1 //== llvm/Support/LowLevelTypeImpl.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 /// Implement a low-level type suitable for MachineInstr level instruction 10 /// selection. 11 /// 12 /// For a type attached to a MachineInstr, we only care about 2 details: total 13 /// size and the number of vector lanes (if any). Accordingly, there are 4 14 /// possible valid type-kinds: 15 /// 16 /// * `sN` for scalars and aggregates 17 /// * `<N x sM>` for vectors, which must have at least 2 elements. 18 /// * `pN` for pointers 19 /// 20 /// Other information required for correct selection is expected to be carried 21 /// by the opcode, or non-type flags. For example the distinction between G_ADD 22 /// and G_FADD for int/float or fast-math flags. 23 // 24 //===----------------------------------------------------------------------===// 25 26 #ifndef LLVM_SUPPORT_LOWLEVELTYPEIMPL_H 27 #define LLVM_SUPPORT_LOWLEVELTYPEIMPL_H 28 29 #include "llvm/ADT/DenseMapInfo.h" 30 #include "llvm/Support/MachineValueType.h" 31 #include <cassert> 32 33 namespace llvm { 34 35 class DataLayout; 36 class Type; 37 class raw_ostream; 38 39 class LLT { 40 public: 41 /// Get a low-level scalar or aggregate "bag of bits". scalar(unsigned SizeInBits)42 static LLT scalar(unsigned SizeInBits) { 43 assert(SizeInBits > 0 && "invalid scalar size"); 44 return LLT{/*isPointer=*/false, /*isVector=*/false, /*NumElements=*/0, 45 SizeInBits, /*AddressSpace=*/0}; 46 } 47 48 /// Get a low-level pointer in the given address space. pointer(unsigned AddressSpace,unsigned SizeInBits)49 static LLT pointer(unsigned AddressSpace, unsigned SizeInBits) { 50 assert(SizeInBits > 0 && "invalid pointer size"); 51 return LLT{/*isPointer=*/true, /*isVector=*/false, /*NumElements=*/0, 52 SizeInBits, AddressSpace}; 53 } 54 55 /// Get a low-level vector of some number of elements and element width. 56 /// \p NumElements must be at least 2. vector(uint16_t NumElements,unsigned ScalarSizeInBits)57 static LLT vector(uint16_t NumElements, unsigned ScalarSizeInBits) { 58 assert(NumElements > 1 && "invalid number of vector elements"); 59 assert(ScalarSizeInBits > 0 && "invalid vector element size"); 60 return LLT{/*isPointer=*/false, /*isVector=*/true, NumElements, 61 ScalarSizeInBits, /*AddressSpace=*/0}; 62 } 63 64 /// Get a low-level vector of some number of elements and element type. vector(uint16_t NumElements,LLT ScalarTy)65 static LLT vector(uint16_t NumElements, LLT ScalarTy) { 66 assert(NumElements > 1 && "invalid number of vector elements"); 67 assert(!ScalarTy.isVector() && "invalid vector element type"); 68 return LLT{ScalarTy.isPointer(), /*isVector=*/true, NumElements, 69 ScalarTy.getSizeInBits(), 70 ScalarTy.isPointer() ? ScalarTy.getAddressSpace() : 0}; 71 } 72 scalarOrVector(uint16_t NumElements,LLT ScalarTy)73 static LLT scalarOrVector(uint16_t NumElements, LLT ScalarTy) { 74 return NumElements == 1 ? ScalarTy : LLT::vector(NumElements, ScalarTy); 75 } 76 scalarOrVector(uint16_t NumElements,unsigned ScalarSize)77 static LLT scalarOrVector(uint16_t NumElements, unsigned ScalarSize) { 78 return scalarOrVector(NumElements, LLT::scalar(ScalarSize)); 79 } 80 LLT(bool isPointer,bool isVector,uint16_t NumElements,unsigned SizeInBits,unsigned AddressSpace)81 explicit LLT(bool isPointer, bool isVector, uint16_t NumElements, 82 unsigned SizeInBits, unsigned AddressSpace) { 83 init(isPointer, isVector, NumElements, SizeInBits, AddressSpace); 84 } LLT()85 explicit LLT() : IsPointer(false), IsVector(false), RawData(0) {} 86 87 explicit LLT(MVT VT); 88 isValid()89 bool isValid() const { return RawData != 0; } 90 isScalar()91 bool isScalar() const { return isValid() && !IsPointer && !IsVector; } 92 isPointer()93 bool isPointer() const { return isValid() && IsPointer && !IsVector; } 94 isVector()95 bool isVector() const { return isValid() && IsVector; } 96 97 /// Returns the number of elements in a vector LLT. Must only be called on 98 /// vector types. getNumElements()99 uint16_t getNumElements() const { 100 assert(IsVector && "cannot get number of elements on scalar/aggregate"); 101 if (!IsPointer) 102 return getFieldValue(VectorElementsFieldInfo); 103 else 104 return getFieldValue(PointerVectorElementsFieldInfo); 105 } 106 107 /// Returns the total size of the type. Must only be called on sized types. getSizeInBits()108 unsigned getSizeInBits() const { 109 if (isPointer() || isScalar()) 110 return getScalarSizeInBits(); 111 return getScalarSizeInBits() * getNumElements(); 112 } 113 114 /// Returns the total size of the type in bytes, i.e. number of whole bytes 115 /// needed to represent the size in bits. Must only be called on sized types. getSizeInBytes()116 unsigned getSizeInBytes() const { 117 return (getSizeInBits() + 7) / 8; 118 } 119 getScalarType()120 LLT getScalarType() const { 121 return isVector() ? getElementType() : *this; 122 } 123 124 /// If this type is a vector, return a vector with the same number of elements 125 /// but the new element type. Otherwise, return the new element type. changeElementType(LLT NewEltTy)126 LLT changeElementType(LLT NewEltTy) const { 127 return isVector() ? LLT::vector(getNumElements(), NewEltTy) : NewEltTy; 128 } 129 130 /// If this type is a vector, return a vector with the same number of elements 131 /// but the new element size. Otherwise, return the new element type. Invalid 132 /// for pointer types. For pointer types, use changeElementType. changeElementSize(unsigned NewEltSize)133 LLT changeElementSize(unsigned NewEltSize) const { 134 assert(!getScalarType().isPointer() && 135 "invalid to directly change element size for pointers"); 136 return isVector() ? LLT::vector(getNumElements(), NewEltSize) 137 : LLT::scalar(NewEltSize); 138 } 139 isByteSized()140 bool isByteSized() const { return (getSizeInBits() & 7) == 0; } 141 getScalarSizeInBits()142 unsigned getScalarSizeInBits() const { 143 assert(RawData != 0 && "Invalid Type"); 144 if (!IsVector) { 145 if (!IsPointer) 146 return getFieldValue(ScalarSizeFieldInfo); 147 else 148 return getFieldValue(PointerSizeFieldInfo); 149 } else { 150 if (!IsPointer) 151 return getFieldValue(VectorSizeFieldInfo); 152 else 153 return getFieldValue(PointerVectorSizeFieldInfo); 154 } 155 } 156 getAddressSpace()157 unsigned getAddressSpace() const { 158 assert(RawData != 0 && "Invalid Type"); 159 assert(IsPointer && "cannot get address space of non-pointer type"); 160 if (!IsVector) 161 return getFieldValue(PointerAddressSpaceFieldInfo); 162 else 163 return getFieldValue(PointerVectorAddressSpaceFieldInfo); 164 } 165 166 /// Returns the vector's element type. Only valid for vector types. getElementType()167 LLT getElementType() const { 168 assert(isVector() && "cannot get element type of scalar/aggregate"); 169 if (IsPointer) 170 return pointer(getAddressSpace(), getScalarSizeInBits()); 171 else 172 return scalar(getScalarSizeInBits()); 173 } 174 175 void print(raw_ostream &OS) const; 176 177 bool operator==(const LLT &RHS) const { 178 return IsPointer == RHS.IsPointer && IsVector == RHS.IsVector && 179 RHS.RawData == RawData; 180 } 181 182 bool operator!=(const LLT &RHS) const { return !(*this == RHS); } 183 184 friend struct DenseMapInfo<LLT>; 185 friend class GISelInstProfileBuilder; 186 187 private: 188 /// LLT is packed into 64 bits as follows: 189 /// isPointer : 1 190 /// isVector : 1 191 /// with 62 bits remaining for Kind-specific data, packed in bitfields 192 /// as described below. As there isn't a simple portable way to pack bits 193 /// into bitfields, here the different fields in the packed structure is 194 /// described in static const *Field variables. Each of these variables 195 /// is a 2-element array, with the first element describing the bitfield size 196 /// and the second element describing the bitfield offset. 197 typedef int BitFieldInfo[2]; 198 /// 199 /// This is how the bitfields are packed per Kind: 200 /// * Invalid: 201 /// gets encoded as RawData == 0, as that is an invalid encoding, since for 202 /// valid encodings, SizeInBits/SizeOfElement must be larger than 0. 203 /// * Non-pointer scalar (isPointer == 0 && isVector == 0): 204 /// SizeInBits: 32; 205 static const constexpr BitFieldInfo ScalarSizeFieldInfo{32, 0}; 206 /// * Pointer (isPointer == 1 && isVector == 0): 207 /// SizeInBits: 16; 208 /// AddressSpace: 24; 209 static const constexpr BitFieldInfo PointerSizeFieldInfo{16, 0}; 210 static const constexpr BitFieldInfo PointerAddressSpaceFieldInfo{ 211 24, PointerSizeFieldInfo[0] + PointerSizeFieldInfo[1]}; 212 /// * Vector-of-non-pointer (isPointer == 0 && isVector == 1): 213 /// NumElements: 16; 214 /// SizeOfElement: 32; 215 static const constexpr BitFieldInfo VectorElementsFieldInfo{16, 0}; 216 static const constexpr BitFieldInfo VectorSizeFieldInfo{ 217 32, VectorElementsFieldInfo[0] + VectorElementsFieldInfo[1]}; 218 /// * Vector-of-pointer (isPointer == 1 && isVector == 1): 219 /// NumElements: 16; 220 /// SizeOfElement: 16; 221 /// AddressSpace: 24; 222 static const constexpr BitFieldInfo PointerVectorElementsFieldInfo{16, 0}; 223 static const constexpr BitFieldInfo PointerVectorSizeFieldInfo{ 224 16, 225 PointerVectorElementsFieldInfo[1] + PointerVectorElementsFieldInfo[0]}; 226 static const constexpr BitFieldInfo PointerVectorAddressSpaceFieldInfo{ 227 24, PointerVectorSizeFieldInfo[1] + PointerVectorSizeFieldInfo[0]}; 228 229 uint64_t IsPointer : 1; 230 uint64_t IsVector : 1; 231 uint64_t RawData : 62; 232 233 static uint64_t getMask(const BitFieldInfo FieldInfo) { 234 const int FieldSizeInBits = FieldInfo[0]; 235 return (((uint64_t)1) << FieldSizeInBits) - 1; 236 } 237 static uint64_t maskAndShift(uint64_t Val, uint64_t Mask, uint8_t Shift) { 238 assert(Val <= Mask && "Value too large for field"); 239 return (Val & Mask) << Shift; 240 } 241 static uint64_t maskAndShift(uint64_t Val, const BitFieldInfo FieldInfo) { 242 return maskAndShift(Val, getMask(FieldInfo), FieldInfo[1]); 243 } 244 uint64_t getFieldValue(const BitFieldInfo FieldInfo) const { 245 return getMask(FieldInfo) & (RawData >> FieldInfo[1]); 246 } 247 248 void init(bool IsPointer, bool IsVector, uint16_t NumElements, 249 unsigned SizeInBits, unsigned AddressSpace) { 250 this->IsPointer = IsPointer; 251 this->IsVector = IsVector; 252 if (!IsVector) { 253 if (!IsPointer) 254 RawData = maskAndShift(SizeInBits, ScalarSizeFieldInfo); 255 else 256 RawData = maskAndShift(SizeInBits, PointerSizeFieldInfo) | 257 maskAndShift(AddressSpace, PointerAddressSpaceFieldInfo); 258 } else { 259 assert(NumElements > 1 && "invalid number of vector elements"); 260 if (!IsPointer) 261 RawData = maskAndShift(NumElements, VectorElementsFieldInfo) | 262 maskAndShift(SizeInBits, VectorSizeFieldInfo); 263 else 264 RawData = 265 maskAndShift(NumElements, PointerVectorElementsFieldInfo) | 266 maskAndShift(SizeInBits, PointerVectorSizeFieldInfo) | 267 maskAndShift(AddressSpace, PointerVectorAddressSpaceFieldInfo); 268 } 269 } 270 271 uint64_t getUniqueRAWLLTData() const { 272 return ((uint64_t)RawData) << 2 | ((uint64_t)IsPointer) << 1 | 273 ((uint64_t)IsVector); 274 } 275 }; 276 277 inline raw_ostream& operator<<(raw_ostream &OS, const LLT &Ty) { 278 Ty.print(OS); 279 return OS; 280 } 281 282 template<> struct DenseMapInfo<LLT> { 283 static inline LLT getEmptyKey() { 284 LLT Invalid; 285 Invalid.IsPointer = true; 286 return Invalid; 287 } 288 static inline LLT getTombstoneKey() { 289 LLT Invalid; 290 Invalid.IsVector = true; 291 return Invalid; 292 } 293 static inline unsigned getHashValue(const LLT &Ty) { 294 uint64_t Val = Ty.getUniqueRAWLLTData(); 295 return DenseMapInfo<uint64_t>::getHashValue(Val); 296 } 297 static bool isEqual(const LLT &LHS, const LLT &RHS) { 298 return LHS == RHS; 299 } 300 }; 301 302 } 303 304 #endif // LLVM_SUPPORT_LOWLEVELTYPEIMPL_H 305