| 1 | //===- BPF.cpp ------------------------------------------------------------===// |
|---|---|
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | #include "ABIInfoImpl.h" |
| 10 | #include "TargetInfo.h" |
| 11 | |
| 12 | using namespace clang; |
| 13 | using namespace clang::CodeGen; |
| 14 | |
| 15 | //===----------------------------------------------------------------------===// |
| 16 | // BPF ABI Implementation |
| 17 | //===----------------------------------------------------------------------===// |
| 18 | |
| 19 | namespace { |
| 20 | |
| 21 | class BPFABIInfo : public DefaultABIInfo { |
| 22 | public: |
| 23 | BPFABIInfo(CodeGenTypes &CGT) : DefaultABIInfo(CGT) {} |
| 24 | |
| 25 | ABIArgInfo classifyArgumentType(QualType Ty) const { |
| 26 | Ty = useFirstFieldIfTransparentUnion(Ty); |
| 27 | |
| 28 | if (isAggregateTypeForABI(T: Ty)) { |
| 29 | uint64_t Bits = getContext().getTypeSize(T: Ty); |
| 30 | if (Bits == 0) |
| 31 | return ABIArgInfo::getIgnore(); |
| 32 | |
| 33 | // If the aggregate needs 1 or 2 registers, do not use reference. |
| 34 | if (Bits <= 128) { |
| 35 | llvm::Type *CoerceTy; |
| 36 | if (Bits <= 64) { |
| 37 | CoerceTy = |
| 38 | llvm::IntegerType::get(C&: getVMContext(), NumBits: llvm::alignTo(Value: Bits, Align: 8)); |
| 39 | } else { |
| 40 | llvm::Type *RegTy = llvm::IntegerType::get(C&: getVMContext(), NumBits: 64); |
| 41 | CoerceTy = llvm::ArrayType::get(ElementType: RegTy, NumElements: 2); |
| 42 | } |
| 43 | return ABIArgInfo::getDirect(T: CoerceTy); |
| 44 | } else { |
| 45 | return getNaturalAlignIndirect(Ty); |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | if (const EnumType *EnumTy = Ty->getAs<EnumType>()) |
| 50 | Ty = EnumTy->getDecl()->getIntegerType(); |
| 51 | |
| 52 | ASTContext &Context = getContext(); |
| 53 | if (const auto *EIT = Ty->getAs<BitIntType>()) |
| 54 | if (EIT->getNumBits() > Context.getTypeSize(Context.Int128Ty)) |
| 55 | return getNaturalAlignIndirect(Ty); |
| 56 | |
| 57 | return (isPromotableIntegerTypeForABI(Ty) ? ABIArgInfo::getExtend(Ty) |
| 58 | : ABIArgInfo::getDirect()); |
| 59 | } |
| 60 | |
| 61 | ABIArgInfo classifyReturnType(QualType RetTy) const { |
| 62 | if (RetTy->isVoidType()) |
| 63 | return ABIArgInfo::getIgnore(); |
| 64 | |
| 65 | if (isAggregateTypeForABI(T: RetTy)) |
| 66 | return getNaturalAlignIndirect(Ty: RetTy); |
| 67 | |
| 68 | // Treat an enum type as its underlying type. |
| 69 | if (const EnumType *EnumTy = RetTy->getAs<EnumType>()) |
| 70 | RetTy = EnumTy->getDecl()->getIntegerType(); |
| 71 | |
| 72 | ASTContext &Context = getContext(); |
| 73 | if (const auto *EIT = RetTy->getAs<BitIntType>()) |
| 74 | if (EIT->getNumBits() > Context.getTypeSize(Context.Int128Ty)) |
| 75 | return getNaturalAlignIndirect(Ty: RetTy); |
| 76 | |
| 77 | // Caller will do necessary sign/zero extension. |
| 78 | return ABIArgInfo::getDirect(); |
| 79 | } |
| 80 | |
| 81 | void computeInfo(CGFunctionInfo &FI) const override { |
| 82 | FI.getReturnInfo() = classifyReturnType(RetTy: FI.getReturnType()); |
| 83 | for (auto &I : FI.arguments()) |
| 84 | I.info = classifyArgumentType(Ty: I.type); |
| 85 | } |
| 86 | |
| 87 | }; |
| 88 | |
| 89 | class BPFTargetCodeGenInfo : public TargetCodeGenInfo { |
| 90 | public: |
| 91 | BPFTargetCodeGenInfo(CodeGenTypes &CGT) |
| 92 | : TargetCodeGenInfo(std::make_unique<BPFABIInfo>(args&: CGT)) {} |
| 93 | }; |
| 94 | |
| 95 | } |
| 96 | |
| 97 | std::unique_ptr<TargetCodeGenInfo> |
| 98 | CodeGen::createBPFTargetCodeGenInfo(CodeGenModule &CGM) { |
| 99 | return std::make_unique<BPFTargetCodeGenInfo>(args&: CGM.getTypes()); |
| 100 | } |
| 101 |