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| 1 : | pazsan | 1.1 | /* This file defines a number of threading schemes. |
| 2 : | anton | 1.2 | |
| 3 : | anton | 1.4 | Copyright (C) 1995, 1996 Free Software Foundation, Inc. |
| 4 : | anton | 1.2 | |
| 5 : | This file is part of Gforth. | ||
| 6 : | |||
| 7 : | Gforth is free software; you can redistribute it and/or | ||
| 8 : | modify it under the terms of the GNU General Public License | ||
| 9 : | as published by the Free Software Foundation; either version 2 | ||
| 10 : | of the License, or (at your option) any later version. | ||
| 11 : | |||
| 12 : | This program 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 : | You should have received a copy of the GNU General Public License | ||
| 18 : | along with this program; if not, write to the Free Software | ||
| 19 : | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | ||
| 20 : | |||
| 21 : | |||
| 22 : | anton | 1.4 | This files defines macros for threading. Many sets of macros are |
| 23 : | defined. Functionally they have only one difference: Some implement | ||
| 24 : | direct threading, some indirect threading. The other differences are | ||
| 25 : | just variations to help GCC generate faster code for various | ||
| 26 : | machines. | ||
| 27 : | |||
| 28 : | (Well, to tell the truth, there actually is another functional | ||
| 29 : | difference in some pathological cases: e.g., a '!' stores into the | ||
| 30 : | cell where the next executed word comes from; or, the next word | ||
| 31 : | executed comes from the top-of-stack. These differences are one of | ||
| 32 : | the reasons why GCC cannot produce the right variation by itself. We | ||
| 33 : | chose disallowing such practices and using the added implementation | ||
| 34 : | freedom to achieve a significant speedup, because these practices | ||
| 35 : | are not common in Forth (I have never heard of or seen anyone using | ||
| 36 : | them), and it is easy to circumvent problems: A control flow change | ||
| 37 : | will flush any prefetched words; you may want to do a "0 | ||
| 38 : | drop" before that to write back the top-of-stack cache.) | ||
| 39 : | |||
| 40 : | These macro sets are used in the following ways: After translation | ||
| 41 : | to C a typical primitive looks like | ||
| 42 : | |||
| 43 : | ... | ||
| 44 : | { | ||
| 45 : | DEF_CA | ||
| 46 : | other declarations | ||
| 47 : | NEXT_P0; | ||
| 48 : | main part of the primitive | ||
| 49 : | NEXT_P1; | ||
| 50 : | store results to stack | ||
| 51 : | NEXT_P2; | ||
| 52 : | } | ||
| 53 : | |||
| 54 : | DEF_CA and all the NEXT_P* together must implement NEXT; In the main | ||
| 55 : | part the instruction pointer can be read with IP, changed with | ||
| 56 : | INC_IP(const_inc), and the cell right behind the presently executing | ||
| 57 : | word (i.e. the value of *IP) is accessed with NEXT_INST. | ||
| 58 : | |||
| 59 : | If a primitive does not fall through the main part, it has to do the | ||
| 60 : | rest by itself. If it changes ip, it has to redo NEXT_P0 (perhaps we | ||
| 61 : | should define a macro SET_IP). | ||
| 62 : | |||
| 63 : | Some primitives (execute, dodefer) do not end with NEXT, but with | ||
| 64 : | EXEC(.). If NEXT_P0 has been called earlier, it has to perform | ||
| 65 : | "ip=IP;" to ensure that ip has the right value (NEXT_P0 may change | ||
| 66 : | it). | ||
| 67 : | |||
| 68 : | Finally, there is NEXT1_P1 and NEXT1_P2, which are parts of EXEC | ||
| 69 : | (EXEC(XT) could be defined as "cfa=XT; NEXT1_P1; NEXT1_P2;" (is this | ||
| 70 : | true?)) and are used for making docol faster. | ||
| 71 : | |||
| 72 : | We can define the ways in which these macros are used with a regular | ||
| 73 : | expression: | ||
| 74 : | |||
| 75 : | For a primitive | ||
| 76 : | |||
| 77 : | DEF_CA NEXT_P0 ( IP | INC_IP | NEXT_INST | ip=...; NEXT_P0 ) * ( NEXT_P1 NEXT_P2 | EXEC(...) ) | ||
| 78 : | |||
| 79 : | For a run-time routine, e.g., docol: | ||
| 80 : | PFA1(cfa) ( NEXT_P0 NEXT | cfa=...; NEXT1_P1; NEXT1_P2 | EXEC(...) ) | ||
| 81 : | |||
| 82 : | This comment does not yet describe all the dependences that the | ||
| 83 : | macros have to satisfy. | ||
| 84 : | |||
| 85 : | anton | 1.2 | To organize the former ifdef chaos, each path is separated |
| 86 : | This gives a quite impressive number of paths, but you clearly | ||
| 87 : | find things that go together. | ||
| 88 : | anton | 1.4 | |
| 89 : | It should be possible to organize the whole thing in a way that | ||
| 90 : | contains less redundancy and allows a simpler description. | ||
| 91 : | |||
| 92 : | anton | 1.2 | */ |
| 93 : | pazsan | 1.1 | |
| 94 : | #ifndef GETCFA | ||
| 95 : | # define CFA_NEXT | ||
| 96 : | #endif | ||
| 97 : | |||
| 98 : | anton | 1.5 | #ifdef DOUBLY_INDIRECT |
| 99 : | # define NEXT_P0 ({cfa=*ip;}) | ||
| 100 : | # define IP (ip) | ||
| 101 : | # define NEXT_INST (cfa) | ||
| 102 : | # define INC_IP(const_inc) ({cfa=IP[const_inc]; ip+=(const_inc);}) | ||
| 103 : | # define DEF_CA Label ca; | ||
| 104 : | # define NEXT_P1 ({ip++; ca=**cfa;}) | ||
| 105 : | # define NEXT_P2 ({goto *ca;}) | ||
| 106 : | # define EXEC(XT) ({DEF_CA cfa=(XT); ca=**cfa; goto *ca;}) | ||
| 107 : | # define NEXT1_P1 ({ca = **cfa;}) | ||
| 108 : | # define NEXT1_P2 ({goto *ca;}) | ||
| 109 : | |||
| 110 : | #else /* !defined(DOUBLY_INDIRECT) */ | ||
| 111 : | |||
| 112 : | pazsan | 1.1 | #if defined(DIRECT_THREADED) && defined(AUTO_INCREMENT)\ |
| 113 : | && defined(LONG_LATENCY) && defined(CFA_NEXT) | ||
| 114 : | #warning scheme 1 | ||
| 115 : | # define NEXT_P0 ({cfa=*ip++;}) | ||
| 116 : | # define IP (ip-1) | ||
| 117 : | # define NEXT_INST (cfa) | ||
| 118 : | # define INC_IP(const_inc) ({cfa=IP[const_inc]; ip+=(const_inc);}) | ||
| 119 : | # define DEF_CA | ||
| 120 : | # define NEXT_P1 | ||
| 121 : | # define NEXT_P2 ({goto *cfa;}) | ||
| 122 : | # define EXEC(XT) ({cfa=(XT); goto *cfa;}) | ||
| 123 : | #endif | ||
| 124 : | |||
| 125 : | #if defined(DIRECT_THREADED) && defined(AUTO_INCREMENT)\ | ||
| 126 : | && defined(LONG_LATENCY) && !defined(CFA_NEXT) | ||
| 127 : | #warning scheme 2 | ||
| 128 : | # define NEXT_P0 (ip++) | ||
| 129 : | # define IP (ip-1) | ||
| 130 : | # define NEXT_INST (*(ip-1)) | ||
| 131 : | # define INC_IP(const_inc) ({ ip+=(const_inc);}) | ||
| 132 : | # define DEF_CA | ||
| 133 : | # define NEXT_P1 | ||
| 134 : | # define NEXT_P2 ({goto **(ip-1);}) | ||
| 135 : | # define EXEC(XT) ({goto *(XT);}) | ||
| 136 : | #endif | ||
| 137 : | |||
| 138 : | |||
| 139 : | #if defined(DIRECT_THREADED) && defined(AUTO_INCREMENT)\ | ||
| 140 : | && !defined(LONG_LATENCY) && defined(CFA_NEXT) | ||
| 141 : | #warning scheme 3 | ||
| 142 : | # define NEXT_P0 | ||
| 143 : | # define IP (ip) | ||
| 144 : | # define NEXT_INST (*ip) | ||
| 145 : | # define INC_IP(const_inc) ({ip+=(const_inc);}) | ||
| 146 : | # define DEF_CA | ||
| 147 : | # define NEXT_P1 ({cfa=*ip++;}) | ||
| 148 : | # define NEXT_P2 ({goto *cfa;}) | ||
| 149 : | # define EXEC(XT) ({cfa=(XT); goto *cfa;}) | ||
| 150 : | #endif | ||
| 151 : | |||
| 152 : | #if defined(DIRECT_THREADED) && defined(AUTO_INCREMENT)\ | ||
| 153 : | && !defined(LONG_LATENCY) && !defined(CFA_NEXT) | ||
| 154 : | #warning scheme 4 | ||
| 155 : | # define NEXT_P0 | ||
| 156 : | # define IP (ip) | ||
| 157 : | # define NEXT_INST (*ip) | ||
| 158 : | # define INC_IP(const_inc) ({ ip+=(const_inc);}) | ||
| 159 : | # define DEF_CA | ||
| 160 : | # define NEXT_P1 | ||
| 161 : | # define NEXT_P2 ({goto **(ip++);}) | ||
| 162 : | # define EXEC(XT) ({goto *(XT);}) | ||
| 163 : | #endif | ||
| 164 : | |||
| 165 : | /* without autoincrement */ | ||
| 166 : | |||
| 167 : | #if defined(DIRECT_THREADED) && !defined(AUTO_INCREMENT)\ | ||
| 168 : | && defined(LONG_LATENCY) && defined(CFA_NEXT) | ||
| 169 : | #warning scheme 5 | ||
| 170 : | # define NEXT_P0 ({cfa=*ip;}) | ||
| 171 : | # define IP (ip) | ||
| 172 : | # define NEXT_INST (cfa) | ||
| 173 : | # define INC_IP(const_inc) ({cfa=IP[const_inc]; ip+=(const_inc);}) | ||
| 174 : | # define DEF_CA | ||
| 175 : | # define NEXT_P1 (ip++) | ||
| 176 : | # define NEXT_P2 ({goto *cfa;}) | ||
| 177 : | # define EXEC(XT) ({cfa=(XT); goto *cfa;}) | ||
| 178 : | #endif | ||
| 179 : | |||
| 180 : | #if defined(DIRECT_THREADED) && !defined(AUTO_INCREMENT)\ | ||
| 181 : | && defined(LONG_LATENCY) && !defined(CFA_NEXT) | ||
| 182 : | #warning scheme 6 | ||
| 183 : | # define NEXT_P0 | ||
| 184 : | # define IP (ip) | ||
| 185 : | # define NEXT_INST (*ip) | ||
| 186 : | anton | 1.2 | # define INC_IP(const_inc) ({ip+=(const_inc);}) |
| 187 : | pazsan | 1.1 | # define DEF_CA |
| 188 : | # define NEXT_P1 (ip++) | ||
| 189 : | # define NEXT_P2 ({goto **(ip-1);}) | ||
| 190 : | # define EXEC(XT) ({goto *(XT);}) | ||
| 191 : | #endif | ||
| 192 : | |||
| 193 : | |||
| 194 : | #if defined(DIRECT_THREADED) && !defined(AUTO_INCREMENT)\ | ||
| 195 : | && !defined(LONG_LATENCY) && defined(CFA_NEXT) | ||
| 196 : | #warning scheme 7 | ||
| 197 : | # define NEXT_P0 | ||
| 198 : | # define IP (ip) | ||
| 199 : | # define NEXT_INST (*ip) | ||
| 200 : | # define INC_IP(const_inc) ({ip+=(const_inc);}) | ||
| 201 : | # define DEF_CA | ||
| 202 : | # define NEXT_P1 ({cfa=*ip++;}) | ||
| 203 : | # define NEXT_P2 ({goto *cfa;}) | ||
| 204 : | # define EXEC(XT) ({cfa=(XT); goto *cfa;}) | ||
| 205 : | #endif | ||
| 206 : | |||
| 207 : | #if defined(DIRECT_THREADED) && !defined(AUTO_INCREMENT)\ | ||
| 208 : | && !defined(LONG_LATENCY) && !defined(CFA_NEXT) | ||
| 209 : | #warning scheme 8 | ||
| 210 : | # define NEXT_P0 | ||
| 211 : | # define IP (ip) | ||
| 212 : | # define NEXT_INST (*IP) | ||
| 213 : | # define INC_IP(const_inc) ({ ip+=(const_inc);}) | ||
| 214 : | # define DEF_CA | ||
| 215 : | # define NEXT_P1 (ip++) | ||
| 216 : | # define NEXT_P2 ({goto **(ip-1);}) | ||
| 217 : | # define EXEC(XT) ({goto *(XT);}) | ||
| 218 : | #endif | ||
| 219 : | |||
| 220 : | /* common settings for direct THREADED */ | ||
| 221 : | |||
| 222 : | |||
| 223 : | /* indirect THREADED */ | ||
| 224 : | |||
| 225 : | #if !defined(DIRECT_THREADED) && defined(AUTO_INCREMENT)\ | ||
| 226 : | && defined(LONG_LATENCY) && defined(CISC_NEXT) | ||
| 227 : | # define NEXT_P0 ({cfa=*ip++;}) | ||
| 228 : | # define IP (ip-1) | ||
| 229 : | # define NEXT_INST (cfa) | ||
| 230 : | # define INC_IP(const_inc) ({cfa=IP[const_inc]; ip+=(const_inc);}) | ||
| 231 : | # define DEF_CA | ||
| 232 : | # define NEXT_P1 | ||
| 233 : | # define NEXT_P2 ({goto **cfa;}) | ||
| 234 : | # define EXEC(XT) ({cfa=(XT); goto **cfa;}) | ||
| 235 : | #endif | ||
| 236 : | |||
| 237 : | #if !defined(DIRECT_THREADED) && defined(AUTO_INCREMENT)\ | ||
| 238 : | && defined(LONG_LATENCY) && !defined(CISC_NEXT) | ||
| 239 : | # define NEXT_P0 ({cfa=*ip++;}) | ||
| 240 : | # define IP (ip-1) | ||
| 241 : | # define NEXT_INST (cfa) | ||
| 242 : | # define INC_IP(const_inc) ({cfa=IP[const_inc]; ip+=(const_inc);}) | ||
| 243 : | # define DEF_CA Label ca; | ||
| 244 : | # define NEXT_P1 ({ca=*cfa;}) | ||
| 245 : | # define NEXT_P2 ({goto *ca;}) | ||
| 246 : | # define EXEC(XT) ({DEF_CA cfa=(XT); ca=*cfa; goto *ca;}) | ||
| 247 : | #endif | ||
| 248 : | |||
| 249 : | |||
| 250 : | #if !defined(DIRECT_THREADED) && defined(AUTO_INCREMENT)\ | ||
| 251 : | && !defined(LONG_LATENCY) && defined(CISC_NEXT) | ||
| 252 : | # define NEXT_P0 | ||
| 253 : | # define IP (ip) | ||
| 254 : | # define NEXT_INST (*ip) | ||
| 255 : | # define INC_IP(const_inc) ({ip+=(const_inc);}) | ||
| 256 : | # define DEF_CA | ||
| 257 : | pazsan | 1.3 | # define NEXT_P1 |
| 258 : | # define NEXT_P2 ({cfa=*ip++; goto **cfa;}) | ||
| 259 : | pazsan | 1.1 | # define EXEC(XT) ({cfa=(XT); goto **cfa;}) |
| 260 : | #endif | ||
| 261 : | |||
| 262 : | #if !defined(DIRECT_THREADED) && defined(AUTO_INCREMENT)\ | ||
| 263 : | && !defined(LONG_LATENCY) && !defined(CISC_NEXT) | ||
| 264 : | # define NEXT_P0 ({cfa=*ip++;}) | ||
| 265 : | # define IP (ip-1) | ||
| 266 : | # define NEXT_INST (cfa) | ||
| 267 : | # define INC_IP(const_inc) ({cfa=IP[const_inc]; ip+=(const_inc);}) | ||
| 268 : | # define DEF_CA Label ca; | ||
| 269 : | # define NEXT_P1 ({ca=*cfa;}) | ||
| 270 : | # define NEXT_P2 ({goto *ca;}) | ||
| 271 : | # define EXEC(XT) ({DEF_CA cfa=(XT); ca=*cfa; goto *ca;}) | ||
| 272 : | #endif | ||
| 273 : | |||
| 274 : | |||
| 275 : | /* without autoincrement */ | ||
| 276 : | |||
| 277 : | #if !defined(DIRECT_THREADED) && !defined(AUTO_INCREMENT)\ | ||
| 278 : | && defined(LONG_LATENCY) && defined(CISC_NEXT) | ||
| 279 : | # define NEXT_P0 ({cfa=*ip;}) | ||
| 280 : | # define IP (ip) | ||
| 281 : | # define NEXT_INST (cfa) | ||
| 282 : | # define INC_IP(const_inc) ({cfa=IP[const_inc]; ip+=(const_inc);}) | ||
| 283 : | # define DEF_CA | ||
| 284 : | # define NEXT_P1 (ip++) | ||
| 285 : | # define NEXT_P2 ({goto **cfa;}) | ||
| 286 : | # define EXEC(XT) ({cfa=(XT); goto **cfa;}) | ||
| 287 : | #endif | ||
| 288 : | |||
| 289 : | #if !defined(DIRECT_THREADED) && !defined(AUTO_INCREMENT)\ | ||
| 290 : | && defined(LONG_LATENCY) && !defined(CISC_NEXT) | ||
| 291 : | # define NEXT_P0 ({cfa=*ip;}) | ||
| 292 : | # define IP (ip) | ||
| 293 : | # define NEXT_INST (cfa) | ||
| 294 : | # define INC_IP(const_inc) ({cfa=IP[const_inc]; ip+=(const_inc);}) | ||
| 295 : | # define DEF_CA Label ca; | ||
| 296 : | # define NEXT_P1 ({ip++; ca=*cfa;}) | ||
| 297 : | # define NEXT_P2 ({goto *ca;}) | ||
| 298 : | # define EXEC(XT) ({DEF_CA cfa=(XT); ca=*cfa; goto *ca;}) | ||
| 299 : | #endif | ||
| 300 : | |||
| 301 : | |||
| 302 : | #if !defined(DIRECT_THREADED) && !defined(AUTO_INCREMENT)\ | ||
| 303 : | && !defined(LONG_LATENCY) && defined(CISC_NEXT) | ||
| 304 : | # define NEXT_P0 | ||
| 305 : | # define IP (ip) | ||
| 306 : | # define NEXT_INST (*ip) | ||
| 307 : | # define INC_IP(const_inc) ({ip+=(const_inc);}) | ||
| 308 : | # define DEF_CA | ||
| 309 : | pazsan | 1.3 | # define NEXT_P1 |
| 310 : | # define NEXT_P2 ({cfa=*ip++; goto **cfa;}) | ||
| 311 : | pazsan | 1.1 | # define EXEC(XT) ({cfa=(XT); goto **cfa;}) |
| 312 : | #endif | ||
| 313 : | |||
| 314 : | #if !defined(DIRECT_THREADED) && !defined(AUTO_INCREMENT)\ | ||
| 315 : | && !defined(LONG_LATENCY) && !defined(CISC_NEXT) | ||
| 316 : | # define NEXT_P0 ({cfa=*ip;}) | ||
| 317 : | # define IP (ip) | ||
| 318 : | # define NEXT_INST (cfa) | ||
| 319 : | # define INC_IP(const_inc) ({cfa=IP[const_inc]; ip+=(const_inc);}) | ||
| 320 : | # define DEF_CA Label ca; | ||
| 321 : | # define NEXT_P1 ({ip++; ca=*cfa;}) | ||
| 322 : | # define NEXT_P2 ({goto *ca;}) | ||
| 323 : | # define EXEC(XT) ({DEF_CA cfa=(XT); ca=*cfa; goto *ca;}) | ||
| 324 : | #endif | ||
| 325 : | |||
| 326 : | #if defined(CISC_NEXT) && !defined(LONG_LATENCY) | ||
| 327 : | # define NEXT1_P1 | ||
| 328 : | # ifdef DIRECT_THREADED | ||
| 329 : | # define NEXT1_P2 ({goto *cfa;}) | ||
| 330 : | # else | ||
| 331 : | # define NEXT1_P2 ({goto **cfa;}) | ||
| 332 : | # endif /* DIRECT_THREADED */ | ||
| 333 : | anton | 1.5 | #else /* !defined(CISC_NEXT) || defined(LONG_LATENCY) */ |
| 334 : | pazsan | 1.1 | # ifdef DIRECT_THREADED |
| 335 : | # define NEXT1_P1 | ||
| 336 : | # define NEXT1_P2 ({goto *cfa;}) | ||
| 337 : | anton | 1.5 | # else /* !DIRECT_THREADED */ |
| 338 : | pazsan | 1.1 | # define NEXT1_P1 ({ca = *cfa;}) |
| 339 : | # define NEXT1_P2 ({goto *ca;}) | ||
| 340 : | anton | 1.5 | # endif /* !DIRECT_THREADED */ |
| 341 : | #endif /* !defined(CISC_NEXT) || defined(LONG_LATENCY) */ | ||
| 342 : | |||
| 343 : | #endif /* !defined(DOUBLY_INDIRECT) */ | ||
| 344 : | |||
| 345 : | #define NEXT ({DEF_CA NEXT_P1; NEXT_P2;}) | ||
| 346 : |
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