LLVM API Documentation
00001 //===-- Writer.cpp - Library for converting LLVM code to C ----------------===// 00002 // 00003 // The LLVM Compiler Infrastructure 00004 // 00005 // This file was developed by the LLVM research group and is distributed under 00006 // the University of Illinois Open Source License. See LICENSE.TXT for details. 00007 // 00008 //===----------------------------------------------------------------------===// 00009 // 00010 // This library converts LLVM code to C code, compilable by GCC and other C 00011 // compilers. 00012 // 00013 //===----------------------------------------------------------------------===// 00014 00015 #include "CTargetMachine.h" 00016 #include "llvm/Constants.h" 00017 #include "llvm/DerivedTypes.h" 00018 #include "llvm/Module.h" 00019 #include "llvm/Instructions.h" 00020 #include "llvm/Pass.h" 00021 #include "llvm/PassManager.h" 00022 #include "llvm/SymbolTable.h" 00023 #include "llvm/Intrinsics.h" 00024 #include "llvm/Analysis/ConstantsScanner.h" 00025 #include "llvm/Analysis/FindUsedTypes.h" 00026 #include "llvm/Analysis/LoopInfo.h" 00027 #include "llvm/CodeGen/IntrinsicLowering.h" 00028 #include "llvm/Transforms/Scalar.h" 00029 #include "llvm/Target/TargetMachineRegistry.h" 00030 #include "llvm/Support/CallSite.h" 00031 #include "llvm/Support/CFG.h" 00032 #include "llvm/Support/GetElementPtrTypeIterator.h" 00033 #include "llvm/Support/InstVisitor.h" 00034 #include "llvm/Support/Mangler.h" 00035 #include "llvm/ADT/StringExtras.h" 00036 #include "llvm/Support/MathExtras.h" 00037 #include "llvm/Config/config.h" 00038 #include <algorithm> 00039 #include <iostream> 00040 #include <sstream> 00041 using namespace llvm; 00042 00043 namespace { 00044 // Register the target. 00045 RegisterTarget<CTargetMachine> X("c", " C backend"); 00046 00047 /// NameAllUsedStructs - This pass inserts names for any unnamed structure 00048 /// types that are used by the program. 00049 /// 00050 class CBackendNameAllUsedStructs : public ModulePass { 00051 void getAnalysisUsage(AnalysisUsage &AU) const { 00052 AU.addRequired<FindUsedTypes>(); 00053 } 00054 00055 virtual const char *getPassName() const { 00056 return "C backend type canonicalizer"; 00057 } 00058 00059 virtual bool runOnModule(Module &M); 00060 }; 00061 00062 /// CWriter - This class is the main chunk of code that converts an LLVM 00063 /// module to a C translation unit. 00064 class CWriter : public FunctionPass, public InstVisitor<CWriter> { 00065 std::ostream &Out; 00066 IntrinsicLowering &IL; 00067 Mangler *Mang; 00068 LoopInfo *LI; 00069 const Module *TheModule; 00070 std::map<const Type *, std::string> TypeNames; 00071 00072 std::map<const ConstantFP *, unsigned> FPConstantMap; 00073 public: 00074 CWriter(std::ostream &o, IntrinsicLowering &il) : Out(o), IL(il) {} 00075 00076 virtual const char *getPassName() const { return "C backend"; } 00077 00078 void getAnalysisUsage(AnalysisUsage &AU) const { 00079 AU.addRequired<LoopInfo>(); 00080 AU.setPreservesAll(); 00081 } 00082 00083 virtual bool doInitialization(Module &M); 00084 00085 bool runOnFunction(Function &F) { 00086 LI = &getAnalysis<LoopInfo>(); 00087 00088 // Get rid of intrinsics we can't handle. 00089 lowerIntrinsics(F); 00090 00091 // Output all floating point constants that cannot be printed accurately. 00092 printFloatingPointConstants(F); 00093 00094 // Ensure that no local symbols conflict with global symbols. 00095 F.renameLocalSymbols(); 00096 00097 printFunction(F); 00098 FPConstantMap.clear(); 00099 return false; 00100 } 00101 00102 virtual bool doFinalization(Module &M) { 00103 // Free memory... 00104 delete Mang; 00105 TypeNames.clear(); 00106 return false; 00107 } 00108 00109 std::ostream &printType(std::ostream &Out, const Type *Ty, 00110 const std::string &VariableName = "", 00111 bool IgnoreName = false); 00112 00113 void writeOperand(Value *Operand); 00114 void writeOperandInternal(Value *Operand); 00115 00116 private : 00117 void lowerIntrinsics(Function &F); 00118 00119 bool nameAllUsedStructureTypes(Module &M); 00120 void printModule(Module *M); 00121 void printModuleTypes(const SymbolTable &ST); 00122 void printContainedStructs(const Type *Ty, std::set<const StructType *> &); 00123 void printFloatingPointConstants(Function &F); 00124 void printFunctionSignature(const Function *F, bool Prototype); 00125 00126 void printFunction(Function &); 00127 void printBasicBlock(BasicBlock *BB); 00128 void printLoop(Loop *L); 00129 00130 void printConstant(Constant *CPV); 00131 void printConstantArray(ConstantArray *CPA); 00132 00133 // isInlinableInst - Attempt to inline instructions into their uses to build 00134 // trees as much as possible. To do this, we have to consistently decide 00135 // what is acceptable to inline, so that variable declarations don't get 00136 // printed and an extra copy of the expr is not emitted. 00137 // 00138 static bool isInlinableInst(const Instruction &I) { 00139 // Always inline setcc instructions, even if they are shared by multiple 00140 // expressions. GCC generates horrible code if we don't. 00141 if (isa<SetCondInst>(I)) return true; 00142 00143 // Must be an expression, must be used exactly once. If it is dead, we 00144 // emit it inline where it would go. 00145 if (I.getType() == Type::VoidTy || !I.hasOneUse() || 00146 isa<TerminatorInst>(I) || isa<CallInst>(I) || isa<PHINode>(I) || 00147 isa<LoadInst>(I) || isa<VAArgInst>(I) || isa<VANextInst>(I)) 00148 // Don't inline a load across a store or other bad things! 00149 return false; 00150 00151 // Only inline instruction it it's use is in the same BB as the inst. 00152 return I.getParent() == cast<Instruction>(I.use_back())->getParent(); 00153 } 00154 00155 // isDirectAlloca - Define fixed sized allocas in the entry block as direct 00156 // variables which are accessed with the & operator. This causes GCC to 00157 // generate significantly better code than to emit alloca calls directly. 00158 // 00159 static const AllocaInst *isDirectAlloca(const Value *V) { 00160 const AllocaInst *AI = dyn_cast<AllocaInst>(V); 00161 if (!AI) return false; 00162 if (AI->isArrayAllocation()) 00163 return 0; // FIXME: we can also inline fixed size array allocas! 00164 if (AI->getParent() != &AI->getParent()->getParent()->getEntryBlock()) 00165 return 0; 00166 return AI; 00167 } 00168 00169 // Instruction visitation functions 00170 friend class InstVisitor<CWriter>; 00171 00172 void visitReturnInst(ReturnInst &I); 00173 void visitBranchInst(BranchInst &I); 00174 void visitSwitchInst(SwitchInst &I); 00175 void visitInvokeInst(InvokeInst &I) { 00176 assert(0 && "Lowerinvoke pass didn't work!"); 00177 } 00178 00179 void visitUnwindInst(UnwindInst &I) { 00180 assert(0 && "Lowerinvoke pass didn't work!"); 00181 } 00182 void visitUnreachableInst(UnreachableInst &I); 00183 00184 void visitPHINode(PHINode &I); 00185 void visitBinaryOperator(Instruction &I); 00186 00187 void visitCastInst (CastInst &I); 00188 void visitSelectInst(SelectInst &I); 00189 void visitCallInst (CallInst &I); 00190 void visitShiftInst(ShiftInst &I) { visitBinaryOperator(I); } 00191 00192 void visitMallocInst(MallocInst &I); 00193 void visitAllocaInst(AllocaInst &I); 00194 void visitFreeInst (FreeInst &I); 00195 void visitLoadInst (LoadInst &I); 00196 void visitStoreInst (StoreInst &I); 00197 void visitGetElementPtrInst(GetElementPtrInst &I); 00198 void visitVANextInst(VANextInst &I); 00199 void visitVAArgInst (VAArgInst &I); 00200 00201 void visitInstruction(Instruction &I) { 00202 std::cerr << "C Writer does not know about " << I; 00203 abort(); 00204 } 00205 00206 void outputLValue(Instruction *I) { 00207 Out << " " << Mang->getValueName(I) << " = "; 00208 } 00209 00210 bool isGotoCodeNecessary(BasicBlock *From, BasicBlock *To); 00211 void printPHICopiesForSuccessor(BasicBlock *CurBlock, 00212 BasicBlock *Successor, unsigned Indent); 00213 void printBranchToBlock(BasicBlock *CurBlock, BasicBlock *SuccBlock, 00214 unsigned Indent); 00215 void printIndexingExpression(Value *Ptr, gep_type_iterator I, 00216 gep_type_iterator E); 00217 }; 00218 } 00219 00220 /// This method inserts names for any unnamed structure types that are used by 00221 /// the program, and removes names from structure types that are not used by the 00222 /// program. 00223 /// 00224 bool CBackendNameAllUsedStructs::runOnModule(Module &M) { 00225 // Get a set of types that are used by the program... 00226 std::set<const Type *> UT = getAnalysis<FindUsedTypes>().getTypes(); 00227 00228 // Loop over the module symbol table, removing types from UT that are 00229 // already named, and removing names for structure types that are not used. 00230 // 00231 SymbolTable &MST = M.getSymbolTable(); 00232 for (SymbolTable::type_iterator TI = MST.type_begin(), TE = MST.type_end(); 00233 TI != TE; ) { 00234 SymbolTable::type_iterator I = TI++; 00235 if (const StructType *STy = dyn_cast<StructType>(I->second)) { 00236 // If this is not used, remove it from the symbol table. 00237 std::set<const Type *>::iterator UTI = UT.find(STy); 00238 if (UTI == UT.end()) 00239 MST.remove(I); 00240 else 00241 UT.erase(UTI); 00242 } 00243 } 00244 00245 // UT now contains types that are not named. Loop over it, naming 00246 // structure types. 00247 // 00248 bool Changed = false; 00249 unsigned RenameCounter = 0; 00250 for (std::set<const Type *>::const_iterator I = UT.begin(), E = UT.end(); 00251 I != E; ++I) 00252 if (const StructType *ST = dyn_cast<StructType>(*I)) { 00253 while (M.addTypeName("unnamed"+utostr(RenameCounter), ST)) 00254 ++RenameCounter; 00255 Changed = true; 00256 } 00257 return Changed; 00258 } 00259 00260 00261 // Pass the Type* and the variable name and this prints out the variable 00262 // declaration. 00263 // 00264 std::ostream &CWriter::printType(std::ostream &Out, const Type *Ty, 00265 const std::string &NameSoFar, 00266 bool IgnoreName) { 00267 if (Ty->isPrimitiveType()) 00268 switch (Ty->getTypeID()) { 00269 case Type::VoidTyID: return Out << "void " << NameSoFar; 00270 case Type::BoolTyID: return Out << "bool " << NameSoFar; 00271 case Type::UByteTyID: return Out << "unsigned char " << NameSoFar; 00272 case Type::SByteTyID: return Out << "signed char " << NameSoFar; 00273 case Type::UShortTyID: return Out << "unsigned short " << NameSoFar; 00274 case Type::ShortTyID: return Out << "short " << NameSoFar; 00275 case Type::UIntTyID: return Out << "unsigned " << NameSoFar; 00276 case Type::IntTyID: return Out << "int " << NameSoFar; 00277 case Type::ULongTyID: return Out << "unsigned long long " << NameSoFar; 00278 case Type::LongTyID: return Out << "signed long long " << NameSoFar; 00279 case Type::FloatTyID: return Out << "float " << NameSoFar; 00280 case Type::DoubleTyID: return Out << "double " << NameSoFar; 00281 default : 00282 std::cerr << "Unknown primitive type: " << *Ty << "\n"; 00283 abort(); 00284 } 00285 00286 // Check to see if the type is named. 00287 if (!IgnoreName || isa<OpaqueType>(Ty)) { 00288 std::map<const Type *, std::string>::iterator I = TypeNames.find(Ty); 00289 if (I != TypeNames.end()) return Out << I->second << " " << NameSoFar; 00290 } 00291 00292 switch (Ty->getTypeID()) { 00293 case Type::FunctionTyID: { 00294 const FunctionType *MTy = cast<FunctionType>(Ty); 00295 std::stringstream FunctionInnards; 00296 FunctionInnards << " (" << NameSoFar << ") ("; 00297 for (FunctionType::param_iterator I = MTy->param_begin(), 00298 E = MTy->param_end(); I != E; ++I) { 00299 if (I != MTy->param_begin()) 00300 FunctionInnards << ", "; 00301 printType(FunctionInnards, *I, ""); 00302 } 00303 if (MTy->isVarArg()) { 00304 if (MTy->getNumParams()) 00305 FunctionInnards << ", ..."; 00306 } else if (!MTy->getNumParams()) { 00307 FunctionInnards << "void"; 00308 } 00309 FunctionInnards << ")"; 00310 std::string tstr = FunctionInnards.str(); 00311 printType(Out, MTy->getReturnType(), tstr); 00312 return Out; 00313 } 00314 case Type::StructTyID: { 00315 const StructType *STy = cast<StructType>(Ty); 00316 Out << NameSoFar + " {\n"; 00317 unsigned Idx = 0; 00318 for (StructType::element_iterator I = STy->element_begin(), 00319 E = STy->element_end(); I != E; ++I) { 00320 Out << " "; 00321 printType(Out, *I, "field" + utostr(Idx++)); 00322 Out << ";\n"; 00323 } 00324 return Out << "}"; 00325 } 00326 00327 case Type::PointerTyID: { 00328 const PointerType *PTy = cast<PointerType>(Ty); 00329 std::string ptrName = "*" + NameSoFar; 00330 00331 if (isa<ArrayType>(PTy->getElementType())) 00332 ptrName = "(" + ptrName + ")"; 00333 00334 return printType(Out, PTy->getElementType(), ptrName); 00335 } 00336 00337 case Type::ArrayTyID: { 00338 const ArrayType *ATy = cast<ArrayType>(Ty); 00339 unsigned NumElements = ATy->getNumElements(); 00340 return printType(Out, ATy->getElementType(), 00341 NameSoFar + "[" + utostr(NumElements) + "]"); 00342 } 00343 00344 case Type::OpaqueTyID: { 00345 static int Count = 0; 00346 std::string TyName = "struct opaque_" + itostr(Count++); 00347 assert(TypeNames.find(Ty) == TypeNames.end()); 00348 TypeNames[Ty] = TyName; 00349 return Out << TyName << " " << NameSoFar; 00350 } 00351 default: 00352 assert(0 && "Unhandled case in getTypeProps!"); 00353 abort(); 00354 } 00355 00356 return Out; 00357 } 00358 00359 void CWriter::printConstantArray(ConstantArray *CPA) { 00360 00361 // As a special case, print the array as a string if it is an array of 00362 // ubytes or an array of sbytes with positive values. 00363 // 00364 const Type *ETy = CPA->getType()->getElementType(); 00365 bool isString = (ETy == Type::SByteTy || ETy == Type::UByteTy); 00366 00367 // Make sure the last character is a null char, as automatically added by C 00368 if (isString && (CPA->getNumOperands() == 0 || 00369 !cast<Constant>(*(CPA->op_end()-1))->isNullValue())) 00370 isString = false; 00371 00372 if (isString) { 00373 Out << "\""; 00374 // Keep track of whether the last number was a hexadecimal escape 00375 bool LastWasHex = false; 00376 00377 // Do not include the last character, which we know is null 00378 for (unsigned i = 0, e = CPA->getNumOperands()-1; i != e; ++i) { 00379 unsigned char C = cast<ConstantInt>(CPA->getOperand(i))->getRawValue(); 00380 00381 // Print it out literally if it is a printable character. The only thing 00382 // to be careful about is when the last letter output was a hex escape 00383 // code, in which case we have to be careful not to print out hex digits 00384 // explicitly (the C compiler thinks it is a continuation of the previous 00385 // character, sheesh...) 00386 // 00387 if (isprint(C) && (!LastWasHex || !isxdigit(C))) { 00388 LastWasHex = false; 00389 if (C == '"' || C == '\\') 00390 Out << "\\" << C; 00391 else 00392 Out << C; 00393 } else { 00394 LastWasHex = false; 00395 switch (C) { 00396 case '\n': Out << "\\n"; break; 00397 case '\t': Out << "\\t"; break; 00398 case '\r': Out << "\\r"; break; 00399 case '\v': Out << "\\v"; break; 00400 case '\a': Out << "\\a"; break; 00401 case '\"': Out << "\\\""; break; 00402 case '\'': Out << "\\\'"; break; 00403 default: 00404 Out << "\\x"; 00405 Out << (char)(( C/16 < 10) ? ( C/16 +'0') : ( C/16 -10+'A')); 00406 Out << (char)(((C&15) < 10) ? ((C&15)+'0') : ((C&15)-10+'A')); 00407 LastWasHex = true; 00408 break; 00409 } 00410 } 00411 } 00412 Out << "\""; 00413 } else { 00414 Out << "{"; 00415 if (CPA->getNumOperands()) { 00416 Out << " "; 00417 printConstant(cast<Constant>(CPA->getOperand(0))); 00418 for (unsigned i = 1, e = CPA->getNumOperands(); i != e; ++i) { 00419 Out << ", "; 00420 printConstant(cast<Constant>(CPA->getOperand(i))); 00421 } 00422 } 00423 Out << " }"; 00424 } 00425 } 00426 00427 // isFPCSafeToPrint - Returns true if we may assume that CFP may be written out 00428 // textually as a double (rather than as a reference to a stack-allocated 00429 // variable). We decide this by converting CFP to a string and back into a 00430 // double, and then checking whether the conversion results in a bit-equal 00431 // double to the original value of CFP. This depends on us and the target C 00432 // compiler agreeing on the conversion process (which is pretty likely since we 00433 // only deal in IEEE FP). 00434 // 00435 static bool isFPCSafeToPrint(const ConstantFP *CFP) { 00436 #if HAVE_PRINTF_A 00437 char Buffer[100]; 00438 sprintf(Buffer, "%a", CFP->getValue()); 00439 00440 if (!strncmp(Buffer, "0x", 2) || 00441 !strncmp(Buffer, "-0x", 3) || 00442 !strncmp(Buffer, "+0x", 3)) 00443 return atof(Buffer) == CFP->getValue(); 00444 return false; 00445 #else 00446 std::string StrVal = ftostr(CFP->getValue()); 00447 00448 while (StrVal[0] == ' ') 00449 StrVal.erase(StrVal.begin()); 00450 00451 // Check to make sure that the stringized number is not some string like "Inf" 00452 // or NaN. Check that the string matches the "[-+]?[0-9]" regex. 00453 if ((StrVal[0] >= '0' && StrVal[0] <= '9') || 00454 ((StrVal[0] == '-' || StrVal[0] == '+') && 00455 (StrVal[1] >= '0' && StrVal[1] <= '9'))) 00456 // Reparse stringized version! 00457 return atof(StrVal.c_str()) == CFP->getValue(); 00458 return false; 00459 #endif 00460 } 00461 00462 // printConstant - The LLVM Constant to C Constant converter. 00463 void CWriter::printConstant(Constant *CPV) { 00464 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) { 00465 switch (CE->getOpcode()) { 00466 case Instruction::Cast: 00467 Out << "(("; 00468 printType(Out, CPV->getType()); 00469 Out << ")"; 00470 printConstant(CE->getOperand(0)); 00471 Out << ")"; 00472 return; 00473 00474 case Instruction::GetElementPtr: 00475 Out << "(&("; 00476 printIndexingExpression(CE->getOperand(0), gep_type_begin(CPV), 00477 gep_type_end(CPV)); 00478 Out << "))"; 00479 return; 00480 case Instruction::Select: 00481 Out << "("; 00482 printConstant(CE->getOperand(0)); 00483 Out << "?"; 00484 printConstant(CE->getOperand(1)); 00485 Out << ":"; 00486 printConstant(CE->getOperand(2)); 00487 Out << ")"; 00488 return; 00489 case Instruction::Add: 00490 case Instruction::Sub: 00491 case Instruction::Mul: 00492 case Instruction::Div: 00493 case Instruction::Rem: 00494 case Instruction::SetEQ: 00495 case Instruction::SetNE: 00496 case Instruction::SetLT: 00497 case Instruction::SetLE: 00498 case Instruction::SetGT: 00499 case Instruction::SetGE: 00500 case Instruction::Shl: 00501 case Instruction::Shr: 00502 Out << "("; 00503 printConstant(CE->getOperand(0)); 00504 switch (CE->getOpcode()) { 00505 case Instruction::Add: Out << " + "; break; 00506 case Instruction::Sub: Out << " - "; break; 00507 case Instruction::Mul: Out << " * "; break; 00508 case Instruction::Div: Out << " / "; break; 00509 case Instruction::Rem: Out << " % "; break; 00510 case Instruction::SetEQ: Out << " == "; break; 00511 case Instruction::SetNE: Out << " != "; break; 00512 case Instruction::SetLT: Out << " < "; break; 00513 case Instruction::SetLE: Out << " <= "; break; 00514 case Instruction::SetGT: Out << " > "; break; 00515 case Instruction::SetGE: Out << " >= "; break; 00516 case Instruction::Shl: Out << " << "; break; 00517 case Instruction::Shr: Out << " >> "; break; 00518 default: assert(0 && "Illegal opcode here!"); 00519 } 00520 printConstant(CE->getOperand(1)); 00521 Out << ")"; 00522 return; 00523 00524 default: 00525 std::cerr << "CWriter Error: Unhandled constant expression: " 00526 << *CE << "\n"; 00527 abort(); 00528 } 00529 } else if (isa<UndefValue>(CPV) && CPV->getType()->isFirstClassType()) { 00530 Out << "(("; 00531 printType(Out, CPV->getType()); 00532 Out << ")/*UNDEF*/0)"; 00533 return; 00534 } 00535 00536 switch (CPV->getType()->getTypeID()) { 00537 case Type::BoolTyID: 00538 Out << (CPV == ConstantBool::False ? "0" : "1"); break; 00539 case Type::SByteTyID: 00540 case Type::ShortTyID: 00541 Out << cast<ConstantSInt>(CPV)->getValue(); break; 00542 case Type::IntTyID: 00543 if ((int)cast<ConstantSInt>(CPV)->getValue() == (int)0x80000000) 00544 Out << "((int)0x80000000U)"; // Handle MININT specially to avoid warning 00545 else 00546 Out << cast<ConstantSInt>(CPV)->getValue(); 00547 break; 00548 00549 case Type::LongTyID: 00550 if (cast<ConstantSInt>(CPV)->isMinValue()) 00551 Out << "(/*INT64_MIN*/(-9223372036854775807LL)-1)"; 00552 else 00553 Out << cast<ConstantSInt>(CPV)->getValue() << "ll"; break; 00554 00555 case Type::UByteTyID: 00556 case Type::UShortTyID: 00557 Out << cast<ConstantUInt>(CPV)->getValue(); break; 00558 case Type::UIntTyID: 00559 Out << cast<ConstantUInt>(CPV)->getValue() << "u"; break; 00560 case Type::ULongTyID: 00561 Out << cast<ConstantUInt>(CPV)->getValue() << "ull"; break; 00562 00563 case Type::FloatTyID: 00564 case Type::DoubleTyID: { 00565 ConstantFP *FPC = cast<ConstantFP>(CPV); 00566 std::map<const ConstantFP*, unsigned>::iterator I = FPConstantMap.find(FPC); 00567 if (I != FPConstantMap.end()) { 00568 // Because of FP precision problems we must load from a stack allocated 00569 // value that holds the value in hex. 00570 Out << "(*(" << (FPC->getType() == Type::FloatTy ? "float" : "double") 00571 << "*)&FPConstant" << I->second << ")"; 00572 } else { 00573 if (IsNAN(FPC->getValue())) { 00574 // The value is NaN 00575 00576 // The prefix for a quiet NaN is 0x7FF8. For a signalling NaN, 00577 // it's 0x7ff4. 00578 const unsigned long QuietNaN = 0x7ff8UL; 00579 const unsigned long SignalNaN = 0x7ff4UL; 00580 00581 // We need to grab the first part of the FP # 00582 union { 00583 double d; 00584 uint64_t ll; 00585 } DHex; 00586 char Buffer[100]; 00587 00588 DHex.d = FPC->getValue(); 00589 sprintf(Buffer, "0x%llx", (unsigned long long)DHex.ll); 00590 00591 std::string Num(&Buffer[0], &Buffer[6]); 00592 unsigned long Val = strtoul(Num.c_str(), 0, 16); 00593 00594 if (FPC->getType() == Type::FloatTy) 00595 Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "F(\"" 00596 << Buffer << "\") /*nan*/ "; 00597 else 00598 Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "(\"" 00599 << Buffer << "\") /*nan*/ "; 00600 } else if (IsInf(FPC->getValue())) { 00601 // The value is Inf 00602 if (FPC->getValue() < 0) Out << "-"; 00603 Out << "LLVM_INF" << (FPC->getType() == Type::FloatTy ? "F" : "") 00604 << " /*inf*/ "; 00605 } else { 00606 std::string Num; 00607 #if HAVE_PRINTF_A 00608 // Print out the constant as a floating point number. 00609 char Buffer[100]; 00610 sprintf(Buffer, "%a", FPC->getValue()); 00611 Num = Buffer; 00612 #else 00613 Num = ftostr(FPC->getValue()); 00614 #endif 00615 Out << Num; 00616 } 00617 } 00618 break; 00619 } 00620 00621 case Type::ArrayTyID: 00622 if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) { 00623 const ArrayType *AT = cast<ArrayType>(CPV->getType()); 00624 Out << "{"; 00625 if (AT->getNumElements()) { 00626 Out << " "; 00627 Constant *CZ = Constant::getNullValue(AT->getElementType()); 00628 printConstant(CZ); 00629 for (unsigned i = 1, e = AT->getNumElements(); i != e; ++i) { 00630 Out << ", "; 00631 printConstant(CZ); 00632 } 00633 } 00634 Out << " }"; 00635 } else { 00636 printConstantArray(cast<ConstantArray>(CPV)); 00637 } 00638 break; 00639 00640 case Type::StructTyID: 00641 if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) { 00642 const StructType *ST = cast<StructType>(CPV->getType()); 00643 Out << "{"; 00644 if (ST->getNumElements()) { 00645 Out << " "; 00646 printConstant(Constant::getNullValue(ST->getElementType(0))); 00647 for (unsigned i = 1, e = ST->getNumElements(); i != e; ++i) { 00648 Out << ", "; 00649 printConstant(Constant::getNullValue(ST->getElementType(i))); 00650 } 00651 } 00652 Out << " }"; 00653 } else { 00654 Out << "{"; 00655 if (CPV->getNumOperands()) { 00656 Out << " "; 00657 printConstant(cast<Constant>(CPV->getOperand(0))); 00658 for (unsigned i = 1, e = CPV->getNumOperands(); i != e; ++i) { 00659 Out << ", "; 00660 printConstant(cast<Constant>(CPV->getOperand(i))); 00661 } 00662 } 00663 Out << " }"; 00664 } 00665 break; 00666 00667 case Type::PointerTyID: 00668 if (isa<ConstantPointerNull>(CPV)) { 00669 Out << "(("; 00670 printType(Out, CPV->getType()); 00671 Out << ")/*NULL*/0)"; 00672 break; 00673 } else if (GlobalValue *GV = dyn_cast<GlobalValue>(CPV)) { 00674 writeOperand(GV); 00675 break; 00676 } 00677 // FALL THROUGH 00678 default: 00679 std::cerr << "Unknown constant type: " << *CPV << "\n"; 00680 abort(); 00681 } 00682 } 00683 00684 void CWriter::writeOperandInternal(Value *Operand) { 00685 if (Instruction *I = dyn_cast<Instruction>(Operand)) 00686 if (isInlinableInst(*I) && !isDirectAlloca(I)) { 00687 // Should we inline this instruction to build a tree? 00688 Out << "("; 00689 visit(*I); 00690 Out << ")"; 00691 return; 00692 } 00693 00694 Constant* CPV = dyn_cast<Constant>(Operand); 00695 if (CPV && !isa<GlobalValue>(CPV)) { 00696 printConstant(CPV); 00697 } else { 00698 Out << Mang->getValueName(Operand); 00699 } 00700 } 00701 00702 void CWriter::writeOperand(Value *Operand) { 00703 if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand)) 00704 Out << "(&"; // Global variables are references as their addresses by llvm 00705 00706 writeOperandInternal(Operand); 00707 00708 if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand)) 00709 Out << ")"; 00710 } 00711 00712 // generateCompilerSpecificCode - This is where we add conditional compilation 00713 // directives to cater to specific compilers as need be. 00714 // 00715 static void generateCompilerSpecificCode(std::ostream& Out) { 00716 // Alloca is hard to get, and we don't want to include stdlib.h here... 00717 Out << "/* get a declaration for alloca */\n" 00718 << "#if defined(sun) || defined(__CYGWIN__) || defined(__APPLE__)\n" 00719 << "extern void *__builtin_alloca(unsigned long);\n" 00720 << "#define alloca(x) __builtin_alloca(x)\n" 00721 << "#elif defined(__FreeBSD__)\n" 00722 << "#define alloca(x) __builtin_alloca(x)\n" 00723 << "#else\n" 00724 << "#include <alloca.h>\n" 00725 << "#endif\n\n"; 00726 00727 // We output GCC specific attributes to preserve 'linkonce'ness on globals. 00728 // If we aren't being compiled with GCC, just drop these attributes. 00729 Out << "#ifndef __GNUC__ /* Can only support \"linkonce\" vars with GCC */\n" 00730 << "#define __attribute__(X)\n" 00731 << "#endif\n\n"; 00732 00733 #if 0 00734 // At some point, we should support "external weak" vs. "weak" linkages. 00735 // On Mac OS X, "external weak" is spelled "__attribute__((weak_import))". 00736 Out << "#if defined(__GNUC__) && defined(__APPLE_CC__)\n" 00737 << "#define __EXTERNAL_WEAK__ __attribute__((weak_import))\n" 00738 << "#elif defined(__GNUC__)\n" 00739 << "#define __EXTERNAL_WEAK__ __attribute__((weak))\n" 00740 << "#else\n" 00741 << "#define __EXTERNAL_WEAK__\n" 00742 << "#endif\n\n"; 00743 #endif 00744 00745 // For now, turn off the weak linkage attribute on Mac OS X. (See above.) 00746 Out << "#if defined(__GNUC__) && defined(__APPLE_CC__)\n" 00747 << "#define __ATTRIBUTE_WEAK__\n" 00748 << "#elif defined(__GNUC__)\n" 00749 << "#define __ATTRIBUTE_WEAK__ __attribute__((weak))\n" 00750 << "#else\n" 00751 << "#define __ATTRIBUTE_WEAK__\n" 00752 << "#endif\n\n"; 00753 00754 // Define NaN and Inf as GCC builtins if using GCC, as 0 otherwise 00755 // From the GCC documentation: 00756 // 00757 // double __builtin_nan (const char *str) 00758 // 00759 // This is an implementation of the ISO C99 function nan. 00760 // 00761 // Since ISO C99 defines this function in terms of strtod, which we do 00762 // not implement, a description of the parsing is in order. The string is 00763 // parsed as by strtol; that is, the base is recognized by leading 0 or 00764 // 0x prefixes. The number parsed is placed in the significand such that 00765 // the least significant bit of the number is at the least significant 00766 // bit of the significand. The number is truncated to fit the significand 00767 // field provided. The significand is forced to be a quiet NaN. 00768 // 00769 // This function, if given a string literal, is evaluated early enough 00770 // that it is considered a compile-time constant. 00771 // 00772 // float __builtin_nanf (const char *str) 00773 // 00774 // Similar to __builtin_nan, except the return type is float. 00775 // 00776 // double __builtin_inf (void) 00777 // 00778 // Similar to __builtin_huge_val, except a warning is generated if the 00779 // target floating-point format does not support infinities. This 00780 // function is suitable for implementing the ISO C99 macro INFINITY. 00781 // 00782 // float __builtin_inff (void) 00783 // 00784 // Similar to __builtin_inf, except the return type is float. 00785 Out << "#ifdef __GNUC__\n" 00786 << "#define LLVM_NAN(NanStr) __builtin_nan(NanStr) /* Double */\n" 00787 << "#define LLVM_NANF(NanStr) __builtin_nanf(NanStr) /* Float */\n" 00788 << "#define LLVM_NANS(NanStr) __builtin_nans(NanStr) /* Double */\n" 00789 << "#define LLVM_NANSF(NanStr) __builtin_nansf(NanStr) /* Float */\n" 00790 << "#define LLVM_INF __builtin_inf() /* Double */\n" 00791 << "#define LLVM_INFF __builtin_inff() /* Float */\n" 00792 << "#else\n" 00793 << "#define LLVM_NAN(NanStr) ((double)0.0) /* Double */\n" 00794 << "#define LLVM_NANF(NanStr) 0.0F /* Float */\n" 00795 << "#define LLVM_NANS(NanStr) ((double)0.0) /* Double */\n" 00796 << "#define LLVM_NANSF(NanStr) 0.0F /* Float */\n" 00797 << "#define LLVM_INF ((double)0.0) /* Double */\n" 00798 << "#define LLVM_INFF 0.0F /* Float */\n" 00799 << "#endif\n"; 00800 } 00801 00802 bool CWriter::doInitialization(Module &M) { 00803 // Initialize 00804 TheModule = &M; 00805 00806 IL.AddPrototypes(M); 00807 00808 // Ensure that all structure types have names... 00809 Mang = new Mangler(M); 00810 00811 // get declaration for alloca 00812 Out << "/* Provide Declarations */\n"; 00813 Out << "#include <stdarg.h>\n"; // Varargs support 00814 Out << "#include <setjmp.h>\n"; // Unwind support 00815 generateCompilerSpecificCode(Out); 00816 00817 // Provide a definition for `bool' if not compiling with a C++ compiler. 00818 Out << "\n" 00819 << "#ifndef __cplusplus\ntypedef unsigned char bool;\n#endif\n" 00820 00821 << "\n\n/* Support for floating point constants */\n" 00822 << "typedef unsigned long long ConstantDoubleTy;\n" 00823 << "typedef unsigned int ConstantFloatTy;\n" 00824 00825 << "\n\n/* Global Declarations */\n"; 00826 00827 // First output all the declarations for the program, because C requires 00828 // Functions & globals to be declared before they are used. 00829 // 00830 00831 // Loop over the symbol table, emitting all named constants... 00832 printModuleTypes(M.getSymbolTable()); 00833 00834 // Global variable declarations... 00835 if (!M.gempty()) { 00836 Out << "\n/* External Global Variable Declarations */\n"; 00837 for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I) { 00838 if (I->hasExternalLinkage()) { 00839 Out << "extern "; 00840 printType(Out, I->getType()->getElementType(), Mang->getValueName(I)); 00841 Out << ";\n"; 00842 } 00843 } 00844 } 00845 00846 // Function declarations 00847 if (!M.empty()) { 00848 Out << "\n/* Function Declarations */\n"; 00849 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) { 00850 // Don't print declarations for intrinsic functions. 00851 if (!I->getIntrinsicID() && 00852 I->getName() != "setjmp" && I->getName() != "longjmp") { 00853 printFunctionSignature(I, true); 00854 if (I->hasWeakLinkage()) Out << " __ATTRIBUTE_WEAK__"; 00855 if (I->hasLinkOnceLinkage()) Out << " __ATTRIBUTE_WEAK__"; 00856 Out << ";\n"; 00857 } 00858 } 00859 } 00860 00861 // Output the global variable declarations 00862 if (!M.gempty()) { 00863 Out << "\n\n/* Global Variable Declarations */\n"; 00864 for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I) 00865 if (!I->isExternal()) { 00866 if (I->hasInternalLinkage()) 00867 Out << "static "; 00868 else 00869 Out << "extern "; 00870 printType(Out, I->getType()->getElementType(), Mang->getValueName(I)); 00871 00872 if (I->hasLinkOnceLinkage()) 00873 Out << " __attribute__((common))"; 00874 else if (I->hasWeakLinkage()) 00875 Out << " __ATTRIBUTE_WEAK__"; 00876 Out << ";\n"; 00877 } 00878 } 00879 00880 // Output the global variable definitions and contents... 00881 if (!M.gempty()) { 00882 Out << "\n\n/* Global Variable Definitions and Initialization */\n"; 00883 for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I) 00884 if (!I->isExternal()) { 00885 if (I->hasInternalLinkage()) 00886 Out << "static "; 00887 printType(Out, I->getType()->getElementType(), Mang->getValueName(I)); 00888 if (I->hasLinkOnceLinkage()) 00889 Out << " __attribute__((common))"; 00890 else if (I->hasWeakLinkage()) 00891 Out << " __ATTRIBUTE_WEAK__"; 00892 00893 // If the initializer is not null, emit the initializer. If it is null, 00894 // we try to avoid emitting large amounts of zeros. The problem with 00895 // this, however, occurs when the variable has weak linkage. In this 00896 // case, the assembler will complain about the variable being both weak 00897 // and common, so we disable this optimization. 00898 if (!I->getInitializer()->isNullValue()) { 00899 Out << " = " ; 00900 writeOperand(I->getInitializer()); 00901 } else if (I->hasWeakLinkage()) { 00902 // We have to specify an initializer, but it doesn't have to be 00903 // complete. If the value is an aggregate, print out { 0 }, and let 00904 // the compiler figure out the rest of the zeros. 00905 Out << " = " ; 00906 if (isa<StructType>(I->getInitializer()->getType()) || 00907 isa<ArrayType>(I->getInitializer()->getType())) { 00908 Out << "{ 0 }"; 00909 } else { 00910 // Just print it out normally. 00911 writeOperand(I->getInitializer()); 00912 } 00913 } 00914 Out << ";\n"; 00915 } 00916 } 00917 00918 if (!M.empty()) 00919 Out << "\n\n/* Function Bodies */\n"; 00920 return false; 00921 } 00922 00923 00924 /// Output all floating point constants that cannot be printed accurately... 00925 void CWriter::printFloatingPointConstants(Function &F) { 00926 union { 00927 double D; 00928 uint64_t U; 00929 } DBLUnion; 00930 00931 union { 00932 float F; 00933 unsigned U; 00934 } FLTUnion; 00935 00936 // Scan the module for floating point constants. If any FP constant is used 00937 // in the function, we want to redirect it here so that we do not depend on 00938 // the precision of the printed form, unless the printed form preserves 00939 // precision. 00940 // 00941 static unsigned FPCounter = 0; 00942 for (constant_iterator I = constant_begin(&F), E = constant_end(&F); 00943 I != E; ++I) 00944 if (const ConstantFP *FPC = dyn_cast<ConstantFP>(*I)) 00945 if (!isFPCSafeToPrint(FPC) && // Do not put in FPConstantMap if safe. 00946 !FPConstantMap.count(FPC)) { 00947 double Val = FPC->getValue(); 00948 00949 FPConstantMap[FPC] = FPCounter; // Number the FP constants 00950 00951 if (FPC->getType() == Type::DoubleTy) { 00952 DBLUnion.D = Val; 00953 Out << "static const ConstantDoubleTy FPConstant" << FPCounter++ 00954 << " = 0x" << std::hex << DBLUnion.U << std::dec 00955 << "ULL; /* " << Val << " */\n"; 00956 } else if (FPC->getType() == Type::FloatTy) { 00957 FLTUnion.F = Val; 00958 Out << "static const ConstantFloatTy FPConstant" << FPCounter++ 00959 << " = 0x" << std::hex << FLTUnion.U << std::dec 00960 << "U; /* " << Val << " */\n"; 00961 } else 00962 assert(0 && "Unknown float type!"); 00963 } 00964 00965 Out << "\n"; 00966 } 00967 00968 00969 /// printSymbolTable - Run through symbol table looking for type names. If a 00970 /// type name is found, emit it's declaration... 00971 /// 00972 void CWriter::printModuleTypes(const SymbolTable &ST) { 00973 // If there are no type names, exit early. 00974 if ( ! ST.hasTypes() ) 00975 return; 00976 00977 // We are only interested in the type plane of the symbol table... 00978 SymbolTable::type_const_iterator I = ST.type_begin(); 00979 SymbolTable::type_const_iterator End = ST.type_end(); 00980 00981 // Print out forward declarations for structure types before anything else! 00982 Out << "/* Structure forward decls */\n"; 00983 for (; I != End; ++I) 00984 if (const Type *STy = dyn_cast<StructType>(I->second)) { 00985 std::string Name = "struct l_" + Mangler::makeNameProper(I->first); 00986 Out << Name << ";\n"; 00987 TypeNames.insert(std::make_pair(STy, Name)); 00988 } 00989 00990 Out << "\n"; 00991 00992 // Now we can print out typedefs... 00993 Out << "/* Typedefs */\n"; 00994 for (I = ST.type_begin(); I != End; ++I) { 00995 const Type *Ty = cast<Type>(I->second); 00996 std::string Name = "l_" + Mangler::makeNameProper(I->first); 00997 Out << "typedef "; 00998 printType(Out, Ty, Name); 00999 Out << ";\n"; 01000 } 01001 01002 Out << "\n"; 01003 01004 // Keep track of which structures have been printed so far... 01005 std::set<const StructType *> StructPrinted; 01006 01007 // Loop over all structures then push them into the stack so they are 01008 // printed in the correct order. 01009 // 01010 Out << "/* Structure contents */\n"; 01011 for (I = ST.type_begin(); I != End; ++I) 01012 if (const StructType *STy = dyn_cast<StructType>(I->second)) 01013 // Only print out used types! 01014 printContainedStructs(STy, StructPrinted); 01015 } 01016 01017 // Push the struct onto the stack and recursively push all structs 01018 // this one depends on. 01019 void CWriter::printContainedStructs(const Type *Ty, 01020 std::set<const StructType*> &StructPrinted){ 01021 if (const StructType *STy = dyn_cast<StructType>(Ty)) { 01022 //Check to see if we have already printed this struct 01023 if (StructPrinted.count(STy) == 0) { 01024 // Print all contained types first... 01025 for (StructType::element_iterator I = STy->element_begin(), 01026 E = STy->element_end(); I != E; ++I) { 01027 const Type *Ty1 = I->get(); 01028 if (isa<StructType>(Ty1) || isa<ArrayType>(Ty1)) 01029 printContainedStructs(*I, StructPrinted); 01030 } 01031 01032 //Print structure type out.. 01033 StructPrinted.insert(STy); 01034 std::string Name = TypeNames[STy]; 01035 printType(Out, STy, Name, true); 01036 Out << ";\n\n"; 01037 } 01038 01039 // If it is an array, check contained types and continue 01040 } else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)){ 01041 const Type *Ty1 = ATy->getElementType(); 01042 if (isa<StructType>(Ty1) || isa<ArrayType>(Ty1)) 01043 printContainedStructs(Ty1, StructPrinted); 01044 } 01045 } 01046 01047 01048 void CWriter::printFunctionSignature(const Function *F, bool Prototype) { 01049 if (F->hasInternalLinkage()) Out << "static "; 01050 01051 // Loop over the arguments, printing them... 01052 const FunctionType *FT = cast<FunctionType>(F->getFunctionType()); 01053 01054 std::stringstream FunctionInnards; 01055 01056 // Print out the name... 01057 FunctionInnards << Mang->getValueName(F) << "("; 01058 01059 if (!F->isExternal()) { 01060 if (!F->aempty()) { 01061 std::string ArgName; 01062 if (F->abegin()->hasName() || !Prototype) 01063 ArgName = Mang->getValueName(F->abegin()); 01064 printType(FunctionInnards, F->afront().getType(), ArgName); 01065 for (Function::const_aiterator I = ++F->abegin(), E = F->aend(); 01066 I != E; ++I) { 01067 FunctionInnards << ", "; 01068 if (I->hasName() || !Prototype) 01069 ArgName = Mang->getValueName(I); 01070 else 01071 ArgName = ""; 01072 printType(FunctionInnards, I->getType(), ArgName); 01073 } 01074 } 01075 } else { 01076 // Loop over the arguments, printing them... 01077 for (FunctionType::param_iterator I = FT->param_begin(), 01078 E = FT->param_end(); I != E; ++I) { 01079 if (I != FT->param_begin()) FunctionInnards << ", "; 01080 printType(FunctionInnards, *I); 01081 } 01082 } 01083 01084 // Finish printing arguments... if this is a vararg function, print the ..., 01085 // unless there are no known types, in which case, we just emit (). 01086 // 01087 if (FT->isVarArg() && FT->getNumParams()) { 01088 if (FT->getNumParams()) FunctionInnards << ", "; 01089 FunctionInnards << "..."; // Output varargs portion of signature! 01090 } else if (!FT->isVarArg() && FT->getNumParams() == 0) { 01091 FunctionInnards << "void"; // ret() -> ret(void) in C. 01092 } 01093 FunctionInnards << ")"; 01094 // Print out the return type and the entire signature for that matter 01095 printType(Out, F->getReturnType(), FunctionInnards.str()); 01096 } 01097 01098 void CWriter::printFunction(Function &F) { 01099 printFunctionSignature(&F, false); 01100 Out << " {\n"; 01101 01102 // print local variable information for the function 01103 for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ++I) 01104 if (const AllocaInst *AI = isDirectAlloca(&*I)) { 01105 Out << " "; 01106 printType(Out, AI->getAllocatedType(), Mang->getValueName(AI)); 01107 Out << "; /* Address exposed local */\n"; 01108 } else if (I->getType() != Type::VoidTy && !isInlinableInst(*I)) { 01109 Out << " "; 01110 printType(Out, I->getType(), Mang->getValueName(&*I)); 01111 Out << ";\n"; 01112 01113 if (isa<PHINode>(*I)) { // Print out PHI node temporaries as well... 01114 Out << " "; 01115 printType(Out, I->getType(), 01116 Mang->getValueName(&*I)+"__PHI_TEMPORARY"); 01117 Out << ";\n"; 01118 } 01119 } 01120 01121 Out << "\n"; 01122 01123 // print the basic blocks 01124 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { 01125 if (Loop *L = LI->getLoopFor(BB)) { 01126 if (L->getHeader() == BB && L->getParentLoop() == 0) 01127 printLoop(L); 01128 } else { 01129 printBasicBlock(BB); 01130 } 01131 } 01132 01133 Out << "}\n\n"; 01134 } 01135 01136 void CWriter::printLoop(Loop *L) { 01137 Out << " do { /* Syntactic loop '" << L->getHeader()->getName() 01138 << "' to make GCC happy */\n"; 01139 for (unsigned i = 0, e = L->getBlocks().size(); i != e; ++i) { 01140 BasicBlock *BB = L->getBlocks()[i]; 01141 Loop *BBLoop = LI->getLoopFor(BB); 01142 if (BBLoop == L) 01143 printBasicBlock(BB); 01144 else if (BB == BBLoop->getHeader() && BBLoop->getParentLoop() == L) 01145 printLoop(BBLoop); 01146 } 01147 Out << " } while (1); /* end of syntactic loop '" 01148 << L->getHeader()->getName() << "' */\n"; 01149 } 01150 01151 void CWriter::printBasicBlock(BasicBlock *BB) { 01152 01153 // Don't print the label for the basic block if there are no uses, or if 01154 // the only terminator use is the predecessor basic block's terminator. 01155 // We have to scan the use list because PHI nodes use basic blocks too but 01156 // do not require a label to be generated. 01157 // 01158 bool NeedsLabel = false; 01159 for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) 01160 if (isGotoCodeNecessary(*PI, BB)) { 01161 NeedsLabel = true; 01162 break; 01163 } 01164 01165 if (NeedsLabel) Out << Mang->getValueName(BB) << ":\n"; 01166 01167 // Output all of the instructions in the basic block... 01168 for (BasicBlock::iterator II = BB->begin(), E = --BB->end(); II != E; 01169 ++II) { 01170 if (!isInlinableInst(*II) && !isDirectAlloca(II)) { 01171 if (II->getType() != Type::VoidTy) 01172 outputLValue(II); 01173 else 01174 Out << " "; 01175 visit(*II); 01176 Out << ";\n"; 01177 } 01178 } 01179 01180 // Don't emit prefix or suffix for the terminator... 01181 visit(*BB->getTerminator()); 01182 } 01183 01184 01185 // Specific Instruction type classes... note that all of the casts are 01186 // necessary because we use the instruction classes as opaque types... 01187 // 01188 void CWriter::visitReturnInst(ReturnInst &I) { 01189 // Don't output a void return if this is the last basic block in the function 01190 if (I.getNumOperands() == 0 && 01191 &*--I.getParent()->getParent()->end() == I.getParent() && 01192 !I.getParent()->size() == 1) { 01193 return; 01194 } 01195 01196 Out << " return"; 01197 if (I.getNumOperands()) { 01198 Out << " "; 01199 writeOperand(I.getOperand(0)); 01200 } 01201 Out << ";\n"; 01202 } 01203 01204 void CWriter::visitSwitchInst(SwitchInst &SI) { 01205 01206 Out << " switch ("; 01207 writeOperand(SI.getOperand(0)); 01208 Out << ") {\n default:\n"; 01209 printPHICopiesForSuccessor (SI.getParent(), SI.getDefaultDest(), 2); 01210 printBranchToBlock(SI.getParent(), SI.getDefaultDest(), 2); 01211 Out << ";\n"; 01212 for (unsigned i = 2, e = SI.getNumOperands(); i != e; i += 2) { 01213 Out << " case "; 01214 writeOperand(SI.getOperand(i)); 01215 Out << ":\n"; 01216 BasicBlock *Succ = cast<BasicBlock>(SI.getOperand(i+1)); 01217 printPHICopiesForSuccessor (SI.getParent(), Succ, 2); 01218 printBranchToBlock(SI.getParent(), Succ, 2); 01219 if (Succ == SI.getParent()->getNext()) 01220 Out << " break;\n"; 01221 } 01222 Out << " }\n"; 01223 } 01224 01225 void CWriter::visitUnreachableInst(UnreachableInst &I) { 01226 Out << " /*UNREACHABLE*/;\n"; 01227 } 01228 01229 bool CWriter::isGotoCodeNecessary(BasicBlock *From, BasicBlock *To) { 01230 /// FIXME: This should be reenabled, but loop reordering safe!! 01231 return true; 01232 01233 if (From->getNext() != To) // Not the direct successor, we need a goto 01234 return true; 01235 01236 //isa<SwitchInst>(From->getTerminator()) 01237 01238 01239 if (LI->getLoopFor(From) != LI->getLoopFor(To)) 01240 return true; 01241 return false; 01242 } 01243 01244 void CWriter::printPHICopiesForSuccessor (BasicBlock *CurBlock, 01245 BasicBlock *Successor, 01246 unsigned Indent) { 01247 for (BasicBlock::iterator I = Successor->begin(); isa<PHINode>(I); ++I) { 01248 PHINode *PN = cast<PHINode>(I); 01249 // Now we have to do the printing. 01250 Value *IV = PN->getIncomingValueForBlock(CurBlock); 01251 if (!isa<UndefValue>(IV)) { 01252 Out << std::string(Indent, ' '); 01253 Out << " " << Mang->getValueName(I) << "__PHI_TEMPORARY = "; 01254 writeOperand(IV); 01255 Out << "; /* for PHI node */\n"; 01256 } 01257 } 01258 } 01259 01260 void CWriter::printBranchToBlock(BasicBlock *CurBB, BasicBlock *Succ, 01261 unsigned Indent) { 01262 if (isGotoCodeNecessary(CurBB, Succ)) { 01263 Out << std::string(Indent, ' ') << " goto "; 01264 writeOperand(Succ); 01265 Out << ";\n"; 01266 } 01267 } 01268 01269 // Branch instruction printing - Avoid printing out a branch to a basic block 01270 // that immediately succeeds the current one. 01271 // 01272 void CWriter::visitBranchInst(BranchInst &I) { 01273 01274 if (I.isConditional()) { 01275 if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(0))) { 01276 Out << " if ("; 01277 writeOperand(I.getCondition()); 01278 Out << ") {\n"; 01279 01280 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(0), 2); 01281 printBranchToBlock(I.getParent(), I.getSuccessor(0), 2); 01282 01283 if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(1))) { 01284 Out << " } else {\n"; 01285 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(1), 2); 01286 printBranchToBlock(I.getParent(), I.getSuccessor(1), 2); 01287 } 01288 } else { 01289 // First goto not necessary, assume second one is... 01290 Out << " if (!"; 01291 writeOperand(I.getCondition()); 01292 Out << ") {\n"; 01293 01294 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(1), 2); 01295 printBranchToBlock(I.getParent(), I.getSuccessor(1), 2); 01296 } 01297 01298 Out << " }\n"; 01299 } else { 01300 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(0), 0); 01301 printBranchToBlock(I.getParent(), I.getSuccessor(0), 0); 01302 } 01303 Out << "\n"; 01304 } 01305 01306 // PHI nodes get copied into temporary values at the end of predecessor basic 01307 // blocks. We now need to copy these temporary values into the REAL value for 01308 // the PHI. 01309 void CWriter::visitPHINode(PHINode &I) { 01310 writeOperand(&I); 01311 Out << "__PHI_TEMPORARY"; 01312 } 01313 01314 01315 void CWriter::visitBinaryOperator(Instruction &I) { 01316 // binary instructions, shift instructions, setCond instructions. 01317 assert(!isa<PointerType>(I.getType())); 01318 01319 // We must cast the results of binary operations which might be promoted. 01320 bool needsCast = false; 01321 if ((I.getType() == Type::UByteTy) || (I.getType() == Type::SByteTy) 01322 || (I.getType() == Type::UShortTy) || (I.getType() == Type::ShortTy) 01323 || (I.getType() == Type::FloatTy)) { 01324 needsCast = true; 01325 Out << "(("; 01326 printType(Out, I.getType()); 01327 Out << ")("; 01328 } 01329 01330 writeOperand(I.getOperand(0)); 01331 01332 switch (I.getOpcode()) { 01333 case Instruction::Add: Out << " + "; break; 01334 case Instruction::Sub: Out << " - "; break; 01335 case Instruction::Mul: Out << "*"; break; 01336 case Instruction::Div: Out << "/"; break; 01337 case Instruction::Rem: Out << "%"; break; 01338 case Instruction::And: Out << " & "; break; 01339 case Instruction::Or: Out << " | "; break; 01340 case Instruction::Xor: Out << " ^ "; break; 01341 case Instruction::SetEQ: Out << " == "; break; 01342 case Instruction::SetNE: Out << " != "; break; 01343 case Instruction::SetLE: Out << " <= "; break; 01344 case Instruction::SetGE: Out << " >= "; break; 01345 case Instruction::SetLT: Out << " < "; break; 01346 case Instruction::SetGT: Out << " > "; break; 01347 case Instruction::Shl : Out << " << "; break; 01348 case Instruction::Shr : Out << " >> "; break; 01349 default: std::cerr << "Invalid operator type!" << I; abort(); 01350 } 01351 01352 writeOperand(I.getOperand(1)); 01353 01354 if (needsCast) { 01355 Out << "))"; 01356 } 01357 } 01358 01359 void CWriter::visitCastInst(CastInst &I) { 01360 if (I.getType() == Type::BoolTy) { 01361 Out << "("; 01362 writeOperand(I.getOperand(0)); 01363 Out << " != 0)"; 01364 return; 01365 } 01366 Out << "("; 01367 printType(Out, I.getType()); 01368 Out << ")"; 01369 if (isa<PointerType>(I.getType())&&I.getOperand(0)->getType()->isIntegral() || 01370 isa<PointerType>(I.getOperand(0)->getType())&&I.getType()->isIntegral()) { 01371 // Avoid "cast to pointer from integer of different size" warnings 01372 Out << "(long)"; 01373 } 01374 01375 writeOperand(I.getOperand(0)); 01376 } 01377 01378 void CWriter::visitSelectInst(SelectInst &I) { 01379 Out << "(("; 01380 writeOperand(I.getCondition()); 01381 Out << ") ? ("; 01382 writeOperand(I.getTrueValue()); 01383 Out << ") : ("; 01384 writeOperand(I.getFalseValue()); 01385 Out << "))"; 01386 } 01387 01388 01389 void CWriter::lowerIntrinsics(Function &F) { 01390 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) 01391 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) 01392 if (CallInst *CI = dyn_cast<CallInst>(I++)) 01393 if (Function *F = CI->getCalledFunction()) 01394 switch (F->getIntrinsicID()) { 01395 case Intrinsic::not_intrinsic: 01396 case Intrinsic::vastart: 01397 case Intrinsic::vacopy: 01398 case Intrinsic::vaend: 01399 case Intrinsic::returnaddress: 01400 case Intrinsic::frameaddress: 01401 case Intrinsic::setjmp: 01402 case Intrinsic::longjmp: 01403 // We directly implement these intrinsics 01404 break; 01405 default: 01406 // All other intrinsic calls we must lower. 01407 Instruction *Before = CI->getPrev(); 01408 IL.LowerIntrinsicCall(CI); 01409 if (Before) { // Move iterator to instruction after call 01410 I = Before; ++I; 01411 } else { 01412 I = BB->begin(); 01413 } 01414 } 01415 } 01416 01417 01418 01419 void CWriter::visitCallInst(CallInst &I) { 01420 // Handle intrinsic function calls first... 01421 if (Function *F = I.getCalledFunction()) 01422 if (Intrinsic::ID ID = (Intrinsic::ID)F->getIntrinsicID()) { 01423 switch (ID) { 01424 default: assert(0 && "Unknown LLVM intrinsic!"); 01425 case Intrinsic::vastart: 01426 Out << "0; "; 01427 01428 Out << "va_start(*(va_list*)&" << Mang->getValueName(&I) << ", "; 01429 // Output the last argument to the enclosing function... 01430 if (I.getParent()->getParent()->aempty()) { 01431 std::cerr << "The C backend does not currently support zero " 01432 << "argument varargs functions, such as '" 01433 << I.getParent()->getParent()->getName() << "'!\n"; 01434 abort(); 01435 } 01436 writeOperand(&I.getParent()->getParent()->aback()); 01437 Out << ")"; 01438 return; 01439 case Intrinsic::vaend: 01440 if (!isa<ConstantPointerNull>(I.getOperand(1))) { 01441 Out << "va_end(*(va_list*)&"; 01442 writeOperand(I.getOperand(1)); 01443 Out << ")"; 01444 } else { 01445 Out << "va_end(*(va_list*)0)"; 01446 } 01447 return; 01448 case Intrinsic::vacopy: 01449 Out << "0;"; 01450 Out << "va_copy(*(va_list*)&" << Mang->getValueName(&I) << ", "; 01451 Out << "*(va_list*)&"; 01452 writeOperand(I.getOperand(1)); 01453 Out << ")"; 01454 return; 01455 case Intrinsic::returnaddress: 01456 Out << "__builtin_return_address("; 01457 writeOperand(I.getOperand(1)); 01458 Out << ")"; 01459 return; 01460 case Intrinsic::frameaddress: 01461 Out << "__builtin_frame_address("; 01462 writeOperand(I.getOperand(1)); 01463 Out << ")"; 01464 return; 01465 case Intrinsic::setjmp: 01466 Out << "setjmp(*(jmp_buf*)"; 01467 writeOperand(I.getOperand(1)); 01468 Out << ")"; 01469 return; 01470 case Intrinsic::longjmp: 01471 Out << "longjmp(*(jmp_buf*)"; 01472 writeOperand(I.getOperand(1)); 01473 Out << ", "; 01474 writeOperand(I.getOperand(2)); 01475 Out << ")"; 01476 return; 01477 } 01478 } 01479 01480 Value *Callee = I.getCalledValue(); 01481 01482 // GCC is really a PITA. It does not permit codegening casts of functions to 01483 // function pointers if they are in a call (it generates a trap instruction 01484 // instead!). We work around this by inserting a cast to void* in between the 01485 // function and the function pointer cast. Unfortunately, we can't just form 01486 // the constant expression here, because the folder will immediately nuke it. 01487 // 01488 // Note finally, that this is completely unsafe. ANSI C does not guarantee 01489 // that void* and function pointers have the same size. :( To deal with this 01490 // in the common case, we handle casts where the number of arguments passed 01491 // match exactly. 01492 // 01493 bool WroteCallee = false; 01494 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Callee)) 01495 if (CE->getOpcode() == Instruction::Cast) 01496 if (Function *RF = dyn_cast<Function>(CE->getOperand(0))) { 01497 const FunctionType *RFTy = RF->getFunctionType(); 01498 if (RFTy->getNumParams() == I.getNumOperands()-1) { 01499 // If the call site expects a value, and the actual callee doesn't 01500 // provide one, return 0. 01501 if (I.getType() != Type::VoidTy && 01502 RFTy->getReturnType() == Type::VoidTy) 01503 Out << "0 /*actual callee doesn't return value*/; "; 01504 Callee = RF; 01505 } else { 01506 // Ok, just cast the pointer type. 01507 Out << "(("; 01508 printType(Out, CE->getType()); 01509 Out << ")(void*)"; 01510 printConstant(RF); 01511 Out << ")"; 01512 WroteCallee = true; 01513 } 01514 } 01515 01516 const PointerType *PTy = cast<PointerType>(Callee->getType()); 01517 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); 01518 const Type *RetTy = FTy->getReturnType(); 01519 01520 if (!WroteCallee) writeOperand(Callee); 01521 Out << "("; 01522 01523 unsigned NumDeclaredParams = FTy->getNumParams(); 01524 01525 if (I.getNumOperands() != 1) { 01526 CallSite::arg_iterator AI = I.op_begin()+1, AE = I.op_end(); 01527 if (NumDeclaredParams && (*AI)->getType() != FTy->getParamType(0)) { 01528 Out << "("; 01529 printType(Out, FTy->getParamType(0)); 01530 Out << ")"; 01531 } 01532 01533 writeOperand(*AI); 01534 01535 unsigned ArgNo; 01536 for (ArgNo = 1, ++AI; AI != AE; ++AI, ++ArgNo) { 01537 Out << ", "; 01538 if (ArgNo < NumDeclaredParams && 01539 (*AI)->getType() != FTy->getParamType(ArgNo)) { 01540 Out << "("; 01541 printType(Out, FTy->getParamType(ArgNo)); 01542 Out << ")"; 01543 } 01544 writeOperand(*AI); 01545 } 01546 } 01547 Out << ")"; 01548 } 01549 01550 void CWriter::visitMallocInst(MallocInst &I) { 01551 assert(0 && "lowerallocations pass didn't work!"); 01552 } 01553 01554 void CWriter::visitAllocaInst(AllocaInst &I) { 01555 Out << "("; 01556 printType(Out, I.getType()); 01557 Out << ") alloca(sizeof("; 01558 printType(Out, I.getType()->getElementType()); 01559 Out << ")"; 01560 if (I.isArrayAllocation()) { 01561 Out << " * " ; 01562 writeOperand(I.getOperand(0)); 01563 } 01564 Out << ")"; 01565 } 01566 01567 void CWriter::visitFreeInst(FreeInst &I) { 01568 assert(0 && "lowerallocations pass didn't work!"); 01569 } 01570 01571 void CWriter::printIndexingExpression(Value *Ptr, gep_type_iterator I, 01572 gep_type_iterator E) { 01573 bool HasImplicitAddress = false; 01574 // If accessing a global value with no indexing, avoid *(&GV) syndrome 01575 if (GlobalValue *V = dyn_cast<GlobalValue>(Ptr)) { 01576 HasImplicitAddress = true; 01577 } else if (isDirectAlloca(Ptr)) { 01578 HasImplicitAddress = true; 01579 } 01580 01581 if (I == E) { 01582 if (!HasImplicitAddress) 01583 Out << "*"; // Implicit zero first argument: '*x' is equivalent to 'x[0]' 01584 01585 writeOperandInternal(Ptr); 01586 return; 01587 } 01588 01589 const Constant *CI = dyn_cast<Constant>(I.getOperand()); 01590 if (HasImplicitAddress && (!CI || !CI->isNullValue())) 01591 Out << "(&"; 01592 01593 writeOperandInternal(Ptr); 01594 01595 if (HasImplicitAddress && (!CI || !CI->isNullValue())) { 01596 Out << ")"; 01597 HasImplicitAddress = false; // HIA is only true if we haven't addressed yet 01598 } 01599 01600 assert(!HasImplicitAddress || (CI && CI->isNullValue()) && 01601 "Can only have implicit address with direct accessing"); 01602 01603 if (HasImplicitAddress) { 01604 ++I; 01605 } else if (CI && CI->isNullValue()) { 01606 gep_type_iterator TmpI = I; ++TmpI; 01607 01608 // Print out the -> operator if possible... 01609 if (TmpI != E && isa<StructType>(*TmpI)) { 01610 Out << (HasImplicitAddress ? "." : "->"); 01611 Out << "field" << cast<ConstantUInt>(TmpI.getOperand())->getValue(); 01612 I = ++TmpI; 01613 } 01614 } 01615 01616 for (; I != E; ++I) 01617 if (isa<StructType>(*I)) { 01618 Out << ".field" << cast<ConstantUInt>(I.getOperand())->getValue(); 01619 } else { 01620 Out << "["; 01621 writeOperand(I.getOperand()); 01622 Out << "]"; 01623 } 01624 } 01625 01626 void CWriter::visitLoadInst(LoadInst &I) { 01627 Out << "*"; 01628 writeOperand(I.getOperand(0)); 01629 } 01630 01631 void CWriter::visitStoreInst(StoreInst &I) { 01632 Out << "*"; 01633 writeOperand(I.getPointerOperand()); 01634 Out << " = "; 01635 writeOperand(I.getOperand(0)); 01636 } 01637 01638 void CWriter::visitGetElementPtrInst(GetElementPtrInst &I) { 01639 Out << "&"; 01640 printIndexingExpression(I.getPointerOperand(), gep_type_begin(I), 01641 gep_type_end(I)); 01642 } 01643 01644 void CWriter::visitVANextInst(VANextInst &I) { 01645 Out << Mang->getValueName(I.getOperand(0)); 01646 Out << "; va_arg(*(va_list*)&" << Mang->getValueName(&I) << ", "; 01647 printType(Out, I.getArgType()); 01648 Out << ")"; 01649 } 01650 01651 void CWriter::visitVAArgInst(VAArgInst &I) { 01652 Out << "0;\n"; 01653 Out << "{ va_list Tmp; va_copy(Tmp, *(va_list*)&"; 01654 writeOperand(I.getOperand(0)); 01655 Out << ");\n " << Mang->getValueName(&I) << " = va_arg(Tmp, "; 01656 printType(Out, I.getType()); 01657 Out << ");\n va_end(Tmp); }"; 01658 } 01659 01660 //===----------------------------------------------------------------------===// 01661 // External Interface declaration 01662 //===----------------------------------------------------------------------===// 01663 01664 bool CTargetMachine::addPassesToEmitAssembly(PassManager &PM, std::ostream &o) { 01665 PM.add(createLowerGCPass()); 01666 PM.add(createLowerAllocationsPass()); 01667 PM.add(createLowerInvokePass()); 01668 PM.add(new CBackendNameAllUsedStructs()); 01669 PM.add(new CWriter(o, getIntrinsicLowering())); 01670 return false; 01671 } 01672 01673 // vim: sw=2