intrin.h

   1 /*
   2  * Copyright (C) 2012, 2013
   3  *     Dale Weiler
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy of
   6  * this software and associated documentation files (the "Software"), to deal in
   7  * the Software without restriction, including without limitation the rights to
   8  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
   9  * of the Software, and to permit persons to whom the Software is furnished to do
  10  * so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in all
  13  * copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23
  24 /*
  25  * Provides all the "intrinsics" / "builtins" for GMQCC. These can do
  26  * a few things, they can provide fall back implementations for math
  27  * functions if the definitions don't exist for some given engine. Or
  28  * then can determine definitions for existing builtins, and simply
  29  * wrap back to them instead.  This is like a "portable" intrface that
  30  * is entered when -fintrin is used (causing all existing builtins to
  31  * be ignored by the compiler and instead interface through here.
  32  */
  33 typedef struct {
  34     ast_expression *(*intrin)(parser_t *);
  35     const char       *name;
  36     const char       *alias;
  37 } intrin_t;
  38
  39 ht intrin_intrinsics() {
  40     static ht intrinsics = NULL;
  41     if (!intrinsics)
  42         intrinsics = util_htnew(PARSER_HT_SIZE);
  43
  44     return intrinsics;
  45 }
  46
  47 #define INTRIN_VAL(VALUE, NAME, FUNC, STYPE, VTYPE)                   \
  48     do {                                                              \
  49         (VALUE) = ast_value_new (                                     \
  50             parser_ctx(parser),                                       \
  51             "__builtin_" NAME,                                        \
  52             TYPE_FUNCTION                                             \
  53         );                                                            \
  54         (VALUE)->expression.next = (ast_expression*)ast_value_new (   \
  55             parser_ctx(parser),                                       \
  56             STYPE,                                                    \
  57             VTYPE                                                     \
  58         );                                                            \
  59         (FUNC) = ast_function_new (                                   \
  60             parser_ctx(parser),                                       \
  61             "__builtin_" NAME,                                        \
  62             (VALUE)                                                   \
  63         );                                                            \
  64     } while (0)
  65
  66 #define INTRIN_REG(FUNC, VALUE)                                       \
  67     do {                                                              \
  68         vec_push(parser->functions, (FUNC));                          \
  69         vec_push(parser->globals,   (ast_expression*)(VALUE));        \
  70     } while (0)
  71
  72
  73 ast_expression *intrin_func (parser_t *parser, const char *name);
  74
  75 #define QC_M_E 2.71828182845905
  76
  77 ast_expression *intrin_pow(parser_t *parser) {
  78     /*
  79      * float pow(float x, float y) {
  80      *   float local = 1.0f;
  81      *   while (y > 0) {
  82      *     while (!(y & 1)) {
  83      *       y >>= 2;
  84      *       x *=  x;
  85      *     }
  86      *     y--;
  87      *     local *= x;
  88      *   }
  89      *   return local;
  90      * }
  91      */
  92     static ast_value *value = NULL;
  93
  94     if (!value) {
  95         ast_value    *arg1  = ast_value_new(parser_ctx(parser), "x",     TYPE_FLOAT);
  96         ast_value    *arg2  = ast_value_new(parser_ctx(parser), "y",     TYPE_FLOAT);
  97         ast_value    *local = ast_value_new(parser_ctx(parser), "local", TYPE_FLOAT);
  98         ast_block    *body  = ast_block_new(parser_ctx(parser));
  99         ast_block    *l1b   = ast_block_new(parser_ctx(parser)); /* loop 1 body */
 100         ast_block    *l2b   = ast_block_new(parser_ctx(parser)); /* looo 2 body */
 101         ast_loop     *loop1 = NULL;
 102         ast_loop     *loop2 = NULL;
 103         ast_function *func  = NULL;
 104
 105         INTRIN_VAL(value, "pow", func, "<float>", TYPE_FLOAT);
 106
 107         /* arguments */
 108         vec_push(value->expression.params, arg1);
 109         vec_push(value->expression.params, arg2);
 110
 111         /* local */
 112         vec_push(body->locals, local);
 113
 114         /* assignment to local of value 1.0f */
 115         vec_push(body->exprs,
 116             (ast_expression*)ast_store_new (
 117                 parser_ctx(parser),
 118                 INSTR_STORE_F,
 119                 (ast_expression*)local,
 120                 (ast_expression*)parser_const_float_1(parser)
 121             )
 122         );
 123
 124         /* y >>= 2 */
 125         vec_push(l2b->exprs,
 126             (ast_expression*)ast_binstore_new (
 127                 parser_ctx(parser),
 128                 INSTR_STORE_F,
 129                 INSTR_MUL_F,
 130                 (ast_expression*)arg2,
 131                 (ast_expression*)parser_const_float(parser, 0.25f)
 132             )
 133         );
 134
 135         /* x *= x */
 136         vec_push(l2b->exprs,
 137             (ast_expression*)ast_binstore_new (
 138                 parser_ctx(parser),
 139                 INSTR_STORE_F,
 140                 INSTR_MUL_F,
 141                 (ast_expression*)arg1,
 142                 (ast_expression*)arg1
 143             )
 144         );
 145
 146         /* while (!(y&1)) */
 147         loop2 = ast_loop_new (
 148             parser_ctx(parser),
 149             NULL,
 150             (ast_expression*)ast_binary_new (
 151                 parser_ctx(parser),
 152                 INSTR_AND,
 153                 (ast_expression*)arg2,
 154                 (ast_expression*)parser_const_float_1(parser)
 155             ),
 156             true, /* ! not */
 157             NULL,
 158             false,
 159             NULL,
 160             (ast_expression*)l2b
 161         );
 162
 163         /* push nested loop into loop expressions */
 164         vec_push(l1b->exprs, (ast_expression*)loop2);
 165
 166         /* y-- */
 167         vec_push(l1b->exprs,
 168             (ast_expression*)ast_binstore_new (
 169                 parser_ctx(parser),
 170                 INSTR_STORE_F,
 171                 INSTR_SUB_F,
 172                 (ast_expression*)arg2,
 173                 (ast_expression*)parser_const_float_1(parser)
 174             )
 175         );
 176         /* local *= x */
 177         vec_push(l1b->exprs,
 178             (ast_expression*)ast_binstore_new (
 179                 parser_ctx(parser),
 180                 INSTR_STORE_F,
 181                 INSTR_MUL_F,
 182                 (ast_expression*)local,
 183                 (ast_expression*)arg1
 184             )
 185         );
 186
 187         /* while (y > 0) */
 188         loop1 = ast_loop_new (
 189             parser_ctx(parser),
 190             NULL,
 191             (ast_expression*)ast_binary_new (
 192                 parser_ctx(parser),
 193                 INSTR_GT,
 194                 (ast_expression*)arg2,
 195                 (ast_expression*)parser_const_float_0(parser)
 196             ),
 197             false,
 198             NULL,
 199             false,
 200             NULL,
 201             (ast_expression*)l1b
 202         );
 203
 204         /* push the loop1 into the body for the function */
 205         vec_push(body->exprs, (ast_expression*)loop1);
 206
 207         /* return local; */
 208         vec_push(body->exprs,
 209             (ast_expression*)ast_return_new (
 210                 parser_ctx(parser),
 211                 (ast_expression*)local
 212             )
 213         );
 214
 215         /* push block and register intrin for codegen */
 216         vec_push(func->blocks, body);
 217
 218         INTRIN_REG(func, value);
 219     }
 220
 221     return (ast_expression*)value;
 222 }
 223
 224 ast_expression *intrin_mod(parser_t *parser) {
 225     /*
 226      * float mod(float x, float y) {
 227      *   return x - y * floor(x / y);
 228      * }
 229      */
 230     static ast_value *value = NULL;
 231
 232     if (!value) {
 233         ast_call     *call  = ast_call_new (parser_ctx(parser), intrin_func(parser, "floor"));
 234         ast_value    *arg1  = ast_value_new(parser_ctx(parser), "x", TYPE_FLOAT);
 235         ast_value    *arg2  = ast_value_new(parser_ctx(parser), "y", TYPE_FLOAT);
 236         ast_block    *body  = ast_block_new(parser_ctx(parser));
 237         ast_function *func  = NULL;
 238
 239         INTRIN_VAL(value, "mod", func, "<float>", TYPE_FLOAT);
 240
 241         /* floor(x/y) */
 242         vec_push(call->params,
 243             (ast_expression*)ast_binary_new (
 244                 parser_ctx(parser),
 245                 INSTR_DIV_F,
 246                 (ast_expression*)arg1,
 247                 (ast_expression*)arg2
 248             )
 249         );
 250
 251         vec_push(body->exprs,
 252             (ast_expression*)ast_return_new(
 253                 parser_ctx(parser),
 254                 (ast_expression*)ast_binary_new(
 255                     parser_ctx(parser),
 256                     INSTR_SUB_F,
 257                     (ast_expression*)arg1,
 258                     (ast_expression*)ast_binary_new(
 259                         parser_ctx(parser),
 260                         INSTR_MUL_F,
 261                         (ast_expression*)arg2,
 262                         (ast_expression*)call
 263                     )
 264                 )
 265             )
 266         );
 267
 268         vec_push(value->expression.params, arg1); /* float x (for param) */
 269         vec_push(value->expression.params, arg2); /* float y (for param) */
 270
 271         vec_push(func->blocks,            body); /* {{{ body }}} */
 272
 273         INTRIN_REG(func, value);
 274     }
 275
 276     return (ast_expression*)value;
 277 }
 278
 279 ast_expression *intrin_exp(parser_t *parser) {
 280     /*
 281      * float exp(float x) {
 282      *     return pow(QC_M_E, x);
 283      * }
 284      */
 285     static ast_value *value = NULL;
 286
 287     if (!value) {
 288         ast_call     *call = ast_call_new    (parser_ctx(parser), intrin_func(parser, "pow"));
 289         ast_value    *arg1 = ast_value_new   (parser_ctx(parser), "x", TYPE_FLOAT);
 290         ast_block    *body = ast_block_new   (parser_ctx(parser));
 291         ast_function *func = NULL;
 292
 293         INTRIN_VAL(value, "exp", func, "<float>", TYPE_FLOAT);
 294
 295         /* push arguments for params to call */
 296         vec_push(call->params, (ast_expression*)parser_const_float(parser, QC_M_E));
 297         vec_push(call->params, (ast_expression*)arg1);
 298
 299         /* return pow(QC_M_E, x) */
 300         vec_push(body->exprs,
 301             (ast_expression*)ast_return_new(
 302                 parser_ctx(parser),
 303                 (ast_expression*)call
 304             )
 305         );
 306
 307         vec_push(value->expression.params, arg1); /* float x (for param) */
 308
 309         vec_push(func->blocks,             body); /* {{{ body }}} */
 310
 311         INTRIN_REG(func, value);
 312     }
 313
 314     return (ast_expression*)value;
 315 }
 316
 317 ast_expression *intrin_isnan(parser_t *parser) {
 318     /*
 319      * float isnan(float x) {
 320      *   float local;
 321      *   local = x;
 322      *
 323      *   return (x != local);
 324      * }
 325      */
 326     static ast_value *value = NULL;
 327
 328     if (!value) {
 329         ast_value    *arg1   = ast_value_new (parser_ctx(parser), "x", TYPE_FLOAT);
 330         ast_value    *local  = ast_value_new (parser_ctx(parser), "local", TYPE_FLOAT);
 331         ast_block    *body   = ast_block_new (parser_ctx(parser));
 332         ast_function *func   = NULL;
 333
 334         INTRIN_VAL(value, "isnan", func, "<float>", TYPE_FLOAT);
 335
 336         vec_push(body->locals, local);
 337         vec_push(body->exprs,
 338             (ast_expression*)ast_store_new(
 339                 parser_ctx(parser),
 340                 INSTR_STORE_F,
 341                 (ast_expression*)local,
 342                 (ast_expression*)arg1
 343             )
 344         );
 345
 346         vec_push(body->exprs,
 347             (ast_expression*)ast_return_new(
 348                 parser_ctx(parser),
 349                 (ast_expression*)ast_binary_new(
 350                     parser_ctx(parser),
 351                     INSTR_NE_F,
 352                     (ast_expression*)arg1,
 353                     (ast_expression*)local
 354                 )
 355             )
 356         );
 357
 358         vec_push(value->expression.params, arg1);
 359
 360         vec_push(func->blocks, body);
 361
 362         INTRIN_REG(func, value);
 363     }
 364
 365     return (ast_expression*)value;
 366 }
 367
 368 static intrin_t intrinsics[] = {
 369     {&intrin_exp,   "__builtin_exp",   "exp"},
 370     {&intrin_mod,   "__builtin_mod",   "mod"},
 371     {&intrin_pow,   "__builtin_pow",   "pow"},
 372     {&intrin_isnan, "__builtin_isnan", "isnan"}
 373 };
 374
 375 void intrin_intrinsics_destroy(parser_t *parser) {
 376     /*size_t i;*/
 377     (void)parser;
 378     util_htdel(intrin_intrinsics());
 379 #if 0
 380     for (i = 0; i < sizeof(intrinsics)/sizeof(intrin_t); i++)
 381         ast_value_delete( (ast_value*) intrinsics[i].intrin(parser));
 382 #endif
 383 }
 384
 385
 386 ast_expression *intrin_func(parser_t *parser, const char *name) {
 387     static bool  init = false;
 388     size_t       i    = 0;
 389     void        *find;
 390
 391     /* register the intrinsics in the hashtable for O(1) lookup */
 392     if (!init) {
 393         for (i = 0; i < sizeof(intrinsics)/sizeof(*intrinsics); i++)
 394             util_htset(intrin_intrinsics(), intrinsics[i].alias, &intrinsics[i]);
 395
 396         init = true; /* only once */
 397     }
 398
 399     /*
 400      * jesus fucking christ, Blub design something less fucking
 401      * impossible to use, like a ast_is_builtin(ast_expression *), also
 402      * use a hashtable :P
 403      */
 404     if ((find = (void*)parser_find_global(parser, name)) && ((ast_value*)find)->expression.vtype == TYPE_FUNCTION)
 405         for (i = 0; i < vec_size(parser->functions); ++i)
 406             if (((ast_value*)find)->name && !strcmp(parser->functions[i]->name, ((ast_value*)find)->name) && parser->functions[i]->builtin < 0)
 407                 return find;
 408
 409     if ((find = util_htget(intrin_intrinsics(), name))) {
 410         /* intrinsic is in table. This will "generate the function" so
 411          * to speak (if it's not already generated).
 412          */
 413         return ((intrin_t*)find)->intrin(parser);
 414     }
 415
 416     parseerror(parser, "need function: `%s` compiler depends on it", name);
 417     return NULL;
 418 }