// Transforms a call to printf into a call to the NVPTX vprintf syscall (which
// isn't particularly special; it's invoked just like a regular function).
// vprintf takes two args: A format string, and a pointer to a buffer containing
// the varargs.
//
// For example, the call
//
//   printf("format string", arg1, arg2, arg3);
//
// is converted into something resembling
//
//   struct Tmp {
//     Arg1 a1;
//     Arg2 a2;
//     Arg3 a3;
//   };
//   char* buf = alloca(sizeof(Tmp));
//   *(Tmp*)buf = {a1, a2, a3};
//   vprintf("format string", buf);
//
// buf is aligned to the max of {alignof(Arg1), ...}.  Furthermore, each of the
// args is itself aligned to its preferred alignment.
//
// Note that by the time this function runs, E's args have already undergone the
// standard C vararg promotion (short -> int, float -> double, etc.).
RValue
CodeGenFunction::EmitNVPTXDevicePrintfCallExpr(const CallExpr *E,
                                               ReturnValueSlot ReturnValue) {
  assert(getTarget().getTriple().isNVPTX());
  assert(E->getBuiltinCallee() == Builtin::BIprintf);
  assert(E->getNumArgs() >= 1); // printf always has at least one arg.

  const llvm::DataLayout &DL = CGM.getDataLayout();
  llvm::LLVMContext &Ctx = CGM.getLLVMContext();

  CallArgList Args;
  EmitCallArgs(Args,
               E->getDirectCallee()->getType()->getAs<FunctionProtoType>(),
               E->arguments(), E->getDirectCallee(),
               /* ParamsToSkip = */ 0);

  // We don't know how to emit non-scalar varargs.
  if (std::any_of(Args.begin() + 1, Args.end(), [&](const CallArg &A) {
        return !A.getRValue(*this).isScalar();
      })) {
    CGM.ErrorUnsupported(E, "non-scalar arg to printf");
    return RValue::get(llvm::ConstantInt::get(IntTy, 0));
  }

  // Construct and fill the args buffer that we'll pass to vprintf.
  llvm::Value *BufferPtr;
  if (Args.size() <= 1) {
    // If there are no args, pass a null pointer to vprintf.
    BufferPtr = llvm::ConstantPointerNull::get(llvm::Type::getInt8PtrTy(Ctx));
  } else {
    llvm::SmallVector<llvm::Type *, 8> ArgTypes;
    for (unsigned I = 1, NumArgs = Args.size(); I < NumArgs; ++I)
      ArgTypes.push_back(Args[I].getRValue(*this).getScalarVal()->getType());

    // Using llvm::StructType is correct only because printf doesn't accept
    // aggregates.  If we had to handle aggregates here, we'd have to manually
    // compute the offsets within the alloca -- we wouldn't be able to assume
    // that the alignment of the llvm type was the same as the alignment of the
    // clang type.
    llvm::Type *AllocaTy = llvm::StructType::create(ArgTypes, "printf_args");
    llvm::Value *Alloca = CreateTempAlloca(AllocaTy);

    for (unsigned I = 1, NumArgs = Args.size(); I < NumArgs; ++I) {
      llvm::Value *P = Builder.CreateStructGEP(AllocaTy, Alloca, I - 1);
      llvm::Value *Arg = Args[I].getRValue(*this).getScalarVal();
      Builder.CreateAlignedStore(Arg, P, DL.getPrefTypeAlignment(Arg->getType()));
    }
    BufferPtr = Builder.CreatePointerCast(Alloca, llvm::Type::getInt8PtrTy(Ctx));
  }

  // Invoke vprintf and return.
  llvm::Function* VprintfFunc = GetVprintfDeclaration(CGM.getModule());
  return RValue::get(Builder.CreateCall(
      VprintfFunc, {Args[0].getRValue(*this).getScalarVal(), BufferPtr}));
}
Beispiel #2
0
// Transforms a call to printf into a call to the NVPTX vprintf syscall (which
// isn't particularly special; it's invoked just like a regular function).
// vprintf takes two args: A format string, and a pointer to a buffer containing
// the varargs.
//
// For example, the call
//
//   printf("format string", arg1, arg2, arg3);
//
// is converted into something resembling
//
//   struct Tmp {
//     Arg1 a1;
//     Arg2 a2;
//     Arg3 a3;
//   };
//   char* buf = alloca(sizeof(Tmp));
//   *(Tmp*)buf = {a1, a2, a3};
//   vprintf("format string", buf);
//
// buf is aligned to the max of {alignof(Arg1), ...}.  Furthermore, each of the
// args is itself aligned to its preferred alignment.
//
// Note that by the time this function runs, E's args have already undergone the
// standard C vararg promotion (short -> int, float -> double, etc.).
RValue
CodeGenFunction::EmitCUDADevicePrintfCallExpr(const CallExpr *E,
                                              ReturnValueSlot ReturnValue) {
  assert(getLangOpts().CUDA);
  assert(getLangOpts().CUDAIsDevice);
  assert(E->getBuiltinCallee() == Builtin::BIprintf);
  assert(E->getNumArgs() >= 1); // printf always has at least one arg.

  const llvm::DataLayout &DL = CGM.getDataLayout();
  llvm::LLVMContext &Ctx = CGM.getLLVMContext();

  CallArgList Args;
  EmitCallArgs(Args,
               E->getDirectCallee()->getType()->getAs<FunctionProtoType>(),
               E->arguments(), E->getDirectCallee(),
               /* ParamsToSkip = */ 0);

  // Construct and fill the args buffer that we'll pass to vprintf.
  llvm::Value *BufferPtr;
  if (Args.size() <= 1) {
    // If there are no args, pass a null pointer to vprintf.
    BufferPtr = llvm::ConstantPointerNull::get(llvm::Type::getInt8PtrTy(Ctx));
  } else {
    llvm::SmallVector<llvm::Type *, 8> ArgTypes;
    for (unsigned I = 1, NumArgs = Args.size(); I < NumArgs; ++I)
      ArgTypes.push_back(Args[I].RV.getScalarVal()->getType());
    llvm::Type *AllocaTy = llvm::StructType::create(ArgTypes, "printf_args");
    llvm::Value *Alloca = CreateTempAlloca(AllocaTy);

    for (unsigned I = 1, NumArgs = Args.size(); I < NumArgs; ++I) {
      llvm::Value *P = Builder.CreateStructGEP(AllocaTy, Alloca, I - 1);
      llvm::Value *Arg = Args[I].RV.getScalarVal();
      Builder.CreateAlignedStore(Arg, P, DL.getPrefTypeAlignment(Arg->getType()));
    }
    BufferPtr = Builder.CreatePointerCast(Alloca, llvm::Type::getInt8PtrTy(Ctx));
  }

  // Invoke vprintf and return.
  llvm::Function* VprintfFunc = GetVprintfDeclaration(CGM.getModule());
  return RValue::get(
      Builder.CreateCall(VprintfFunc, {Args[0].RV.getScalarVal(), BufferPtr}));
}
Beispiel #3
0
void CodeGenFunction::EmitCallAndReturnForThunk(llvm::Constant *CalleePtr,
                                                const ThunkInfo *Thunk) {
  assert(isa<CXXMethodDecl>(CurGD.getDecl()) &&
         "Please use a new CGF for this thunk");
  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CurGD.getDecl());

  // Adjust the 'this' pointer if necessary
  llvm::Value *AdjustedThisPtr =
    Thunk ? CGM.getCXXABI().performThisAdjustment(
                          *this, LoadCXXThisAddress(), Thunk->This)
          : LoadCXXThis();

  if (CurFnInfo->usesInAlloca()) {
    // We don't handle return adjusting thunks, because they require us to call
    // the copy constructor.  For now, fall through and pretend the return
    // adjustment was empty so we don't crash.
    if (Thunk && !Thunk->Return.isEmpty()) {
      CGM.ErrorUnsupported(
          MD, "non-trivial argument copy for return-adjusting thunk");
    }
    EmitMustTailThunk(MD, AdjustedThisPtr, CalleePtr);
    return;
  }

  // Start building CallArgs.
  CallArgList CallArgs;
  QualType ThisType = MD->getThisType(getContext());
  CallArgs.add(RValue::get(AdjustedThisPtr), ThisType);

  if (isa<CXXDestructorDecl>(MD))
    CGM.getCXXABI().adjustCallArgsForDestructorThunk(*this, CurGD, CallArgs);

#ifndef NDEBUG
  unsigned PrefixArgs = CallArgs.size() - 1;
#endif
  // Add the rest of the arguments.
  for (const ParmVarDecl *PD : MD->parameters())
    EmitDelegateCallArg(CallArgs, PD, SourceLocation());

  const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();

#ifndef NDEBUG
  const CGFunctionInfo &CallFnInfo = CGM.getTypes().arrangeCXXMethodCall(
      CallArgs, FPT, RequiredArgs::forPrototypePlus(FPT, 1, MD), PrefixArgs);
  assert(CallFnInfo.getRegParm() == CurFnInfo->getRegParm() &&
         CallFnInfo.isNoReturn() == CurFnInfo->isNoReturn() &&
         CallFnInfo.getCallingConvention() == CurFnInfo->getCallingConvention());
  assert(isa<CXXDestructorDecl>(MD) || // ignore dtor return types
         similar(CallFnInfo.getReturnInfo(), CallFnInfo.getReturnType(),
                 CurFnInfo->getReturnInfo(), CurFnInfo->getReturnType()));
  assert(CallFnInfo.arg_size() == CurFnInfo->arg_size());
  for (unsigned i = 0, e = CurFnInfo->arg_size(); i != e; ++i)
    assert(similar(CallFnInfo.arg_begin()[i].info,
                   CallFnInfo.arg_begin()[i].type,
                   CurFnInfo->arg_begin()[i].info,
                   CurFnInfo->arg_begin()[i].type));
#endif

  // Determine whether we have a return value slot to use.
  QualType ResultType = CGM.getCXXABI().HasThisReturn(CurGD)
                            ? ThisType
                            : CGM.getCXXABI().hasMostDerivedReturn(CurGD)
                                  ? CGM.getContext().VoidPtrTy
                                  : FPT->getReturnType();
  ReturnValueSlot Slot;
  if (!ResultType->isVoidType() &&
      CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect &&
      !hasScalarEvaluationKind(CurFnInfo->getReturnType()))
    Slot = ReturnValueSlot(ReturnValue, ResultType.isVolatileQualified());

  // Now emit our call.
  llvm::Instruction *CallOrInvoke;
  CGCallee Callee = CGCallee::forDirect(CalleePtr, MD);
  RValue RV = EmitCall(*CurFnInfo, Callee, Slot, CallArgs, &CallOrInvoke);

  // Consider return adjustment if we have ThunkInfo.
  if (Thunk && !Thunk->Return.isEmpty())
    RV = PerformReturnAdjustment(*this, ResultType, RV, *Thunk);
  else if (llvm::CallInst* Call = dyn_cast<llvm::CallInst>(CallOrInvoke))
    Call->setTailCallKind(llvm::CallInst::TCK_Tail);

  // Emit return.
  if (!ResultType->isVoidType() && Slot.isNull())
    CGM.getCXXABI().EmitReturnFromThunk(*this, RV, ResultType);

  // Disable the final ARC autorelease.
  AutoreleaseResult = false;

  FinishThunk();
}
Beispiel #4
0
RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
                                 llvm::Value *Callee,
                                 const CallArgList &CallArgs,
                                 const Decl *TargetDecl) {
  // FIXME: We no longer need the types from CallArgs; lift up and simplify.
  llvm::SmallVector<llvm::Value*, 16> Args;

  // Handle struct-return functions by passing a pointer to the
  // location that we would like to return into.
  QualType RetTy = CallInfo.getReturnType();
  const ABIArgInfo &RetAI = CallInfo.getReturnInfo();


  // If the call returns a temporary with struct return, create a temporary
  // alloca to hold the result.
  if (CGM.ReturnTypeUsesSret(CallInfo))
    Args.push_back(CreateTempAlloca(ConvertTypeForMem(RetTy)));

  assert(CallInfo.arg_size() == CallArgs.size() &&
         "Mismatch between function signature & arguments.");
  CGFunctionInfo::const_arg_iterator info_it = CallInfo.arg_begin();
  for (CallArgList::const_iterator I = CallArgs.begin(), E = CallArgs.end();
       I != E; ++I, ++info_it) {
    const ABIArgInfo &ArgInfo = info_it->info;
    RValue RV = I->first;

    switch (ArgInfo.getKind()) {
    case ABIArgInfo::Indirect:
      if (RV.isScalar() || RV.isComplex()) {
        // Make a temporary alloca to pass the argument.
        Args.push_back(CreateTempAlloca(ConvertTypeForMem(I->second)));
        if (RV.isScalar())
          EmitStoreOfScalar(RV.getScalarVal(), Args.back(), false, I->second);
        else
          StoreComplexToAddr(RV.getComplexVal(), Args.back(), false);
      } else {
        Args.push_back(RV.getAggregateAddr());
      }
      break;

    case ABIArgInfo::Extend:
    case ABIArgInfo::Direct:
      if (RV.isScalar()) {
        Args.push_back(RV.getScalarVal());
      } else if (RV.isComplex()) {
        llvm::Value *Tmp = llvm::UndefValue::get(ConvertType(I->second));
        Tmp = Builder.CreateInsertValue(Tmp, RV.getComplexVal().first, 0);
        Tmp = Builder.CreateInsertValue(Tmp, RV.getComplexVal().second, 1);
        Args.push_back(Tmp);
      } else {
        Args.push_back(Builder.CreateLoad(RV.getAggregateAddr()));
      }
      break;

    case ABIArgInfo::Ignore:
      break;

    case ABIArgInfo::Coerce: {
      // FIXME: Avoid the conversion through memory if possible.
      llvm::Value *SrcPtr;
      if (RV.isScalar()) {
        SrcPtr = CreateTempAlloca(ConvertTypeForMem(I->second), "coerce");
        EmitStoreOfScalar(RV.getScalarVal(), SrcPtr, false, I->second);
      } else if (RV.isComplex()) {
        SrcPtr = CreateTempAlloca(ConvertTypeForMem(I->second), "coerce");
        StoreComplexToAddr(RV.getComplexVal(), SrcPtr, false);
      } else
        SrcPtr = RV.getAggregateAddr();
      Args.push_back(CreateCoercedLoad(SrcPtr, ArgInfo.getCoerceToType(),
                                       *this));
      break;
    }

    case ABIArgInfo::Expand:
      ExpandTypeToArgs(I->second, RV, Args);
      break;
    }
  }

  // If the callee is a bitcast of a function to a varargs pointer to function
  // type, check to see if we can remove the bitcast.  This handles some cases
  // with unprototyped functions.
  if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Callee))
    if (llvm::Function *CalleeF = dyn_cast<llvm::Function>(CE->getOperand(0))) {
      const llvm::PointerType *CurPT=cast<llvm::PointerType>(Callee->getType());
      const llvm::FunctionType *CurFT =
        cast<llvm::FunctionType>(CurPT->getElementType());
      const llvm::FunctionType *ActualFT = CalleeF->getFunctionType();

      if (CE->getOpcode() == llvm::Instruction::BitCast &&
          ActualFT->getReturnType() == CurFT->getReturnType() &&
          ActualFT->getNumParams() == CurFT->getNumParams() &&
          ActualFT->getNumParams() == Args.size()) {
        bool ArgsMatch = true;
        for (unsigned i = 0, e = ActualFT->getNumParams(); i != e; ++i)
          if (ActualFT->getParamType(i) != CurFT->getParamType(i)) {
            ArgsMatch = false;
            break;
          }

        // Strip the cast if we can get away with it.  This is a nice cleanup,
        // but also allows us to inline the function at -O0 if it is marked
        // always_inline.
        if (ArgsMatch)
          Callee = CalleeF;
      }
    }


  llvm::BasicBlock *InvokeDest = getInvokeDest();
  unsigned CallingConv;
  CodeGen::AttributeListType AttributeList;
  CGM.ConstructAttributeList(CallInfo, TargetDecl, AttributeList, CallingConv);
  llvm::AttrListPtr Attrs = llvm::AttrListPtr::get(AttributeList.begin(),
                                                   AttributeList.end());

  llvm::CallSite CS;
  if (!InvokeDest || (Attrs.getFnAttributes() & llvm::Attribute::NoUnwind)) {
    CS = Builder.CreateCall(Callee, Args.data(), Args.data()+Args.size());
  } else {
    llvm::BasicBlock *Cont = createBasicBlock("invoke.cont");
    CS = Builder.CreateInvoke(Callee, Cont, InvokeDest,
                              Args.data(), Args.data()+Args.size());
    EmitBlock(Cont);
  }

  CS.setAttributes(Attrs);
  CS.setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));

  // If the call doesn't return, finish the basic block and clear the
  // insertion point; this allows the rest of IRgen to discard
  // unreachable code.
  if (CS.doesNotReturn()) {
    Builder.CreateUnreachable();
    Builder.ClearInsertionPoint();

    // FIXME: For now, emit a dummy basic block because expr emitters in
    // generally are not ready to handle emitting expressions at unreachable
    // points.
    EnsureInsertPoint();

    // Return a reasonable RValue.
    return GetUndefRValue(RetTy);
  }

  llvm::Instruction *CI = CS.getInstruction();
  if (Builder.isNamePreserving() && !CI->getType()->isVoidTy())
    CI->setName("call");

  switch (RetAI.getKind()) {
  case ABIArgInfo::Indirect:
    if (RetTy->isAnyComplexType())
      return RValue::getComplex(LoadComplexFromAddr(Args[0], false));
    if (CodeGenFunction::hasAggregateLLVMType(RetTy))
      return RValue::getAggregate(Args[0]);
    return RValue::get(EmitLoadOfScalar(Args[0], false, RetTy));

  case ABIArgInfo::Extend:
  case ABIArgInfo::Direct:
    if (RetTy->isAnyComplexType()) {
      llvm::Value *Real = Builder.CreateExtractValue(CI, 0);
      llvm::Value *Imag = Builder.CreateExtractValue(CI, 1);
      return RValue::getComplex(std::make_pair(Real, Imag));
    }
    if (CodeGenFunction::hasAggregateLLVMType(RetTy)) {
      llvm::Value *V = CreateTempAlloca(ConvertTypeForMem(RetTy), "agg.tmp");
      Builder.CreateStore(CI, V);
      return RValue::getAggregate(V);
    }
    return RValue::get(CI);

  case ABIArgInfo::Ignore:
    // If we are ignoring an argument that had a result, make sure to
    // construct the appropriate return value for our caller.
    return GetUndefRValue(RetTy);

  case ABIArgInfo::Coerce: {
    // FIXME: Avoid the conversion through memory if possible.
    llvm::Value *V = CreateTempAlloca(ConvertTypeForMem(RetTy), "coerce");
    CreateCoercedStore(CI, V, *this);
    if (RetTy->isAnyComplexType())
      return RValue::getComplex(LoadComplexFromAddr(V, false));
    if (CodeGenFunction::hasAggregateLLVMType(RetTy))
      return RValue::getAggregate(V);
    return RValue::get(EmitLoadOfScalar(V, false, RetTy));
  }

  case ABIArgInfo::Expand:
    assert(0 && "Invalid ABI kind for return argument");
  }

  assert(0 && "Unhandled ABIArgInfo::Kind");
  return RValue::get(0);
}