1 //===- ABIInfoImpl.h --------------------------------------------*- C++ -*-===// 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 #ifndef LLVM_CLANG_LIB_CODEGEN_ABIINFOIMPL_H 10 #define LLVM_CLANG_LIB_CODEGEN_ABIINFOIMPL_H 11 12 #include "ABIInfo.h" 13 #include "CGCXXABI.h" 14 15 namespace clang::CodeGen { 16 17 /// DefaultABIInfo - The default implementation for ABI specific 18 /// details. This implementation provides information which results in 19 /// self-consistent and sensible LLVM IR generation, but does not 20 /// conform to any particular ABI. 21 class DefaultABIInfo : public ABIInfo { 22 public: 23 DefaultABIInfo(CodeGen::CodeGenTypes &CGT) : ABIInfo(CGT) {} 24 25 virtual ~DefaultABIInfo(); 26 27 ABIArgInfo classifyReturnType(QualType RetTy) const; 28 ABIArgInfo classifyArgumentType(QualType RetTy) const; 29 30 void computeInfo(CGFunctionInfo &FI) const override; 31 32 Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr, 33 QualType Ty) const override; 34 }; 35 36 // Helper for coercing an aggregate argument or return value into an integer 37 // array of the same size (including padding) and alignment. This alternate 38 // coercion happens only for the RenderScript ABI and can be removed after 39 // runtimes that rely on it are no longer supported. 40 // 41 // RenderScript assumes that the size of the argument / return value in the IR 42 // is the same as the size of the corresponding qualified type. This helper 43 // coerces the aggregate type into an array of the same size (including 44 // padding). This coercion is used in lieu of expansion of struct members or 45 // other canonical coercions that return a coerced-type of larger size. 46 // 47 // Ty - The argument / return value type 48 // Context - The associated ASTContext 49 // LLVMContext - The associated LLVMContext 50 ABIArgInfo coerceToIntArray(QualType Ty, ASTContext &Context, 51 llvm::LLVMContext &LLVMContext); 52 53 void AssignToArrayRange(CodeGen::CGBuilderTy &Builder, llvm::Value *Array, 54 llvm::Value *Value, unsigned FirstIndex, 55 unsigned LastIndex); 56 57 bool isAggregateTypeForABI(QualType T); 58 59 llvm::Type *getVAListElementType(CodeGenFunction &CGF); 60 61 CGCXXABI::RecordArgABI getRecordArgABI(const RecordType *RT, CGCXXABI &CXXABI); 62 63 CGCXXABI::RecordArgABI getRecordArgABI(QualType T, CGCXXABI &CXXABI); 64 65 bool classifyReturnType(const CGCXXABI &CXXABI, CGFunctionInfo &FI, 66 const ABIInfo &Info); 67 68 /// Pass transparent unions as if they were the type of the first element. Sema 69 /// should ensure that all elements of the union have the same "machine type". 70 QualType useFirstFieldIfTransparentUnion(QualType Ty); 71 72 // Dynamically round a pointer up to a multiple of the given alignment. 73 llvm::Value *emitRoundPointerUpToAlignment(CodeGenFunction &CGF, 74 llvm::Value *Ptr, CharUnits Align); 75 76 /// Emit va_arg for a platform using the common void* representation, 77 /// where arguments are simply emitted in an array of slots on the stack. 78 /// 79 /// This version implements the core direct-value passing rules. 80 /// 81 /// \param SlotSize - The size and alignment of a stack slot. 82 /// Each argument will be allocated to a multiple of this number of 83 /// slots, and all the slots will be aligned to this value. 84 /// \param AllowHigherAlign - The slot alignment is not a cap; 85 /// an argument type with an alignment greater than the slot size 86 /// will be emitted on a higher-alignment address, potentially 87 /// leaving one or more empty slots behind as padding. If this 88 /// is false, the returned address might be less-aligned than 89 /// DirectAlign. 90 /// \param ForceRightAdjust - Default is false. On big-endian platform and 91 /// if the argument is smaller than a slot, set this flag will force 92 /// right-adjust the argument in its slot irrespective of the type. 93 Address emitVoidPtrDirectVAArg(CodeGenFunction &CGF, Address VAListAddr, 94 llvm::Type *DirectTy, CharUnits DirectSize, 95 CharUnits DirectAlign, CharUnits SlotSize, 96 bool AllowHigherAlign, 97 bool ForceRightAdjust = false); 98 99 /// Emit va_arg for a platform using the common void* representation, 100 /// where arguments are simply emitted in an array of slots on the stack. 101 /// 102 /// \param IsIndirect - Values of this type are passed indirectly. 103 /// \param ValueInfo - The size and alignment of this type, generally 104 /// computed with getContext().getTypeInfoInChars(ValueTy). 105 /// \param SlotSizeAndAlign - The size and alignment of a stack slot. 106 /// Each argument will be allocated to a multiple of this number of 107 /// slots, and all the slots will be aligned to this value. 108 /// \param AllowHigherAlign - The slot alignment is not a cap; 109 /// an argument type with an alignment greater than the slot size 110 /// will be emitted on a higher-alignment address, potentially 111 /// leaving one or more empty slots behind as padding. 112 /// \param ForceRightAdjust - Default is false. On big-endian platform and 113 /// if the argument is smaller than a slot, set this flag will force 114 /// right-adjust the argument in its slot irrespective of the type. 115 Address emitVoidPtrVAArg(CodeGenFunction &CGF, Address VAListAddr, 116 QualType ValueTy, bool IsIndirect, 117 TypeInfoChars ValueInfo, CharUnits SlotSizeAndAlign, 118 bool AllowHigherAlign, bool ForceRightAdjust = false); 119 120 Address emitMergePHI(CodeGenFunction &CGF, Address Addr1, 121 llvm::BasicBlock *Block1, Address Addr2, 122 llvm::BasicBlock *Block2, const llvm::Twine &Name = ""); 123 124 /// isEmptyField - Return true iff a the field is "empty", that is it 125 /// is an unnamed bit-field or an (array of) empty record(s). If 126 /// AsIfNoUniqueAddr is true, then C++ record fields are considered empty if 127 /// the [[no_unique_address]] attribute would have made them empty. 128 bool isEmptyField(ASTContext &Context, const FieldDecl *FD, bool AllowArrays, 129 bool AsIfNoUniqueAddr = false); 130 131 /// isEmptyRecord - Return true iff a structure contains only empty 132 /// fields. Note that a structure with a flexible array member is not 133 /// considered empty. If AsIfNoUniqueAddr is true, then C++ record fields are 134 /// considered empty if the [[no_unique_address]] attribute would have made 135 /// them empty. 136 bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays, 137 bool AsIfNoUniqueAddr = false); 138 139 /// isSingleElementStruct - Determine if a structure is a "single 140 /// element struct", i.e. it has exactly one non-empty field or 141 /// exactly one field which is itself a single element 142 /// struct. Structures with flexible array members are never 143 /// considered single element structs. 144 /// 145 /// \return The field declaration for the single non-empty field, if 146 /// it exists. 147 const Type *isSingleElementStruct(QualType T, ASTContext &Context); 148 149 Address EmitVAArgInstr(CodeGenFunction &CGF, Address VAListAddr, QualType Ty, 150 const ABIArgInfo &AI); 151 152 bool isSIMDVectorType(ASTContext &Context, QualType Ty); 153 154 bool isRecordWithSIMDVectorType(ASTContext &Context, QualType Ty); 155 156 } // namespace clang::CodeGen 157 158 #endif // LLVM_CLANG_LIB_CODEGEN_ABIINFOIMPL_H 159