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/Support/MathExtras.h"
36 #include "llvm/ADT/StringExtras.h"
37 #include "llvm/ADT/STLExtras.h"
38 #include "llvm/Support/MathExtras.h"
39 #include "llvm/Config/config.h"
47 // Register the target.
48 RegisterTarget<CTargetMachine> X("c", " C backend");
50 /// NameAllUsedStructs - This pass inserts names for any unnamed structure
51 /// types that are used by the program.
53 class CBackendNameAllUsedStructs : public ModulePass {
54 void getAnalysisUsage(AnalysisUsage &AU) const {
55 AU.addRequired<FindUsedTypes>();
58 virtual const char *getPassName() const {
59 return "C backend type canonicalizer";
62 virtual bool runOnModule(Module &M);
65 /// CWriter - This class is the main chunk of code that converts an LLVM
66 /// module to a C translation unit.
67 class CWriter : public FunctionPass, public InstVisitor<CWriter> {
69 IntrinsicLowering &IL;
72 const Module *TheModule;
73 std::map<const Type *, std::string> TypeNames;
75 std::map<const ConstantFP *, unsigned> FPConstantMap;
77 CWriter(std::ostream &o, IntrinsicLowering &il) : Out(o), IL(il) {}
79 virtual const char *getPassName() const { return "C backend"; }
81 void getAnalysisUsage(AnalysisUsage &AU) const {
82 AU.addRequired<LoopInfo>();
86 virtual bool doInitialization(Module &M);
88 bool runOnFunction(Function &F) {
89 LI = &getAnalysis<LoopInfo>();
91 // Get rid of intrinsics we can't handle.
94 // Output all floating point constants that cannot be printed accurately.
95 printFloatingPointConstants(F);
97 // Ensure that no local symbols conflict with global symbols.
98 F.renameLocalSymbols();
101 FPConstantMap.clear();
105 virtual bool doFinalization(Module &M) {
112 std::ostream &printType(std::ostream &Out, const Type *Ty,
113 const std::string &VariableName = "",
114 bool IgnoreName = false);
116 void writeOperand(Value *Operand);
117 void writeOperandInternal(Value *Operand);
120 void lowerIntrinsics(Function &F);
122 bool nameAllUsedStructureTypes(Module &M);
123 void printModule(Module *M);
124 void printModuleTypes(const SymbolTable &ST);
125 void printContainedStructs(const Type *Ty, std::set<const StructType *> &);
126 void printFloatingPointConstants(Function &F);
127 void printFunctionSignature(const Function *F, bool Prototype);
129 void printFunction(Function &);
130 void printBasicBlock(BasicBlock *BB);
131 void printLoop(Loop *L);
133 void printConstant(Constant *CPV);
134 void printConstantArray(ConstantArray *CPA);
136 // isInlinableInst - Attempt to inline instructions into their uses to build
137 // trees as much as possible. To do this, we have to consistently decide
138 // what is acceptable to inline, so that variable declarations don't get
139 // printed and an extra copy of the expr is not emitted.
141 static bool isInlinableInst(const Instruction &I) {
142 // Always inline setcc instructions, even if they are shared by multiple
143 // expressions. GCC generates horrible code if we don't.
144 if (isa<SetCondInst>(I)) return true;
146 // Must be an expression, must be used exactly once. If it is dead, we
147 // emit it inline where it would go.
148 if (I.getType() == Type::VoidTy || !I.hasOneUse() ||
149 isa<TerminatorInst>(I) || isa<CallInst>(I) || isa<PHINode>(I) ||
150 isa<LoadInst>(I) || isa<VAArgInst>(I))
151 // Don't inline a load across a store or other bad things!
154 // Only inline instruction it it's use is in the same BB as the inst.
155 return I.getParent() == cast<Instruction>(I.use_back())->getParent();
158 // isDirectAlloca - Define fixed sized allocas in the entry block as direct
159 // variables which are accessed with the & operator. This causes GCC to
160 // generate significantly better code than to emit alloca calls directly.
162 static const AllocaInst *isDirectAlloca(const Value *V) {
163 const AllocaInst *AI = dyn_cast<AllocaInst>(V);
164 if (!AI) return false;
165 if (AI->isArrayAllocation())
166 return 0; // FIXME: we can also inline fixed size array allocas!
167 if (AI->getParent() != &AI->getParent()->getParent()->getEntryBlock())
172 // Instruction visitation functions
173 friend class InstVisitor<CWriter>;
175 void visitReturnInst(ReturnInst &I);
176 void visitBranchInst(BranchInst &I);
177 void visitSwitchInst(SwitchInst &I);
178 void visitInvokeInst(InvokeInst &I) {
179 assert(0 && "Lowerinvoke pass didn't work!");
182 void visitUnwindInst(UnwindInst &I) {
183 assert(0 && "Lowerinvoke pass didn't work!");
185 void visitUnreachableInst(UnreachableInst &I);
187 void visitPHINode(PHINode &I);
188 void visitBinaryOperator(Instruction &I);
190 void visitCastInst (CastInst &I);
191 void visitSelectInst(SelectInst &I);
192 void visitCallInst (CallInst &I);
193 void visitShiftInst(ShiftInst &I) { visitBinaryOperator(I); }
195 void visitMallocInst(MallocInst &I);
196 void visitAllocaInst(AllocaInst &I);
197 void visitFreeInst (FreeInst &I);
198 void visitLoadInst (LoadInst &I);
199 void visitStoreInst (StoreInst &I);
200 void visitGetElementPtrInst(GetElementPtrInst &I);
201 void visitVAArgInst (VAArgInst &I);
203 void visitInstruction(Instruction &I) {
204 std::cerr << "C Writer does not know about " << I;
208 void outputLValue(Instruction *I) {
209 Out << " " << Mang->getValueName(I) << " = ";
212 bool isGotoCodeNecessary(BasicBlock *From, BasicBlock *To);
213 void printPHICopiesForSuccessor(BasicBlock *CurBlock,
214 BasicBlock *Successor, unsigned Indent);
215 void printBranchToBlock(BasicBlock *CurBlock, BasicBlock *SuccBlock,
217 void printIndexingExpression(Value *Ptr, gep_type_iterator I,
218 gep_type_iterator E);
222 /// This method inserts names for any unnamed structure types that are used by
223 /// the program, and removes names from structure types that are not used by the
226 bool CBackendNameAllUsedStructs::runOnModule(Module &M) {
227 // Get a set of types that are used by the program...
228 std::set<const Type *> UT = getAnalysis<FindUsedTypes>().getTypes();
230 // Loop over the module symbol table, removing types from UT that are
231 // already named, and removing names for types that are not used.
233 SymbolTable &MST = M.getSymbolTable();
234 for (SymbolTable::type_iterator TI = MST.type_begin(), TE = MST.type_end();
236 SymbolTable::type_iterator I = TI++;
238 // If this is not used, remove it from the symbol table.
239 std::set<const Type *>::iterator UTI = UT.find(I->second);
243 UT.erase(UTI); // Only keep one name for this type.
246 // UT now contains types that are not named. Loop over it, naming
249 bool Changed = false;
250 unsigned RenameCounter = 0;
251 for (std::set<const Type *>::const_iterator I = UT.begin(), E = UT.end();
253 if (const StructType *ST = dyn_cast<StructType>(*I)) {
254 while (M.addTypeName("unnamed"+utostr(RenameCounter), ST))
262 // Pass the Type* and the variable name and this prints out the variable
265 std::ostream &CWriter::printType(std::ostream &Out, const Type *Ty,
266 const std::string &NameSoFar,
268 if (Ty->isPrimitiveType())
269 switch (Ty->getTypeID()) {
270 case Type::VoidTyID: return Out << "void " << NameSoFar;
271 case Type::BoolTyID: return Out << "bool " << NameSoFar;
272 case Type::UByteTyID: return Out << "unsigned char " << NameSoFar;
273 case Type::SByteTyID: return Out << "signed char " << NameSoFar;
274 case Type::UShortTyID: return Out << "unsigned short " << NameSoFar;
275 case Type::ShortTyID: return Out << "short " << NameSoFar;
276 case Type::UIntTyID: return Out << "unsigned " << NameSoFar;
277 case Type::IntTyID: return Out << "int " << NameSoFar;
278 case Type::ULongTyID: return Out << "unsigned long long " << NameSoFar;
279 case Type::LongTyID: return Out << "signed long long " << NameSoFar;
280 case Type::FloatTyID: return Out << "float " << NameSoFar;
281 case Type::DoubleTyID: return Out << "double " << NameSoFar;
283 std::cerr << "Unknown primitive type: " << *Ty << "\n";
287 // Check to see if the type is named.
288 if (!IgnoreName || isa<OpaqueType>(Ty)) {
289 std::map<const Type *, std::string>::iterator I = TypeNames.find(Ty);
290 if (I != TypeNames.end()) return Out << I->second << ' ' << NameSoFar;
293 switch (Ty->getTypeID()) {
294 case Type::FunctionTyID: {
295 const FunctionType *MTy = cast<FunctionType>(Ty);
296 std::stringstream FunctionInnards;
297 FunctionInnards << " (" << NameSoFar << ") (";
298 for (FunctionType::param_iterator I = MTy->param_begin(),
299 E = MTy->param_end(); I != E; ++I) {
300 if (I != MTy->param_begin())
301 FunctionInnards << ", ";
302 printType(FunctionInnards, *I, "");
304 if (MTy->isVarArg()) {
305 if (MTy->getNumParams())
306 FunctionInnards << ", ...";
307 } else if (!MTy->getNumParams()) {
308 FunctionInnards << "void";
310 FunctionInnards << ')';
311 std::string tstr = FunctionInnards.str();
312 printType(Out, MTy->getReturnType(), tstr);
315 case Type::StructTyID: {
316 const StructType *STy = cast<StructType>(Ty);
317 Out << NameSoFar + " {\n";
319 for (StructType::element_iterator I = STy->element_begin(),
320 E = STy->element_end(); I != E; ++I) {
322 printType(Out, *I, "field" + utostr(Idx++));
328 case Type::PointerTyID: {
329 const PointerType *PTy = cast<PointerType>(Ty);
330 std::string ptrName = "*" + NameSoFar;
332 if (isa<ArrayType>(PTy->getElementType()))
333 ptrName = "(" + ptrName + ")";
335 return printType(Out, PTy->getElementType(), ptrName);
338 case Type::ArrayTyID: {
339 const ArrayType *ATy = cast<ArrayType>(Ty);
340 unsigned NumElements = ATy->getNumElements();
341 if (NumElements == 0) NumElements = 1;
342 return printType(Out, ATy->getElementType(),
343 NameSoFar + "[" + utostr(NumElements) + "]");
346 case Type::OpaqueTyID: {
347 static int Count = 0;
348 std::string TyName = "struct opaque_" + itostr(Count++);
349 assert(TypeNames.find(Ty) == TypeNames.end());
350 TypeNames[Ty] = TyName;
351 return Out << TyName << ' ' << NameSoFar;
354 assert(0 && "Unhandled case in getTypeProps!");
361 void CWriter::printConstantArray(ConstantArray *CPA) {
363 // As a special case, print the array as a string if it is an array of
364 // ubytes or an array of sbytes with positive values.
366 const Type *ETy = CPA->getType()->getElementType();
367 bool isString = (ETy == Type::SByteTy || ETy == Type::UByteTy);
369 // Make sure the last character is a null char, as automatically added by C
370 if (isString && (CPA->getNumOperands() == 0 ||
371 !cast<Constant>(*(CPA->op_end()-1))->isNullValue()))
376 // Keep track of whether the last number was a hexadecimal escape
377 bool LastWasHex = false;
379 // Do not include the last character, which we know is null
380 for (unsigned i = 0, e = CPA->getNumOperands()-1; i != e; ++i) {
381 unsigned char C = cast<ConstantInt>(CPA->getOperand(i))->getRawValue();
383 // Print it out literally if it is a printable character. The only thing
384 // to be careful about is when the last letter output was a hex escape
385 // code, in which case we have to be careful not to print out hex digits
386 // explicitly (the C compiler thinks it is a continuation of the previous
387 // character, sheesh...)
389 if (isprint(C) && (!LastWasHex || !isxdigit(C))) {
391 if (C == '"' || C == '\\')
398 case '\n': Out << "\\n"; break;
399 case '\t': Out << "\\t"; break;
400 case '\r': Out << "\\r"; break;
401 case '\v': Out << "\\v"; break;
402 case '\a': Out << "\\a"; break;
403 case '\"': Out << "\\\""; break;
404 case '\'': Out << "\\\'"; break;
407 Out << (char)(( C/16 < 10) ? ( C/16 +'0') : ( C/16 -10+'A'));
408 Out << (char)(((C&15) < 10) ? ((C&15)+'0') : ((C&15)-10+'A'));
417 if (CPA->getNumOperands()) {
419 printConstant(cast<Constant>(CPA->getOperand(0)));
420 for (unsigned i = 1, e = CPA->getNumOperands(); i != e; ++i) {
422 printConstant(cast<Constant>(CPA->getOperand(i)));
429 // isFPCSafeToPrint - Returns true if we may assume that CFP may be written out
430 // textually as a double (rather than as a reference to a stack-allocated
431 // variable). We decide this by converting CFP to a string and back into a
432 // double, and then checking whether the conversion results in a bit-equal
433 // double to the original value of CFP. This depends on us and the target C
434 // compiler agreeing on the conversion process (which is pretty likely since we
435 // only deal in IEEE FP).
437 static bool isFPCSafeToPrint(const ConstantFP *CFP) {
440 sprintf(Buffer, "%a", CFP->getValue());
442 if (!strncmp(Buffer, "0x", 2) ||
443 !strncmp(Buffer, "-0x", 3) ||
444 !strncmp(Buffer, "+0x", 3))
445 return atof(Buffer) == CFP->getValue();
448 std::string StrVal = ftostr(CFP->getValue());
450 while (StrVal[0] == ' ')
451 StrVal.erase(StrVal.begin());
453 // Check to make sure that the stringized number is not some string like "Inf"
454 // or NaN. Check that the string matches the "[-+]?[0-9]" regex.
455 if ((StrVal[0] >= '0' && StrVal[0] <= '9') ||
456 ((StrVal[0] == '-' || StrVal[0] == '+') &&
457 (StrVal[1] >= '0' && StrVal[1] <= '9')))
458 // Reparse stringized version!
459 return atof(StrVal.c_str()) == CFP->getValue();
464 // printConstant - The LLVM Constant to C Constant converter.
465 void CWriter::printConstant(Constant *CPV) {
466 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
467 switch (CE->getOpcode()) {
468 case Instruction::Cast:
470 printType(Out, CPV->getType());
472 printConstant(CE->getOperand(0));
476 case Instruction::GetElementPtr:
478 printIndexingExpression(CE->getOperand(0), gep_type_begin(CPV),
482 case Instruction::Select:
484 printConstant(CE->getOperand(0));
486 printConstant(CE->getOperand(1));
488 printConstant(CE->getOperand(2));
491 case Instruction::Add:
492 case Instruction::Sub:
493 case Instruction::Mul:
494 case Instruction::Div:
495 case Instruction::Rem:
496 case Instruction::And:
497 case Instruction::Or:
498 case Instruction::Xor:
499 case Instruction::SetEQ:
500 case Instruction::SetNE:
501 case Instruction::SetLT:
502 case Instruction::SetLE:
503 case Instruction::SetGT:
504 case Instruction::SetGE:
505 case Instruction::Shl:
506 case Instruction::Shr:
508 printConstant(CE->getOperand(0));
509 switch (CE->getOpcode()) {
510 case Instruction::Add: Out << " + "; break;
511 case Instruction::Sub: Out << " - "; break;
512 case Instruction::Mul: Out << " * "; break;
513 case Instruction::Div: Out << " / "; break;
514 case Instruction::Rem: Out << " % "; break;
515 case Instruction::And: Out << " & "; break;
516 case Instruction::Or: Out << " | "; break;
517 case Instruction::Xor: Out << " ^ "; break;
518 case Instruction::SetEQ: Out << " == "; break;
519 case Instruction::SetNE: Out << " != "; break;
520 case Instruction::SetLT: Out << " < "; break;
521 case Instruction::SetLE: Out << " <= "; break;
522 case Instruction::SetGT: Out << " > "; break;
523 case Instruction::SetGE: Out << " >= "; break;
524 case Instruction::Shl: Out << " << "; break;
525 case Instruction::Shr: Out << " >> "; break;
526 default: assert(0 && "Illegal opcode here!");
528 printConstant(CE->getOperand(1));
533 std::cerr << "CWriter Error: Unhandled constant expression: "
537 } else if (isa<UndefValue>(CPV) && CPV->getType()->isFirstClassType()) {
539 printType(Out, CPV->getType());
540 Out << ")/*UNDEF*/0)";
544 switch (CPV->getType()->getTypeID()) {
546 Out << (CPV == ConstantBool::False ? '0' : '1'); break;
547 case Type::SByteTyID:
548 case Type::ShortTyID:
549 Out << cast<ConstantSInt>(CPV)->getValue(); break;
551 if ((int)cast<ConstantSInt>(CPV)->getValue() == (int)0x80000000)
552 Out << "((int)0x80000000U)"; // Handle MININT specially to avoid warning
554 Out << cast<ConstantSInt>(CPV)->getValue();
558 if (cast<ConstantSInt>(CPV)->isMinValue())
559 Out << "(/*INT64_MIN*/(-9223372036854775807LL)-1)";
561 Out << cast<ConstantSInt>(CPV)->getValue() << "ll"; break;
563 case Type::UByteTyID:
564 case Type::UShortTyID:
565 Out << cast<ConstantUInt>(CPV)->getValue(); break;
567 Out << cast<ConstantUInt>(CPV)->getValue() << 'u'; break;
568 case Type::ULongTyID:
569 Out << cast<ConstantUInt>(CPV)->getValue() << "ull"; break;
571 case Type::FloatTyID:
572 case Type::DoubleTyID: {
573 ConstantFP *FPC = cast<ConstantFP>(CPV);
574 std::map<const ConstantFP*, unsigned>::iterator I = FPConstantMap.find(FPC);
575 if (I != FPConstantMap.end()) {
576 // Because of FP precision problems we must load from a stack allocated
577 // value that holds the value in hex.
578 Out << "(*(" << (FPC->getType() == Type::FloatTy ? "float" : "double")
579 << "*)&FPConstant" << I->second << ')';
581 if (IsNAN(FPC->getValue())) {
584 // The prefix for a quiet NaN is 0x7FF8. For a signalling NaN,
586 const unsigned long QuietNaN = 0x7ff8UL;
587 const unsigned long SignalNaN = 0x7ff4UL;
589 // We need to grab the first part of the FP #
592 uint64_t ll = DoubleToBits(FPC->getValue());
593 sprintf(Buffer, "0x%llx", (unsigned long long)ll);
595 std::string Num(&Buffer[0], &Buffer[6]);
596 unsigned long Val = strtoul(Num.c_str(), 0, 16);
598 if (FPC->getType() == Type::FloatTy)
599 Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "F(\""
600 << Buffer << "\") /*nan*/ ";
602 Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "(\""
603 << Buffer << "\") /*nan*/ ";
604 } else if (IsInf(FPC->getValue())) {
606 if (FPC->getValue() < 0) Out << '-';
607 Out << "LLVM_INF" << (FPC->getType() == Type::FloatTy ? "F" : "")
612 // Print out the constant as a floating point number.
614 sprintf(Buffer, "%a", FPC->getValue());
617 Num = ftostr(FPC->getValue());
625 case Type::ArrayTyID:
626 if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) {
627 const ArrayType *AT = cast<ArrayType>(CPV->getType());
629 if (AT->getNumElements()) {
631 Constant *CZ = Constant::getNullValue(AT->getElementType());
633 for (unsigned i = 1, e = AT->getNumElements(); i != e; ++i) {
640 printConstantArray(cast<ConstantArray>(CPV));
644 case Type::StructTyID:
645 if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) {
646 const StructType *ST = cast<StructType>(CPV->getType());
648 if (ST->getNumElements()) {
650 printConstant(Constant::getNullValue(ST->getElementType(0)));
651 for (unsigned i = 1, e = ST->getNumElements(); i != e; ++i) {
653 printConstant(Constant::getNullValue(ST->getElementType(i)));
659 if (CPV->getNumOperands()) {
661 printConstant(cast<Constant>(CPV->getOperand(0)));
662 for (unsigned i = 1, e = CPV->getNumOperands(); i != e; ++i) {
664 printConstant(cast<Constant>(CPV->getOperand(i)));
671 case Type::PointerTyID:
672 if (isa<ConstantPointerNull>(CPV)) {
674 printType(Out, CPV->getType());
675 Out << ")/*NULL*/0)";
677 } else if (GlobalValue *GV = dyn_cast<GlobalValue>(CPV)) {
683 std::cerr << "Unknown constant type: " << *CPV << "\n";
688 void CWriter::writeOperandInternal(Value *Operand) {
689 if (Instruction *I = dyn_cast<Instruction>(Operand))
690 if (isInlinableInst(*I) && !isDirectAlloca(I)) {
691 // Should we inline this instruction to build a tree?
698 Constant* CPV = dyn_cast<Constant>(Operand);
699 if (CPV && !isa<GlobalValue>(CPV)) {
702 Out << Mang->getValueName(Operand);
706 void CWriter::writeOperand(Value *Operand) {
707 if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand))
708 Out << "(&"; // Global variables are references as their addresses by llvm
710 writeOperandInternal(Operand);
712 if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand))
716 // generateCompilerSpecificCode - This is where we add conditional compilation
717 // directives to cater to specific compilers as need be.
719 static void generateCompilerSpecificCode(std::ostream& Out) {
720 // Alloca is hard to get, and we don't want to include stdlib.h here...
721 Out << "/* get a declaration for alloca */\n"
722 << "#if defined(__CYGWIN__)\n"
723 << "extern void *_alloca(unsigned long);\n"
724 << "#define alloca(x) _alloca(x)\n"
725 << "#elif defined(__APPLE__)\n"
726 << "extern void *__builtin_alloca(unsigned long);\n"
727 << "#define alloca(x) __builtin_alloca(x)\n"
728 << "#elif defined(__sun__)\n"
729 << "#if defined(__sparcv9)\n"
730 << "extern void *__builtin_alloca(unsigned long);\n"
732 << "extern void *__builtin_alloca(unsigned int);\n"
734 << "#define alloca(x) __builtin_alloca(x)\n"
735 << "#elif defined(__FreeBSD__)\n"
736 << "#define alloca(x) __builtin_alloca(x)\n"
737 << "#elif !defined(_MSC_VER)\n"
738 << "#include <alloca.h>\n"
741 // We output GCC specific attributes to preserve 'linkonce'ness on globals.
742 // If we aren't being compiled with GCC, just drop these attributes.
743 Out << "#ifndef __GNUC__ /* Can only support \"linkonce\" vars with GCC */\n"
744 << "#define __attribute__(X)\n"
748 // At some point, we should support "external weak" vs. "weak" linkages.
749 // On Mac OS X, "external weak" is spelled "__attribute__((weak_import))".
750 Out << "#if defined(__GNUC__) && defined(__APPLE_CC__)\n"
751 << "#define __EXTERNAL_WEAK__ __attribute__((weak_import))\n"
752 << "#elif defined(__GNUC__)\n"
753 << "#define __EXTERNAL_WEAK__ __attribute__((weak))\n"
755 << "#define __EXTERNAL_WEAK__\n"
759 // For now, turn off the weak linkage attribute on Mac OS X. (See above.)
760 Out << "#if defined(__GNUC__) && defined(__APPLE_CC__)\n"
761 << "#define __ATTRIBUTE_WEAK__\n"
762 << "#elif defined(__GNUC__)\n"
763 << "#define __ATTRIBUTE_WEAK__ __attribute__((weak))\n"
765 << "#define __ATTRIBUTE_WEAK__\n"
768 // Define NaN and Inf as GCC builtins if using GCC, as 0 otherwise
769 // From the GCC documentation:
771 // double __builtin_nan (const char *str)
773 // This is an implementation of the ISO C99 function nan.
775 // Since ISO C99 defines this function in terms of strtod, which we do
776 // not implement, a description of the parsing is in order. The string is
777 // parsed as by strtol; that is, the base is recognized by leading 0 or
778 // 0x prefixes. The number parsed is placed in the significand such that
779 // the least significant bit of the number is at the least significant
780 // bit of the significand. The number is truncated to fit the significand
781 // field provided. The significand is forced to be a quiet NaN.
783 // This function, if given a string literal, is evaluated early enough
784 // that it is considered a compile-time constant.
786 // float __builtin_nanf (const char *str)
788 // Similar to __builtin_nan, except the return type is float.
790 // double __builtin_inf (void)
792 // Similar to __builtin_huge_val, except a warning is generated if the
793 // target floating-point format does not support infinities. This
794 // function is suitable for implementing the ISO C99 macro INFINITY.
796 // float __builtin_inff (void)
798 // Similar to __builtin_inf, except the return type is float.
799 Out << "#ifdef __GNUC__\n"
800 << "#define LLVM_NAN(NanStr) __builtin_nan(NanStr) /* Double */\n"
801 << "#define LLVM_NANF(NanStr) __builtin_nanf(NanStr) /* Float */\n"
802 << "#define LLVM_NANS(NanStr) __builtin_nans(NanStr) /* Double */\n"
803 << "#define LLVM_NANSF(NanStr) __builtin_nansf(NanStr) /* Float */\n"
804 << "#define LLVM_INF __builtin_inf() /* Double */\n"
805 << "#define LLVM_INFF __builtin_inff() /* Float */\n"
806 << "#define LLVM_PREFETCH(addr,rw,locality) __builtin_prefetch(addr,rw,locality)\n"
808 << "#define LLVM_NAN(NanStr) ((double)0.0) /* Double */\n"
809 << "#define LLVM_NANF(NanStr) 0.0F /* Float */\n"
810 << "#define LLVM_NANS(NanStr) ((double)0.0) /* Double */\n"
811 << "#define LLVM_NANSF(NanStr) 0.0F /* Float */\n"
812 << "#define LLVM_INF ((double)0.0) /* Double */\n"
813 << "#define LLVM_INFF 0.0F /* Float */\n"
814 << "#define LLVM_PREFETCH(addr,rw,locality) /* PREFETCH */\n"
817 // Output target-specific code that should be inserted into main.
818 Out << "#define CODE_FOR_MAIN() /* Any target-specific code for main()*/\n";
819 // On X86, set the FP control word to 64-bits of precision instead of 80 bits.
820 Out << "#if defined(__GNUC__) && !defined(__llvm__)\n"
821 << "#if defined(i386) || defined(__i386__) || defined(__i386)\n"
822 << "#undef CODE_FOR_MAIN\n"
823 << "#define CODE_FOR_MAIN() \\\n"
824 << " {short F;__asm__ (\"fnstcw %0\" : \"=m\" (*&F)); \\\n"
825 << " F=(F&~0x300)|0x200;__asm__(\"fldcw %0\"::\"m\"(*&F));}\n"
826 << "#endif\n#endif\n";
830 bool CWriter::doInitialization(Module &M) {
836 // Ensure that all structure types have names...
837 Mang = new Mangler(M);
838 Mang->markCharUnacceptable('.');
840 // get declaration for alloca
841 Out << "/* Provide Declarations */\n";
842 Out << "#include <stdarg.h>\n"; // Varargs support
843 Out << "#include <setjmp.h>\n"; // Unwind support
844 generateCompilerSpecificCode(Out);
846 // Provide a definition for `bool' if not compiling with a C++ compiler.
848 << "#ifndef __cplusplus\ntypedef unsigned char bool;\n#endif\n"
850 << "\n\n/* Support for floating point constants */\n"
851 << "typedef unsigned long long ConstantDoubleTy;\n"
852 << "typedef unsigned int ConstantFloatTy;\n"
854 << "\n\n/* Global Declarations */\n";
856 // First output all the declarations for the program, because C requires
857 // Functions & globals to be declared before they are used.
860 // Loop over the symbol table, emitting all named constants...
861 printModuleTypes(M.getSymbolTable());
863 // Global variable declarations...
864 if (!M.global_empty()) {
865 Out << "\n/* External Global Variable Declarations */\n";
866 for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I) {
867 if (I->hasExternalLinkage()) {
869 printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
875 // Function declarations
876 Out << "double fmod(double, double);\n"; // Support for FP rem
877 Out << "float fmodf(float, float);\n";
880 Out << "\n/* Function Declarations */\n";
881 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
882 // Don't print declarations for intrinsic functions.
883 if (!I->getIntrinsicID() &&
884 I->getName() != "setjmp" && I->getName() != "longjmp") {
885 printFunctionSignature(I, true);
886 if (I->hasWeakLinkage()) Out << " __ATTRIBUTE_WEAK__";
887 if (I->hasLinkOnceLinkage()) Out << " __ATTRIBUTE_WEAK__";
893 // Output the global variable declarations
894 if (!M.global_empty()) {
895 Out << "\n\n/* Global Variable Declarations */\n";
896 for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I)
897 if (!I->isExternal()) {
898 if (I->hasInternalLinkage())
902 printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
904 if (I->hasLinkOnceLinkage())
905 Out << " __attribute__((common))";
906 else if (I->hasWeakLinkage())
907 Out << " __ATTRIBUTE_WEAK__";
912 // Output the global variable definitions and contents...
913 if (!M.global_empty()) {
914 Out << "\n\n/* Global Variable Definitions and Initialization */\n";
915 for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I)
916 if (!I->isExternal()) {
917 if (I->hasInternalLinkage())
919 printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
920 if (I->hasLinkOnceLinkage())
921 Out << " __attribute__((common))";
922 else if (I->hasWeakLinkage())
923 Out << " __ATTRIBUTE_WEAK__";
925 // If the initializer is not null, emit the initializer. If it is null,
926 // we try to avoid emitting large amounts of zeros. The problem with
927 // this, however, occurs when the variable has weak linkage. In this
928 // case, the assembler will complain about the variable being both weak
929 // and common, so we disable this optimization.
930 if (!I->getInitializer()->isNullValue()) {
932 writeOperand(I->getInitializer());
933 } else if (I->hasWeakLinkage()) {
934 // We have to specify an initializer, but it doesn't have to be
935 // complete. If the value is an aggregate, print out { 0 }, and let
936 // the compiler figure out the rest of the zeros.
938 if (isa<StructType>(I->getInitializer()->getType()) ||
939 isa<ArrayType>(I->getInitializer()->getType())) {
942 // Just print it out normally.
943 writeOperand(I->getInitializer());
951 Out << "\n\n/* Function Bodies */\n";
956 /// Output all floating point constants that cannot be printed accurately...
957 void CWriter::printFloatingPointConstants(Function &F) {
958 // Scan the module for floating point constants. If any FP constant is used
959 // in the function, we want to redirect it here so that we do not depend on
960 // the precision of the printed form, unless the printed form preserves
963 static unsigned FPCounter = 0;
964 for (constant_iterator I = constant_begin(&F), E = constant_end(&F);
966 if (const ConstantFP *FPC = dyn_cast<ConstantFP>(*I))
967 if (!isFPCSafeToPrint(FPC) && // Do not put in FPConstantMap if safe.
968 !FPConstantMap.count(FPC)) {
969 double Val = FPC->getValue();
971 FPConstantMap[FPC] = FPCounter; // Number the FP constants
973 if (FPC->getType() == Type::DoubleTy) {
974 Out << "static const ConstantDoubleTy FPConstant" << FPCounter++
975 << " = 0x" << std::hex << DoubleToBits(Val) << std::dec
976 << "ULL; /* " << Val << " */\n";
977 } else if (FPC->getType() == Type::FloatTy) {
978 Out << "static const ConstantFloatTy FPConstant" << FPCounter++
979 << " = 0x" << std::hex << FloatToBits(Val) << std::dec
980 << "U; /* " << Val << " */\n";
982 assert(0 && "Unknown float type!");
989 /// printSymbolTable - Run through symbol table looking for type names. If a
990 /// type name is found, emit it's declaration...
992 void CWriter::printModuleTypes(const SymbolTable &ST) {
993 // We are only interested in the type plane of the symbol table.
994 SymbolTable::type_const_iterator I = ST.type_begin();
995 SymbolTable::type_const_iterator End = ST.type_end();
997 // If there are no type names, exit early.
998 if (I == End) return;
1000 // Print out forward declarations for structure types before anything else!
1001 Out << "/* Structure forward decls */\n";
1002 for (; I != End; ++I)
1003 if (const Type *STy = dyn_cast<StructType>(I->second)) {
1004 std::string Name = "struct l_" + Mang->makeNameProper(I->first);
1005 Out << Name << ";\n";
1006 TypeNames.insert(std::make_pair(STy, Name));
1011 // Now we can print out typedefs...
1012 Out << "/* Typedefs */\n";
1013 for (I = ST.type_begin(); I != End; ++I) {
1014 const Type *Ty = cast<Type>(I->second);
1015 std::string Name = "l_" + Mang->makeNameProper(I->first);
1017 printType(Out, Ty, Name);
1023 // Keep track of which structures have been printed so far...
1024 std::set<const StructType *> StructPrinted;
1026 // Loop over all structures then push them into the stack so they are
1027 // printed in the correct order.
1029 Out << "/* Structure contents */\n";
1030 for (I = ST.type_begin(); I != End; ++I)
1031 if (const StructType *STy = dyn_cast<StructType>(I->second))
1032 // Only print out used types!
1033 printContainedStructs(STy, StructPrinted);
1036 // Push the struct onto the stack and recursively push all structs
1037 // this one depends on.
1038 void CWriter::printContainedStructs(const Type *Ty,
1039 std::set<const StructType*> &StructPrinted){
1040 // Don't walk through pointers.
1041 if (isa<PointerType>(Ty) || Ty->isPrimitiveType()) return;
1043 // Print all contained types first.
1044 for (Type::subtype_iterator I = Ty->subtype_begin(),
1045 E = Ty->subtype_end(); I != E; ++I)
1046 printContainedStructs(*I, StructPrinted);
1048 if (const StructType *STy = dyn_cast<StructType>(Ty)) {
1049 // Check to see if we have already printed this struct.
1050 if (StructPrinted.insert(STy).second) {
1051 // Print structure type out.
1052 std::string Name = TypeNames[STy];
1053 printType(Out, STy, Name, true);
1060 void CWriter::printFunctionSignature(const Function *F, bool Prototype) {
1061 if (F->hasInternalLinkage()) Out << "static ";
1063 // Loop over the arguments, printing them...
1064 const FunctionType *FT = cast<FunctionType>(F->getFunctionType());
1066 std::stringstream FunctionInnards;
1068 // Print out the name...
1069 FunctionInnards << Mang->getValueName(F) << '(';
1071 if (!F->isExternal()) {
1072 if (!F->arg_empty()) {
1073 std::string ArgName;
1074 if (F->arg_begin()->hasName() || !Prototype)
1075 ArgName = Mang->getValueName(F->arg_begin());
1076 printType(FunctionInnards, F->arg_begin()->getType(), ArgName);
1077 for (Function::const_arg_iterator I = ++F->arg_begin(), E = F->arg_end();
1079 FunctionInnards << ", ";
1080 if (I->hasName() || !Prototype)
1081 ArgName = Mang->getValueName(I);
1084 printType(FunctionInnards, I->getType(), ArgName);
1088 // Loop over the arguments, printing them...
1089 for (FunctionType::param_iterator I = FT->param_begin(),
1090 E = FT->param_end(); I != E; ++I) {
1091 if (I != FT->param_begin()) FunctionInnards << ", ";
1092 printType(FunctionInnards, *I);
1096 // Finish printing arguments... if this is a vararg function, print the ...,
1097 // unless there are no known types, in which case, we just emit ().
1099 if (FT->isVarArg() && FT->getNumParams()) {
1100 if (FT->getNumParams()) FunctionInnards << ", ";
1101 FunctionInnards << "..."; // Output varargs portion of signature!
1102 } else if (!FT->isVarArg() && FT->getNumParams() == 0) {
1103 FunctionInnards << "void"; // ret() -> ret(void) in C.
1105 FunctionInnards << ')';
1106 // Print out the return type and the entire signature for that matter
1107 printType(Out, F->getReturnType(), FunctionInnards.str());
1110 void CWriter::printFunction(Function &F) {
1111 printFunctionSignature(&F, false);
1114 // print local variable information for the function
1115 for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ++I)
1116 if (const AllocaInst *AI = isDirectAlloca(&*I)) {
1118 printType(Out, AI->getAllocatedType(), Mang->getValueName(AI));
1119 Out << "; /* Address-exposed local */\n";
1120 } else if (I->getType() != Type::VoidTy && !isInlinableInst(*I)) {
1122 printType(Out, I->getType(), Mang->getValueName(&*I));
1125 if (isa<PHINode>(*I)) { // Print out PHI node temporaries as well...
1127 printType(Out, I->getType(),
1128 Mang->getValueName(&*I)+"__PHI_TEMPORARY");
1135 if (F.hasExternalLinkage() && F.getName() == "main")
1136 Out << " CODE_FOR_MAIN();\n";
1138 // print the basic blocks
1139 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
1140 if (Loop *L = LI->getLoopFor(BB)) {
1141 if (L->getHeader() == BB && L->getParentLoop() == 0)
1144 printBasicBlock(BB);
1151 void CWriter::printLoop(Loop *L) {
1152 Out << " do { /* Syntactic loop '" << L->getHeader()->getName()
1153 << "' to make GCC happy */\n";
1154 for (unsigned i = 0, e = L->getBlocks().size(); i != e; ++i) {
1155 BasicBlock *BB = L->getBlocks()[i];
1156 Loop *BBLoop = LI->getLoopFor(BB);
1158 printBasicBlock(BB);
1159 else if (BB == BBLoop->getHeader() && BBLoop->getParentLoop() == L)
1162 Out << " } while (1); /* end of syntactic loop '"
1163 << L->getHeader()->getName() << "' */\n";
1166 void CWriter::printBasicBlock(BasicBlock *BB) {
1168 // Don't print the label for the basic block if there are no uses, or if
1169 // the only terminator use is the predecessor basic block's terminator.
1170 // We have to scan the use list because PHI nodes use basic blocks too but
1171 // do not require a label to be generated.
1173 bool NeedsLabel = false;
1174 for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
1175 if (isGotoCodeNecessary(*PI, BB)) {
1180 if (NeedsLabel) Out << Mang->getValueName(BB) << ":\n";
1182 // Output all of the instructions in the basic block...
1183 for (BasicBlock::iterator II = BB->begin(), E = --BB->end(); II != E;
1185 if (!isInlinableInst(*II) && !isDirectAlloca(II)) {
1186 if (II->getType() != Type::VoidTy)
1195 // Don't emit prefix or suffix for the terminator...
1196 visit(*BB->getTerminator());
1200 // Specific Instruction type classes... note that all of the casts are
1201 // necessary because we use the instruction classes as opaque types...
1203 void CWriter::visitReturnInst(ReturnInst &I) {
1204 // Don't output a void return if this is the last basic block in the function
1205 if (I.getNumOperands() == 0 &&
1206 &*--I.getParent()->getParent()->end() == I.getParent() &&
1207 !I.getParent()->size() == 1) {
1212 if (I.getNumOperands()) {
1214 writeOperand(I.getOperand(0));
1219 void CWriter::visitSwitchInst(SwitchInst &SI) {
1222 writeOperand(SI.getOperand(0));
1223 Out << ") {\n default:\n";
1224 printPHICopiesForSuccessor (SI.getParent(), SI.getDefaultDest(), 2);
1225 printBranchToBlock(SI.getParent(), SI.getDefaultDest(), 2);
1227 for (unsigned i = 2, e = SI.getNumOperands(); i != e; i += 2) {
1229 writeOperand(SI.getOperand(i));
1231 BasicBlock *Succ = cast<BasicBlock>(SI.getOperand(i+1));
1232 printPHICopiesForSuccessor (SI.getParent(), Succ, 2);
1233 printBranchToBlock(SI.getParent(), Succ, 2);
1234 if (Function::iterator(Succ) == next(Function::iterator(SI.getParent())))
1240 void CWriter::visitUnreachableInst(UnreachableInst &I) {
1241 Out << " /*UNREACHABLE*/;\n";
1244 bool CWriter::isGotoCodeNecessary(BasicBlock *From, BasicBlock *To) {
1245 /// FIXME: This should be reenabled, but loop reordering safe!!
1248 if (next(Function::iterator(From)) != Function::iterator(To))
1249 return true; // Not the direct successor, we need a goto.
1251 //isa<SwitchInst>(From->getTerminator())
1253 if (LI->getLoopFor(From) != LI->getLoopFor(To))
1258 void CWriter::printPHICopiesForSuccessor (BasicBlock *CurBlock,
1259 BasicBlock *Successor,
1261 for (BasicBlock::iterator I = Successor->begin(); isa<PHINode>(I); ++I) {
1262 PHINode *PN = cast<PHINode>(I);
1263 // Now we have to do the printing.
1264 Value *IV = PN->getIncomingValueForBlock(CurBlock);
1265 if (!isa<UndefValue>(IV)) {
1266 Out << std::string(Indent, ' ');
1267 Out << " " << Mang->getValueName(I) << "__PHI_TEMPORARY = ";
1269 Out << "; /* for PHI node */\n";
1274 void CWriter::printBranchToBlock(BasicBlock *CurBB, BasicBlock *Succ,
1276 if (isGotoCodeNecessary(CurBB, Succ)) {
1277 Out << std::string(Indent, ' ') << " goto ";
1283 // Branch instruction printing - Avoid printing out a branch to a basic block
1284 // that immediately succeeds the current one.
1286 void CWriter::visitBranchInst(BranchInst &I) {
1288 if (I.isConditional()) {
1289 if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(0))) {
1291 writeOperand(I.getCondition());
1294 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(0), 2);
1295 printBranchToBlock(I.getParent(), I.getSuccessor(0), 2);
1297 if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(1))) {
1298 Out << " } else {\n";
1299 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(1), 2);
1300 printBranchToBlock(I.getParent(), I.getSuccessor(1), 2);
1303 // First goto not necessary, assume second one is...
1305 writeOperand(I.getCondition());
1308 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(1), 2);
1309 printBranchToBlock(I.getParent(), I.getSuccessor(1), 2);
1314 printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(0), 0);
1315 printBranchToBlock(I.getParent(), I.getSuccessor(0), 0);
1320 // PHI nodes get copied into temporary values at the end of predecessor basic
1321 // blocks. We now need to copy these temporary values into the REAL value for
1323 void CWriter::visitPHINode(PHINode &I) {
1325 Out << "__PHI_TEMPORARY";
1329 void CWriter::visitBinaryOperator(Instruction &I) {
1330 // binary instructions, shift instructions, setCond instructions.
1331 assert(!isa<PointerType>(I.getType()));
1333 // We must cast the results of binary operations which might be promoted.
1334 bool needsCast = false;
1335 if ((I.getType() == Type::UByteTy) || (I.getType() == Type::SByteTy)
1336 || (I.getType() == Type::UShortTy) || (I.getType() == Type::ShortTy)
1337 || (I.getType() == Type::FloatTy)) {
1340 printType(Out, I.getType());
1344 // If this is a negation operation, print it out as such. For FP, we don't
1345 // want to print "-0.0 - X".
1346 if (BinaryOperator::isNeg(&I)) {
1348 writeOperand(BinaryOperator::getNegArgument(cast<BinaryOperator>(&I)));
1350 } else if (I.getOpcode() == Instruction::Rem &&
1351 I.getType()->isFloatingPoint()) {
1352 // Output a call to fmod/fmodf instead of emitting a%b
1353 if (I.getType() == Type::FloatTy)
1357 writeOperand(I.getOperand(0));
1359 writeOperand(I.getOperand(1));
1362 writeOperand(I.getOperand(0));
1364 switch (I.getOpcode()) {
1365 case Instruction::Add: Out << " + "; break;
1366 case Instruction::Sub: Out << " - "; break;
1367 case Instruction::Mul: Out << '*'; break;
1368 case Instruction::Div: Out << '/'; break;
1369 case Instruction::Rem: Out << '%'; break;
1370 case Instruction::And: Out << " & "; break;
1371 case Instruction::Or: Out << " | "; break;
1372 case Instruction::Xor: Out << " ^ "; break;
1373 case Instruction::SetEQ: Out << " == "; break;
1374 case Instruction::SetNE: Out << " != "; break;
1375 case Instruction::SetLE: Out << " <= "; break;
1376 case Instruction::SetGE: Out << " >= "; break;
1377 case Instruction::SetLT: Out << " < "; break;
1378 case Instruction::SetGT: Out << " > "; break;
1379 case Instruction::Shl : Out << " << "; break;
1380 case Instruction::Shr : Out << " >> "; break;
1381 default: std::cerr << "Invalid operator type!" << I; abort();
1384 writeOperand(I.getOperand(1));
1392 void CWriter::visitCastInst(CastInst &I) {
1393 if (I.getType() == Type::BoolTy) {
1395 writeOperand(I.getOperand(0));
1400 printType(Out, I.getType());
1402 if (isa<PointerType>(I.getType())&&I.getOperand(0)->getType()->isIntegral() ||
1403 isa<PointerType>(I.getOperand(0)->getType())&&I.getType()->isIntegral()) {
1404 // Avoid "cast to pointer from integer of different size" warnings
1408 writeOperand(I.getOperand(0));
1411 void CWriter::visitSelectInst(SelectInst &I) {
1413 writeOperand(I.getCondition());
1415 writeOperand(I.getTrueValue());
1417 writeOperand(I.getFalseValue());
1422 void CWriter::lowerIntrinsics(Function &F) {
1423 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1424 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; )
1425 if (CallInst *CI = dyn_cast<CallInst>(I++))
1426 if (Function *F = CI->getCalledFunction())
1427 switch (F->getIntrinsicID()) {
1428 case Intrinsic::not_intrinsic:
1429 case Intrinsic::vastart:
1430 case Intrinsic::vacopy:
1431 case Intrinsic::vaend:
1432 case Intrinsic::returnaddress:
1433 case Intrinsic::frameaddress:
1434 case Intrinsic::setjmp:
1435 case Intrinsic::longjmp:
1436 case Intrinsic::prefetch:
1437 // We directly implement these intrinsics
1440 // All other intrinsic calls we must lower.
1441 Instruction *Before = 0;
1442 if (CI != &BB->front())
1443 Before = prior(BasicBlock::iterator(CI));
1445 IL.LowerIntrinsicCall(CI);
1446 if (Before) { // Move iterator to instruction after call
1456 void CWriter::visitCallInst(CallInst &I) {
1457 // Handle intrinsic function calls first...
1458 if (Function *F = I.getCalledFunction())
1459 if (Intrinsic::ID ID = (Intrinsic::ID)F->getIntrinsicID()) {
1461 default: assert(0 && "Unknown LLVM intrinsic!");
1462 case Intrinsic::vastart:
1465 // Out << "va_start(*(va_list*)&" << Mang->getValueName(&I) << ", ";
1466 Out << "va_start(*(va_list*)";
1467 writeOperand(I.getOperand(1));
1469 // Output the last argument to the enclosing function...
1470 if (I.getParent()->getParent()->arg_empty()) {
1471 std::cerr << "The C backend does not currently support zero "
1472 << "argument varargs functions, such as '"
1473 << I.getParent()->getParent()->getName() << "'!\n";
1476 writeOperand(--I.getParent()->getParent()->arg_end());
1479 case Intrinsic::vaend:
1480 if (!isa<ConstantPointerNull>(I.getOperand(1))) {
1481 Out << "0; va_end(*(va_list*)";
1482 writeOperand(I.getOperand(1));
1485 Out << "va_end(*(va_list*)0)";
1488 case Intrinsic::vacopy:
1490 Out << "va_copy(*(va_list*)";
1491 writeOperand(I.getOperand(1));
1492 Out << ", *(va_list*)";
1493 writeOperand(I.getOperand(2));
1496 case Intrinsic::returnaddress:
1497 Out << "__builtin_return_address(";
1498 writeOperand(I.getOperand(1));
1501 case Intrinsic::frameaddress:
1502 Out << "__builtin_frame_address(";
1503 writeOperand(I.getOperand(1));
1506 case Intrinsic::setjmp:
1507 Out << "setjmp(*(jmp_buf*)";
1508 writeOperand(I.getOperand(1));
1511 case Intrinsic::longjmp:
1512 Out << "longjmp(*(jmp_buf*)";
1513 writeOperand(I.getOperand(1));
1515 writeOperand(I.getOperand(2));
1518 case Intrinsic::prefetch:
1519 Out << "LLVM_PREFETCH((const void *)";
1520 writeOperand(I.getOperand(1));
1522 writeOperand(I.getOperand(2));
1524 writeOperand(I.getOperand(3));
1530 Value *Callee = I.getCalledValue();
1532 // GCC is really a PITA. It does not permit codegening casts of functions to
1533 // function pointers if they are in a call (it generates a trap instruction
1534 // instead!). We work around this by inserting a cast to void* in between the
1535 // function and the function pointer cast. Unfortunately, we can't just form
1536 // the constant expression here, because the folder will immediately nuke it.
1538 // Note finally, that this is completely unsafe. ANSI C does not guarantee
1539 // that void* and function pointers have the same size. :( To deal with this
1540 // in the common case, we handle casts where the number of arguments passed
1543 bool WroteCallee = false;
1544 if (I.isTailCall()) Out << " /*tail*/ ";
1545 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Callee))
1546 if (CE->getOpcode() == Instruction::Cast)
1547 if (Function *RF = dyn_cast<Function>(CE->getOperand(0))) {
1548 const FunctionType *RFTy = RF->getFunctionType();
1549 if (RFTy->getNumParams() == I.getNumOperands()-1) {
1550 // If the call site expects a value, and the actual callee doesn't
1551 // provide one, return 0.
1552 if (I.getType() != Type::VoidTy &&
1553 RFTy->getReturnType() == Type::VoidTy)
1554 Out << "0 /*actual callee doesn't return value*/; ";
1557 // Ok, just cast the pointer type.
1559 printType(Out, CE->getType());
1567 const PointerType *PTy = cast<PointerType>(Callee->getType());
1568 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1569 const Type *RetTy = FTy->getReturnType();
1571 if (!WroteCallee) writeOperand(Callee);
1574 unsigned NumDeclaredParams = FTy->getNumParams();
1576 if (I.getNumOperands() != 1) {
1577 CallSite::arg_iterator AI = I.op_begin()+1, AE = I.op_end();
1578 if (NumDeclaredParams && (*AI)->getType() != FTy->getParamType(0)) {
1580 printType(Out, FTy->getParamType(0));
1587 for (ArgNo = 1, ++AI; AI != AE; ++AI, ++ArgNo) {
1589 if (ArgNo < NumDeclaredParams &&
1590 (*AI)->getType() != FTy->getParamType(ArgNo)) {
1592 printType(Out, FTy->getParamType(ArgNo));
1601 void CWriter::visitMallocInst(MallocInst &I) {
1602 assert(0 && "lowerallocations pass didn't work!");
1605 void CWriter::visitAllocaInst(AllocaInst &I) {
1607 printType(Out, I.getType());
1608 Out << ") alloca(sizeof(";
1609 printType(Out, I.getType()->getElementType());
1611 if (I.isArrayAllocation()) {
1613 writeOperand(I.getOperand(0));
1618 void CWriter::visitFreeInst(FreeInst &I) {
1619 assert(0 && "lowerallocations pass didn't work!");
1622 void CWriter::printIndexingExpression(Value *Ptr, gep_type_iterator I,
1623 gep_type_iterator E) {
1624 bool HasImplicitAddress = false;
1625 // If accessing a global value with no indexing, avoid *(&GV) syndrome
1626 if (GlobalValue *V = dyn_cast<GlobalValue>(Ptr)) {
1627 HasImplicitAddress = true;
1628 } else if (isDirectAlloca(Ptr)) {
1629 HasImplicitAddress = true;
1633 if (!HasImplicitAddress)
1634 Out << '*'; // Implicit zero first argument: '*x' is equivalent to 'x[0]'
1636 writeOperandInternal(Ptr);
1640 const Constant *CI = dyn_cast<Constant>(I.getOperand());
1641 if (HasImplicitAddress && (!CI || !CI->isNullValue()))
1644 writeOperandInternal(Ptr);
1646 if (HasImplicitAddress && (!CI || !CI->isNullValue())) {
1648 HasImplicitAddress = false; // HIA is only true if we haven't addressed yet
1651 assert(!HasImplicitAddress || (CI && CI->isNullValue()) &&
1652 "Can only have implicit address with direct accessing");
1654 if (HasImplicitAddress) {
1656 } else if (CI && CI->isNullValue()) {
1657 gep_type_iterator TmpI = I; ++TmpI;
1659 // Print out the -> operator if possible...
1660 if (TmpI != E && isa<StructType>(*TmpI)) {
1661 Out << (HasImplicitAddress ? "." : "->");
1662 Out << "field" << cast<ConstantUInt>(TmpI.getOperand())->getValue();
1668 if (isa<StructType>(*I)) {
1669 Out << ".field" << cast<ConstantUInt>(I.getOperand())->getValue();
1672 writeOperand(I.getOperand());
1677 void CWriter::visitLoadInst(LoadInst &I) {
1679 if (I.isVolatile()) {
1681 printType(Out, I.getType(), "volatile*");
1685 writeOperand(I.getOperand(0));
1691 void CWriter::visitStoreInst(StoreInst &I) {
1693 if (I.isVolatile()) {
1695 printType(Out, I.getOperand(0)->getType(), " volatile*");
1698 writeOperand(I.getPointerOperand());
1699 if (I.isVolatile()) Out << ')';
1701 writeOperand(I.getOperand(0));
1704 void CWriter::visitGetElementPtrInst(GetElementPtrInst &I) {
1706 printIndexingExpression(I.getPointerOperand(), gep_type_begin(I),
1710 void CWriter::visitVAArgInst(VAArgInst &I) {
1711 Out << "va_arg(*(va_list*)";
1712 writeOperand(I.getOperand(0));
1714 printType(Out, I.getType());
1718 //===----------------------------------------------------------------------===//
1719 // External Interface declaration
1720 //===----------------------------------------------------------------------===//
1722 bool CTargetMachine::addPassesToEmitFile(PassManager &PM, std::ostream &o,
1723 CodeGenFileType FileType, bool Fast) {
1724 if (FileType != TargetMachine::AssemblyFile) return true;
1726 PM.add(createLowerGCPass());
1727 PM.add(createLowerAllocationsPass(true));
1728 PM.add(createLowerInvokePass());
1729 PM.add(createCFGSimplificationPass()); // clean up after lower invoke.
1730 PM.add(new CBackendNameAllUsedStructs());
1731 PM.add(new CWriter(o, getIntrinsicLowering()));