1/* 2 * Copyright (c) 2003-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Steve Reinhardt 29 * Nathan Binkert 30 */ 31 32#ifndef __BASE_BITFIELD_HH__ 33#define __BASE_BITFIELD_HH__ 34 35#include <inttypes.h>
|
36//#include "base/misc.hh"
|
36 37/** 38 * Generate a 64-bit mask of 'nbits' 1s, right justified. 39 */ 40inline uint64_t 41mask(int nbits) 42{ 43 return (nbits == 64) ? (uint64_t)-1LL : (1ULL << nbits) - 1; 44} 45 46 47 48/** 49 * Extract the bitfield from position 'first' to 'last' (inclusive) 50 * from 'val' and right justify it. MSB is numbered 63, LSB is 0. 51 */ 52template <class T> 53inline 54T 55bits(T val, int first, int last) 56{ 57 int nbits = first - last + 1; 58 return (val >> last) & mask(nbits); 59} 60 61/** 62 * Mask off the given bits in place like bits() but without shifting. 63 * msb = 63, lsb = 0 64 */ 65template <class T> 66inline 67T 68mbits(T val, int first, int last) 69{ 70 return val & (mask(first+1) & ~mask(last)); 71} 72 73inline uint64_t 74mask(int first, int last) 75{ 76 return mbits((uint64_t)-1LL, first, last); 77} 78 79/** 80 * Sign-extend an N-bit value to 64 bits. 81 */ 82template <int N> 83inline 84int64_t 85sext(uint64_t val) 86{ 87 int sign_bit = bits(val, N-1, N-1); 88 return sign_bit ? (val | ~mask(N)) : val; 89} 90 91/** 92 * Return val with bits first to last set to bit_val 93 */ 94template <class T, class B> 95inline 96T 97insertBits(T val, int first, int last, B bit_val) 98{ 99 T bmask = mask(first - last + 1) << last; 100 return ((bit_val << last) & bmask) | (val & ~bmask); 101} 102 103/** 104 * A convenience function to replace bits first to last of val with bit_val 105 * in place. 106 */ 107template <class T, class B> 108inline 109void 110replaceBits(T& val, int first, int last, B bit_val) 111{ 112 val = insertBits(val, first, last, bit_val); 113} 114 115/** 116 * Returns the bit position of the MSB that is set in the input 117 */ 118inline 119int 120findMsbSet(uint64_t val) { 121 int msb = 0; 122 if (!val) 123 return 0; 124 if (bits(val, 63,32)) { msb += 32; val >>= 32; } 125 if (bits(val, 31,16)) { msb += 16; val >>= 16; } 126 if (bits(val, 15,8)) { msb += 8; val >>= 8; } 127 if (bits(val, 7,4)) { msb += 4; val >>= 4; } 128 if (bits(val, 3,2)) { msb += 2; val >>= 2; } 129 if (bits(val, 1,1)) { msb += 1; } 130 return msb; 131} 132
|
134template<class Data, int first, int last=first>
135class BitfieldBase
|
133namespace BitfieldBackend |
134{
|
137 protected:
138 uint8_t __data[sizeof(Data)];
139
140 //These are defined here so it can be specialized for Data, but can be
141 //hidden by RO and WO variants.
142 inline uint64_t getBits(int _first, int _last)
|
135 template<class Data> 136 class BitfieldBase |
137 {
|
144 //build up the right bits from the byte array "data"
145 //panic("Not yet implemented.\n");
146 return 0;
147 }
|
138 protected: 139 Data __data; |
140
|
149 inline void setBits(int _first, int _last, uint64_t val)
150 {
151 //Set the right bits from the byte array "data"
152 //panic("Not yet implemented.\n");
153 }
154};
|
141 inline uint64_t 142 getBits(int first, int last) 143 { 144 return bits(__data, first, last); 145 } |
146
|
156template<class Data, int first, int last=first>
157class BitfieldNativeBase
158{
159 protected:
160 Data __data;
|
147 inline void 148 setBits(int first, int last, uint64_t val) 149 { 150 replaceBits(__data, first, last, val); 151 } 152 }; |
153
|
162 inline uint64_t getBits(int _first, int _last)
|
154 template<class Type, class Base> 155 class _BitfieldRO : public Base |
156 {
|
164 return bits(__data, first, last);
165 }
|
157 public: 158 operator const Type () 159 { 160 return *((Base *)this); 161 } 162 }; |
163
|
167 inline void setBits(int _first, int _last, uint64_t val)
|
164 template<class Type, class Base> 165 class _BitfieldWO : public Base |
166 {
|
169 replaceBits(__data, first, last, val);
170 }
171};
|
167 public: 168 const Type operator = (const Type & _data) 169 { 170 *((Base *)this) = _data; 171 return _data; 172 } 173 }; |
174
|
173template <int first>
174class BitfieldBase<uint64_t, first, first> :
175 public BitfieldNativeBase<uint64_t, first, first>
176{};
177
178template <int first, int last>
179class BitfieldBase<uint64_t, first, last> :
180 public BitfieldNativeBase<uint64_t, first, last>
181{};
182
183template <int first>
184class BitfieldBase<uint32_t, first, first> :
185 public BitfieldNativeBase<uint32_t, first, first>
186{};
187
188template <int first, int last>
189class BitfieldBase<uint32_t, first, last> :
190 public BitfieldNativeBase<uint32_t, first, last>
191{};
192
193template <int first>
194class BitfieldBase<uint16_t, first, first> :
195 public BitfieldNativeBase<uint16_t, first, first>
196{};
197
198template <int first, int last>
199class BitfieldBase<uint16_t, first, last> :
200 public BitfieldNativeBase<uint16_t, first, last>
201{};
202
203template <int first>
204class BitfieldBase<uint8_t, first, first> :
205 public BitfieldNativeBase<uint8_t, first, first>
206{};
207
208template <int first, int last>
209class BitfieldBase<uint8_t, first, last> :
210 public BitfieldNativeBase<uint8_t, first, last>
211{};
212
213template<class Data, int first, int last=first>
214class _BitfieldRO : public BitfieldBase<Data, first, last>
215{
216 public:
217 operator const Data & ()
|
175 template<class Data, int first, int last=first> 176 class _Bitfield : public BitfieldBase<Data> |
177 {
|
219 return this->getBits(first, last);
220 }
221};
|
178 public: 179 operator const Data () 180 { 181 return this->getBits(first, last); 182 } |
183
|
223template<class Data, int first, int last=first>
224class _BitfieldWO : public BitfieldBase<Data, first, last>
225{
226 public:
227 const Data & operator = (const Data & _data)
228 {
229 this->setBits(first, last, _data);
230 return *this;
231 }
232};
|
184 const Data 185 operator = (const Data & _data) 186 { 187 this->setBits(first, last, _data); 188 return _data; 189 } 190 }; |
191
|
234template<class Data, int first, int last=first>
235class _BitfieldRW : public BitfieldBase<Data, first, last>
236{
237 public:
238 operator const Data ()
|
192 template <class Type, class Base> 193 class BitUnionOperators : public Base |
194 {
|
240 return this->getBits(first, last);
241 }
|
195 public: 196 operator const Type () 197 { 198 return Base::__data; 199 } |
200
|
243 const Data operator = (const Data & _data)
244 {
245 this->setBits(first, last, _data);
246 return *this;
247 }
248};
|
201 const Type 202 operator = (const Type & _data) 203 { 204 Base::__data = _data; 205 } |
206
|
250template <class Type, class Base>
251class BitUnionOperators : public Base
252{
253 public:
254 operator const Type ()
255 {
256 return Base::__data;
257 }
|
207 bool 208 operator < (const Base & base) 209 { 210 return Base::__data < base.__data; 211 } |
212
|
259 const Type operator = (const Type & _data)
260 {
261 Base::__data = _data;
262 }
|
213 bool 214 operator == (const Base & base) 215 { 216 return Base::__data == base.__data; 217 } 218 }; 219} |
220
|
264 bool operator < (const Base & base)
265 {
266 return Base::__data < base.__data;
267 }
268
269 bool operator == (const Base & base)
270 {
271 return Base::__data == base.__data;
272 }
273};
274
|
221#define __BitUnion(type, name) \
|
276 class __##name { \
|
222 namespace BitfieldUnderlyingClasses \ 223 { \ 224 class name; \ 225 } \ 226 class BitfieldUnderlyingClasses::name { \ |
227 public: \ 228 typedef type __DataType; \ 229 union { \ 230 type __data;\ 231 232#define EndBitUnion(name) \ 233 }; \ 234 }; \
|
285 typedef BitUnionOperators<__##name::__DataType, __##name> name;
|
235 typedef BitfieldBackend::BitUnionOperators< \ 236 BitfieldUnderlyingClasses::name::__DataType, \ 237 BitfieldUnderlyingClasses::name> name; |
238 239#define __SubBitUnion(type, name) \ 240 union { \ 241 type __data; \ 242 inline operator const __DataType () \ 243 { return __data; } \ 244 \ 245 inline const __DataType operator = (const __DataType & _data) \ 246 { __data = _data; } 247 248#define EndSubBitUnion(name) } name; 249
|
298//Regular read/write bitfields
299#define BitfieldRW(first, last) _BitfieldRW<__DataType, first, last>
300#define SubBitUnionRW(name, first, last) \
301 __SubBitUnion(BitfieldRW(first, last), name)
302#define Bitfield(first, last) BitfieldRW(first, last)
303#define SubBitUnion(name, first, last) SubBitUnionRW(name, first, last)
|
250//This is so we can send in parameters with commas 251#define wrap(guts) guts |
252 253//Read only bitfields
|
306#define BitfieldRO(first, last) _BitfieldRO<__DataType, first, last>
307#define SubBitUnionRO(name, first, last) \
308 __SubBitUnion(BitfieldRO(first, last), name)
|
254#define __BitfieldRO(base) \ 255 BitfieldBackend::_BitfieldRO<__DataType, base> 256#define __SubBitUnionRO(name, base) \ 257 __SubBitUnion(wrap(_BitfieldRO<__DataType, base>), name) |
258 259//Write only bitfields
|
311#define BitfieldWO(first, last) _BitfieldWO<__DataType, first, last>
|
260#define __BitfieldWO(base) \ 261 BitfieldBackend::_BitfieldWO<__DataType, base> 262#define __SubBitUnionWO(name, base) \ 263 __SubBitUnion(wrap(_BitfieldWO<__DataType, base>), name) 264 265//Regular bitfields 266#define Bitfield(first, last) \ 267 BitfieldBackend::_Bitfield<__DataType, first, last> 268#define SubBitUnion(name, first, last) \ 269 __SubBitUnion(Bitfield(first, last), name) 270#define BitfieldRO(first, last) __BitfieldRO(Bitfield(first, last)) 271#define SubBitUnionRO(name, first, last) \ 272 __SubBitUnionRO(Bitfield(first, last), name) 273#define BitfieldWO(first, last) __BitfieldWO(Bitfield(first, last)) |
274#define SubBitUnionWO(name, first, last) \
|
313 __SubBitUnion(BitfieldWO(first, last), name)
|
275 __SubBitUnionWO(Bitfield(first, last), name) |
276 277#define BitUnion(type, name) __BitUnion(type, name) 278 279#define BitUnion64(name) __BitUnion(uint64_t, name) 280#define BitUnion32(name) __BitUnion(uint32_t, name) 281#define BitUnion16(name) __BitUnion(uint16_t, name) 282#define BitUnion8(name) __BitUnion(uint8_t, name) 283 284#endif // __BASE_BITFIELD_HH__
|