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//===- Lanai.cpp ----------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "ABIInfoImpl.h"
#include "TargetInfo.h"
using namespace clang;
using namespace clang::CodeGen;
//===----------------------------------------------------------------------===//
// Lanai ABI Implementation
//===----------------------------------------------------------------------===//
namespace {
class LanaiABIInfo : public DefaultABIInfo {
struct CCState {
unsigned FreeRegs;
};
public:
LanaiABIInfo(CodeGen::CodeGenTypes &CGT) : DefaultABIInfo(CGT) {}
bool shouldUseInReg(QualType Ty, CCState &State) const;
void computeInfo(CGFunctionInfo &FI) const override {
CCState State;
// Lanai uses 4 registers to pass arguments unless the function has the
// regparm attribute set.
if (FI.getHasRegParm()) {
State.FreeRegs = FI.getRegParm();
} else {
State.FreeRegs = 4;
}
if (!getCXXABI().classifyReturnType(FI))
FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
for (auto &I : FI.arguments())
I.info = classifyArgumentType(I.type, State);
}
ABIArgInfo getIndirectResult(QualType Ty, bool ByVal, CCState &State) const;
ABIArgInfo classifyArgumentType(QualType RetTy, CCState &State) const;
};
} // end anonymous namespace
bool LanaiABIInfo::shouldUseInReg(QualType Ty, CCState &State) const {
unsigned Size = getContext().getTypeSize(Ty);
unsigned SizeInRegs = llvm::alignTo(Size, 32U) / 32U;
if (SizeInRegs == 0)
return false;
if (SizeInRegs > State.FreeRegs) {
State.FreeRegs = 0;
return false;
}
State.FreeRegs -= SizeInRegs;
return true;
}
ABIArgInfo LanaiABIInfo::getIndirectResult(QualType Ty, bool ByVal,
CCState &State) const {
if (!ByVal) {
if (State.FreeRegs) {
--State.FreeRegs; // Non-byval indirects just use one pointer.
return getNaturalAlignIndirectInReg(Ty);
}
return getNaturalAlignIndirect(Ty, false);
}
// Compute the byval alignment.
const unsigned MinABIStackAlignInBytes = 4;
unsigned TypeAlign = getContext().getTypeAlign(Ty) / 8;
return ABIArgInfo::getIndirect(CharUnits::fromQuantity(4), /*ByVal=*/true,
/*Realign=*/TypeAlign >
MinABIStackAlignInBytes);
}
ABIArgInfo LanaiABIInfo::classifyArgumentType(QualType Ty,
CCState &State) const {
// Check with the C++ ABI first.
const RecordType *RT = Ty->getAs<RecordType>();
if (RT) {
CGCXXABI::RecordArgABI RAA = getRecordArgABI(RT, getCXXABI());
if (RAA == CGCXXABI::RAA_Indirect) {
return getIndirectResult(Ty, /*ByVal=*/false, State);
} else if (RAA == CGCXXABI::RAA_DirectInMemory) {
return getNaturalAlignIndirect(Ty, /*ByVal=*/true);
}
}
if (isAggregateTypeForABI(Ty)) {
// Structures with flexible arrays are always indirect.
if (RT && RT->getDecl()->hasFlexibleArrayMember())
return getIndirectResult(Ty, /*ByVal=*/true, State);
// Ignore empty structs/unions.
if (isEmptyRecord(getContext(), Ty, true))
return ABIArgInfo::getIgnore();
llvm::LLVMContext &LLVMContext = getVMContext();
unsigned SizeInRegs = (getContext().getTypeSize(Ty) + 31) / 32;
if (SizeInRegs <= State.FreeRegs) {
llvm::IntegerType *Int32 = llvm::Type::getInt32Ty(LLVMContext);
SmallVector<llvm::Type *, 3> Elements(SizeInRegs, Int32);
llvm::Type *Result = llvm::StructType::get(LLVMContext, Elements);
State.FreeRegs -= SizeInRegs;
return ABIArgInfo::getDirectInReg(Result);
} else {
State.FreeRegs = 0;
}
return getIndirectResult(Ty, true, State);
}
// Treat an enum type as its underlying type.
if (const auto *EnumTy = Ty->getAs<EnumType>())
Ty = EnumTy->getDecl()->getIntegerType();
bool InReg = shouldUseInReg(Ty, State);
// Don't pass >64 bit integers in registers.
if (const auto *EIT = Ty->getAs<BitIntType>())
if (EIT->getNumBits() > 64)
return getIndirectResult(Ty, /*ByVal=*/true, State);
if (isPromotableIntegerTypeForABI(Ty)) {
if (InReg)
return ABIArgInfo::getDirectInReg();
return ABIArgInfo::getExtend(Ty);
}
if (InReg)
return ABIArgInfo::getDirectInReg();
return ABIArgInfo::getDirect();
}
namespace {
class LanaiTargetCodeGenInfo : public TargetCodeGenInfo {
public:
LanaiTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
: TargetCodeGenInfo(std::make_unique<LanaiABIInfo>(CGT)) {}
};
}
std::unique_ptr<TargetCodeGenInfo>
CodeGen::createLanaiTargetCodeGenInfo(CodeGenModule &CGM) {
return std::make_unique<LanaiTargetCodeGenInfo>(CGM.getTypes());
}
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