1 //===-- Writer.cpp - Library for converting LLVM code to C ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This library converts LLVM code to C code, compilable by GCC and other C
13 //===----------------------------------------------------------------------===//
15 #include "CTargetMachine.h"
16 #include "llvm/Constants.h"
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/Module.h"
19 #include "llvm/Instructions.h"
20 #include "llvm/Pass.h"
21 #include "llvm/PassManager.h"
22 #include "llvm/SymbolTable.h"
23 #include "llvm/Intrinsics.h"
24 #include "llvm/Analysis/ConstantsScanner.h"
25 #include "llvm/Analysis/FindUsedTypes.h"
26 #include "llvm/Analysis/LoopInfo.h"
27 #include "llvm/CodeGen/IntrinsicLowering.h"
28 #include "llvm/Transforms/Scalar.h"
29 #include "llvm/Target/TargetMachineRegistry.h"
30 #include "llvm/Support/CallSite.h"
31 #include "llvm/Support/CFG.h"
32 #include "llvm/Support/GetElementPtrTypeIterator.h"
33 #include "llvm/Support/InstVisitor.h"
34 #include "llvm/Support/Mangler.h"
35 #include "llvm/ADT/StringExtras.h"
36 #include "llvm/ADT/STLExtras.h"
37 #include "llvm/Support/MathExtras.h"
38 #include "llvm/Config/config.h"
45 // Register the target.
46 RegisterTarget<CTargetMachine> X("c", " C backend");
48 /// NameAllUsedStructs - This pass inserts names for any unnamed structure
49 /// types that are used by the program.
51 class CBackendNameAllUsedStructs : public ModulePass {
52 void getAnalysisUsage(AnalysisUsage &AU) const {
53 AU.addRequired<FindUsedTypes>();
56 virtual const char *getPassName() const {
57 return "C backend type canonicalizer";
60 virtual bool runOnModule(Module &M);
63 /// CWriter - This class is the main chunk of code that converts an LLVM
64 /// module to a C translation unit.
65 class CWriter : public FunctionPass, public InstVisitor<CWriter> {
67 IntrinsicLowering &IL;
70 const Module *TheModule;
71 std::map<const Type *, std::string> TypeNames;
73 std::map<const ConstantFP *, unsigned> FPConstantMap;
75 CWriter(std::ostream &o, IntrinsicLowering &il) : Out(o), IL(il) {}
77 virtual const char *getPassName() const { return "C backend"; }
79 void getAnalysisUsage(AnalysisUsage &AU) const {
80 AU.addRequired<LoopInfo>();
84 virtual bool doInitialization(Module &M);
86 bool runOnFunction(Function &F) {
87 LI = &getAnalysis<LoopInfo>();
89 // Get rid of intrinsics we can't handle.
92 // Output all floating point constants that cannot be printed accurately.
93 printFloatingPointConstants(F);
95 // Ensure that no local symbols conflict with global symbols.
96 F.renameLocalSymbols();
99 FPConstantMap.clear();
103 virtual bool doFinalization(Module &M) {
110 std::ostream &printType(std::ostream &Out, const Type *Ty,
111 const std::string &VariableName = "",
112 bool IgnoreName = false);
114 void writeOperand(Value *Operand);
115 void writeOperandInternal(Value *Operand);
118 void lowerIntrinsics(Function &F);
120 bool nameAllUsedStructureTypes(Module &M);
121 void printModule(Module *M);
122 void printModuleTypes(const SymbolTable &ST);
123 void printContainedStructs(const Type *Ty, std::set<const StructType *> &);
124 void printFloatingPointConstants(Function &F);
125 void printFunctionSignature(const Function *F, bool Prototype);
127 void printFunction(Function &);
128 void printBasicBlock(BasicBlock *BB);
129 void printLoop(Loop *L);
131 void printConstant(Constant *CPV);
132 void printConstantArray(ConstantArray *CPA);
134 // isInlinableInst - Attempt to inline instructions into their uses to build
135 // trees as much as possible. To do this, we have to consistently decide
136 // what is acceptable to inline, so that variable declarations don't get
137 // printed and an extra copy of the expr is not emitted.
139 static bool isInlinableInst(const Instruction &I) {
140 // Always inline setcc instructions, even if they are shared by multiple
141 // expressions. GCC generates horrible code if we don't.
142 if (isa<SetCondInst>(I)) return true;
144 // Must be an expression, must be used exactly once. If it is dead, we
145 // emit it inline where it would go.
146 if (I.getType() == Type::VoidTy || !I.hasOneUse() ||
147 isa<TerminatorInst>(I) || isa<CallInst>(I) || isa<PHINode>(I) ||
148 isa<LoadInst>(I) || isa<VAArgInst>(I))
149 // Don't inline a load across a store or other bad things!
152 // Only inline instruction it it's use is in the same BB as the inst.
153 return I.getParent() == cast<Instruction>(I.use_back())->getParent();
156 // isDirectAlloca - Define fixed sized allocas in the entry block as direct
157 // variables which are accessed with the & operator. This causes GCC to
158 // generate significantly better code than to emit alloca calls directly.
160 static const AllocaInst *isDirectAlloca(const Value *V) {
161 const AllocaInst *AI = dyn_cast<AllocaInst>(V);
162 if (!AI) return false;
163 if (AI->isArrayAllocation())
164 return 0; // FIXME: we can also inline fixed size array allocas!
165 if (AI->getParent() != &AI->getParent()->getParent()->getEntryBlock())
170 // Instruction visitation functions
171 friend class InstVisitor<CWriter>;
173 void visitReturnInst(ReturnInst &I);
174 void visitBranchInst(BranchInst &I);
175 void visitSwitchInst(SwitchInst &I);
176 void visitInvokeInst(InvokeInst &I) {
177 assert(0 && "Lowerinvoke pass didn't work!");
180 void visitUnwindInst(UnwindInst &I) {
181 assert(0 && "Lowerinvoke pass didn't work!");
183 void visitUnreachableInst(UnreachableInst &I);
185 void visitPHINode(PHINode &I);
186 void visitBinaryOperator(Instruction &I);
188 void visitCastInst (CastInst &I);
189 void visitSelectInst(SelectInst &I);
190 void visitCallInst (CallInst &I);
191 void visitShiftInst(ShiftInst &I) { visitBinaryOperator(I); }
193 void visitMallocInst(MallocInst &I);
194 void visitAllocaInst(AllocaInst &I);
195 void visitFreeInst (FreeInst &I);
196 void visitLoadInst (LoadInst &I);
197 void visitStoreInst (StoreInst &I);
198 void visitGetElementPtrInst(GetElementPtrInst &I);
199 void visitVAArgInst (VAArgInst &I);
201 void visitInstruction(Instruction &I) {
202 std::cerr << "C Writer does not know about " << I;
206 void outputLValue(Instruction *I) {
207 Out << " " << Mang->getValueName(I) << " = ";
210 bool isGotoCodeNecessary(BasicBlock *From, BasicBlock *To);
211 void printPHICopiesForSuccessor(BasicBlock *CurBlock,
212 BasicBlock *Successor, unsigned Indent);
213 void printBranchToBlock(BasicBlock *CurBlock, BasicBlock *SuccBlock,
215 void printIndexingExpression(Value *Ptr, gep_type_iterator I,
216 gep_type_iterator E);
220 /// This method inserts names for any unnamed structure types that are used by
221 /// the program, and removes names from structure types that are not used by the
224 bool CBackendNameAllUsedStructs::runOnModule(Module &M) {
225 // Get a set of types that are used by the program...
226 std::set<const Type *> UT = getAnalysis<FindUsedTypes>().getTypes();
228 // Loop over the module symbol table, removing types from UT that are
229 // already named, and removing names for types that are not used.
231 SymbolTable &MST = M.getSymbolTable();
232 for (SymbolTable::type_iterator TI = MST.type_begin(), TE = MST.type_end();
234 SymbolTable::type_iterator I = TI++;
236 // If this is not used, remove it from the symbol table.
237 std::set<const Type *>::iterator UTI = UT.find(I->second);
241 UT.erase(UTI); // Only keep one name for this type.
244 // UT now contains types that are not named. Loop over it, naming
247 bool Changed = false;
248 unsigned RenameCounter = 0;
249 for (std::set<const Type *>::const_iterator I = UT.begin(), E = UT.end();
251 if (const StructType *ST = dyn_cast<StructType>(*I)) {
252 while (M.addTypeName("unnamed"+utostr(RenameCounter), ST))
260 // Pass the Type* and the variable name and this prints out the variable
263 std::ostream &CWriter::printType(std::ostream &Out, const Type *Ty,
264 const std::string &NameSoFar,
266 if (Ty->isPrimitiveType())
267 switch (Ty->getTypeID()) {
268 case Type::VoidTyID: return Out << "void " << NameSoFar;
269 case Type::BoolTyID: return Out << "bool " << NameSoFar;
270 case Type::UByteTyID: return Out << "unsigned char " << NameSoFar;
271 case Type::SByteTyID: return Out << "signed char " << NameSoFar;
272 case Type::UShortTyID: return Out << "unsigned short " << NameSoFar;
273 case Type::ShortTyID: return Out << "short " << NameSoFar;
274 case Type::UIntTyID: return Out << "unsigned " << NameSoFar;
275 case Type::IntTyID: return Out << "int " << NameSoFar;
276 case Type::ULongTyID: return Out << "unsigned long long " << NameSoFar;
277 case Type::LongTyID: return Out << "signed long long " << NameSoFar;
278 case Type::FloatTyID: return Out << "float " << NameSoFar;
279 case Type::DoubleTyID: return Out << "double " << NameSoFar;
281 std::cerr << "Unknown primitive type: " << *Ty << "\n";
285 // Check to see if the type is named.
286 if (!IgnoreName || isa<OpaqueType>(Ty)) {
287 std::map<const Type *, std::string>::iterator I = TypeNames.find(Ty);
288 if (I != TypeNames.end()) return Out << I->second << ' ' << NameSoFar;
291 switch (Ty->getTypeID()) {
292 case Type::FunctionTyID: {
293 const FunctionType *MTy = cast<FunctionType>(Ty);
294 std::stringstream FunctionInnards;
295 FunctionInnards << " (" << NameSoFar << ") (";
296 for (FunctionType::param_iterator I = MTy->param_begin(),
297 E = MTy->param_end(); I != E; ++I) {
298 if (I != MTy->param_begin())
299 FunctionInnards << ", ";
300 printType(FunctionInnards, *I, "");
302 if (MTy->isVarArg()) {
303 if (MTy->getNumParams())
304 FunctionInnards << ", ...";
305 } else if (!MTy->getNumParams()) {
306 FunctionInnards << "void";
308 FunctionInnards << ')';
309 std::string tstr = FunctionInnards.str();
310 printType(Out, MTy->getReturnType(), tstr);
313 case Type::StructTyID: {
314 const StructType *STy = cast<StructType>(Ty);
315 Out << NameSoFar + " {\n";
317 for (StructType::element_iterator I = STy->element_begin(),
318 E = STy->element_end(); I != E; ++I) {
320 printType(Out, *I, "field" + utostr(Idx++));
326 case Type::PointerTyID: {
327 const PointerType *PTy = cast<PointerType>(Ty);
328 std::string ptrName = "*" + NameSoFar;
330 if (isa<ArrayType>(PTy->getElementType()))
331 ptrName = "(" + ptrName + ")";
333 return printType(Out, PTy->getElementType(), ptrName);
336 case Type::ArrayTyID: {
337 const ArrayType *ATy = cast<ArrayType>(Ty);
338 unsigned NumElements = ATy->getNumElements();
339 if (NumElements == 0) NumElements = 1;
340 return printType(Out, ATy->getElementType(),
341 NameSoFar + "[" + utostr(NumElements) + "]");
344 case Type::OpaqueTyID: {
345 static int Count = 0;
346 std::string TyName = "struct opaque_" + itostr(Count++);
347 assert(TypeNames.find(Ty) == TypeNames.end());
348 TypeNames[Ty] = TyName;
349 return Out << TyName << ' ' << NameSoFar;
352 assert(0 && "Unhandled case in getTypeProps!");
359 void CWriter::printConstantArray(ConstantArray *CPA) {
361 // As a special case, print the array as a string if it is an array of
362 // ubytes or an array of sbytes with positive values.
364 const Type *ETy = CPA->getType()->getElementType();
365 bool isString = (ETy == Type::SByteTy || ETy == Type::UByteTy);
367 // Make sure the last character is a null char, as automatically added by C
368 if (isString && (CPA->getNumOperands() == 0 ||
369 !cast<Constant>(*(CPA->op_end()-1))->isNullValue()))
374 // Keep track of whether the last number was a hexadecimal escape
375 bool LastWasHex = false;
377 // Do not include the last character, which we know is null
378 for (unsigned i = 0, e = CPA->getNumOperands()-1; i != e; ++i) {
379 unsigned char C = cast<ConstantInt>(CPA->getOperand(i))->getRawValue();
381 // Print it out literally if it is a printable character. The only thing
382 // to be careful about is when the last letter output was a hex escape
383 // code, in which case we have to be careful not to print out hex digits
384 // explicitly (the C compiler thinks it is a continuation of the previous
385 // character, sheesh...)
387 if (isprint(C) && (!LastWasHex || !isxdigit(C))) {
389 if (C == '"' || C == '\\')
396 case '\n': Out << "\\n"; break;
397 case '\t': Out << "\\t"; break;
398 case '\r': Out << "\\r"; break;
399 case '\v': Out << "\\v"; break;
400 case '\a': Out << "\\a"; break;
401 case '\"': Out << "\\\""; break;
402 case '\'': Out << "\\\'"; break;
405 Out << (char)(( C/16 < 10) ? ( C/16 +'0') : ( C/16 -10+'A'));
406 Out << (char)(((C&15) < 10) ? ((C&15)+'0') : ((C&15)-10+'A'));
415 if (CPA->getNumOperands()) {
417 printConstant(cast<Constant>(CPA->getOperand(0)));
418 for (unsigned i = 1, e = CPA->getNumOperands(); i != e; ++i) {
420 printConstant(cast<Constant>(CPA->getOperand(i)));
427 // isFPCSafeToPrint - Returns true if we may assume that CFP may be written out
428 // textually as a double (rather than as a reference to a stack-allocated
429 // variable). We decide this by converting CFP to a string and back into a
430 // double, and then checking whether the conversion results in a bit-equal
431 // double to the original value of CFP. This depends on us and the target C
432 // compiler agreeing on the conversion process (which is pretty likely since we
433 // only deal in IEEE FP).
435 static bool isFPCSafeToPrint(const ConstantFP *CFP) {
438 sprintf(Buffer, "%a", CFP->getValue());
440 if (!strncmp(Buffer, "0x", 2) ||
441 !strncmp(Buffer, "-0x", 3) ||
442 !strncmp(Buffer, "+0x", 3))
443 return atof(Buffer) == CFP->getValue();
446 std::string StrVal = ftostr(CFP->getValue());
448 while (StrVal[0] == ' ')
449 StrVal.erase(StrVal.begin());
451 // Check to make sure that the stringized number is not some string like "Inf"
452 // or NaN. Check that the string matches the "[-+]?[0-9]" regex.
453 if ((StrVal[0] >= '0' && StrVal[0] <= '9') ||
454 ((StrVal[0] == '-' || StrVal[0] == '+') &&
455 (StrVal[1] >= '0' && StrVal[1] <= '9')))
456 // Reparse stringized version!
457 return atof(StrVal.c_str()) == CFP->getValue();
462 // printConstant - The LLVM Constant to C Constant converter.
463 void CWriter::printConstant(Constant *CPV) {
464 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
465 switch (CE->getOpcode()) {
466 case Instruction::Cast:
468 printType(Out, CPV->getType());
470 printConstant(CE->getOperand(0));
474 case Instruction::GetElementPtr:
476 printIndexingExpression(CE->getOperand(0), gep_type_begin(CPV),
480 case Instruction::Select:
482 printConstant(CE->getOperand(0));
484 printConstant(CE->getOperand(1));
486 printConstant(CE->getOperand(2));
489 case Instruction::Add:
490 case Instruction::Sub:
491 case Instruction::Mul:
492 case Instruction::Div:
493 case Instruction::Rem:
494 case Instruction::And:
495 case Instruction::Or:
496 case Instruction::Xor:
497 case Instruction::SetEQ:
498 case Instruction::SetNE:
499 case Instruction::SetLT:
500 case Instruction::SetLE:
501 case Instruction::SetGT:
502 case Instruction::SetGE:
503 case Instruction::Shl:
504 case Instruction::Shr:
506 printConstant(CE->getOperand(0));
507 switch (CE->getOpcode()) {
508 case Instruction::Add: Out << " + "; break;
509 case Instruction::Sub: Out << " - "; break;
510 case Instruction::Mul: Out << " * "; break;
511 case Instruction::Div: Out << " / "; break;
512 case Instruction::Rem: Out << " % "; break;
513 case Instruction::And: Out << " & "; break;
514 case Instruction::Or: Out << " | "; break;
515 case Instruction::Xor: Out << " ^ "; break;
516 case Instruction::SetEQ: Out << " == "; break;
517 case Instruction::SetNE: Out << " != "; break;
518 case Instruction::SetLT: Out << " < "; break;
519 case Instruction::SetLE: Out << " <= "; break;
520 case Instruction::SetGT: Out << " > "; break;
521 case Instruction::SetGE: Out << " >= "; break;
522 case Instruction::Shl: Out << " << "; break;
523 case Instruction::Shr: Out << " >> "; break;
524 default: assert(0 && "Illegal opcode here!");
526 printConstant(CE->getOperand(1));
531 std::cerr << "CWriter Error: Unhandled constant expression: "
535 } else if (isa<UndefValue>(CPV) && CPV->getType()->isFirstClassType()) {
537 printType(Out, CPV->getType());
538 Out << ")/*UNDEF*/0)";
542 switch (CPV->getType()->getTypeID()) {
544 Out << (CPV == ConstantBool::False ? '0' : '1'); break;
545 case Type::SByteTyID:
546 case Type::ShortTyID:
547 Out << cast<ConstantSInt>(CPV)->getValue(); break;
549 if ((int)cast<ConstantSInt>(CPV)->getValue() == (int)0x80000000)
550 Out << "((int)0x80000000U)"; // Handle MININT specially to avoid warning
552 Out << cast<ConstantSInt>(CPV)->getValue();
556 if (cast<ConstantSInt>(CPV)->isMinValue())
557 Out << "(/*INT64_MIN*/(-9223372036854775807LL)-1)";
559 Out << cast<ConstantSInt>(CPV)->getValue() << "ll"; break;
561 case Type::UByteTyID:
562 case Type::UShortTyID:
563 Out << cast<ConstantUInt>(CPV)->getValue(); break;
565 Out << cast<ConstantUInt>(CPV)->getValue() << 'u'; break;
566 case Type::ULongTyID:
567 Out << cast<ConstantUInt>(CPV)->getValue() << "ull"; break;
569 case Type::FloatTyID:
570 case Type::DoubleTyID: {
571 ConstantFP *FPC = cast<ConstantFP>(CPV);
572 std::map<const ConstantFP*, unsigned>::iterator I = FPConstantMap.find(FPC);
573 if (I != FPConstantMap.end()) {
574 // Because of FP precision problems we must load from a stack allocated
575 // value that holds the value in hex.
576 Out << "(*(" << (FPC->getType() == Type::FloatTy ? "float" : "double")
577 << "*)&FPConstant" << I->second << ')';
579 if (IsNAN(FPC->getValue())) {
582 // The prefix for a quiet NaN is 0x7FF8. For a signalling NaN,
584 const unsigned long QuietNaN = 0x7ff8UL;
585 const unsigned long SignalNaN = 0x7ff4UL;
587 // We need to grab the first part of the FP #
594 DHex.d = FPC->getValue();
595 sprintf(Buffer, "0x%llx", (unsigned long long)DHex.ll);
597 std::string Num(&Buffer[0], &Buffer[6]);
598 unsigned long Val = strtoul(Num.c_str(), 0, 16);
600 if (FPC->getType() == Type::FloatTy)
601 Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "F(\""
602 << Buffer << "\") /*nan*/ ";
604 Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "(\""
605 << Buffer << "\") /*nan*/ ";
606 } else if (IsInf(FPC->getValue())) {
608 if (FPC->getValue() < 0) Out << '-';
609 Out << "LLVM_INF" << (FPC->getType() == Type::FloatTy ? "F" : "")
614 // Print out the constant as a floating point number.
616 sprintf(Buffer, "%a", FPC->getValue());
619 Num = ftostr(FPC->getValue());
627 case Type::ArrayTyID:
628 if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) {
629 const ArrayType *AT = cast<ArrayType>(CPV->getType());
631 if (AT->getNumElements()) {
633 Constant *CZ = Constant::getNullValue(AT->getElementType());
635 for (unsigned i = 1, e = AT->getNumElements(); i != e; ++i) {
642 printConstantArray(cast<ConstantArray>(CPV));
646 case Type::StructTyID:
647 if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) {
648 const StructType *ST = cast<StructType>(CPV->getType());
650 if (ST->getNumElements()) {
652 printConstant(Constant::getNullValue(ST->getElementType(0)));
653 for (unsigned i = 1, e = ST->getNumElements(); i != e; ++i) {
655 printConstant(Constant::getNullValue(ST->getElementType(i)));
661 if (CPV->getNumOperands()) {
663 printConstant(cast<Constant>(CPV->getOperand(0)));
664 for (unsigned i = 1, e = CPV->getNumOperands(); i != e; ++i) {
666 printConstant(cast<Constant>(CPV->getOperand(i)));
673 case Type::PointerTyID:
674 if (isa<ConstantPointerNull>(CPV)) {
676 printType(Out, CPV->getType());
677 Out << ")/*NULL*/0)";
679 } else if (GlobalValue *GV = dyn_cast<GlobalValue>(CPV)) {
685 std::cerr << "Unknown constant type: " << *CPV << "\n";
690 void CWriter::writeOperandInternal(Value *Operand) {
691 if (Instruction *I = dyn_cast<Instruction>(Operand))
692 if (isInlinableInst(*I) && !isDirectAlloca(I)) {
693 // Should we inline this instruction to build a tree?
700 Constant* CPV = dyn_cast<Constant>(Operand);
701 if (CPV && !isa<GlobalValue>(CPV)) {
704 Out << Mang->getValueName(Operand);
708 void CWriter::writeOperand(Value *Operand) {
709 if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand))
710 Out << "(&"; // Global variables are references as their addresses by llvm
712 writeOperandInternal(Operand);
714 if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand))
718 // generateCompilerSpecificCode - This is where we add conditional compilation
719 // directives to cater to specific compilers as need be.
721 static void generateCompilerSpecificCode(std::ostream& Out) {
722 // Alloca is hard to get, and we don't want to include stdlib.h here...
723 Out << "/* get a declaration for alloca */\n"
724 << "#if defined(__CYGWIN__)\n"
725 << "extern void *_alloca(unsigned long);\n"
726 << "#define alloca(x) _alloca(x)\n"
727 << "#elif defined(__APPLE__)\n"
728 << "extern void *__builtin_alloca(unsigned long);\n"
729 << "#define alloca(x) __builtin_alloca(x)\n"
730 << "#elif defined(__sun__)\n"
731 << "#if defined(__sparcv9)\n"
732 << "extern void *__builtin_alloca(unsigned long);\n"
734 << "extern void *__builtin_alloca(unsigned int);\n"
736 << "#define alloca(x) __builtin_alloca(x)\n"
737 << "#elif defined(__FreeBSD__)\n"
738 << "#define alloca(x) __builtin_alloca(x)\n"
739 << "#elif !defined(_MSC_VER)\n"
740 << "#include <alloca.h>\n"
743 // We output GCC specific attributes to preserve 'linkonce'ness on globals.
744 // If we aren't being compiled with GCC, just drop these attributes.
745 Out << "#ifndef __GNUC__ /* Can only support \"linkonce\" vars with GCC */\n"
746 << "#define __attribute__(X)\n"
750 // At some point, we should support "external weak" vs. "weak" linkages.
751 // On Mac OS X, "external weak" is spelled "__attribute__((weak_import))".
752 Out << "#if defined(__GNUC__) && defined(__APPLE_CC__)\n"
753 << "#define __EXTERNAL_WEAK__ __attribute__((weak_import))\n"
754 << "#elif defined(__GNUC__)\n"
755 << "#define __EXTERNAL_WEAK__ __attribute__((weak))\n"
757 << "#define __EXTERNAL_WEAK__\n"
761 // For now, turn off the weak linkage attribute on Mac OS X. (See above.)
762 Out << "#if defined(__GNUC__) && defined(__APPLE_CC__)\n"
763 << "#define __ATTRIBUTE_WEAK__\n"
764 << "#elif defined(__GNUC__)\n"
765 << "#define __ATTRIBUTE_WEAK__ __attribute__((weak))\n"
767 << "#define __ATTRIBUTE_WEAK__\n"
770 // Define NaN and Inf as GCC builtins if using GCC, as 0 otherwise
771 // From the GCC documentation:
773 // double __builtin_nan (const char *str)
775 // This is an implementation of the ISO C99 function nan.
777 // Since ISO C99 defines this function in terms of strtod, which we do
778 // not implement, a description of the parsing is in order. The string is
779 // parsed as by strtol; that is, the base is recognized by leading 0 or
780 // 0x prefixes. The number parsed is placed in the significand such that
781 // the least significant bit of the number is at the least significant
782 // bit of the significand. The number is truncated to fit the significand
783 // field provided. The significand is forced to be a quiet NaN.
785 // This function, if given a string literal, is evaluated early enough
786 // that it is considered a compile-time constant.
788 // float __builtin_nanf (const char *str)
790 // Similar to __builtin_nan, except the return type is float.
792 // double __builtin_inf (void)
794 // Similar to __builtin_huge_val, except a warning is generated if the
795 // target floating-point format does not support infinities. This
796 // function is suitable for implementing the ISO C99 macro INFINITY.
798 // float __builtin_inff (void)
800 // Similar to __builtin_inf, except the return type is float.
801 Out << "#ifdef __GNUC__\n"
802 << "#define LLVM_NAN(NanStr) __builtin_nan(NanStr) /* Double */\n"
803 << "#define LLVM_NANF(NanStr) __builtin_nanf(NanStr) /* Float */\n"
804 << "#define LLVM_NANS(NanStr) __builtin_nans(NanStr) /* Double */\n"
805 << "#define LLVM_NANSF(NanStr) __builtin_nansf(NanStr) /* Float */\n"
806 << "#define LLVM_INF __builtin_inf() /* Double */\n"
807 << "#define LLVM_INFF __builtin_inff() /* Float */\n"
808 << "#define LLVM_PREFETCH(addr,rw,locality) __builtin_prefetch(addr,rw,locality)\n"
810 << "#define LLVM_NAN(NanStr) ((double)0.0) /* Double */\n"
811 << "#define LLVM_NANF(NanStr) 0.0F /* Float */\n"
812 << "#define LLVM_NANS(NanStr) ((double)0.0) /* Double */\n"
813 << "#define LLVM_NANSF(NanStr) 0.0F /* Float */\n"
814 << "#define LLVM_INF ((double)0.0) /* Double */\n"
815 << "#define LLVM_INFF 0.0F /* Float */\n"
816 << "#define LLVM_PREFETCH(addr,rw,locality) /* PREFETCH */\n"
819 // Output target-specific code that should be inserted into main.
820 Out << "#define CODE_FOR_MAIN() /* Any target-specific code for main()*/\n";
821 // On X86, set the FP control word to 64-bits of precision instead of 80 bits.
822 Out << "#if defined(__GNUC__) && !defined(__llvm__)\n"
823 << "#if defined(i386) || defined(__i386__) || defined(__i386)\n"
824 << "#undef CODE_FOR_MAIN\n"
825 << "#define CODE_FOR_MAIN() \\\n"
826 << " {short F;__asm__ (\"fnstcw %0\" : \"=m\" (*&F)); \\\n"
827 << " F=(F&~0x300)|0x200;__asm__(\"fldcw %0\"::\"m\"(*&F));}\n"
828 << "#endif\n#endif\n";
832 bool CWriter::doInitialization(Module &M) {
838 // Ensure that all structure types have names...
839 Mang = new Mangler(M);
841 // get declaration for alloca
842 Out << "/* Provide Declarations */\n";
843 Out << "#include <stdarg.h>\n"; // Varargs support
844 Out << "#include <setjmp.h>\n"; // Unwind support
845 generateCompilerSpecificCode(Out);
847 // Provide a definition for `bool' if not compiling with a C++ compiler.
849 << "#ifndef __cplusplus\ntypedef unsigned char bool;\n#endif\n"
851 << "\n\n/* Support for floating point constants */\n"
852 << "typedef unsigned long long ConstantDoubleTy;\n"
853 << "typedef unsigned int ConstantFloatTy;\n"
855 << "\n\n/* Global Declarations */\n";
857 // First output all the declarations for the program, because C requires
858 // Functions & globals to be declared before they are used.
861 // Loop over the symbol table, emitting all named constants...
862 printModuleTypes(M.getSymbolTable());
864 // Global variable declarations...
865 if (!M.global_empty()) {
866 Out << "\n/* External Global Variable Declarations */\n";
867 for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I) {
868 if (I->hasExternalLinkage()) {
870 printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
876 // Function declarations
878 Out << "\n/* Function Declarations */\n";
879 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
880 // Don't print declarations for intrinsic functions.
881 if (!I->getIntrinsicID() &&
882 I->getName() != "setjmp" && I->getName() != "longjmp") {
883 printFunctionSignature(I, true);
884 if (I->hasWeakLinkage()) Out << " __ATTRIBUTE_WEAK__";
885 if (I->hasLinkOnceLinkage()) Out << " __ATTRIBUTE_WEAK__";
891 // Output the global variable declarations
892 if (!M.global_empty()) {
893 Out << "\n\n/* Global Variable Declarations */\n";
894 for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I)
895 if (!I->isExternal()) {
896 if (I->hasInternalLinkage())
900 printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
902 if (I->hasLinkOnceLinkage())
903 Out << " __attribute__((common))";
904 else if (I->hasWeakLinkage())
905 Out << " __ATTRIBUTE_WEAK__";
910 // Output the global variable definitions and contents...
911 if (!M.global_empty()) {
912 Out << "\n\n/* Global Variable Definitions and Initialization */\n";
913 for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I)
914 if (!I->isExternal()) {
915 if (I->hasInternalLinkage())
917 printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
918 if (I->hasLinkOnceLinkage())
919 Out << " __attribute__((common))";
920 else if (I->hasWeakLinkage())
921 Out << " __ATTRIBUTE_WEAK__";
923 // If the initializer is not null, emit the initializer. If it is null,
924 // we try to avoid emitting large amounts of zeros. The problem with
925 // this, however, occurs when the variable has weak linkage. In this
926 // case, the assembler will complain about the variable being both weak
927 // and common, so we disable this optimization.
928 if (!I->getInitializer()->isNullValue()) {
930 writeOperand(I->getInitializer());
931 } else if (I->hasWeakLinkage()) {
932 // We have to specify an initializer, but it doesn't have to be
933 // complete. If the value is an aggregate, print out { 0 }, and let
934 // the compiler figure out the rest of the zeros.
936 if (isa<StructType>(I->getInitializer()->getType()) ||
937 isa<ArrayType>(I->getInitializer()->getType())) {
940 // Just print it out normally.
941 writeOperand(I->getInitializer());
949 Out << "\n\n/* Function Bodies */\n";
954 /// Output all floating point constants that cannot be printed accurately...
955 void CWriter::printFloatingPointConstants(Function &F) {
966 // Scan the module for floating point constants. If any FP constant is used
967 // in the function, we want to redirect it here so that we do not depend on
968 // the precision of the printed form, unless the printed form preserves
971 static unsigned FPCounter = 0;
972 for (constant_iterator I = constant_begin(&F), E = constant_end(&F);
974 if (const ConstantFP *FPC = dyn_cast<ConstantFP>(*I))
975 if (!isFPCSafeToPrint(FPC) && // Do not put in FPConstantMap if safe.
976 !FPConstantMap.count(FPC)) {
977 double Val = FPC->getValue();
979 FPConstantMap[FPC] = FPCounter; // Number the FP constants
981 if (FPC->getType() == Type::DoubleTy) {
983 Out << "static const ConstantDoubleTy FPConstant" << FPCounter++
984 << " = 0x" << std::hex << DBLUnion.U << std::dec
985 << "ULL; /* " << Val << " */\n";
986 } else if (FPC->getType() == Type::FloatTy) {
988 Out << "static const ConstantFloatTy FPConstant" << FPCounter++
989 << " = 0x" << std::hex << FLTUnion.U << std::dec
990 << "U; /* " << Val << " */\n";
992 assert(0 && "Unknown float type!");
999 /// printSymbolTable - Run through symbol table looking for type names. If a
1000 /// type name is found, emit it's declaration...
1002 void CWriter::printModuleTypes(const SymbolTable &ST) {
1003 // We are only interested in the type plane of the symbol table.
1004 SymbolTable::type_const_iterator I = ST.type_begin();
1005 SymbolTable::type_const_iterator End = ST.type_end();
1007 // If there are no type names, exit early.
1008 if (I == End) return;
1010 // Print out forward declarations for structure types before anything else!
1011 Out << "/* Structure forward decls */\n";
1012 for (; I != End; ++I)
1013 if (const Type *STy = dyn_cast<StructType>(I->second)) {
1014 std::string Name = "struct l_" + Mangler::makeNameProper(I->first);
1015 Out << Name << ";\n";
1016 TypeNames.insert(std::make_pair(STy, Name));
1021 // Now we can print out typedefs...
1022 Out << "/* Typedefs */\n";
1023 for (I = ST.type_begin(); I != End; ++I) {
1024 const Type *Ty = cast<Type>(I->second);
1025 std::string Name = "l_" + Mangler::makeNameProper(I->first);
1027 printType(Out, Ty, Name);
1033 // Keep track of which structures have been printed so far...
1034 std::set<const StructType *> StructPrinted;
1036 // Loop over all structures then push them into the stack so they are
1037 // printed in the correct order.
1039 Out << "/* Structure contents */\n";
1040 for (I = ST.type_begin(); I != End; ++I)
1041 if (const StructType *STy = dyn_cast<StructType>(I->second))
1042 // Only print out used types!
1043 printContainedStructs(STy, StructPrinted);
1046 // Push the struct onto the stack and recursively push all structs
1047 // this one depends on.
1048 void CWriter::printContainedStructs(const Type *Ty,
1049 std::set<const StructType*> &StructPrinted){
1050 if (const StructType *STy = dyn_cast<StructType>(Ty)) {
1051 //Check to see if we have already printed this struct
1052 if (StructPrinted.count(STy) == 0) {
1053 // Print all contained types first...
1054 for (StructType::element_iterator I = STy->element_begin(),
1055 E = STy->element_end(); I != E; ++I) {
1056 const Type *Ty1 = I->get();
1057 if (isa<StructType>(Ty1) || isa<ArrayType>(Ty1))
1058 printContainedStructs(*I, StructPrinted);
1061 //Print structure type out..
1062 StructPrinted.insert(STy);
1063 std::string Name = TypeNames[STy];
1064 printType(Out, STy, Name, true);
1068 // If it is an array, check contained types and continue
1069 } else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)){
1070 const Type *Ty1 = ATy->getElementType();
1071 if (isa<StructType>(Ty1) || isa<ArrayType>(Ty1))
1072 printContainedStructs(Ty1, StructPrinted);
1077 void CWriter::printFunctionSignature(const Function *F, bool Prototype) {
1078 if (F->hasInternalLinkage()) Out << "static ";
1080 // Loop over the arguments, printing them...
1081 const FunctionType *FT = cast<FunctionType>(F->getFunctionType());
1083 std::stringstream FunctionInnards;
1085 // Print out the name...
1086 FunctionInnards << Mang->getValueName(F) << '(';
1088 if (!F->isExternal()) {
1089 if (!F->arg_empty()) {
1090 std::string ArgName;
1091 if (F->arg_begin()->hasName() || !Prototype)
1092 ArgName = Mang->getValueName(F->arg_begin());
1093 printType(FunctionInnards, F->arg_begin()->getType(), ArgName);
1094 for (Function::const_arg_iterator I = ++F->arg_begin(), E = F->arg_end();
1096 FunctionInnards << ", ";
1097 if (I->hasName() || !Prototype)
1098 ArgName = Mang->getValueName(I);
1101 printType(FunctionInnards, I->getType(), ArgName);
1105 // Loop over the arguments, printing them...
1106 for (FunctionType::param_iterator I = FT->param_begin(),
1107 E = FT->param_end(); I != E; ++I) {
1108 if (I != FT->param_begin()) FunctionInnards << ", ";
1109 printType(FunctionInnards, *I);
1113 // Finish printing arguments... if this is a vararg function, print the ...,
1114 // unless there are no known types, in which case, we just emit ().
1116 if (FT->isVarArg() && FT->getNumParams()) {
1117 if (FT->getNumParams()) FunctionInnards << ", ";
1118 FunctionInnards << "..."; // Output varargs portion of signature!
1119 } else if (!FT->isVarArg() && FT->getNumParams() == 0) {
1120 FunctionInnards << "void"; // ret() -> ret(void) in C.
1122 FunctionInnards << ')';
1123 // Print out the return type and the entire signature for that matter
1124 printType(Out, F->getReturnType(), FunctionInnards.str());
1127 void CWriter::printFunction(Function &F) {
1128 printFunctionSignature(&F, false);
1131 // print local variable information for the function
1132 for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ++I)
1133 if (const AllocaInst *AI = isDirectAlloca(&*I)) {
1135 printType(Out, AI->getAllocatedType(), Mang->getValueName(AI));
1136 Out << "; /* Address-exposed local */\n";
1137 } else if (I->getType() != Type::VoidTy && !isInlinableInst(*I)) {
1139 printType(Out, I->getType(), Mang->getValueName(&*I));
1142 if (isa<PHINode>(*I)) { // Print out PHI node temporaries as well...
1144 printType(Out, I->getType(),
1145 Mang->getValueName(&*I)+"__PHI_TEMPORARY");
1152 if (F.hasExternalLinkage() && F.getName() == "main")
1153 Out << " CODE_FOR_MAIN();\n";
1155 // print the basic blocks
1156 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
1157 if (Loop *L = LI->getLoopFor(BB)) {
1158 if (L->getHeader() == BB && L->getParentLoop() == 0)
1161 printBasicBlock(BB);
1168 void CWriter::printLoop(Loop *L) {
1169 Out << " do { /* Syntactic loop '" << L->getHeader()->getName()
1170 << "' to make GCC happy */\n";
1171 for (unsigned i = 0, e = L->getBlocks().size(); i != e; ++i) {
1172 BasicBlock *BB = L->getBlocks()[i];
1173 Loop *BBLoop = LI->getLoopFor(BB);
1175 printBasicBlock(BB);
1176 else if (BB == BBLoop->getHeader() && BBLoop->getParentLoop() == L)
1179 Out << " } while (1); /* end of syntactic loop '"
1180 << L->getHeader()->getName() << "' */\n";
1183 void CWriter::printBasicBlock(BasicBlock *BB) {
1185 // Don't print the label for the basic block if there are no uses, or if
1186 // the only terminator use is the predecessor basic block's terminator.
1187 // We have to scan the use list because PHI nodes use basic blocks too but
1188 // do not require a label to be generated.
1190 bool NeedsLabel = false;
1191 for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
1192 if (isGotoCodeNecessary(*PI, BB)) {
1197 if (NeedsLabel) Out << Mang->getValueName(BB) << ":\n";
1199 // Output all of the instructions in the basic block...
1200 for (BasicBlock::iterator II = BB->begin(), E = --BB->end(); II != E;
1202 if (!isInlinableInst(*II) && !isDirectAlloca(II)) {
1203 if (II->getType() != Type::VoidTy)
1212 // Don't emit prefix or suffix for the terminator...
1213 visit(*BB->getTerminator());
1217 // Specific Instruction type classes... note that all of the casts are
1218 // necessary because we use the instruction classes as opaque types...
1220 void CWriter::visitReturnInst(ReturnInst &I) {
1221 // Don't output a void return if this is the last basic block in the function
1222 if (I.getNumOperands() == 0 &&
1223 &*--I.getParent()->getParent()->end() == I.getParent() &&
1224 !I.getParent()->size() == 1) {
1229 if (I.getNumOperands()) {
1231 writeOperand(I.getOperand(0));
1236 void CWriter::visitSwitchInst(SwitchInst &SI) {
1239 writeOperand(SI.getOperand(0));
1240 Out << ") {\n default:\n";
1241 printPHICopiesForSuccessor (SI.getParent(), SI.getDefaultDest(), 2);
1242 printBranchToBlock(SI.getParent(), SI.getDefaultDest(), 2);
1244 for (unsigned i = 2, e = SI.getNumOperands(); i != e; i += 2) {
1246 writeOperand(SI.getOperand(i));
1248 BasicBlock *Succ = cast<BasicBlock>(SI.getOperand(i+1));
1249 printPHICopiesForSuccessor (SI.getParent(), Succ, 2);
1250 printBranchToBlock(SI.getParent(), Succ, 2);
1251 if (Function::iterator(Succ) == next(Function::iterator(SI.getParent())))
1257 void CWriter::visitUnreachableInst(UnreachableInst &I) {
1258 Out << " /*UNREACHABLE*/;\n";
1261 bool CWriter::isGotoCodeNecessary(BasicBlock *From, BasicBlock *To) {
1262 /// FIXME: This should be reenabled, but loop reordering safe!!
1265 if (next(Function::iterator(From)) != Function::iterator(To))
1266 return true; // Not the direct successor, we need a goto.
1268 //isa<SwitchInst>(From->getTerminator())
1270 if (LI->getLoopFor(From) != LI->getLoopFor(To))
1275 void CWriter::printPHICopiesForSuccessor (BasicBlock *CurBlock,
1276 BasicBlock *Successor,
1278 for (BasicBlock::iterator I = Successor->begin(); isa<PHINode>(I); ++I) {
1279 PHINode *PN = cast<PHINode>(I);
1280 // Now we have to do the printing.
1281 Value *IV = PN->getIncomingValueForBlock(CurBlock);
1282 if (!isa<UndefValue>(IV)) {
1283 Out << std::string(Indent, ' ');
1284 Out << " " << Mang->getValueName(I) << "__PHI_TEMPORARY = ";
1286 Out << "; /* for PHI node */\n";
1291 void CWriter::printBranchToBlock(BasicBlock *CurBB, BasicBlock *Succ,
1293 if (isGotoCodeNecessary(CurBB, Succ)) {
1294 Out << std::string(Indent, ' ') << " goto ";
1300 // Branch instruction printing - Avoid printing out a branch to a basic block
1301 // that immediately succeeds the current one.
1303 void CWriter::visitBranchInst(BranchInst &I) {
1305 if (I.isConditional()) {
1306 if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(0))) {
1308 writeOperand(I.getCondition());
1311 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(0), 2);
1312 printBranchToBlock(I.getParent(), I.getSuccessor(0), 2);
1314 if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(1))) {
1315 Out << " } else {\n";
1316 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(1), 2);
1317 printBranchToBlock(I.getParent(), I.getSuccessor(1), 2);
1320 // First goto not necessary, assume second one is...
1322 writeOperand(I.getCondition());
1325 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(1), 2);
1326 printBranchToBlock(I.getParent(), I.getSuccessor(1), 2);
1331 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(0), 0);
1332 printBranchToBlock(I.getParent(), I.getSuccessor(0), 0);
1337 // PHI nodes get copied into temporary values at the end of predecessor basic
1338 // blocks. We now need to copy these temporary values into the REAL value for
1340 void CWriter::visitPHINode(PHINode &I) {
1342 Out << "__PHI_TEMPORARY";
1346 void CWriter::visitBinaryOperator(Instruction &I) {
1347 // binary instructions, shift instructions, setCond instructions.
1348 assert(!isa<PointerType>(I.getType()));
1350 // We must cast the results of binary operations which might be promoted.
1351 bool needsCast = false;
1352 if ((I.getType() == Type::UByteTy) || (I.getType() == Type::SByteTy)
1353 || (I.getType() == Type::UShortTy) || (I.getType() == Type::ShortTy)
1354 || (I.getType() == Type::FloatTy)) {
1357 printType(Out, I.getType());
1361 // If this is a negation operation, print it out as such. For FP, we don't
1362 // want to print "-0.0 - X".
1363 if (BinaryOperator::isNeg(&I)) {
1365 writeOperand(BinaryOperator::getNegArgument(cast<BinaryOperator>(&I)));
1368 writeOperand(I.getOperand(0));
1370 switch (I.getOpcode()) {
1371 case Instruction::Add: Out << " + "; break;
1372 case Instruction::Sub: Out << " - "; break;
1373 case Instruction::Mul: Out << '*'; break;
1374 case Instruction::Div: Out << '/'; break;
1375 case Instruction::Rem: Out << '%'; break;
1376 case Instruction::And: Out << " & "; break;
1377 case Instruction::Or: Out << " | "; break;
1378 case Instruction::Xor: Out << " ^ "; break;
1379 case Instruction::SetEQ: Out << " == "; break;
1380 case Instruction::SetNE: Out << " != "; break;
1381 case Instruction::SetLE: Out << " <= "; break;
1382 case Instruction::SetGE: Out << " >= "; break;
1383 case Instruction::SetLT: Out << " < "; break;
1384 case Instruction::SetGT: Out << " > "; break;
1385 case Instruction::Shl : Out << " << "; break;
1386 case Instruction::Shr : Out << " >> "; break;
1387 default: std::cerr << "Invalid operator type!" << I; abort();
1390 writeOperand(I.getOperand(1));
1398 void CWriter::visitCastInst(CastInst &I) {
1399 if (I.getType() == Type::BoolTy) {
1401 writeOperand(I.getOperand(0));
1406 printType(Out, I.getType());
1408 if (isa<PointerType>(I.getType())&&I.getOperand(0)->getType()->isIntegral() ||
1409 isa<PointerType>(I.getOperand(0)->getType())&&I.getType()->isIntegral()) {
1410 // Avoid "cast to pointer from integer of different size" warnings
1414 writeOperand(I.getOperand(0));
1417 void CWriter::visitSelectInst(SelectInst &I) {
1419 writeOperand(I.getCondition());
1421 writeOperand(I.getTrueValue());
1423 writeOperand(I.getFalseValue());
1428 void CWriter::lowerIntrinsics(Function &F) {
1429 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1430 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; )
1431 if (CallInst *CI = dyn_cast<CallInst>(I++))
1432 if (Function *F = CI->getCalledFunction())
1433 switch (F->getIntrinsicID()) {
1434 case Intrinsic::not_intrinsic:
1435 case Intrinsic::vastart:
1436 case Intrinsic::vacopy:
1437 case Intrinsic::vaend:
1438 case Intrinsic::returnaddress:
1439 case Intrinsic::frameaddress:
1440 case Intrinsic::setjmp:
1441 case Intrinsic::longjmp:
1442 case Intrinsic::prefetch:
1443 // We directly implement these intrinsics
1446 // All other intrinsic calls we must lower.
1447 Instruction *Before = 0;
1448 if (CI != &BB->front())
1449 Before = prior(BasicBlock::iterator(CI));
1451 IL.LowerIntrinsicCall(CI);
1452 if (Before) { // Move iterator to instruction after call
1462 void CWriter::visitCallInst(CallInst &I) {
1463 // Handle intrinsic function calls first...
1464 if (Function *F = I.getCalledFunction())
1465 if (Intrinsic::ID ID = (Intrinsic::ID)F->getIntrinsicID()) {
1467 default: assert(0 && "Unknown LLVM intrinsic!");
1468 case Intrinsic::vastart:
1471 // Out << "va_start(*(va_list*)&" << Mang->getValueName(&I) << ", ";
1472 Out << "va_start(*(va_list*)";
1473 writeOperand(I.getOperand(1));
1475 // Output the last argument to the enclosing function...
1476 if (I.getParent()->getParent()->arg_empty()) {
1477 std::cerr << "The C backend does not currently support zero "
1478 << "argument varargs functions, such as '"
1479 << I.getParent()->getParent()->getName() << "'!\n";
1482 writeOperand(--I.getParent()->getParent()->arg_end());
1485 case Intrinsic::vaend:
1486 if (!isa<ConstantPointerNull>(I.getOperand(1))) {
1487 Out << "0; va_end(*(va_list*)";
1488 writeOperand(I.getOperand(1));
1491 Out << "va_end(*(va_list*)0)";
1494 case Intrinsic::vacopy:
1496 Out << "va_copy(*(va_list*)";
1497 writeOperand(I.getOperand(1));
1498 Out << ", *(va_list*)";
1499 writeOperand(I.getOperand(2));
1502 case Intrinsic::returnaddress:
1503 Out << "__builtin_return_address(";
1504 writeOperand(I.getOperand(1));
1507 case Intrinsic::frameaddress:
1508 Out << "__builtin_frame_address(";
1509 writeOperand(I.getOperand(1));
1512 case Intrinsic::setjmp:
1513 Out << "setjmp(*(jmp_buf*)";
1514 writeOperand(I.getOperand(1));
1517 case Intrinsic::longjmp:
1518 Out << "longjmp(*(jmp_buf*)";
1519 writeOperand(I.getOperand(1));
1521 writeOperand(I.getOperand(2));
1524 case Intrinsic::prefetch:
1525 Out << "LLVM_PREFETCH((const void *)";
1526 writeOperand(I.getOperand(1));
1528 writeOperand(I.getOperand(2));
1530 writeOperand(I.getOperand(3));
1536 Value *Callee = I.getCalledValue();
1538 // GCC is really a PITA. It does not permit codegening casts of functions to
1539 // function pointers if they are in a call (it generates a trap instruction
1540 // instead!). We work around this by inserting a cast to void* in between the
1541 // function and the function pointer cast. Unfortunately, we can't just form
1542 // the constant expression here, because the folder will immediately nuke it.
1544 // Note finally, that this is completely unsafe. ANSI C does not guarantee
1545 // that void* and function pointers have the same size. :( To deal with this
1546 // in the common case, we handle casts where the number of arguments passed
1549 bool WroteCallee = false;
1550 if (I.isTailCall()) Out << " /*tail*/ ";
1551 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Callee))
1552 if (CE->getOpcode() == Instruction::Cast)
1553 if (Function *RF = dyn_cast<Function>(CE->getOperand(0))) {
1554 const FunctionType *RFTy = RF->getFunctionType();
1555 if (RFTy->getNumParams() == I.getNumOperands()-1) {
1556 // If the call site expects a value, and the actual callee doesn't
1557 // provide one, return 0.
1558 if (I.getType() != Type::VoidTy &&
1559 RFTy->getReturnType() == Type::VoidTy)
1560 Out << "0 /*actual callee doesn't return value*/; ";
1563 // Ok, just cast the pointer type.
1565 printType(Out, CE->getType());
1573 const PointerType *PTy = cast<PointerType>(Callee->getType());
1574 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1575 const Type *RetTy = FTy->getReturnType();
1577 if (!WroteCallee) writeOperand(Callee);
1580 unsigned NumDeclaredParams = FTy->getNumParams();
1582 if (I.getNumOperands() != 1) {
1583 CallSite::arg_iterator AI = I.op_begin()+1, AE = I.op_end();
1584 if (NumDeclaredParams && (*AI)->getType() != FTy->getParamType(0)) {
1586 printType(Out, FTy->getParamType(0));
1593 for (ArgNo = 1, ++AI; AI != AE; ++AI, ++ArgNo) {
1595 if (ArgNo < NumDeclaredParams &&
1596 (*AI)->getType() != FTy->getParamType(ArgNo)) {
1598 printType(Out, FTy->getParamType(ArgNo));
1607 void CWriter::visitMallocInst(MallocInst &I) {
1608 assert(0 && "lowerallocations pass didn't work!");
1611 void CWriter::visitAllocaInst(AllocaInst &I) {
1613 printType(Out, I.getType());
1614 Out << ") alloca(sizeof(";
1615 printType(Out, I.getType()->getElementType());
1617 if (I.isArrayAllocation()) {
1619 writeOperand(I.getOperand(0));
1624 void CWriter::visitFreeInst(FreeInst &I) {
1625 assert(0 && "lowerallocations pass didn't work!");
1628 void CWriter::printIndexingExpression(Value *Ptr, gep_type_iterator I,
1629 gep_type_iterator E) {
1630 bool HasImplicitAddress = false;
1631 // If accessing a global value with no indexing, avoid *(&GV) syndrome
1632 if (GlobalValue *V = dyn_cast<GlobalValue>(Ptr)) {
1633 HasImplicitAddress = true;
1634 } else if (isDirectAlloca(Ptr)) {
1635 HasImplicitAddress = true;
1639 if (!HasImplicitAddress)
1640 Out << '*'; // Implicit zero first argument: '*x' is equivalent to 'x[0]'
1642 writeOperandInternal(Ptr);
1646 const Constant *CI = dyn_cast<Constant>(I.getOperand());
1647 if (HasImplicitAddress && (!CI || !CI->isNullValue()))
1650 writeOperandInternal(Ptr);
1652 if (HasImplicitAddress && (!CI || !CI->isNullValue())) {
1654 HasImplicitAddress = false; // HIA is only true if we haven't addressed yet
1657 assert(!HasImplicitAddress || (CI && CI->isNullValue()) &&
1658 "Can only have implicit address with direct accessing");
1660 if (HasImplicitAddress) {
1662 } else if (CI && CI->isNullValue()) {
1663 gep_type_iterator TmpI = I; ++TmpI;
1665 // Print out the -> operator if possible...
1666 if (TmpI != E && isa<StructType>(*TmpI)) {
1667 Out << (HasImplicitAddress ? "." : "->");
1668 Out << "field" << cast<ConstantUInt>(TmpI.getOperand())->getValue();
1674 if (isa<StructType>(*I)) {
1675 Out << ".field" << cast<ConstantUInt>(I.getOperand())->getValue();
1678 writeOperand(I.getOperand());
1683 void CWriter::visitLoadInst(LoadInst &I) {
1685 if (I.isVolatile()) {
1687 printType(Out, I.getType());
1688 Out << " volatile*)";
1691 writeOperand(I.getOperand(0));
1697 void CWriter::visitStoreInst(StoreInst &I) {
1699 if (I.isVolatile()) {
1701 printType(Out, I.getOperand(0)->getType());
1702 Out << " volatile*)";
1704 writeOperand(I.getPointerOperand());
1705 if (I.isVolatile()) Out << ')';
1707 writeOperand(I.getOperand(0));
1710 void CWriter::visitGetElementPtrInst(GetElementPtrInst &I) {
1712 printIndexingExpression(I.getPointerOperand(), gep_type_begin(I),
1716 void CWriter::visitVAArgInst(VAArgInst &I) {
1717 Out << "va_arg(*(va_list*)";
1718 writeOperand(I.getOperand(0));
1720 printType(Out, I.getType());
1724 //===----------------------------------------------------------------------===//
1725 // External Interface declaration
1726 //===----------------------------------------------------------------------===//
1728 bool CTargetMachine::addPassesToEmitAssembly(PassManager &PM, std::ostream &o) {
1729 PM.add(createLowerGCPass());
1730 PM.add(createLowerAllocationsPass(true));
1731 PM.add(createLowerInvokePass());
1732 PM.add(new CBackendNameAllUsedStructs());
1733 PM.add(new CWriter(o, getIntrinsicLowering()));