1 /* Sparse Arrays for Objective C dispatch tables 2 Copyright (C) 1993, 1995, 1996, 2004, 2009, 2010 Free Software Foundation, Inc. 3 Contributed by Kresten Krab Thorup. 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3, or (at your option) 10 any later version. 11 12 GCC is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 Under Section 7 of GPL version 3, you are granted additional 18 permissions described in the GCC Runtime Library Exception, version 19 3.1, as published by the Free Software Foundation. 20 21 You should have received a copy of the GNU General Public License and 22 a copy of the GCC Runtime Library Exception along with this program; 23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 <http://www.gnu.org/licenses/>. */ 25 26 #ifndef __sarray_INCLUDE_GNU 27 #define __sarray_INCLUDE_GNU 28 29 #define OBJC_SPARSE2 /* 2-level sparse array. */ 30 /* #define OBJC_SPARSE3 */ /* 3-level sparse array. */ 31 32 #ifdef OBJC_SPARSE2 33 extern const char* __objc_sparse2_id; 34 #endif 35 36 #ifdef OBJC_SPARSE3 37 extern const char* __objc_sparse3_id; 38 #endif 39 40 #include <stddef.h> 41 42 extern int nbuckets; /* for stats */ 43 extern int nindices; 44 extern int narrays; 45 extern int idxsize; 46 47 /* An unsigned integer of same size as a pointer. */ 48 #define SIZET_BITS (sizeof (size_t) * 8) 49 50 #if defined (__sparc__) || defined (OBJC_SPARSE2) 51 #define PRECOMPUTE_SELECTORS 52 #endif 53 54 #ifdef OBJC_SPARSE3 55 56 /* Buckets are 8 words each. */ 57 #define BUCKET_BITS 3 58 #define BUCKET_SIZE (1 << BUCKET_BITS) 59 #define BUCKET_MASK (BUCKET_SIZE - 1) 60 61 /* Indices are 16 words each. */ 62 #define INDEX_BITS 4 63 #define INDEX_SIZE (1 << INDEX_BITS) 64 #define INDEX_MASK (INDEX_SIZE - 1) 65 66 #define INDEX_CAPACITY (BUCKET_SIZE * INDEX_SIZE) 67 68 #else /* OBJC_SPARSE2 */ 69 70 /* Buckets are 32 words each. */ 71 #define BUCKET_BITS 5 72 #define BUCKET_SIZE (1 << BUCKET_BITS) 73 #define BUCKET_MASK (BUCKET_SIZE - 1) 74 75 #endif /* OBJC_SPARSE2 */ 76 77 typedef size_t sidx; 78 79 #ifdef PRECOMPUTE_SELECTORS 80 81 struct soffset 82 { 83 #ifdef OBJC_SPARSE3 84 unsigned int unused : SIZET_BITS / 4; 85 unsigned int eoffset : SIZET_BITS / 4; 86 unsigned int boffset : SIZET_BITS / 4; 87 unsigned int ioffset : SIZET_BITS / 4; 88 #else /* OBJC_SPARSE2 */ 89 #ifdef __sparc__ 90 unsigned long boffset : (SIZET_BITS - 2) - BUCKET_BITS; 91 unsigned int eoffset : BUCKET_BITS; 92 unsigned int unused : 2; 93 #else 94 unsigned int boffset : SIZET_BITS / 2; 95 unsigned int eoffset : SIZET_BITS / 2; 96 #endif 97 #endif /* OBJC_SPARSE2 */ 98 }; 99 100 union sofftype 101 { 102 struct soffset off; 103 sidx idx; 104 }; 105 106 #endif /* not PRECOMPUTE_SELECTORS */ 107 108 union sversion 109 { 110 int version; 111 void *next_free; 112 }; 113 114 struct sbucket 115 { 116 /* Elements stored in array. */ 117 void* elems[BUCKET_SIZE]; 118 119 /* Used for copy-on-write. */ 120 union sversion version; 121 }; 122 123 #ifdef OBJC_SPARSE3 124 125 struct sindex 126 { 127 struct sbucket* buckets[INDEX_SIZE]; 128 129 /* Used for copy-on-write. */ 130 union sversion version; 131 }; 132 133 #endif /* OBJC_SPARSE3 */ 134 135 struct sarray 136 { 137 #ifdef OBJC_SPARSE3 138 struct sindex** indices; 139 struct sindex* empty_index; 140 #else /* OBJC_SPARSE2 */ 141 struct sbucket** buckets; 142 #endif /* OBJC_SPARSE2 */ 143 struct sbucket* empty_bucket; 144 145 /* Used for copy-on-write. */ 146 union sversion version; 147 148 short ref_count; 149 struct sarray* is_copy_of; 150 size_t capacity; 151 }; 152 153 struct sarray* sarray_new (int, void* default_element); 154 void sarray_free (struct sarray*); 155 struct sarray* sarray_lazy_copy (struct sarray*); 156 void sarray_realloc (struct sarray*, int new_size); 157 void sarray_at_put (struct sarray*, sidx indx, void* elem); 158 void sarray_at_put_safe (struct sarray*, sidx indx, void* elem); 159 160 struct sarray* sarray_hard_copy (struct sarray*); /* ... like the name ? */ 161 void sarray_remove_garbage (void); 162 163 164 #ifdef PRECOMPUTE_SELECTORS 165 /* Transform soffset values to ints and vice versa. */ 166 static inline unsigned int 167 soffset_decode (sidx indx) 168 { 169 union sofftype x; 170 x.idx = indx; 171 #ifdef OBJC_SPARSE3 172 return x.off.eoffset 173 + (x.off.boffset * BUCKET_SIZE) 174 + (x.off.ioffset * INDEX_CAPACITY); 175 #else /* OBJC_SPARSE2 */ 176 return x.off.eoffset + (x.off.boffset * BUCKET_SIZE); 177 #endif /* OBJC_SPARSE2 */ 178 } 179 180 static inline sidx 181 soffset_encode (size_t offset) 182 { 183 union sofftype x; 184 x.off.eoffset = offset % BUCKET_SIZE; 185 #ifdef OBJC_SPARSE3 186 x.off.boffset = (offset / BUCKET_SIZE) % INDEX_SIZE; 187 x.off.ioffset = offset / INDEX_CAPACITY; 188 #else /* OBJC_SPARSE2 */ 189 x.off.boffset = offset / BUCKET_SIZE; 190 #endif 191 return (sidx)x.idx; 192 } 193 194 #else /* not PRECOMPUTE_SELECTORS */ 195 196 static inline size_t 197 soffset_decode (sidx indx) 198 { 199 return indx; 200 } 201 202 static inline sidx 203 soffset_encode (size_t offset) 204 { 205 return offset; 206 } 207 #endif /* not PRECOMPUTE_SELECTORS */ 208 209 /* Get element from the Sparse array `array' at offset `indx'. */ 210 static inline void* sarray_get (struct sarray* array, sidx indx) 211 { 212 #ifdef PRECOMPUTE_SELECTORS 213 union sofftype x; 214 x.idx = indx; 215 #ifdef OBJC_SPARSE3 216 return array-> 217 indices[x.off.ioffset]-> 218 buckets[x.off.boffset]-> 219 elems[x.off.eoffset]; 220 #else /* OBJC_SPARSE2 */ 221 return array->buckets[x.off.boffset]->elems[x.off.eoffset]; 222 #endif /* OBJC_SPARSE2 */ 223 #else /* not PRECOMPUTE_SELECTORS */ 224 #ifdef OBJC_SPARSE3 225 return array-> 226 indices[indx / INDEX_CAPACITY]-> 227 buckets[(indx / BUCKET_SIZE) % INDEX_SIZE]-> 228 elems[indx % BUCKET_SIZE]; 229 #else /* OBJC_SPARSE2 */ 230 return array->buckets[indx / BUCKET_SIZE]->elems[indx % BUCKET_SIZE]; 231 #endif /* not OBJC_SPARSE3 */ 232 #endif /* not PRECOMPUTE_SELECTORS */ 233 } 234 235 static inline void* sarray_get_safe (struct sarray* array, sidx indx) 236 { 237 if (soffset_decode (indx) < array->capacity) 238 return sarray_get (array, indx); 239 else 240 return (array->empty_bucket->elems[0]); 241 } 242 243 #endif /* __sarray_INCLUDE_GNU */ 244