//===---- CGBuiltin.cpp - Emit LLVM Code for builtins ---------------------===// // // The LLVM Compiler Infrastructure // // This file was developed by Anders Carlsson and is distributed under // the University of Illinois Open Source License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This contains code to emit Builtin calls as LLVM code. // //===----------------------------------------------------------------------===// #include "CodeGenFunction.h" #include "CodeGenModule.h" #include "clang/Basic/TargetInfo.h" #include "clang/AST/ASTContext.h" #include "clang/AST/Builtins.h" #include "clang/AST/Expr.h" #include "llvm/Constants.h" #include "llvm/Function.h" #include "llvm/Intrinsics.h" using namespace clang; using namespace CodeGen; using namespace llvm; RValue CodeGenFunction::EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E) { switch (BuiltinID) { default: { if (getContext().BuiltinInfo.isLibFunction(BuiltinID)) return EmitCallExpr(CGM.getBuiltinLibFunction(BuiltinID), E); // See if we have a target specific intrinsic. llvm::Intrinsic::ID IntrinsicID; const char *TargetPrefix = Target.getTargetPrefix(); const char *BuiltinName = getContext().BuiltinInfo.GetName(BuiltinID); #define GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN #include "llvm/Intrinsics.gen" #undef GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN if (IntrinsicID != Intrinsic::not_intrinsic) { llvm::SmallVector Args; llvm::Function *F = llvm::Intrinsic::getDeclaration(&CGM.getModule(), IntrinsicID); const llvm::FunctionType *FTy = F->getFunctionType(); for (unsigned i = 0, e = E->getNumArgs(); i != e; ++i) { llvm::Value *ArgValue = EmitScalarExpr(E->getArg(i)); // If the intrinsic arg type is different from the builtin arg type // we need to do a bit cast. const llvm::Type *PTy = FTy->getParamType(i); if (PTy != ArgValue->getType()) { assert(PTy->canLosslesslyBitCastTo(FTy->getParamType(i)) && "Must be able to losslessly bit cast to param"); ArgValue = Builder.CreateBitCast(ArgValue, PTy); } Args.push_back(ArgValue); } llvm::Value *V = Builder.CreateCall(F, &Args[0], &Args[0] + Args.size()); QualType BuiltinRetType = E->getType(); const llvm::Type *RetTy = BuiltinRetType->isVoidType() ? llvm::Type::VoidTy : ConvertType(BuiltinRetType); if (RetTy != V->getType()) { assert(V->getType()->canLosslesslyBitCastTo(RetTy) && "Must be able to losslessly bit cast result type"); V = Builder.CreateBitCast(V, RetTy); } return RValue::get(V); } WarnUnsupported(E, "builtin function"); // Unknown builtin, for now just dump it out and return undef. if (hasAggregateLLVMType(E->getType())) return RValue::getAggregate(CreateTempAlloca(ConvertType(E->getType()))); return RValue::get(llvm::UndefValue::get(ConvertType(E->getType()))); } case Builtin::BI__builtin___CFStringMakeConstantString: { const Expr *Arg = E->getArg(0); while (1) { if (const ParenExpr *PE = dyn_cast(Arg)) Arg = PE->getSubExpr(); else if (const ImplicitCastExpr *CE = dyn_cast(Arg)) Arg = CE->getSubExpr(); else break; } const StringLiteral *Literal = cast(Arg); std::string S(Literal->getStrData(), Literal->getByteLength()); return RValue::get(CGM.GetAddrOfConstantCFString(S)); } case Builtin::BI__builtin_va_start: case Builtin::BI__builtin_va_end: { llvm::Value *ArgValue = EmitScalarExpr(E->getArg(0)); const llvm::Type *DestType = llvm::PointerType::get(llvm::Type::Int8Ty); if (ArgValue->getType() != DestType) ArgValue = Builder.CreateBitCast(ArgValue, DestType, ArgValue->getNameStart()); llvm::Intrinsic::ID inst = (BuiltinID == Builtin::BI__builtin_va_start) ? llvm::Intrinsic::vastart : llvm::Intrinsic::vaend; llvm::Value *F = llvm::Intrinsic::getDeclaration(&CGM.getModule(), inst); llvm::Value *V = Builder.CreateCall(F, ArgValue); return RValue::get(V); } case Builtin::BI__builtin_classify_type: { llvm::APSInt Result(32); if (!E->isBuiltinClassifyType(Result)) assert(0 && "Expr not __builtin_classify_type!"); return RValue::get(llvm::ConstantInt::get(Result)); } case Builtin::BI__builtin_constant_p: { llvm::APSInt Result(32); // FIXME: Analyze the parameter and check if it is a constant. Result = 0; return RValue::get(llvm::ConstantInt::get(Result)); } case Builtin::BI__builtin_abs: { llvm::Value *ArgValue = EmitScalarExpr(E->getArg(0)); llvm::BinaryOperator *NegOp = Builder.CreateNeg(ArgValue, (ArgValue->getName() + "neg").c_str()); llvm::Value *CmpResult = Builder.CreateICmpSGE(ArgValue, NegOp->getOperand(0), "abscond"); llvm::Value *Result = Builder.CreateSelect(CmpResult, ArgValue, NegOp, "abs"); return RValue::get(Result); } case Builtin::BI__builtin_expect: { llvm::Value *Condition = EmitScalarExpr(E->getArg(0)); return RValue::get(Condition); } case Builtin::BI__builtin_bswap32: case Builtin::BI__builtin_bswap64: { llvm::Value *ArgValue = EmitScalarExpr(E->getArg(0)); const llvm::Type *ArgType = ArgValue->getType(); llvm::Value *F = llvm::Intrinsic::getDeclaration(&CGM.getModule(), llvm::Intrinsic::bswap, &ArgType, 1); llvm::Value *V = Builder.CreateCall(F, ArgValue, "tmp"); return RValue::get(V); } case Builtin::BI__builtin_inff: { llvm::APFloat f(llvm::APFloat::IEEEsingle, llvm::APFloat::fcInfinity, false); llvm::Value *V = llvm::ConstantFP::get(llvm::Type::FloatTy, f); return RValue::get(V); } case Builtin::BI__builtin_inf: // FIXME: mapping long double onto double. case Builtin::BI__builtin_infl: { llvm::APFloat f(llvm::APFloat::IEEEdouble, llvm::APFloat::fcInfinity, false); llvm::Value *V = llvm::ConstantFP::get(llvm::Type::DoubleTy, f); return RValue::get(V); } } return RValue::get(0); }