TargetLoweringObjectFile.h"
     36 #include "llvm/ADT/SmallString.h"
     37 #include "llvm/ADT/StringExtras.h"
     38 #include "llvm/Support/CommandLine.h"
     39 #include "llvm/Support/ErrorHandling.h"
     40 #include "llvm/Support/TargetRegistry.h"
     41 #include "llvm/Support/raw_ostream.h"
     42 #include <algorithm>
     43 #include <cctype>
     44 using namespace llvm;
     45 
     46 static cl::opt<unsigned> MaxThreads("xcore-max-threads", cl::Optional,
     47   cl::desc("Maximum number of threads (for emulation thread-local storage)"),
     48   cl::Hidden,
     49   cl::value_desc("number"),
     50   cl::init(8));
     51 
     52 namespace {
     53   class XCoreAsmPrinter : public AsmPrinter {
     54     const XCoreSubtarget &Subtarget;
     55     void PrintDebugValueComment(const MachineInstr *MI, raw_ostream &OS);
     56   public:
     57     explicit XCoreAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
     58       : AsmPrinter(TM, Streamer), Subtarget(TM.getSubtarget<XCoreSubtarget>()){}
     59 
     60     virtual const char *getPassName() const {
     61       return "XCore Assembly Printer";
     62     }
     63 
     64     void printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &O);
     65     void printInlineJT(const MachineInstr *MI, int opNum, raw_ostream &O,
     66                        const std::string &directive = ".jmptable");
     67     void printInlineJT32(const MachineInstr *MI, int opNum, raw_ostream &O) {
     68       printInlineJT(MI, opNum, O, ".jmptable32");
     69     }
     70     void printOperand(const MachineInstr *MI, int opNum, raw_ostream &O);
     71     bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
     72                          unsigned AsmVariant, const char *ExtraCode,
     73                          raw_ostream &O);
     74 
     75     void emitArrayBound(MCSymbol *Sym, const GlobalVariable *GV);
     76     virtual void EmitGlobalVariable(const GlobalVariable *GV);
     77 
     78     void printInstruction(const MachineInstr *MI, raw_ostream &O); // autogen'd.
     79     static const char *getRegisterName(unsigned RegNo);
     80 
     81     void EmitFunctionEntryLabel();
     82     void EmitInstruction(const MachineInstr *MI);
     83     void EmitFunctionBodyEnd();
     84     virtual MachineLocation getDebugValueLocation(const MachineInstr *MI) const;
     85   };
     86 } // end of anonymous namespace
     87 
     88 #include "XCoreGenAsmWriter.inc"
     89 
     90 void XCoreAsmPrinter::emitArrayBound(MCSymbol *Sym, const GlobalVariable *GV) {
     91   assert(((GV->hasExternalLinkage() ||
     92     GV->hasWeakLinkage()) ||
     93     GV->hasLinkOnceLinkage()) && "Unexpected linkage");
     94   if (ArrayType *ATy = dyn_cast<ArrayType>(
     95     cast<PointerType>(GV->getType())->getElementType())) {
     96     OutStreamer.EmitSymbolAttribute(Sym, MCSA_Global);
     97     // FIXME: MCStreamerize.
     98     OutStreamer.EmitRawText(StringRef(".globound"));
     99     OutStreamer.EmitRawText("\t.set\t" + Twine(Sym->getName()));
    100     OutStreamer.EmitRawText(".globound," + Twine(ATy->getNumElements()));
    101     if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage()) {
    102       // TODO Use COMDAT groups for LinkOnceLinkage
    103       OutStreamer.EmitRawText(MAI->getWeakDefDirective() +Twine(Sym->getName())+
    104                               ".globound");
    105     }
    106   }
    107 }
    108 
    109 void XCoreAsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
    110   // Check to see if this is a special global used by LLVM, if so, emit it.
    111   if (!GV->hasInitializer() ||
    112       EmitSpecialLLVMGlobal(GV))
    113     return;
    114 
    115   const TargetData *TD = TM.getTargetData();
    116   OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(GV, Mang,TM));
    117 
    118 
    119   MCSymbol *GVSym = Mang->getSymbol(GV);
    120   const Constant *C = GV->getInitializer();
    121   unsigned Align = (unsigned)TD->getPreferredTypeAlignmentShift(C->getType());
    122 
    123   // Mark the start of the global
    124   OutStreamer.EmitRawText("\t.cc_top " + Twine(GVSym->getName()) + ".data," +
    125                           GVSym->getName());
    126 
    127   switch (GV->getLinkage()) {
    128   case GlobalValue::AppendingLinkage:
    129     report_fatal_error("AppendingLinkage is not supported by this target!");
    130   case GlobalValue::LinkOnceAnyLinkage:
    131   case GlobalValue::LinkOnceODRLinkage:
    132   case GlobalValue::WeakAnyLinkage:
    133   case GlobalValue::WeakODRLinkage:
    134   case GlobalValue::ExternalLinkage:
    135     emitArrayBound(GVSym, GV);
    136     OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
    137 
    138     // TODO Use COMDAT groups for LinkOnceLinkage
    139     if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage())
    140       OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
    141     // FALL THROUGH
    142   case GlobalValue::InternalLinkage:
    143   case GlobalValue::PrivateLinkage:
    144     break;
    145   case GlobalValue::DLLImportLinkage:
    146     llvm_unreachable("DLLImport linkage is not supported by this target!");
    147   case GlobalValue::DLLExportLinkage:
    148     llvm_unreachable("DLLExport linkage is not supported by this target!");
    149   default:
    150     llvm_unreachable("Unknown linkage type!");
    151   }
    152 
    153   EmitAlignment(Align > 2 ? Align : 2, GV);
    154 
    155   unsigned Size = TD->getTypeAllocSize(C->getType());
    156   if (GV->isThreadLocal()) {
    157     Size *= MaxThreads;
    158   }
    159   if (MAI->hasDotTypeDotSizeDirective()) {
    160     OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
    161     OutStreamer.EmitRawText("\t.size " + Twine(GVSym->getName()) + "," +
    162                             Twine(Size));
    163   }
    164   OutStreamer.EmitLabel(GVSym);
    165 
    166   EmitGlobalConstant(C);
    167   if (GV->isThreadLocal()) {
    168     for (unsigned i = 1; i < MaxThreads; ++i)
    169       EmitGlobalConstant(C);
    170   }
    171   // The ABI requires that unsigned scalar types smaller than 32 bits
    172   // are padded to 32 bits.
    173   if (Size < 4)
    174     OutStreamer.EmitZeros(4 - Size, 0);
    175 
    176   // Mark the end of the global
    177   OutStreamer.EmitRawText("\t.cc_bottom " + Twine(GVSym->getName()) + ".data");
    178 }
    179 
    180 /// EmitFunctionBodyEnd - Targets can override this to emit stuff after
    181 /// the last basic block in the function.
    182 void XCoreAsmPrinter::EmitFunctionBodyEnd() {
    183   // Emit function end directives
    184   OutStreamer.EmitRawText("\t.cc_bottom " + Twine(CurrentFnSym->getName()) +
    185                           ".function");
    186 }
    187 
    188 void XCoreAsmPrinter::EmitFunctionEntryLabel() {
    189   // Mark the start of the function
    190   OutStreamer.EmitRawText("\t.cc_top " + Twine(CurrentFnSym->getName()) +
    191                           ".function," + CurrentFnSym->getName());
    192   OutStreamer.EmitLabel(CurrentFnSym);
    193 }
    194 
    195 void XCoreAsmPrinter::printMemOperand(const MachineInstr *MI, int opNum,
    196                                       raw_ostream &O) {
    197   printOperand(MI, opNum, O);
    198 
    199   if (MI->getOperand(opNum+1).isImm() && MI->getOperand(opNum+1).getImm() == 0)
    200     return;
    201 
    202   O << "+";
    203   printOperand(MI, opNum+1, O);
    204 }
    205 
    206 void XCoreAsmPrinter::
    207 printInlineJT(const MachineInstr *MI, int opNum, raw_ostream &O,
    208               const std::string &directive) {
    209   unsigned JTI = MI->getOperand(opNum).getIndex();
    210   const MachineFunction *MF = MI->getParent()->getParent();
    211   const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
    212   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
    213   const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
    214   O << "\t" << directive << " ";
    215   for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
    216     MachineBasicBlock *MBB = JTBBs[i];
    217     if (i > 0)
    218       O << ",";
    219     O << *MBB->getSymbol();
    220   }
    221 }
    222 
    223 void XCoreAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
    224                                    raw_ostream &O) {
    225   const MachineOperand &MO = MI->getOperand(opNum);
    226   switch (MO.getType()) {
    227   case MachineOperand::MO_Register:
    228     O << getRegisterName(MO.getReg());
    229     break;
    230   case MachineOperand::MO_Immediate:
    231     O << MO.getImm();
    232     break;
    233   case MachineOperand::MO_MachineBasicBlock:
    234     O << *MO.getMBB()->getSymbol();
    235     break;
    236   case MachineOperand::MO_GlobalAddress:
    237     O << *Mang->getSymbol(MO.getGlobal());
    238     break;
    239   case MachineOperand::MO_ExternalSymbol:
    240     O << MO.getSymbolName();
    241     break;
    242   case MachineOperand::MO_ConstantPoolIndex:
    243     O << MAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber()
    244       << '_' << MO.getIndex();
    245     break;
    246   case MachineOperand::MO_JumpTableIndex:
    247     O << MAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
    248       << '_' << MO.getIndex();
    249     break;
    250   case MachineOperand::MO_BlockAddress:
    251     O << *GetBlockAddressSymbol(MO.getBlockAddress());
    252     break;
    253   default:
    254     llvm_unreachable("not implemented");
    255   }
    256 }
    257 
    258 /// PrintAsmOperand - Print out an operand for an inline asm expression.
    259 ///
    260 bool XCoreAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
    261                                       unsigned AsmVariant,const char *ExtraCode,
    262                                       raw_ostream &O) {
    263   printOperand(MI, OpNo, O);
    264   return false;
    265 }
    266 
    267 void XCoreAsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
    268                                              raw_ostream &OS) {
    269   unsigned NOps = MI->getNumOperands();
    270   assert(NOps == 4);
    271   OS << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
    272   // cast away const; DIetc do not take const operands for some reason.
    273   DIVariable V(const_cast<MDNode *>(MI->getOperand(NOps-1).getMetadata()));
    274   OS << V.getName();
    275   OS << " <- ";
    276   // Frame address.  Currently handles register +- offset only.
    277   assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm());
    278   OS << '['; printOperand(MI, 0, OS); OS << '+'; printOperand(MI, 1, OS);
    279   OS << ']';
    280   OS << "+";
    281   printOperand(MI, NOps-2, OS);
    282 }
    283 
    284 MachineLocation XCoreAsmPrinter::
    285 getDebugValueLocation(const MachineInstr *MI) const {
    286   // Handles frame addresses emitted in XCoreInstrInfo::emitFrameIndexDebugValue.
    287   assert(MI->getNumOperands() == 4 && "Invalid no. of machine operands!");
    288   assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm() &&
    289          "Unexpected MachineOperand types");
    290   return MachineLocation(MI->getOperand(0).getReg(),
    291                          MI->getOperand(1).getImm());
    292 }
    293 
    294 void XCoreAsmPrinter::EmitInstruction(const MachineInstr *MI) {
    295   SmallString<128> Str;
    296   raw_svector_ostream O(Str);
    297 
    298   switch (MI->getOpcode()) {
    299   case XCore::DBG_VALUE: {
    300     if (isVerbose() && OutStreamer.hasRawTextSupport()) {
    301       SmallString<128> TmpStr;
    302       raw_svector_ostream OS(TmpStr);
    303       PrintDebugValueComment(MI, OS);
    304       OutStreamer.EmitRawText(StringRef(OS.str()));
    305     }
    306     return;
    307   }
    308   case XCore::ADD_2rus:
    309     if (MI->getOperand(2).getImm() == 0) {
    310       O << "\tmov " << getRegisterName(MI->getOperand(0).getReg()) << ", "
    311         << getRegisterName(MI->getOperand(1).getReg());
    312       OutStreamer.EmitRawText(O.str());
    313       return;
    314     }
    315     break;
    316   }
    317   printInstruction(MI, O);
    318   OutStreamer.EmitRawText(O.str());
    319 }
    320 
    321 // Force static initialization.
    322 extern "C" void LLVMInitializeXCoreAsmPrinter() {
    323   RegisterAsmPrinter<XCoreAsmPrinter> X(TheXCoreTarget);
    324 }
    325