llvm/lib/Target/CBackend/CBackend.cpp
Chris Lattner 1911fd4f85 Completely rearchitect the interface between targets and the pass manager.
This pass:

1. Splits TargetMachine into TargetMachine (generic targets, can be implemented
any way, like the CBE) and LLVMTargetMachine (subclass of TM that is used by
things using libcodegen and other support).
2. Instead of having each target fully populate the passmgr for file or JIT
   output, move all this to common code, and give targets hooks they can
   implement.
3. Commonalize the target population stuff between file emission and JIT
   emission.
4. All (native code) codegen stuff now happens in a FunctionPassManager, which
   paves the way for "fast -O0" stuff in the CFE later, and now LLC could
   lazily stream .bc files from disk to use less memory.
5. There are now many fewer #includes and the targets don't depend on the
   scalar xforms or libanalysis anymore (but codegen does).
6. Changing common code generator pass ordering stuff no longer requires
   touching all targets.
7. The JIT now has the option of "-fast" codegen or normal optimized codegen,
   which is now orthogonal to the fact that JIT'ing is being done.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30081 91177308-0d34-0410-b5e6-96231b3b80d8
2006-09-04 04:14:57 +00:00

2044 lines
68 KiB
C++

//===-- Writer.cpp - Library for converting LLVM code to C ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This library converts LLVM code to C code, compilable by GCC and other C
// compilers.
//
//===----------------------------------------------------------------------===//
#include "CTargetMachine.h"
#include "llvm/CallingConv.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/PassManager.h"
#include "llvm/SymbolTable.h"
#include "llvm/Intrinsics.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/Analysis/ConstantsScanner.h"
#include "llvm/Analysis/FindUsedTypes.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/CodeGen/IntrinsicLowering.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Target/TargetMachineRegistry.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/InstVisitor.h"
#include "llvm/Support/Mangler.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Config/config.h"
#include <algorithm>
#include <iostream>
#include <ios>
#include <sstream>
using namespace llvm;
namespace {
// Register the target.
RegisterTarget<CTargetMachine> X("c", " C backend");
/// CBackendNameAllUsedStructsAndMergeFunctions - This pass inserts names for
/// any unnamed structure types that are used by the program, and merges
/// external functions with the same name.
///
class CBackendNameAllUsedStructsAndMergeFunctions : public ModulePass {
void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<FindUsedTypes>();
}
virtual const char *getPassName() const {
return "C backend type canonicalizer";
}
virtual bool runOnModule(Module &M);
};
/// CWriter - This class is the main chunk of code that converts an LLVM
/// module to a C translation unit.
class CWriter : public FunctionPass, public InstVisitor<CWriter> {
std::ostream &Out;
DefaultIntrinsicLowering IL;
Mangler *Mang;
LoopInfo *LI;
const Module *TheModule;
std::map<const Type *, std::string> TypeNames;
std::map<const ConstantFP *, unsigned> FPConstantMap;
public:
CWriter(std::ostream &o) : Out(o) {}
virtual const char *getPassName() const { return "C backend"; }
void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<LoopInfo>();
AU.setPreservesAll();
}
virtual bool doInitialization(Module &M);
bool runOnFunction(Function &F) {
LI = &getAnalysis<LoopInfo>();
// Get rid of intrinsics we can't handle.
lowerIntrinsics(F);
// Output all floating point constants that cannot be printed accurately.
printFloatingPointConstants(F);
// Ensure that no local symbols conflict with global symbols.
F.renameLocalSymbols();
printFunction(F);
FPConstantMap.clear();
return false;
}
virtual bool doFinalization(Module &M) {
// Free memory...
delete Mang;
TypeNames.clear();
return false;
}
std::ostream &printType(std::ostream &Out, const Type *Ty,
const std::string &VariableName = "",
bool IgnoreName = false);
void printStructReturnPointerFunctionType(std::ostream &Out,
const PointerType *Ty);
void writeOperand(Value *Operand);
void writeOperandInternal(Value *Operand);
private :
void lowerIntrinsics(Function &F);
void printModule(Module *M);
void printModuleTypes(const SymbolTable &ST);
void printContainedStructs(const Type *Ty, std::set<const StructType *> &);
void printFloatingPointConstants(Function &F);
void printFunctionSignature(const Function *F, bool Prototype);
void printFunction(Function &);
void printBasicBlock(BasicBlock *BB);
void printLoop(Loop *L);
void printConstant(Constant *CPV);
void printConstantArray(ConstantArray *CPA);
void printConstantPacked(ConstantPacked *CP);
// isInlinableInst - Attempt to inline instructions into their uses to build
// trees as much as possible. To do this, we have to consistently decide
// what is acceptable to inline, so that variable declarations don't get
// printed and an extra copy of the expr is not emitted.
//
static bool isInlinableInst(const Instruction &I) {
// Always inline setcc instructions, even if they are shared by multiple
// expressions. GCC generates horrible code if we don't.
if (isa<SetCondInst>(I)) return true;
// Must be an expression, must be used exactly once. If it is dead, we
// emit it inline where it would go.
if (I.getType() == Type::VoidTy || !I.hasOneUse() ||
isa<TerminatorInst>(I) || isa<CallInst>(I) || isa<PHINode>(I) ||
isa<LoadInst>(I) || isa<VAArgInst>(I))
// Don't inline a load across a store or other bad things!
return false;
// Only inline instruction it it's use is in the same BB as the inst.
return I.getParent() == cast<Instruction>(I.use_back())->getParent();
}
// isDirectAlloca - Define fixed sized allocas in the entry block as direct
// variables which are accessed with the & operator. This causes GCC to
// generate significantly better code than to emit alloca calls directly.
//
static const AllocaInst *isDirectAlloca(const Value *V) {
const AllocaInst *AI = dyn_cast<AllocaInst>(V);
if (!AI) return false;
if (AI->isArrayAllocation())
return 0; // FIXME: we can also inline fixed size array allocas!
if (AI->getParent() != &AI->getParent()->getParent()->getEntryBlock())
return 0;
return AI;
}
// Instruction visitation functions
friend class InstVisitor<CWriter>;
void visitReturnInst(ReturnInst &I);
void visitBranchInst(BranchInst &I);
void visitSwitchInst(SwitchInst &I);
void visitInvokeInst(InvokeInst &I) {
assert(0 && "Lowerinvoke pass didn't work!");
}
void visitUnwindInst(UnwindInst &I) {
assert(0 && "Lowerinvoke pass didn't work!");
}
void visitUnreachableInst(UnreachableInst &I);
void visitPHINode(PHINode &I);
void visitBinaryOperator(Instruction &I);
void visitCastInst (CastInst &I);
void visitSelectInst(SelectInst &I);
void visitCallInst (CallInst &I);
void visitShiftInst(ShiftInst &I) { visitBinaryOperator(I); }
void visitMallocInst(MallocInst &I);
void visitAllocaInst(AllocaInst &I);
void visitFreeInst (FreeInst &I);
void visitLoadInst (LoadInst &I);
void visitStoreInst (StoreInst &I);
void visitGetElementPtrInst(GetElementPtrInst &I);
void visitVAArgInst (VAArgInst &I);
void visitInstruction(Instruction &I) {
std::cerr << "C Writer does not know about " << I;
abort();
}
void outputLValue(Instruction *I) {
Out << " " << Mang->getValueName(I) << " = ";
}
bool isGotoCodeNecessary(BasicBlock *From, BasicBlock *To);
void printPHICopiesForSuccessor(BasicBlock *CurBlock,
BasicBlock *Successor, unsigned Indent);
void printBranchToBlock(BasicBlock *CurBlock, BasicBlock *SuccBlock,
unsigned Indent);
void printIndexingExpression(Value *Ptr, gep_type_iterator I,
gep_type_iterator E);
};
}
/// This method inserts names for any unnamed structure types that are used by
/// the program, and removes names from structure types that are not used by the
/// program.
///
bool CBackendNameAllUsedStructsAndMergeFunctions::runOnModule(Module &M) {
// Get a set of types that are used by the program...
std::set<const Type *> UT = getAnalysis<FindUsedTypes>().getTypes();
// Loop over the module symbol table, removing types from UT that are
// already named, and removing names for types that are not used.
//
SymbolTable &MST = M.getSymbolTable();
for (SymbolTable::type_iterator TI = MST.type_begin(), TE = MST.type_end();
TI != TE; ) {
SymbolTable::type_iterator I = TI++;
// If this is not used, remove it from the symbol table.
std::set<const Type *>::iterator UTI = UT.find(I->second);
if (UTI == UT.end())
MST.remove(I);
else
UT.erase(UTI); // Only keep one name for this type.
}
// UT now contains types that are not named. Loop over it, naming
// structure types.
//
bool Changed = false;
unsigned RenameCounter = 0;
for (std::set<const Type *>::const_iterator I = UT.begin(), E = UT.end();
I != E; ++I)
if (const StructType *ST = dyn_cast<StructType>(*I)) {
while (M.addTypeName("unnamed"+utostr(RenameCounter), ST))
++RenameCounter;
Changed = true;
}
// Loop over all external functions and globals. If we have two with
// identical names, merge them.
// FIXME: This code should disappear when we don't allow values with the same
// names when they have different types!
std::map<std::string, GlobalValue*> ExtSymbols;
for (Module::iterator I = M.begin(), E = M.end(); I != E;) {
Function *GV = I++;
if (GV->isExternal() && GV->hasName()) {
std::pair<std::map<std::string, GlobalValue*>::iterator, bool> X
= ExtSymbols.insert(std::make_pair(GV->getName(), GV));
if (!X.second) {
// Found a conflict, replace this global with the previous one.
GlobalValue *OldGV = X.first->second;
GV->replaceAllUsesWith(ConstantExpr::getCast(OldGV, GV->getType()));
GV->eraseFromParent();
Changed = true;
}
}
}
// Do the same for globals.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E;) {
GlobalVariable *GV = I++;
if (GV->isExternal() && GV->hasName()) {
std::pair<std::map<std::string, GlobalValue*>::iterator, bool> X
= ExtSymbols.insert(std::make_pair(GV->getName(), GV));
if (!X.second) {
// Found a conflict, replace this global with the previous one.
GlobalValue *OldGV = X.first->second;
GV->replaceAllUsesWith(ConstantExpr::getCast(OldGV, GV->getType()));
GV->eraseFromParent();
Changed = true;
}
}
}
return Changed;
}
/// printStructReturnPointerFunctionType - This is like printType for a struct
/// return type, except, instead of printing the type as void (*)(Struct*, ...)
/// print it as "Struct (*)(...)", for struct return functions.
void CWriter::printStructReturnPointerFunctionType(std::ostream &Out,
const PointerType *TheTy) {
const FunctionType *FTy = cast<FunctionType>(TheTy->getElementType());
std::stringstream FunctionInnards;
FunctionInnards << " (*) (";
bool PrintedType = false;
FunctionType::param_iterator I = FTy->param_begin(), E = FTy->param_end();
const Type *RetTy = cast<PointerType>(I->get())->getElementType();
for (++I; I != E; ++I) {
if (PrintedType)
FunctionInnards << ", ";
printType(FunctionInnards, *I, "");
PrintedType = true;
}
if (FTy->isVarArg()) {
if (PrintedType)
FunctionInnards << ", ...";
} else if (!PrintedType) {
FunctionInnards << "void";
}
FunctionInnards << ')';
std::string tstr = FunctionInnards.str();
printType(Out, RetTy, tstr);
}
// Pass the Type* and the variable name and this prints out the variable
// declaration.
//
std::ostream &CWriter::printType(std::ostream &Out, const Type *Ty,
const std::string &NameSoFar,
bool IgnoreName) {
if (Ty->isPrimitiveType())
switch (Ty->getTypeID()) {
case Type::VoidTyID: return Out << "void " << NameSoFar;
case Type::BoolTyID: return Out << "bool " << NameSoFar;
case Type::UByteTyID: return Out << "unsigned char " << NameSoFar;
case Type::SByteTyID: return Out << "signed char " << NameSoFar;
case Type::UShortTyID: return Out << "unsigned short " << NameSoFar;
case Type::ShortTyID: return Out << "short " << NameSoFar;
case Type::UIntTyID: return Out << "unsigned " << NameSoFar;
case Type::IntTyID: return Out << "int " << NameSoFar;
case Type::ULongTyID: return Out << "unsigned long long " << NameSoFar;
case Type::LongTyID: return Out << "signed long long " << NameSoFar;
case Type::FloatTyID: return Out << "float " << NameSoFar;
case Type::DoubleTyID: return Out << "double " << NameSoFar;
default :
std::cerr << "Unknown primitive type: " << *Ty << "\n";
abort();
}
// Check to see if the type is named.
if (!IgnoreName || isa<OpaqueType>(Ty)) {
std::map<const Type *, std::string>::iterator I = TypeNames.find(Ty);
if (I != TypeNames.end()) return Out << I->second << ' ' << NameSoFar;
}
switch (Ty->getTypeID()) {
case Type::FunctionTyID: {
const FunctionType *FTy = cast<FunctionType>(Ty);
std::stringstream FunctionInnards;
FunctionInnards << " (" << NameSoFar << ") (";
for (FunctionType::param_iterator I = FTy->param_begin(),
E = FTy->param_end(); I != E; ++I) {
if (I != FTy->param_begin())
FunctionInnards << ", ";
printType(FunctionInnards, *I, "");
}
if (FTy->isVarArg()) {
if (FTy->getNumParams())
FunctionInnards << ", ...";
} else if (!FTy->getNumParams()) {
FunctionInnards << "void";
}
FunctionInnards << ')';
std::string tstr = FunctionInnards.str();
printType(Out, FTy->getReturnType(), tstr);
return Out;
}
case Type::StructTyID: {
const StructType *STy = cast<StructType>(Ty);
Out << NameSoFar + " {\n";
unsigned Idx = 0;
for (StructType::element_iterator I = STy->element_begin(),
E = STy->element_end(); I != E; ++I) {
Out << " ";
printType(Out, *I, "field" + utostr(Idx++));
Out << ";\n";
}
return Out << '}';
}
case Type::PointerTyID: {
const PointerType *PTy = cast<PointerType>(Ty);
std::string ptrName = "*" + NameSoFar;
if (isa<ArrayType>(PTy->getElementType()) ||
isa<PackedType>(PTy->getElementType()))
ptrName = "(" + ptrName + ")";
return printType(Out, PTy->getElementType(), ptrName);
}
case Type::ArrayTyID: {
const ArrayType *ATy = cast<ArrayType>(Ty);
unsigned NumElements = ATy->getNumElements();
if (NumElements == 0) NumElements = 1;
return printType(Out, ATy->getElementType(),
NameSoFar + "[" + utostr(NumElements) + "]");
}
case Type::PackedTyID: {
const PackedType *PTy = cast<PackedType>(Ty);
unsigned NumElements = PTy->getNumElements();
if (NumElements == 0) NumElements = 1;
return printType(Out, PTy->getElementType(),
NameSoFar + "[" + utostr(NumElements) + "]");
}
case Type::OpaqueTyID: {
static int Count = 0;
std::string TyName = "struct opaque_" + itostr(Count++);
assert(TypeNames.find(Ty) == TypeNames.end());
TypeNames[Ty] = TyName;
return Out << TyName << ' ' << NameSoFar;
}
default:
assert(0 && "Unhandled case in getTypeProps!");
abort();
}
return Out;
}
void CWriter::printConstantArray(ConstantArray *CPA) {
// As a special case, print the array as a string if it is an array of
// ubytes or an array of sbytes with positive values.
//
const Type *ETy = CPA->getType()->getElementType();
bool isString = (ETy == Type::SByteTy || ETy == Type::UByteTy);
// Make sure the last character is a null char, as automatically added by C
if (isString && (CPA->getNumOperands() == 0 ||
!cast<Constant>(*(CPA->op_end()-1))->isNullValue()))
isString = false;
if (isString) {
Out << '\"';
// Keep track of whether the last number was a hexadecimal escape
bool LastWasHex = false;
// Do not include the last character, which we know is null
for (unsigned i = 0, e = CPA->getNumOperands()-1; i != e; ++i) {
unsigned char C = cast<ConstantInt>(CPA->getOperand(i))->getRawValue();
// Print it out literally if it is a printable character. The only thing
// to be careful about is when the last letter output was a hex escape
// code, in which case we have to be careful not to print out hex digits
// explicitly (the C compiler thinks it is a continuation of the previous
// character, sheesh...)
//
if (isprint(C) && (!LastWasHex || !isxdigit(C))) {
LastWasHex = false;
if (C == '"' || C == '\\')
Out << "\\" << C;
else
Out << C;
} else {
LastWasHex = false;
switch (C) {
case '\n': Out << "\\n"; break;
case '\t': Out << "\\t"; break;
case '\r': Out << "\\r"; break;
case '\v': Out << "\\v"; break;
case '\a': Out << "\\a"; break;
case '\"': Out << "\\\""; break;
case '\'': Out << "\\\'"; break;
default:
Out << "\\x";
Out << (char)(( C/16 < 10) ? ( C/16 +'0') : ( C/16 -10+'A'));
Out << (char)(((C&15) < 10) ? ((C&15)+'0') : ((C&15)-10+'A'));
LastWasHex = true;
break;
}
}
}
Out << '\"';
} else {
Out << '{';
if (CPA->getNumOperands()) {
Out << ' ';
printConstant(cast<Constant>(CPA->getOperand(0)));
for (unsigned i = 1, e = CPA->getNumOperands(); i != e; ++i) {
Out << ", ";
printConstant(cast<Constant>(CPA->getOperand(i)));
}
}
Out << " }";
}
}
void CWriter::printConstantPacked(ConstantPacked *CP) {
Out << '{';
if (CP->getNumOperands()) {
Out << ' ';
printConstant(cast<Constant>(CP->getOperand(0)));
for (unsigned i = 1, e = CP->getNumOperands(); i != e; ++i) {
Out << ", ";
printConstant(cast<Constant>(CP->getOperand(i)));
}
}
Out << " }";
}
// isFPCSafeToPrint - Returns true if we may assume that CFP may be written out
// textually as a double (rather than as a reference to a stack-allocated
// variable). We decide this by converting CFP to a string and back into a
// double, and then checking whether the conversion results in a bit-equal
// double to the original value of CFP. This depends on us and the target C
// compiler agreeing on the conversion process (which is pretty likely since we
// only deal in IEEE FP).
//
static bool isFPCSafeToPrint(const ConstantFP *CFP) {
#if HAVE_PRINTF_A
char Buffer[100];
sprintf(Buffer, "%a", CFP->getValue());
if (!strncmp(Buffer, "0x", 2) ||
!strncmp(Buffer, "-0x", 3) ||
!strncmp(Buffer, "+0x", 3))
return atof(Buffer) == CFP->getValue();
return false;
#else
std::string StrVal = ftostr(CFP->getValue());
while (StrVal[0] == ' ')
StrVal.erase(StrVal.begin());
// Check to make sure that the stringized number is not some string like "Inf"
// or NaN. Check that the string matches the "[-+]?[0-9]" regex.
if ((StrVal[0] >= '0' && StrVal[0] <= '9') ||
((StrVal[0] == '-' || StrVal[0] == '+') &&
(StrVal[1] >= '0' && StrVal[1] <= '9')))
// Reparse stringized version!
return atof(StrVal.c_str()) == CFP->getValue();
return false;
#endif
}
// printConstant - The LLVM Constant to C Constant converter.
void CWriter::printConstant(Constant *CPV) {
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
switch (CE->getOpcode()) {
case Instruction::Cast:
Out << "((";
printType(Out, CPV->getType());
Out << ')';
printConstant(CE->getOperand(0));
Out << ')';
return;
case Instruction::GetElementPtr:
Out << "(&(";
printIndexingExpression(CE->getOperand(0), gep_type_begin(CPV),
gep_type_end(CPV));
Out << "))";
return;
case Instruction::Select:
Out << '(';
printConstant(CE->getOperand(0));
Out << '?';
printConstant(CE->getOperand(1));
Out << ':';
printConstant(CE->getOperand(2));
Out << ')';
return;
case Instruction::Add:
case Instruction::Sub:
case Instruction::Mul:
case Instruction::Div:
case Instruction::Rem:
case Instruction::And:
case Instruction::Or:
case Instruction::Xor:
case Instruction::SetEQ:
case Instruction::SetNE:
case Instruction::SetLT:
case Instruction::SetLE:
case Instruction::SetGT:
case Instruction::SetGE:
case Instruction::Shl:
case Instruction::Shr:
Out << '(';
printConstant(CE->getOperand(0));
switch (CE->getOpcode()) {
case Instruction::Add: Out << " + "; break;
case Instruction::Sub: Out << " - "; break;
case Instruction::Mul: Out << " * "; break;
case Instruction::Div: Out << " / "; break;
case Instruction::Rem: Out << " % "; break;
case Instruction::And: Out << " & "; break;
case Instruction::Or: Out << " | "; break;
case Instruction::Xor: Out << " ^ "; break;
case Instruction::SetEQ: Out << " == "; break;
case Instruction::SetNE: Out << " != "; break;
case Instruction::SetLT: Out << " < "; break;
case Instruction::SetLE: Out << " <= "; break;
case Instruction::SetGT: Out << " > "; break;
case Instruction::SetGE: Out << " >= "; break;
case Instruction::Shl: Out << " << "; break;
case Instruction::Shr: Out << " >> "; break;
default: assert(0 && "Illegal opcode here!");
}
printConstant(CE->getOperand(1));
Out << ')';
return;
default:
std::cerr << "CWriter Error: Unhandled constant expression: "
<< *CE << "\n";
abort();
}
} else if (isa<UndefValue>(CPV) && CPV->getType()->isFirstClassType()) {
Out << "((";
printType(Out, CPV->getType());
Out << ")/*UNDEF*/0)";
return;
}
switch (CPV->getType()->getTypeID()) {
case Type::BoolTyID:
Out << (CPV == ConstantBool::False ? '0' : '1'); break;
case Type::SByteTyID:
case Type::ShortTyID:
Out << cast<ConstantSInt>(CPV)->getValue(); break;
case Type::IntTyID:
if ((int)cast<ConstantSInt>(CPV)->getValue() == (int)0x80000000)
Out << "((int)0x80000000U)"; // Handle MININT specially to avoid warning
else
Out << cast<ConstantSInt>(CPV)->getValue();
break;
case Type::LongTyID:
if (cast<ConstantSInt>(CPV)->isMinValue())
Out << "(/*INT64_MIN*/(-9223372036854775807LL)-1)";
else
Out << cast<ConstantSInt>(CPV)->getValue() << "ll"; break;
case Type::UByteTyID:
case Type::UShortTyID:
Out << cast<ConstantUInt>(CPV)->getValue(); break;
case Type::UIntTyID:
Out << cast<ConstantUInt>(CPV)->getValue() << 'u'; break;
case Type::ULongTyID:
Out << cast<ConstantUInt>(CPV)->getValue() << "ull"; break;
case Type::FloatTyID:
case Type::DoubleTyID: {
ConstantFP *FPC = cast<ConstantFP>(CPV);
std::map<const ConstantFP*, unsigned>::iterator I = FPConstantMap.find(FPC);
if (I != FPConstantMap.end()) {
// Because of FP precision problems we must load from a stack allocated
// value that holds the value in hex.
Out << "(*(" << (FPC->getType() == Type::FloatTy ? "float" : "double")
<< "*)&FPConstant" << I->second << ')';
} else {
if (IsNAN(FPC->getValue())) {
// The value is NaN
// The prefix for a quiet NaN is 0x7FF8. For a signalling NaN,
// it's 0x7ff4.
const unsigned long QuietNaN = 0x7ff8UL;
const unsigned long SignalNaN = 0x7ff4UL;
// We need to grab the first part of the FP #
char Buffer[100];
uint64_t ll = DoubleToBits(FPC->getValue());
sprintf(Buffer, "0x%llx", static_cast<long long>(ll));
std::string Num(&Buffer[0], &Buffer[6]);
unsigned long Val = strtoul(Num.c_str(), 0, 16);
if (FPC->getType() == Type::FloatTy)
Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "F(\""
<< Buffer << "\") /*nan*/ ";
else
Out << "LLVM_NAN" << (Val == QuietNaN ? "" : "S") << "(\""
<< Buffer << "\") /*nan*/ ";
} else if (IsInf(FPC->getValue())) {
// The value is Inf
if (FPC->getValue() < 0) Out << '-';
Out << "LLVM_INF" << (FPC->getType() == Type::FloatTy ? "F" : "")
<< " /*inf*/ ";
} else {
std::string Num;
#if HAVE_PRINTF_A
// Print out the constant as a floating point number.
char Buffer[100];
sprintf(Buffer, "%a", FPC->getValue());
Num = Buffer;
#else
Num = ftostr(FPC->getValue());
#endif
Out << Num;
}
}
break;
}
case Type::ArrayTyID:
if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) {
const ArrayType *AT = cast<ArrayType>(CPV->getType());
Out << '{';
if (AT->getNumElements()) {
Out << ' ';
Constant *CZ = Constant::getNullValue(AT->getElementType());
printConstant(CZ);
for (unsigned i = 1, e = AT->getNumElements(); i != e; ++i) {
Out << ", ";
printConstant(CZ);
}
}
Out << " }";
} else {
printConstantArray(cast<ConstantArray>(CPV));
}
break;
case Type::PackedTyID:
if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) {
const PackedType *AT = cast<PackedType>(CPV->getType());
Out << '{';
if (AT->getNumElements()) {
Out << ' ';
Constant *CZ = Constant::getNullValue(AT->getElementType());
printConstant(CZ);
for (unsigned i = 1, e = AT->getNumElements(); i != e; ++i) {
Out << ", ";
printConstant(CZ);
}
}
Out << " }";
} else {
printConstantPacked(cast<ConstantPacked>(CPV));
}
break;
case Type::StructTyID:
if (isa<ConstantAggregateZero>(CPV) || isa<UndefValue>(CPV)) {
const StructType *ST = cast<StructType>(CPV->getType());
Out << '{';
if (ST->getNumElements()) {
Out << ' ';
printConstant(Constant::getNullValue(ST->getElementType(0)));
for (unsigned i = 1, e = ST->getNumElements(); i != e; ++i) {
Out << ", ";
printConstant(Constant::getNullValue(ST->getElementType(i)));
}
}
Out << " }";
} else {
Out << '{';
if (CPV->getNumOperands()) {
Out << ' ';
printConstant(cast<Constant>(CPV->getOperand(0)));
for (unsigned i = 1, e = CPV->getNumOperands(); i != e; ++i) {
Out << ", ";
printConstant(cast<Constant>(CPV->getOperand(i)));
}
}
Out << " }";
}
break;
case Type::PointerTyID:
if (isa<ConstantPointerNull>(CPV)) {
Out << "((";
printType(Out, CPV->getType());
Out << ")/*NULL*/0)";
break;
} else if (GlobalValue *GV = dyn_cast<GlobalValue>(CPV)) {
writeOperand(GV);
break;
}
// FALL THROUGH
default:
std::cerr << "Unknown constant type: " << *CPV << "\n";
abort();
}
}
void CWriter::writeOperandInternal(Value *Operand) {
if (Instruction *I = dyn_cast<Instruction>(Operand))
if (isInlinableInst(*I) && !isDirectAlloca(I)) {
// Should we inline this instruction to build a tree?
Out << '(';
visit(*I);
Out << ')';
return;
}
Constant* CPV = dyn_cast<Constant>(Operand);
if (CPV && !isa<GlobalValue>(CPV)) {
printConstant(CPV);
} else {
Out << Mang->getValueName(Operand);
}
}
void CWriter::writeOperand(Value *Operand) {
if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand))
Out << "(&"; // Global variables are references as their addresses by llvm
writeOperandInternal(Operand);
if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand))
Out << ')';
}
// generateCompilerSpecificCode - This is where we add conditional compilation
// directives to cater to specific compilers as need be.
//
static void generateCompilerSpecificCode(std::ostream& Out) {
// Alloca is hard to get, and we don't want to include stdlib.h here.
Out << "/* get a declaration for alloca */\n"
<< "#if defined(__CYGWIN__) || defined(__MINGW32__)\n"
<< "extern void *_alloca(unsigned long);\n"
<< "#define alloca(x) _alloca(x)\n"
<< "#elif defined(__APPLE__)\n"
<< "extern void *__builtin_alloca(unsigned long);\n"
<< "#define alloca(x) __builtin_alloca(x)\n"
<< "#elif defined(__sun__)\n"
<< "#if defined(__sparcv9)\n"
<< "extern void *__builtin_alloca(unsigned long);\n"
<< "#else\n"
<< "extern void *__builtin_alloca(unsigned int);\n"
<< "#endif\n"
<< "#define alloca(x) __builtin_alloca(x)\n"
<< "#elif defined(__FreeBSD__) || defined(__OpenBSD__)\n"
<< "#define alloca(x) __builtin_alloca(x)\n"
<< "#elif !defined(_MSC_VER)\n"
<< "#include <alloca.h>\n"
<< "#endif\n\n";
// We output GCC specific attributes to preserve 'linkonce'ness on globals.
// If we aren't being compiled with GCC, just drop these attributes.
Out << "#ifndef __GNUC__ /* Can only support \"linkonce\" vars with GCC */\n"
<< "#define __attribute__(X)\n"
<< "#endif\n\n";
#if 0
// At some point, we should support "external weak" vs. "weak" linkages.
// On Mac OS X, "external weak" is spelled "__attribute__((weak_import))".
Out << "#if defined(__GNUC__) && defined(__APPLE_CC__)\n"
<< "#define __EXTERNAL_WEAK__ __attribute__((weak_import))\n"
<< "#elif defined(__GNUC__)\n"
<< "#define __EXTERNAL_WEAK__ __attribute__((weak))\n"
<< "#else\n"
<< "#define __EXTERNAL_WEAK__\n"
<< "#endif\n\n";
#endif
// For now, turn off the weak linkage attribute on Mac OS X. (See above.)
Out << "#if defined(__GNUC__) && defined(__APPLE_CC__)\n"
<< "#define __ATTRIBUTE_WEAK__\n"
<< "#elif defined(__GNUC__)\n"
<< "#define __ATTRIBUTE_WEAK__ __attribute__((weak))\n"
<< "#else\n"
<< "#define __ATTRIBUTE_WEAK__\n"
<< "#endif\n\n";
// Define NaN and Inf as GCC builtins if using GCC, as 0 otherwise
// From the GCC documentation:
//
// double __builtin_nan (const char *str)
//
// This is an implementation of the ISO C99 function nan.
//
// Since ISO C99 defines this function in terms of strtod, which we do
// not implement, a description of the parsing is in order. The string is
// parsed as by strtol; that is, the base is recognized by leading 0 or
// 0x prefixes. The number parsed is placed in the significand such that
// the least significant bit of the number is at the least significant
// bit of the significand. The number is truncated to fit the significand
// field provided. The significand is forced to be a quiet NaN.
//
// This function, if given a string literal, is evaluated early enough
// that it is considered a compile-time constant.
//
// float __builtin_nanf (const char *str)
//
// Similar to __builtin_nan, except the return type is float.
//
// double __builtin_inf (void)
//
// Similar to __builtin_huge_val, except a warning is generated if the
// target floating-point format does not support infinities. This
// function is suitable for implementing the ISO C99 macro INFINITY.
//
// float __builtin_inff (void)
//
// Similar to __builtin_inf, except the return type is float.
Out << "#ifdef __GNUC__\n"
<< "#define LLVM_NAN(NanStr) __builtin_nan(NanStr) /* Double */\n"
<< "#define LLVM_NANF(NanStr) __builtin_nanf(NanStr) /* Float */\n"
<< "#define LLVM_NANS(NanStr) __builtin_nans(NanStr) /* Double */\n"
<< "#define LLVM_NANSF(NanStr) __builtin_nansf(NanStr) /* Float */\n"
<< "#define LLVM_INF __builtin_inf() /* Double */\n"
<< "#define LLVM_INFF __builtin_inff() /* Float */\n"
<< "#define LLVM_PREFETCH(addr,rw,locality) "
"__builtin_prefetch(addr,rw,locality)\n"
<< "#define __ATTRIBUTE_CTOR__ __attribute__((constructor))\n"
<< "#define __ATTRIBUTE_DTOR__ __attribute__((destructor))\n"
<< "#define LLVM_ASM __asm__\n"
<< "#else\n"
<< "#define LLVM_NAN(NanStr) ((double)0.0) /* Double */\n"
<< "#define LLVM_NANF(NanStr) 0.0F /* Float */\n"
<< "#define LLVM_NANS(NanStr) ((double)0.0) /* Double */\n"
<< "#define LLVM_NANSF(NanStr) 0.0F /* Float */\n"
<< "#define LLVM_INF ((double)0.0) /* Double */\n"
<< "#define LLVM_INFF 0.0F /* Float */\n"
<< "#define LLVM_PREFETCH(addr,rw,locality) /* PREFETCH */\n"
<< "#define __ATTRIBUTE_CTOR__\n"
<< "#define __ATTRIBUTE_DTOR__\n"
<< "#define LLVM_ASM(X)\n"
<< "#endif\n\n";
// Output target-specific code that should be inserted into main.
Out << "#define CODE_FOR_MAIN() /* Any target-specific code for main()*/\n";
// On X86, set the FP control word to 64-bits of precision instead of 80 bits.
Out << "#if defined(__GNUC__) && !defined(__llvm__)\n"
<< "#if defined(i386) || defined(__i386__) || defined(__i386) || "
<< "defined(__x86_64__)\n"
<< "#undef CODE_FOR_MAIN\n"
<< "#define CODE_FOR_MAIN() \\\n"
<< " {short F;__asm__ (\"fnstcw %0\" : \"=m\" (*&F)); \\\n"
<< " F=(F&~0x300)|0x200;__asm__(\"fldcw %0\"::\"m\"(*&F));}\n"
<< "#endif\n#endif\n";
}
/// FindStaticTors - Given a static ctor/dtor list, unpack its contents into
/// the StaticTors set.
static void FindStaticTors(GlobalVariable *GV, std::set<Function*> &StaticTors){
ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
if (!InitList) return;
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
if (CS->getOperand(1)->isNullValue())
return; // Found a null terminator, exit printing.
Constant *FP = CS->getOperand(1);
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(FP))
if (CE->getOpcode() == Instruction::Cast)
FP = CE->getOperand(0);
if (Function *F = dyn_cast<Function>(FP))
StaticTors.insert(F);
}
}
enum SpecialGlobalClass {
NotSpecial = 0,
GlobalCtors, GlobalDtors,
NotPrinted
};
/// getGlobalVariableClass - If this is a global that is specially recognized
/// by LLVM, return a code that indicates how we should handle it.
static SpecialGlobalClass getGlobalVariableClass(const GlobalVariable *GV) {
// If this is a global ctors/dtors list, handle it now.
if (GV->hasAppendingLinkage() && GV->use_empty()) {
if (GV->getName() == "llvm.global_ctors")
return GlobalCtors;
else if (GV->getName() == "llvm.global_dtors")
return GlobalDtors;
}
// Otherwise, it it is other metadata, don't print it. This catches things
// like debug information.
if (GV->getSection() == "llvm.metadata")
return NotPrinted;
return NotSpecial;
}
bool CWriter::doInitialization(Module &M) {
// Initialize
TheModule = &M;
IL.AddPrototypes(M);
// Ensure that all structure types have names...
Mang = new Mangler(M);
Mang->markCharUnacceptable('.');
// Keep track of which functions are static ctors/dtors so they can have
// an attribute added to their prototypes.
std::set<Function*> StaticCtors, StaticDtors;
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I) {
switch (getGlobalVariableClass(I)) {
default: break;
case GlobalCtors:
FindStaticTors(I, StaticCtors);
break;
case GlobalDtors:
FindStaticTors(I, StaticDtors);
break;
}
}
// get declaration for alloca
Out << "/* Provide Declarations */\n";
Out << "#include <stdarg.h>\n"; // Varargs support
Out << "#include <setjmp.h>\n"; // Unwind support
generateCompilerSpecificCode(Out);
// Provide a definition for `bool' if not compiling with a C++ compiler.
Out << "\n"
<< "#ifndef __cplusplus\ntypedef unsigned char bool;\n#endif\n"
<< "\n\n/* Support for floating point constants */\n"
<< "typedef unsigned long long ConstantDoubleTy;\n"
<< "typedef unsigned int ConstantFloatTy;\n"
<< "\n\n/* Global Declarations */\n";
// First output all the declarations for the program, because C requires
// Functions & globals to be declared before they are used.
//
// Loop over the symbol table, emitting all named constants...
printModuleTypes(M.getSymbolTable());
// Global variable declarations...
if (!M.global_empty()) {
Out << "\n/* External Global Variable Declarations */\n";
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I) {
if (I->hasExternalLinkage()) {
Out << "extern ";
printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
Out << ";\n";
}
}
}
// Function declarations
Out << "\n/* Function Declarations */\n";
Out << "double fmod(double, double);\n"; // Support for FP rem
Out << "float fmodf(float, float);\n";
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
// Don't print declarations for intrinsic functions.
if (!I->getIntrinsicID() &&
I->getName() != "setjmp" && I->getName() != "longjmp") {
printFunctionSignature(I, true);
if (I->hasWeakLinkage() || I->hasLinkOnceLinkage())
Out << " __ATTRIBUTE_WEAK__";
if (StaticCtors.count(I))
Out << " __ATTRIBUTE_CTOR__";
if (StaticDtors.count(I))
Out << " __ATTRIBUTE_DTOR__";
if (I->hasName() && I->getName()[0] == 1)
Out << " LLVM_ASM(\"" << I->getName().c_str()+1 << "\")";
Out << ";\n";
}
}
// Output the global variable declarations
if (!M.global_empty()) {
Out << "\n\n/* Global Variable Declarations */\n";
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I)
if (!I->isExternal()) {
// Ignore special globals, such as debug info.
if (getGlobalVariableClass(I))
continue;
if (I->hasInternalLinkage())
Out << "static ";
else
Out << "extern ";
printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
if (I->hasLinkOnceLinkage())
Out << " __attribute__((common))";
else if (I->hasWeakLinkage())
Out << " __ATTRIBUTE_WEAK__";
Out << ";\n";
}
}
// Output the global variable definitions and contents...
if (!M.global_empty()) {
Out << "\n\n/* Global Variable Definitions and Initialization */\n";
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I)
if (!I->isExternal()) {
// Ignore special globals, such as debug info.
if (getGlobalVariableClass(I))
continue;
if (I->hasInternalLinkage())
Out << "static ";
printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
if (I->hasLinkOnceLinkage())
Out << " __attribute__((common))";
else if (I->hasWeakLinkage())
Out << " __ATTRIBUTE_WEAK__";
// If the initializer is not null, emit the initializer. If it is null,
// we try to avoid emitting large amounts of zeros. The problem with
// this, however, occurs when the variable has weak linkage. In this
// case, the assembler will complain about the variable being both weak
// and common, so we disable this optimization.
if (!I->getInitializer()->isNullValue()) {
Out << " = " ;
writeOperand(I->getInitializer());
} else if (I->hasWeakLinkage()) {
// We have to specify an initializer, but it doesn't have to be
// complete. If the value is an aggregate, print out { 0 }, and let
// the compiler figure out the rest of the zeros.
Out << " = " ;
if (isa<StructType>(I->getInitializer()->getType()) ||
isa<ArrayType>(I->getInitializer()->getType()) ||
isa<PackedType>(I->getInitializer()->getType())) {
Out << "{ 0 }";
} else {
// Just print it out normally.
writeOperand(I->getInitializer());
}
}
Out << ";\n";
}
}
if (!M.empty())
Out << "\n\n/* Function Bodies */\n";
return false;
}
/// Output all floating point constants that cannot be printed accurately...
void CWriter::printFloatingPointConstants(Function &F) {
// Scan the module for floating point constants. If any FP constant is used
// in the function, we want to redirect it here so that we do not depend on
// the precision of the printed form, unless the printed form preserves
// precision.
//
static unsigned FPCounter = 0;
for (constant_iterator I = constant_begin(&F), E = constant_end(&F);
I != E; ++I)
if (const ConstantFP *FPC = dyn_cast<ConstantFP>(*I))
if (!isFPCSafeToPrint(FPC) && // Do not put in FPConstantMap if safe.
!FPConstantMap.count(FPC)) {
double Val = FPC->getValue();
FPConstantMap[FPC] = FPCounter; // Number the FP constants
if (FPC->getType() == Type::DoubleTy) {
Out << "static const ConstantDoubleTy FPConstant" << FPCounter++
<< " = 0x" << std::hex << DoubleToBits(Val) << std::dec
<< "ULL; /* " << Val << " */\n";
} else if (FPC->getType() == Type::FloatTy) {
Out << "static const ConstantFloatTy FPConstant" << FPCounter++
<< " = 0x" << std::hex << FloatToBits(Val) << std::dec
<< "U; /* " << Val << " */\n";
} else
assert(0 && "Unknown float type!");
}
Out << '\n';
}
/// printSymbolTable - Run through symbol table looking for type names. If a
/// type name is found, emit its declaration...
///
void CWriter::printModuleTypes(const SymbolTable &ST) {
// We are only interested in the type plane of the symbol table.
SymbolTable::type_const_iterator I = ST.type_begin();
SymbolTable::type_const_iterator End = ST.type_end();
// If there are no type names, exit early.
if (I == End) return;
// Print out forward declarations for structure types before anything else!
Out << "/* Structure forward decls */\n";
for (; I != End; ++I)
if (const Type *STy = dyn_cast<StructType>(I->second)) {
std::string Name = "struct l_" + Mang->makeNameProper(I->first);
Out << Name << ";\n";
TypeNames.insert(std::make_pair(STy, Name));
}
Out << '\n';
// Now we can print out typedefs...
Out << "/* Typedefs */\n";
for (I = ST.type_begin(); I != End; ++I) {
const Type *Ty = cast<Type>(I->second);
std::string Name = "l_" + Mang->makeNameProper(I->first);
Out << "typedef ";
printType(Out, Ty, Name);
Out << ";\n";
}
Out << '\n';
// Keep track of which structures have been printed so far...
std::set<const StructType *> StructPrinted;
// Loop over all structures then push them into the stack so they are
// printed in the correct order.
//
Out << "/* Structure contents */\n";
for (I = ST.type_begin(); I != End; ++I)
if (const StructType *STy = dyn_cast<StructType>(I->second))
// Only print out used types!
printContainedStructs(STy, StructPrinted);
}
// Push the struct onto the stack and recursively push all structs
// this one depends on.
//
// TODO: Make this work properly with packed types
//
void CWriter::printContainedStructs(const Type *Ty,
std::set<const StructType*> &StructPrinted){
// Don't walk through pointers.
if (isa<PointerType>(Ty) || Ty->isPrimitiveType()) return;
// Print all contained types first.
for (Type::subtype_iterator I = Ty->subtype_begin(),
E = Ty->subtype_end(); I != E; ++I)
printContainedStructs(*I, StructPrinted);
if (const StructType *STy = dyn_cast<StructType>(Ty)) {
// Check to see if we have already printed this struct.
if (StructPrinted.insert(STy).second) {
// Print structure type out.
std::string Name = TypeNames[STy];
printType(Out, STy, Name, true);
Out << ";\n\n";
}
}
}
void CWriter::printFunctionSignature(const Function *F, bool Prototype) {
/// isCStructReturn - Should this function actually return a struct by-value?
bool isCStructReturn = F->getCallingConv() == CallingConv::CSRet;
if (F->hasInternalLinkage()) Out << "static ";
// Loop over the arguments, printing them...
const FunctionType *FT = cast<FunctionType>(F->getFunctionType());
std::stringstream FunctionInnards;
// Print out the name...
FunctionInnards << Mang->getValueName(F) << '(';
bool PrintedArg = false;
if (!F->isExternal()) {
if (!F->arg_empty()) {
Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
// If this is a struct-return function, don't print the hidden
// struct-return argument.
if (isCStructReturn) {
assert(I != E && "Invalid struct return function!");
++I;
}
std::string ArgName;
for (; I != E; ++I) {
if (PrintedArg) FunctionInnards << ", ";
if (I->hasName() || !Prototype)
ArgName = Mang->getValueName(I);
else
ArgName = "";
printType(FunctionInnards, I->getType(), ArgName);
PrintedArg = true;
}
}
} else {
// Loop over the arguments, printing them.
FunctionType::param_iterator I = FT->param_begin(), E = FT->param_end();
// If this is a struct-return function, don't print the hidden
// struct-return argument.
if (isCStructReturn) {
assert(I != E && "Invalid struct return function!");
++I;
}
for (; I != E; ++I) {
if (PrintedArg) FunctionInnards << ", ";
printType(FunctionInnards, *I);
PrintedArg = true;
}
}
// Finish printing arguments... if this is a vararg function, print the ...,
// unless there are no known types, in which case, we just emit ().
//
if (FT->isVarArg() && PrintedArg) {
if (PrintedArg) FunctionInnards << ", ";
FunctionInnards << "..."; // Output varargs portion of signature!
} else if (!FT->isVarArg() && !PrintedArg) {
FunctionInnards << "void"; // ret() -> ret(void) in C.
}
FunctionInnards << ')';
// Get the return tpe for the function.
const Type *RetTy;
if (!isCStructReturn)
RetTy = F->getReturnType();
else {
// If this is a struct-return function, print the struct-return type.
RetTy = cast<PointerType>(FT->getParamType(0))->getElementType();
}
// Print out the return type and the signature built above.
printType(Out, RetTy, FunctionInnards.str());
}
void CWriter::printFunction(Function &F) {
printFunctionSignature(&F, false);
Out << " {\n";
// If this is a struct return function, handle the result with magic.
if (F.getCallingConv() == CallingConv::CSRet) {
const Type *StructTy =
cast<PointerType>(F.arg_begin()->getType())->getElementType();
Out << " ";
printType(Out, StructTy, "StructReturn");
Out << "; /* Struct return temporary */\n";
Out << " ";
printType(Out, F.arg_begin()->getType(), Mang->getValueName(F.arg_begin()));
Out << " = &StructReturn;\n";
}
bool PrintedVar = false;
// print local variable information for the function
for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ++I)
if (const AllocaInst *AI = isDirectAlloca(&*I)) {
Out << " ";
printType(Out, AI->getAllocatedType(), Mang->getValueName(AI));
Out << "; /* Address-exposed local */\n";
PrintedVar = true;
} else if (I->getType() != Type::VoidTy && !isInlinableInst(*I)) {
Out << " ";
printType(Out, I->getType(), Mang->getValueName(&*I));
Out << ";\n";
if (isa<PHINode>(*I)) { // Print out PHI node temporaries as well...
Out << " ";
printType(Out, I->getType(),
Mang->getValueName(&*I)+"__PHI_TEMPORARY");
Out << ";\n";
}
PrintedVar = true;
}
if (PrintedVar)
Out << '\n';
if (F.hasExternalLinkage() && F.getName() == "main")
Out << " CODE_FOR_MAIN();\n";
// print the basic blocks
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
if (Loop *L = LI->getLoopFor(BB)) {
if (L->getHeader() == BB && L->getParentLoop() == 0)
printLoop(L);
} else {
printBasicBlock(BB);
}
}
Out << "}\n\n";
}
void CWriter::printLoop(Loop *L) {
Out << " do { /* Syntactic loop '" << L->getHeader()->getName()
<< "' to make GCC happy */\n";
for (unsigned i = 0, e = L->getBlocks().size(); i != e; ++i) {
BasicBlock *BB = L->getBlocks()[i];
Loop *BBLoop = LI->getLoopFor(BB);
if (BBLoop == L)
printBasicBlock(BB);
else if (BB == BBLoop->getHeader() && BBLoop->getParentLoop() == L)
printLoop(BBLoop);
}
Out << " } while (1); /* end of syntactic loop '"
<< L->getHeader()->getName() << "' */\n";
}
void CWriter::printBasicBlock(BasicBlock *BB) {
// Don't print the label for the basic block if there are no uses, or if
// the only terminator use is the predecessor basic block's terminator.
// We have to scan the use list because PHI nodes use basic blocks too but
// do not require a label to be generated.
//
bool NeedsLabel = false;
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
if (isGotoCodeNecessary(*PI, BB)) {
NeedsLabel = true;
break;
}
if (NeedsLabel) Out << Mang->getValueName(BB) << ":\n";
// Output all of the instructions in the basic block...
for (BasicBlock::iterator II = BB->begin(), E = --BB->end(); II != E;
++II) {
if (!isInlinableInst(*II) && !isDirectAlloca(II)) {
if (II->getType() != Type::VoidTy)
outputLValue(II);
else
Out << " ";
visit(*II);
Out << ";\n";
}
}
// Don't emit prefix or suffix for the terminator...
visit(*BB->getTerminator());
}
// Specific Instruction type classes... note that all of the casts are
// necessary because we use the instruction classes as opaque types...
//
void CWriter::visitReturnInst(ReturnInst &I) {
// If this is a struct return function, return the temporary struct.
if (I.getParent()->getParent()->getCallingConv() == CallingConv::CSRet) {
Out << " return StructReturn;\n";
return;
}
// Don't output a void return if this is the last basic block in the function
if (I.getNumOperands() == 0 &&
&*--I.getParent()->getParent()->end() == I.getParent() &&
!I.getParent()->size() == 1) {
return;
}
Out << " return";
if (I.getNumOperands()) {
Out << ' ';
writeOperand(I.getOperand(0));
}
Out << ";\n";
}
void CWriter::visitSwitchInst(SwitchInst &SI) {
Out << " switch (";
writeOperand(SI.getOperand(0));
Out << ") {\n default:\n";
printPHICopiesForSuccessor (SI.getParent(), SI.getDefaultDest(), 2);
printBranchToBlock(SI.getParent(), SI.getDefaultDest(), 2);
Out << ";\n";
for (unsigned i = 2, e = SI.getNumOperands(); i != e; i += 2) {
Out << " case ";
writeOperand(SI.getOperand(i));
Out << ":\n";
BasicBlock *Succ = cast<BasicBlock>(SI.getOperand(i+1));
printPHICopiesForSuccessor (SI.getParent(), Succ, 2);
printBranchToBlock(SI.getParent(), Succ, 2);
if (Function::iterator(Succ) == next(Function::iterator(SI.getParent())))
Out << " break;\n";
}
Out << " }\n";
}
void CWriter::visitUnreachableInst(UnreachableInst &I) {
Out << " /*UNREACHABLE*/;\n";
}
bool CWriter::isGotoCodeNecessary(BasicBlock *From, BasicBlock *To) {
/// FIXME: This should be reenabled, but loop reordering safe!!
return true;
if (next(Function::iterator(From)) != Function::iterator(To))
return true; // Not the direct successor, we need a goto.
//isa<SwitchInst>(From->getTerminator())
if (LI->getLoopFor(From) != LI->getLoopFor(To))
return true;
return false;
}
void CWriter::printPHICopiesForSuccessor (BasicBlock *CurBlock,
BasicBlock *Successor,
unsigned Indent) {
for (BasicBlock::iterator I = Successor->begin(); isa<PHINode>(I); ++I) {
PHINode *PN = cast<PHINode>(I);
// Now we have to do the printing.
Value *IV = PN->getIncomingValueForBlock(CurBlock);
if (!isa<UndefValue>(IV)) {
Out << std::string(Indent, ' ');
Out << " " << Mang->getValueName(I) << "__PHI_TEMPORARY = ";
writeOperand(IV);
Out << "; /* for PHI node */\n";
}
}
}
void CWriter::printBranchToBlock(BasicBlock *CurBB, BasicBlock *Succ,
unsigned Indent) {
if (isGotoCodeNecessary(CurBB, Succ)) {
Out << std::string(Indent, ' ') << " goto ";
writeOperand(Succ);
Out << ";\n";
}
}
// Branch instruction printing - Avoid printing out a branch to a basic block
// that immediately succeeds the current one.
//
void CWriter::visitBranchInst(BranchInst &I) {
if (I.isConditional()) {
if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(0))) {
Out << " if (";
writeOperand(I.getCondition());
Out << ") {\n";
printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(0), 2);
printBranchToBlock(I.getParent(), I.getSuccessor(0), 2);
if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(1))) {
Out << " } else {\n";
printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(1), 2);
printBranchToBlock(I.getParent(), I.getSuccessor(1), 2);
}
} else {
// First goto not necessary, assume second one is...
Out << " if (!";
writeOperand(I.getCondition());
Out << ") {\n";
printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(1), 2);
printBranchToBlock(I.getParent(), I.getSuccessor(1), 2);
}
Out << " }\n";
} else {
printPHICopiesForSuccessor (I.getParent(), I.getSuccessor(0), 0);
printBranchToBlock(I.getParent(), I.getSuccessor(0), 0);
}
Out << "\n";
}
// PHI nodes get copied into temporary values at the end of predecessor basic
// blocks. We now need to copy these temporary values into the REAL value for
// the PHI.
void CWriter::visitPHINode(PHINode &I) {
writeOperand(&I);
Out << "__PHI_TEMPORARY";
}
void CWriter::visitBinaryOperator(Instruction &I) {
// binary instructions, shift instructions, setCond instructions.
assert(!isa<PointerType>(I.getType()));
// We must cast the results of binary operations which might be promoted.
bool needsCast = false;
if ((I.getType() == Type::UByteTy) || (I.getType() == Type::SByteTy)
|| (I.getType() == Type::UShortTy) || (I.getType() == Type::ShortTy)
|| (I.getType() == Type::FloatTy)) {
needsCast = true;
Out << "((";
printType(Out, I.getType());
Out << ")(";
}
// If this is a negation operation, print it out as such. For FP, we don't
// want to print "-0.0 - X".
if (BinaryOperator::isNeg(&I)) {
Out << "-(";
writeOperand(BinaryOperator::getNegArgument(cast<BinaryOperator>(&I)));
Out << ")";
} else if (I.getOpcode() == Instruction::Rem &&
I.getType()->isFloatingPoint()) {
// Output a call to fmod/fmodf instead of emitting a%b
if (I.getType() == Type::FloatTy)
Out << "fmodf(";
else
Out << "fmod(";
writeOperand(I.getOperand(0));
Out << ", ";
writeOperand(I.getOperand(1));
Out << ")";
} else {
writeOperand(I.getOperand(0));
switch (I.getOpcode()) {
case Instruction::Add: Out << " + "; break;
case Instruction::Sub: Out << " - "; break;
case Instruction::Mul: Out << '*'; break;
case Instruction::Div: Out << '/'; break;
case Instruction::Rem: Out << '%'; break;
case Instruction::And: Out << " & "; break;
case Instruction::Or: Out << " | "; break;
case Instruction::Xor: Out << " ^ "; break;
case Instruction::SetEQ: Out << " == "; break;
case Instruction::SetNE: Out << " != "; break;
case Instruction::SetLE: Out << " <= "; break;
case Instruction::SetGE: Out << " >= "; break;
case Instruction::SetLT: Out << " < "; break;
case Instruction::SetGT: Out << " > "; break;
case Instruction::Shl : Out << " << "; break;
case Instruction::Shr : Out << " >> "; break;
default: std::cerr << "Invalid operator type!" << I; abort();
}
writeOperand(I.getOperand(1));
}
if (needsCast) {
Out << "))";
}
}
void CWriter::visitCastInst(CastInst &I) {
if (I.getType() == Type::BoolTy) {
Out << '(';
writeOperand(I.getOperand(0));
Out << " != 0)";
return;
}
Out << '(';
printType(Out, I.getType());
Out << ')';
if (isa<PointerType>(I.getType())&&I.getOperand(0)->getType()->isIntegral() ||
isa<PointerType>(I.getOperand(0)->getType())&&I.getType()->isIntegral()) {
// Avoid "cast to pointer from integer of different size" warnings
Out << "(long)";
}
writeOperand(I.getOperand(0));
}
void CWriter::visitSelectInst(SelectInst &I) {
Out << "((";
writeOperand(I.getCondition());
Out << ") ? (";
writeOperand(I.getTrueValue());
Out << ") : (";
writeOperand(I.getFalseValue());
Out << "))";
}
void CWriter::lowerIntrinsics(Function &F) {
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; )
if (CallInst *CI = dyn_cast<CallInst>(I++))
if (Function *F = CI->getCalledFunction())
switch (F->getIntrinsicID()) {
case Intrinsic::not_intrinsic:
case Intrinsic::vastart:
case Intrinsic::vacopy:
case Intrinsic::vaend:
case Intrinsic::returnaddress:
case Intrinsic::frameaddress:
case Intrinsic::setjmp:
case Intrinsic::longjmp:
case Intrinsic::prefetch:
case Intrinsic::dbg_stoppoint:
// We directly implement these intrinsics
break;
default:
// If this is an intrinsic that directly corresponds to a GCC
// builtin, we handle it.
const char *BuiltinName = "";
#define GET_GCC_BUILTIN_NAME
#include "llvm/Intrinsics.gen"
#undef GET_GCC_BUILTIN_NAME
// If we handle it, don't lower it.
if (BuiltinName[0]) break;
// All other intrinsic calls we must lower.
Instruction *Before = 0;
if (CI != &BB->front())
Before = prior(BasicBlock::iterator(CI));
IL.LowerIntrinsicCall(CI);
if (Before) { // Move iterator to instruction after call
I = Before; ++I;
} else {
I = BB->begin();
}
break;
}
}
void CWriter::visitCallInst(CallInst &I) {
bool WroteCallee = false;
// Handle intrinsic function calls first...
if (Function *F = I.getCalledFunction())
if (Intrinsic::ID ID = (Intrinsic::ID)F->getIntrinsicID()) {
switch (ID) {
default: {
// If this is an intrinsic that directly corresponds to a GCC
// builtin, we emit it here.
const char *BuiltinName = "";
#define GET_GCC_BUILTIN_NAME
#include "llvm/Intrinsics.gen"
#undef GET_GCC_BUILTIN_NAME
assert(BuiltinName[0] && "Unknown LLVM intrinsic!");
Out << BuiltinName;
WroteCallee = true;
break;
}
case Intrinsic::vastart:
Out << "0; ";
Out << "va_start(*(va_list*)";
writeOperand(I.getOperand(1));
Out << ", ";
// Output the last argument to the enclosing function...
if (I.getParent()->getParent()->arg_empty()) {
std::cerr << "The C backend does not currently support zero "
<< "argument varargs functions, such as '"
<< I.getParent()->getParent()->getName() << "'!\n";
abort();
}
writeOperand(--I.getParent()->getParent()->arg_end());
Out << ')';
return;
case Intrinsic::vaend:
if (!isa<ConstantPointerNull>(I.getOperand(1))) {
Out << "0; va_end(*(va_list*)";
writeOperand(I.getOperand(1));
Out << ')';
} else {
Out << "va_end(*(va_list*)0)";
}
return;
case Intrinsic::vacopy:
Out << "0; ";
Out << "va_copy(*(va_list*)";
writeOperand(I.getOperand(1));
Out << ", *(va_list*)";
writeOperand(I.getOperand(2));
Out << ')';
return;
case Intrinsic::returnaddress:
Out << "__builtin_return_address(";
writeOperand(I.getOperand(1));
Out << ')';
return;
case Intrinsic::frameaddress:
Out << "__builtin_frame_address(";
writeOperand(I.getOperand(1));
Out << ')';
return;
case Intrinsic::setjmp:
#if defined(HAVE__SETJMP) && defined(HAVE__LONGJMP)
Out << "_"; // Use _setjmp on systems that support it!
#endif
Out << "setjmp(*(jmp_buf*)";
writeOperand(I.getOperand(1));
Out << ')';
return;
case Intrinsic::longjmp:
#if defined(HAVE__SETJMP) && defined(HAVE__LONGJMP)
Out << "_"; // Use _longjmp on systems that support it!
#endif
Out << "longjmp(*(jmp_buf*)";
writeOperand(I.getOperand(1));
Out << ", ";
writeOperand(I.getOperand(2));
Out << ')';
return;
case Intrinsic::prefetch:
Out << "LLVM_PREFETCH((const void *)";
writeOperand(I.getOperand(1));
Out << ", ";
writeOperand(I.getOperand(2));
Out << ", ";
writeOperand(I.getOperand(3));
Out << ")";
return;
case Intrinsic::dbg_stoppoint: {
// If we use writeOperand directly we get a "u" suffix which is rejected
// by gcc.
DbgStopPointInst &SPI = cast<DbgStopPointInst>(I);
Out << "\n#line "
<< SPI.getLine()
<< " \"" << SPI.getDirectory()
<< SPI.getFileName() << "\"\n";
return;
}
}
}
Value *Callee = I.getCalledValue();
// If this is a call to a struct-return function, assign to the first
// parameter instead of passing it to the call.
bool isStructRet = I.getCallingConv() == CallingConv::CSRet;
if (isStructRet) {
Out << "*(";
writeOperand(I.getOperand(1));
Out << ") = ";
}
if (I.isTailCall()) Out << " /*tail*/ ";
const PointerType *PTy = cast<PointerType>(Callee->getType());
const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
if (!WroteCallee) {
// If this is an indirect call to a struct return function, we need to cast
// the pointer.
bool NeedsCast = isStructRet && !isa<Function>(Callee);
// GCC is a real PITA. It does not permit codegening casts of functions to
// function pointers if they are in a call (it generates a trap instruction
// instead!). We work around this by inserting a cast to void* in between
// the function and the function pointer cast. Unfortunately, we can't just
// form the constant expression here, because the folder will immediately
// nuke it.
//
// Note finally, that this is completely unsafe. ANSI C does not guarantee
// that void* and function pointers have the same size. :( To deal with this
// in the common case, we handle casts where the number of arguments passed
// match exactly.
//
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Callee))
if (CE->getOpcode() == Instruction::Cast)
if (Function *RF = dyn_cast<Function>(CE->getOperand(0))) {
NeedsCast = true;
Callee = RF;
}
if (NeedsCast) {
// Ok, just cast the pointer type.
Out << "((";
if (!isStructRet)
printType(Out, I.getCalledValue()->getType());
else
printStructReturnPointerFunctionType(Out,
cast<PointerType>(I.getCalledValue()->getType()));
Out << ")(void*)";
}
writeOperand(Callee);
if (NeedsCast) Out << ')';
}
Out << '(';
unsigned NumDeclaredParams = FTy->getNumParams();
CallSite::arg_iterator AI = I.op_begin()+1, AE = I.op_end();
unsigned ArgNo = 0;
if (isStructRet) { // Skip struct return argument.
++AI;
++ArgNo;
}
bool PrintedArg = false;
for (; AI != AE; ++AI, ++ArgNo) {
if (PrintedArg) Out << ", ";
if (ArgNo < NumDeclaredParams &&
(*AI)->getType() != FTy->getParamType(ArgNo)) {
Out << '(';
printType(Out, FTy->getParamType(ArgNo));
Out << ')';
}
writeOperand(*AI);
PrintedArg = true;
}
Out << ')';
}
void CWriter::visitMallocInst(MallocInst &I) {
assert(0 && "lowerallocations pass didn't work!");
}
void CWriter::visitAllocaInst(AllocaInst &I) {
Out << '(';
printType(Out, I.getType());
Out << ") alloca(sizeof(";
printType(Out, I.getType()->getElementType());
Out << ')';
if (I.isArrayAllocation()) {
Out << " * " ;
writeOperand(I.getOperand(0));
}
Out << ')';
}
void CWriter::visitFreeInst(FreeInst &I) {
assert(0 && "lowerallocations pass didn't work!");
}
void CWriter::printIndexingExpression(Value *Ptr, gep_type_iterator I,
gep_type_iterator E) {
bool HasImplicitAddress = false;
// If accessing a global value with no indexing, avoid *(&GV) syndrome
if (GlobalValue *V = dyn_cast<GlobalValue>(Ptr)) {
HasImplicitAddress = true;
} else if (isDirectAlloca(Ptr)) {
HasImplicitAddress = true;
}
if (I == E) {
if (!HasImplicitAddress)
Out << '*'; // Implicit zero first argument: '*x' is equivalent to 'x[0]'
writeOperandInternal(Ptr);
return;
}
const Constant *CI = dyn_cast<Constant>(I.getOperand());
if (HasImplicitAddress && (!CI || !CI->isNullValue()))
Out << "(&";
writeOperandInternal(Ptr);
if (HasImplicitAddress && (!CI || !CI->isNullValue())) {
Out << ')';
HasImplicitAddress = false; // HIA is only true if we haven't addressed yet
}
assert(!HasImplicitAddress || (CI && CI->isNullValue()) &&
"Can only have implicit address with direct accessing");
if (HasImplicitAddress) {
++I;
} else if (CI && CI->isNullValue()) {
gep_type_iterator TmpI = I; ++TmpI;
// Print out the -> operator if possible...
if (TmpI != E && isa<StructType>(*TmpI)) {
Out << (HasImplicitAddress ? "." : "->");
Out << "field" << cast<ConstantUInt>(TmpI.getOperand())->getValue();
I = ++TmpI;
}
}
for (; I != E; ++I)
if (isa<StructType>(*I)) {
Out << ".field" << cast<ConstantUInt>(I.getOperand())->getValue();
} else {
Out << '[';
writeOperand(I.getOperand());
Out << ']';
}
}
void CWriter::visitLoadInst(LoadInst &I) {
Out << '*';
if (I.isVolatile()) {
Out << "((";
printType(Out, I.getType(), "volatile*");
Out << ")";
}
writeOperand(I.getOperand(0));
if (I.isVolatile())
Out << ')';
}
void CWriter::visitStoreInst(StoreInst &I) {
Out << '*';
if (I.isVolatile()) {
Out << "((";
printType(Out, I.getOperand(0)->getType(), " volatile*");
Out << ")";
}
writeOperand(I.getPointerOperand());
if (I.isVolatile()) Out << ')';
Out << " = ";
writeOperand(I.getOperand(0));
}
void CWriter::visitGetElementPtrInst(GetElementPtrInst &I) {
Out << '&';
printIndexingExpression(I.getPointerOperand(), gep_type_begin(I),
gep_type_end(I));
}
void CWriter::visitVAArgInst(VAArgInst &I) {
Out << "va_arg(*(va_list*)";
writeOperand(I.getOperand(0));
Out << ", ";
printType(Out, I.getType());
Out << ");\n ";
}
//===----------------------------------------------------------------------===//
// External Interface declaration
//===----------------------------------------------------------------------===//
bool CTargetMachine::addPassesToEmitWholeFile(PassManager &PM,
std::ostream &o,
CodeGenFileType FileType,
bool Fast) {
if (FileType != TargetMachine::AssemblyFile) return true;
PM.add(createLowerGCPass());
PM.add(createLowerAllocationsPass(true));
PM.add(createLowerInvokePass());
PM.add(createCFGSimplificationPass()); // clean up after lower invoke.
PM.add(new CBackendNameAllUsedStructsAndMergeFunctions());
PM.add(new CWriter(o));
return false;
}