intrin.c

   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 #include <string.h>
  24 #include "parser.h"
  25
  26 /*
  27  * Provides all the "intrinsics" / "builtins" for GMQCC. These can do
  28  * a few things, they can provide fall back implementations for math
  29  * functions if the definitions don't exist for some given engine. Or
  30  * then can determine definitions for existing builtins, and simply
  31  * wrap back to them instead.  This is like a "portable" intrface that
  32  * is entered when -fintrin is used (causing all existing builtins to
  33  * be ignored by the compiler and instead interface through here.
  34  */
  35 #define intrin_ctx(I) parser_ctx((I)->parser)
  36
  37 static GMQCC_INLINE ast_function *intrin_value(intrin_t *intrin, ast_value **out, const char *name, qcint_t vtype) {
  38     ast_value    *value = NULL;
  39     ast_function *func  = NULL;
  40     char          buffer[1024];
  41     char          stype [1024];
  42
  43     util_snprintf(buffer, sizeof(buffer), "__builtin_%s", name);
  44     util_snprintf(stype,  sizeof(stype),   "<%s>",        type_name[vtype]);
  45
  46     value                    = ast_value_new(intrin_ctx(intrin), buffer, TYPE_FUNCTION);
  47     value->intrinsic         = true;
  48     value->expression.next   = (ast_expression*)ast_value_new(intrin_ctx(intrin), stype, vtype);
  49     func                     = ast_function_new(intrin_ctx(intrin), buffer, value);
  50     value->expression.flags |= AST_FLAG_ERASEABLE;
  51
  52     *out = value;
  53     return func;
  54 }
  55
  56 static GMQCC_INLINE void intrin_reg(intrin_t *intrin, ast_value *const value, ast_function *const func) {
  57     vec_push(intrin->parser->functions, func);
  58     vec_push(intrin->parser->globals,   (ast_expression*)value);
  59 }
  60
  61 #define QC_POW_EPSILON 0.00001f
  62
  63 /*
  64  * since some intrinsics depend on each other there is the possibility
  65  * that an intrinsic will fail to get a 'depended' function that a
  66  * builtin needs, causing some dependency in the chain to have a NULL
  67  * function. This will cause a segmentation fault at code generation,
  68  * even though an error was raised. To contiue to allow it (instead
  69  * of stopping compilation right away). We need to return from the
  70  * parser, before compilation stops after all the collected errors.
  71  */
  72 static ast_expression *intrin_func_self(intrin_t *intrin, const char *name, const char *from);
  73 static ast_expression *intrin_nullfunc(intrin_t *intrin) {
  74     ast_value    *value = NULL;
  75     ast_function *func  = intrin_value(intrin, &value, NULL, TYPE_VOID);
  76     intrin_reg(intrin, value, func);
  77     return (ast_expression*)value;
  78 }
  79
  80 static ast_expression *intrin_isfinite(intrin_t *intrin) {
  81     /*
  82      * float isfinite(float x) {
  83      *     return !(isnan(x) || isinf(x));
  84      * }
  85      */
  86     ast_value    *value     = NULL;
  87     ast_value    *x         = ast_value_new(intrin_ctx(intrin), "x", TYPE_FLOAT);
  88     ast_function *func      = intrin_value(intrin, &value, "isfinite", TYPE_FLOAT);
  89     ast_call     *callisnan = ast_call_new(intrin_ctx(intrin), intrin_func_self(intrin, "isnan", "isfinite"));
  90     ast_call     *callisinf = ast_call_new(intrin_ctx(intrin), intrin_func_self(intrin, "isinf", "isfinite"));
  91     ast_block    *block     = ast_block_new(intrin_ctx(intrin));
  92
  93     /* float x; */
  94     vec_push(value->expression.params, x);
  95
  96     /* <callisnan> = isnan(x); */
  97     vec_push(callisnan->params, (ast_expression*)x);
  98
  99     /* <callisinf> = isinf(x); */
 100     vec_push(callisinf->params, (ast_expression*)x);
 101
 102     /* return (!<callisnan> || <callisinf>); */
 103     vec_push(block->exprs,
 104         (ast_expression*)ast_return_new(
 105             intrin_ctx(intrin),
 106             (ast_expression*)ast_unary_new(
 107                 intrin_ctx(intrin),
 108                 INSTR_NOT_F,
 109                 (ast_expression*)ast_binary_new(
 110                     intrin_ctx(intrin),
 111                     INSTR_OR,
 112                     (ast_expression*)callisnan,
 113                     (ast_expression*)callisinf
 114                 )
 115             )
 116         )
 117     );
 118
 119     vec_push(func->blocks, block);
 120     intrin_reg(intrin, value, func);
 121
 122     return (ast_expression*)value;;
 123 }
 124
 125 static ast_expression *intrin_isinf(intrin_t *intrin) {
 126     /*
 127      * float isinf(float x) {
 128      *     return (x != 0.0) && (x + x == x);
 129      * }
 130      */
 131     ast_value    *value = NULL;
 132     ast_value    *x     = ast_value_new(intrin_ctx(intrin), "x", TYPE_FLOAT);
 133     ast_block    *body  = ast_block_new(intrin_ctx(intrin));
 134     ast_function *func  = intrin_value(intrin, &value, "isinf", TYPE_FLOAT);
 135
 136     vec_push(body->exprs,
 137         (ast_expression*)ast_return_new(
 138             intrin_ctx(intrin),
 139             (ast_expression*)ast_binary_new(
 140                 intrin_ctx(intrin),
 141                 INSTR_AND,
 142                 (ast_expression*)ast_binary_new(
 143                     intrin_ctx(intrin),
 144                     INSTR_NE_F,
 145                     (ast_expression*)x,
 146                     (ast_expression*)intrin->fold->imm_float[0]
 147                 ),
 148                 (ast_expression*)ast_binary_new(
 149                     intrin_ctx(intrin),
 150                     INSTR_EQ_F,
 151                     (ast_expression*)ast_binary_new(
 152                         intrin_ctx(intrin),
 153                         INSTR_ADD_F,
 154                         (ast_expression*)x,
 155                         (ast_expression*)x
 156                     ),
 157                     (ast_expression*)x
 158                 )
 159             )
 160         )
 161     );
 162
 163     vec_push(value->expression.params, x);
 164     vec_push(func->blocks, body);
 165
 166     intrin_reg(intrin, value, func);
 167
 168     return (ast_expression*)value;
 169 }
 170
 171 static ast_expression *intrin_isnan(intrin_t *intrin) {
 172     /*
 173      * float isnan(float x) {
 174      *   float local;
 175      *   local = x;
 176      *
 177      *   return (x != local);
 178      * }
 179      */
 180     ast_value    *value  = NULL;
 181     ast_value    *arg1   = ast_value_new(intrin_ctx(intrin), "x",     TYPE_FLOAT);
 182     ast_value    *local  = ast_value_new(intrin_ctx(intrin), "local", TYPE_FLOAT);
 183     ast_block    *body   = ast_block_new(intrin_ctx(intrin));
 184     ast_function *func   = intrin_value(intrin, &value, "isnan", TYPE_FLOAT);
 185
 186     vec_push(body->locals, local);
 187     vec_push(body->exprs,
 188         (ast_expression*)ast_store_new(
 189             intrin_ctx(intrin),
 190             INSTR_STORE_F,
 191             (ast_expression*)local,
 192             (ast_expression*)arg1
 193         )
 194     );
 195
 196     vec_push(body->exprs,
 197         (ast_expression*)ast_return_new(
 198             intrin_ctx(intrin),
 199             (ast_expression*)ast_binary_new(
 200                 intrin_ctx(intrin),
 201                 INSTR_NE_F,
 202                 (ast_expression*)arg1,
 203                 (ast_expression*)local
 204             )
 205         )
 206     );
 207
 208     vec_push(value->expression.params, arg1);
 209     vec_push(func->blocks, body);
 210
 211     intrin_reg(intrin, value, func);
 212
 213     return (ast_expression*)value;
 214 }
 215
 216 static ast_expression *intrin_isnormal(intrin_t *intrin) {
 217     /*
 218      * float isnormal(float x) {
 219      *     return isfinite(x);
 220      * }
 221      */
 222     ast_value    *value         = NULL;
 223     ast_call     *callisfinite  = ast_call_new (intrin_ctx(intrin), intrin_func_self(intrin, "isfinite", "isnormal"));
 224     ast_value    *x             = ast_value_new(intrin_ctx(intrin), "x", TYPE_FLOAT);
 225     ast_block    *body          = ast_block_new(intrin_ctx(intrin));
 226     ast_function *func          = intrin_value(intrin, &value, "isnormal", TYPE_FLOAT);
 227
 228     vec_push(value->expression.params, x);
 229     vec_push(callisfinite->params, (ast_expression*)x);
 230
 231     /* return <callisfinite> */
 232     vec_push(body->exprs,
 233         (ast_expression*)ast_return_new(
 234             intrin_ctx(intrin),
 235             (ast_expression*)callisfinite
 236         )
 237     );
 238
 239     vec_push(func->blocks, body);
 240     intrin_reg(intrin, value, func);
 241     return (ast_expression*)value;
 242 }
 243
 244 static ast_expression *intrin_signbit(intrin_t *intrin) {
 245     /*
 246      * float signbit(float x) {
 247      *     return (x < 0);
 248      * }
 249      */
 250     ast_value    *value  = NULL;
 251     ast_value    *x      = ast_value_new(intrin_ctx(intrin), "x", TYPE_FLOAT);
 252     ast_block    *body   = ast_block_new(intrin_ctx(intrin));
 253     ast_function *func   = intrin_value(intrin, &value, "signbit", TYPE_FLOAT);
 254
 255     vec_push(value->expression.params, x);
 256
 257     /* return (x < 0); */
 258     vec_push(body->exprs,
 259         (ast_expression*)ast_return_new(
 260             intrin_ctx(intrin),
 261             (ast_expression*)ast_ternary_new(
 262                 intrin_ctx(intrin),
 263                 (ast_expression*)ast_binary_new(
 264                     intrin_ctx(intrin),
 265                     INSTR_LT,
 266                     (ast_expression*)x,
 267                     (ast_expression*)intrin->fold->imm_float[0]
 268                 ),
 269                 (ast_expression*)intrin->fold->imm_float[1],
 270                 (ast_expression*)intrin->fold->imm_float[0]
 271             )
 272         )
 273     );
 274
 275     vec_push(func->blocks, body);
 276     intrin_reg(intrin, value, func);
 277     return (ast_expression*)value;
 278 }
 279
 280 static ast_expression *intrin_acosh(intrin_t *intrin) {
 281     /*
 282      * float acosh(float x) {
 283      *     return log(x + sqrt((x * x) - 1));
 284      * }
 285      */
 286     ast_value    *value    = NULL;
 287     ast_value    *x        = ast_value_new(intrin_ctx(intrin), "x", TYPE_FLOAT);
 288     ast_call     *calllog  = ast_call_new(intrin_ctx(intrin), intrin_func_self(intrin, "log", "acosh"));
 289     ast_call     *callsqrt = ast_call_new(intrin_ctx(intrin), intrin_func_self(intrin, "sqrt", "acosh"));
 290     ast_block    *body     = ast_block_new(intrin_ctx(intrin));
 291     ast_function *func     = intrin_value(intrin, &value, "acosh", TYPE_FLOAT);
 292
 293     vec_push(value->expression.params, x);
 294
 295     /* <callsqrt> = sqrt((x * x) - 1); */
 296     vec_push(callsqrt->params,
 297         (ast_expression*)ast_binary_new(
 298             intrin_ctx(intrin),
 299             INSTR_SUB_F,
 300             (ast_expression*)ast_binary_new(
 301                 intrin_ctx(intrin),
 302                 INSTR_MUL_F,
 303                 (ast_expression*)x,
 304                 (ast_expression*)x
 305             ),
 306             (ast_expression*)intrin->fold->imm_float[1]
 307         )
 308     );
 309
 310     /* <calllog> = log(x + <callsqrt>); */
 311     vec_push(calllog->params,
 312         (ast_expression*)ast_binary_new(
 313             intrin_ctx(intrin),
 314             INSTR_ADD_F,
 315             (ast_expression*)x,
 316             (ast_expression*)callsqrt
 317         )
 318     );
 319
 320     /* return <calllog>; */
 321     vec_push(body->exprs,
 322         (ast_expression*)ast_return_new(
 323             intrin_ctx(intrin),
 324             (ast_expression*)calllog
 325         )
 326     );
 327
 328     vec_push(func->blocks, body);
 329     intrin_reg(intrin, value, func);
 330     return (ast_expression*)value;
 331 }
 332
 333 static ast_expression *intrin_asinh(intrin_t *intrin) {
 334     /*
 335      * float asinh(float x) {
 336      *     return log(x + sqrt((x * x) + 1));
 337      * }
 338      */
 339     ast_value    *value    = NULL;
 340     ast_value    *x        = ast_value_new(intrin_ctx(intrin), "x", TYPE_FLOAT);
 341     ast_call     *calllog  = ast_call_new(intrin_ctx(intrin), intrin_func_self(intrin, "log", "asinh"));
 342     ast_call     *callsqrt = ast_call_new(intrin_ctx(intrin), intrin_func_self(intrin, "sqrt", "asinh"));
 343     ast_block    *body     = ast_block_new(intrin_ctx(intrin));
 344     ast_function *func     = intrin_value(intrin, &value, "asinh", TYPE_FLOAT);
 345
 346     vec_push(value->expression.params, x);
 347
 348     /* <callsqrt> = sqrt((x * x) + 1); */
 349     vec_push(callsqrt->params,
 350         (ast_expression*)ast_binary_new(
 351             intrin_ctx(intrin),
 352             INSTR_ADD_F,
 353             (ast_expression*)ast_binary_new(
 354                 intrin_ctx(intrin),
 355                 INSTR_MUL_F,
 356                 (ast_expression*)x,
 357                 (ast_expression*)x
 358             ),
 359             (ast_expression*)intrin->fold->imm_float[1]
 360         )
 361     );
 362
 363     /* <calllog> = log(x + <callsqrt>); */
 364     vec_push(calllog->params,
 365         (ast_expression*)ast_binary_new(
 366             intrin_ctx(intrin),
 367             INSTR_ADD_F,
 368             (ast_expression*)x,
 369             (ast_expression*)callsqrt
 370         )
 371     );
 372
 373     /* return <calllog>; */
 374     vec_push(body->exprs,
 375         (ast_expression*)ast_return_new(
 376             intrin_ctx(intrin),
 377             (ast_expression*)calllog
 378         )
 379     );
 380
 381     vec_push(func->blocks, body);
 382     intrin_reg(intrin, value, func);
 383     return (ast_expression*)value;
 384 }
 385
 386 static ast_expression *intrin_atanh(intrin_t *intrin) {
 387     /*
 388      * float atanh(float x) {
 389      *     return 0.5 * log((1 + x) / (1 - x))
 390      * }
 391      */
 392     ast_value    *value   = NULL;
 393     ast_value    *x       = ast_value_new(intrin_ctx(intrin), "x", TYPE_FLOAT);
 394     ast_call     *calllog = ast_call_new(intrin_ctx(intrin), intrin_func_self(intrin, "log", "atanh"));
 395     ast_block    *body    = ast_block_new(intrin_ctx(intrin));
 396     ast_function *func    = intrin_value(intrin, &value, "atanh", TYPE_FLOAT);
 397
 398     vec_push(value->expression.params, x);
 399
 400     /* <callog> = log((1 + x) / (1 - x)); */
 401     vec_push(calllog->params,
 402         (ast_expression*)ast_binary_new(
 403             intrin_ctx(intrin),
 404             INSTR_DIV_F,
 405             (ast_expression*)ast_binary_new(
 406                 intrin_ctx(intrin),
 407                 INSTR_ADD_F,
 408                 (ast_expression*)intrin->fold->imm_float[1],
 409                 (ast_expression*)x
 410             ),
 411             (ast_expression*)ast_binary_new(
 412                 intrin_ctx(intrin),
 413                 INSTR_SUB_F,
 414                 (ast_expression*)intrin->fold->imm_float[1],
 415                 (ast_expression*)x
 416             )
 417         )
 418     );
 419
 420     /* return 0.5 * <calllog>; */
 421     vec_push(body->exprs,
 422         (ast_expression*)ast_binary_new(
 423             intrin_ctx(intrin),
 424             INSTR_MUL_F,
 425             (ast_expression*)fold_constgen_float(intrin->fold, 0.5),
 426             (ast_expression*)calllog
 427         )
 428     );
 429
 430     vec_push(func->blocks, body);
 431     intrin_reg(intrin, value, func);
 432     return (ast_expression*)value;
 433 }
 434
 435 static ast_expression *intrin_exp(intrin_t *intrin) {
 436     /*
 437      * float exp(float x) {
 438      *     float sum = 1.0;
 439      *     float acc = 1.0;
 440      *     float i;
 441      *     for (i = 1; i < 200; ++i)
 442      *         sum += (acc *= x / i);
 443      *
 444      *     return sum;
 445      * }
 446      */
 447     ast_value    *value = NULL;
 448     ast_value    *x     = ast_value_new(intrin_ctx(intrin), "x",   TYPE_FLOAT);
 449     ast_value    *sum   = ast_value_new(intrin_ctx(intrin), "sum", TYPE_FLOAT);
 450     ast_value    *acc   = ast_value_new(intrin_ctx(intrin), "acc", TYPE_FLOAT);
 451     ast_value    *i     = ast_value_new(intrin_ctx(intrin), "i",   TYPE_FLOAT);
 452     ast_block    *body  = ast_block_new(intrin_ctx(intrin));
 453     ast_function *func  = intrin_value(intrin, &value, "exp", TYPE_FLOAT);
 454
 455     vec_push(value->expression.params, x);
 456     vec_push(body->locals, sum);
 457     vec_push(body->locals, acc);
 458     vec_push(body->locals, i);
 459
 460     /* sum = 1.0; */
 461     vec_push(body->exprs,
 462         (ast_expression*)ast_store_new(
 463             intrin_ctx(intrin),
 464             INSTR_STORE_F,
 465             (ast_expression*)sum,
 466             (ast_expression*)intrin->fold->imm_float[1]
 467         )
 468     );
 469
 470     /* acc = 1.0; */
 471     vec_push(body->exprs,
 472         (ast_expression*)ast_store_new(
 473             intrin_ctx(intrin),
 474             INSTR_STORE_F,
 475             (ast_expression*)acc,
 476             (ast_expression*)intrin->fold->imm_float[1]
 477         )
 478     );
 479
 480     /*
 481      * for (i = 1; i < 200; ++i)
 482      *     sum += (acc *= x / i);
 483      */
 484     vec_push(body->exprs,
 485         (ast_expression*)ast_loop_new(
 486             intrin_ctx(intrin),
 487             /* i = 1; */
 488             (ast_expression*)ast_store_new(
 489                 intrin_ctx(intrin),
 490                 INSTR_STORE_F,
 491                 (ast_expression*)i,
 492                 (ast_expression*)intrin->fold->imm_float[1]
 493             ),
 494             /* i < 200; */
 495             (ast_expression*)ast_binary_new(
 496                 intrin_ctx(intrin),
 497                 INSTR_LT,
 498                 (ast_expression*)i,
 499                 (ast_expression*)fold_constgen_float(intrin->fold, 200.0f)
 500             ),
 501             false,
 502             NULL,
 503             false,
 504             /* ++i; */
 505             (ast_expression*)ast_binstore_new(
 506                 intrin_ctx(intrin),
 507                 INSTR_STORE_F,
 508                 INSTR_ADD_F,
 509                 (ast_expression*)i,
 510                 (ast_expression*)intrin->fold->imm_float[1]
 511             ),
 512             /* sum += (acc *= (x / i)) */
 513             (ast_expression*)ast_binstore_new(
 514                 intrin_ctx(intrin),
 515                 INSTR_STORE_F,
 516                 INSTR_ADD_F,
 517                 (ast_expression*)sum,
 518                 (ast_expression*)ast_binstore_new(
 519                     intrin_ctx(intrin),
 520                     INSTR_STORE_F,
 521                     INSTR_MUL_F,
 522                     (ast_expression*)acc,
 523                     (ast_expression*)ast_binary_new(
 524                         intrin_ctx(intrin),
 525                         INSTR_DIV_F,
 526                         (ast_expression*)x,
 527                         (ast_expression*)i
 528                     )
 529                 )
 530             )
 531         )
 532     );
 533
 534     /* return sum; */
 535     vec_push(body->exprs,
 536         (ast_expression*)ast_return_new(
 537             intrin_ctx(intrin),
 538             (ast_expression*)sum
 539         )
 540     );
 541
 542     vec_push(func->blocks, body); /* {{{ body }}} */
 543
 544     intrin_reg(intrin, value, func);
 545     return (ast_expression*)value;
 546 }
 547
 548 static ast_expression *intrin_exp2(intrin_t *intrin) {
 549     /*
 550      * float exp2(float x) {
 551      *     return pow(2, x);
 552      * }
 553      */
 554     ast_value    *value     = NULL;
 555     ast_call     *callpow   = ast_call_new (intrin_ctx(intrin), intrin_func_self(intrin, "pow", "exp2"));
 556     ast_value    *arg1      = ast_value_new(intrin_ctx(intrin), "x", TYPE_FLOAT);
 557     ast_block    *body      = ast_block_new(intrin_ctx(intrin));
 558     ast_function *func      = intrin_value(intrin, &value, "exp2", TYPE_FLOAT);
 559
 560     vec_push(value->expression.params, arg1);
 561
 562     vec_push(callpow->params, (ast_expression*)fold_constgen_float(intrin->fold, 2.0f));
 563     vec_push(callpow->params, (ast_expression*)arg1);
 564
 565     /* return <callpow> */
 566     vec_push(body->exprs,
 567         (ast_expression*)ast_return_new(
 568             intrin_ctx(intrin),
 569             (ast_expression*)callpow
 570         )
 571     );
 572
 573     vec_push(func->blocks, body);
 574
 575     intrin_reg(intrin, value, func);
 576     return (ast_expression*)value;
 577 }
 578
 579 static ast_expression *intrin_expm1(intrin_t *intrin) {
 580     /*
 581      * float expm1(float x) {
 582      *     return exp(x) - 1;
 583      * }
 584      */
 585     ast_value    *value    = NULL;
 586     ast_call     *callexp  = ast_call_new (intrin_ctx(intrin), intrin_func_self(intrin, "exp", "expm1"));
 587     ast_value    *x        = ast_value_new(intrin_ctx(intrin), "x", TYPE_FLOAT);
 588     ast_block    *body     = ast_block_new(intrin_ctx(intrin));
 589     ast_function *func     = intrin_value(intrin, &value, "expm1", TYPE_FLOAT);
 590
 591     vec_push(value->expression.params, x);
 592
 593     /* <callexp> = exp(x); */
 594     vec_push(callexp->params, (ast_expression*)x);
 595
 596     /* return <callexp> - 1; */
 597     vec_push(body->exprs,
 598         (ast_expression*)ast_return_new(
 599             intrin_ctx(intrin),
 600             (ast_expression*)ast_binary_new(
 601                 intrin_ctx(intrin),
 602                 INSTR_SUB_F,
 603                 (ast_expression*)callexp,
 604                 (ast_expression*)intrin->fold->imm_float[1]
 605             )
 606         )
 607     );
 608
 609     vec_push(func->blocks, body);
 610     intrin_reg(intrin, value, func);
 611     return (ast_expression*)value;
 612 }
 613
 614 static ast_expression *intrin_pow(intrin_t *intrin) {
 615     /*
 616      *
 617      * float pow(float base, float exp) {
 618      *     float result;
 619      *     float low;
 620      *     float high;
 621      *     float mid;
 622      *     float square;
 623      *     float accumulate;
 624      *
 625      *     if (exp == 0.0)
 626      *         return 1;
 627      *     if (exp == 1.0)
 628      *         return base;
 629      *     if (exp < 0)
 630      *         return 1.0 / pow(base, -exp);
 631      *     if (exp >= 1) {
 632      *         result = pow(base, exp / 2);
 633      *         return result * result;
 634      *     }
 635      *
 636      *     low        = 0.0f;
 637      *     high       = 1.0f;
 638      *     square     = sqrt(base);
 639      *     accumulate = square;
 640      *     mid        = high / 2.0f
 641      *
 642      *     while (fabs(mid - exp) > QC_POW_EPSILON) {
 643      *         square = sqrt(square);
 644      *         if (mid < exp) {
 645      *             low         = mid;
 646      *             accumulate *= square;
 647      *         } else {
 648      *             high        = mid;
 649      *             accumulate *= (1.0f / square);
 650      *         }
 651      *         mid = (low + high) / 2;
 652      *     }
 653      *     return accumulate;
 654      * }
 655      */
 656     ast_value    *value = NULL;
 657     ast_function *func = intrin_value(intrin, &value, "pow", TYPE_FLOAT);
 658
 659     /* prepare some calls for later */
 660     ast_call *callpow1  = ast_call_new(intrin_ctx(intrin), (ast_expression*)value);                  /* for pow(base, -exp)    */
 661     ast_call *callpow2  = ast_call_new(intrin_ctx(intrin), (ast_expression*)value);                  /* for pow(vase, exp / 2) */
 662     ast_call *callsqrt1 = ast_call_new(intrin_ctx(intrin), intrin_func_self(intrin, "sqrt", "pow")); /* for sqrt(base)         */
 663     ast_call *callsqrt2 = ast_call_new(intrin_ctx(intrin), intrin_func_self(intrin, "sqrt", "pow")); /* for sqrt(square)       */
 664     ast_call *callfabs  = ast_call_new(intrin_ctx(intrin), intrin_func_self(intrin, "fabs", "pow")); /* for fabs(mid - exp)    */
 665
 666     /* prepare some blocks for later */
 667     ast_block *expgt1       = ast_block_new(intrin_ctx(intrin));
 668     ast_block *midltexp     = ast_block_new(intrin_ctx(intrin));
 669     ast_block *midltexpelse = ast_block_new(intrin_ctx(intrin));
 670     ast_block *whileblock   = ast_block_new(intrin_ctx(intrin));
 671
 672     /* float pow(float base, float exp) */
 673     ast_value    *base = ast_value_new(intrin_ctx(intrin), "base", TYPE_FLOAT);
 674     ast_value    *exp  = ast_value_new(intrin_ctx(intrin), "exp",  TYPE_FLOAT);
 675     /* { */
 676     ast_block    *body = ast_block_new(intrin_ctx(intrin));
 677
 678     /*
 679      * float result;
 680      * float low;
 681      * float high;
 682      * float square;
 683      * float accumulate;
 684      * float mid;
 685      */
 686     ast_value *result     = ast_value_new(intrin_ctx(intrin), "result",     TYPE_FLOAT);
 687     ast_value *low        = ast_value_new(intrin_ctx(intrin), "low",        TYPE_FLOAT);
 688     ast_value *high       = ast_value_new(intrin_ctx(intrin), "high",       TYPE_FLOAT);
 689     ast_value *square     = ast_value_new(intrin_ctx(intrin), "square",     TYPE_FLOAT);
 690     ast_value *accumulate = ast_value_new(intrin_ctx(intrin), "accumulate", TYPE_FLOAT);
 691     ast_value *mid        = ast_value_new(intrin_ctx(intrin), "mid",        TYPE_FLOAT);
 692     vec_push(body->locals, result);
 693     vec_push(body->locals, low);
 694     vec_push(body->locals, high);
 695     vec_push(body->locals, square);
 696     vec_push(body->locals, accumulate);
 697     vec_push(body->locals, mid);
 698
 699     vec_push(value->expression.params, base);
 700     vec_push(value->expression.params, exp);
 701
 702     /*
 703      * if (exp == 0.0)
 704      *     return 1;
 705      */
 706     vec_push(body->exprs,
 707         (ast_expression*)ast_ifthen_new(
 708             intrin_ctx(intrin),
 709             (ast_expression*)ast_binary_new(
 710                 intrin_ctx(intrin),
 711                 INSTR_EQ_F,
 712                 (ast_expression*)exp,
 713                 (ast_expression*)intrin->fold->imm_float[0]
 714             ),
 715             (ast_expression*)ast_return_new(
 716                 intrin_ctx(intrin),
 717                 (ast_expression*)intrin->fold->imm_float[1]
 718             ),
 719             NULL
 720         )
 721     );
 722
 723     /*
 724      * if (exp == 1.0)
 725      *     return base;
 726      */
 727     vec_push(body->exprs,
 728         (ast_expression*)ast_ifthen_new(
 729             intrin_ctx(intrin),
 730             (ast_expression*)ast_binary_new(
 731                 intrin_ctx(intrin),
 732                 INSTR_EQ_F,
 733                 (ast_expression*)exp,
 734                 (ast_expression*)intrin->fold->imm_float[1]
 735             ),
 736             (ast_expression*)ast_return_new(
 737                 intrin_ctx(intrin),
 738                 (ast_expression*)base
 739             ),
 740             NULL
 741         )
 742     );
 743
 744     /* <callpow1> = pow(base, -exp) */
 745     vec_push(callpow1->params, (ast_expression*)base);
 746     vec_push(callpow1->params,
 747         (ast_expression*)ast_unary_new(
 748             intrin_ctx(intrin),
 749             VINSTR_NEG_F,
 750             (ast_expression*)exp
 751         )
 752     );
 753
 754     /*
 755      * if (exp < 0)
 756      *     return 1.0 / <callpow1>;
 757      */
 758     vec_push(body->exprs,
 759         (ast_expression*)ast_ifthen_new(
 760             intrin_ctx(intrin),
 761             (ast_expression*)ast_binary_new(
 762                 intrin_ctx(intrin),
 763                 INSTR_LT,
 764                 (ast_expression*)exp,
 765                 (ast_expression*)intrin->fold->imm_float[0]
 766             ),
 767             (ast_expression*)ast_return_new(
 768                 intrin_ctx(intrin),
 769                 (ast_expression*)ast_binary_new(
 770                     intrin_ctx(intrin),
 771                     INSTR_DIV_F,
 772                     (ast_expression*)intrin->fold->imm_float[1],
 773                     (ast_expression*)callpow1
 774                 )
 775             ),
 776             NULL
 777         )
 778     );
 779
 780     /* <callpow2> = pow(base, exp / 2) */
 781     vec_push(callpow2->params, (ast_expression*)base);
 782     vec_push(callpow2->params,
 783         (ast_expression*)ast_binary_new(
 784             intrin_ctx(intrin),
 785             INSTR_DIV_F,
 786             (ast_expression*)exp,
 787             (ast_expression*)fold_constgen_float(intrin->fold, 2.0f)
 788         )
 789     );
 790
 791     /*
 792      * <expgt1> = {
 793      *     result = <callpow2>;
 794      *     return result * result;
 795      * }
 796      */
 797     vec_push(expgt1->exprs,
 798         (ast_expression*)ast_store_new(
 799             intrin_ctx(intrin),
 800             INSTR_STORE_F,
 801             (ast_expression*)result,
 802             (ast_expression*)callpow2
 803         )
 804     );
 805     vec_push(expgt1->exprs,
 806         (ast_expression*)ast_return_new(
 807             intrin_ctx(intrin),
 808             (ast_expression*)ast_binary_new(
 809                 intrin_ctx(intrin),
 810                 INSTR_MUL_F,
 811                 (ast_expression*)result,
 812                 (ast_expression*)result
 813             )
 814         )
 815     );
 816
 817     /*
 818      * if (exp >= 1) {
 819      *     <expgt1>
 820      * }
 821      */
 822     vec_push(body->exprs,
 823         (ast_expression*)ast_ifthen_new(
 824             intrin_ctx(intrin),
 825             (ast_expression*)ast_binary_new(
 826                 intrin_ctx(intrin),
 827                 INSTR_GE,
 828                 (ast_expression*)exp,
 829                 (ast_expression*)intrin->fold->imm_float[1]
 830             ),
 831             (ast_expression*)expgt1,
 832             NULL
 833         )
 834     );
 835
 836     /*
 837      * <callsqrt1> = sqrt(base)
 838      */
 839     vec_push(callsqrt1->params, (ast_expression*)base);
 840
 841     /*
 842      * low        = 0.0f;
 843      * high       = 1.0f;
 844      * square     = sqrt(base);
 845      * accumulate = square;
 846      * mid        = high / 2.0f;
 847      */
 848     vec_push(body->exprs,
 849         (ast_expression*)ast_store_new(intrin_ctx(intrin),
 850             INSTR_STORE_F,
 851             (ast_expression*)low,
 852             (ast_expression*)intrin->fold->imm_float[0]
 853         )
 854     );
 855     vec_push(body->exprs,
 856         (ast_expression*)ast_store_new(
 857             intrin_ctx(intrin),
 858             INSTR_STORE_F,
 859             (ast_expression*)high,
 860             (ast_expression*)intrin->fold->imm_float[1]
 861         )
 862     );
 863
 864     vec_push(body->exprs,
 865         (ast_expression*)ast_store_new(
 866             intrin_ctx(intrin),
 867             INSTR_STORE_F,
 868             (ast_expression*)square,
 869             (ast_expression*)callsqrt1
 870         )
 871     );
 872
 873     vec_push(body->exprs,
 874         (ast_expression*)ast_store_new(
 875             intrin_ctx(intrin),
 876             INSTR_STORE_F,
 877             (ast_expression*)accumulate,
 878             (ast_expression*)square
 879         )
 880     );
 881     vec_push(body->exprs,
 882         (ast_expression*)ast_store_new(
 883             intrin_ctx(intrin),
 884             INSTR_STORE_F,
 885             (ast_expression*)mid,
 886             (ast_expression*)ast_binary_new(
 887                 intrin_ctx(intrin),
 888                 INSTR_DIV_F,
 889                 (ast_expression*)high,
 890                 (ast_expression*)fold_constgen_float(intrin->fold, 2.0f)
 891             )
 892         )
 893     );
 894
 895     /*
 896      * <midltexp> = {
 897      *     low         = mid;
 898      *     accumulate *= square;
 899      * }
 900      */
 901     vec_push(midltexp->exprs,
 902         (ast_expression*)ast_store_new(
 903             intrin_ctx(intrin),
 904             INSTR_STORE_F,
 905             (ast_expression*)low,
 906             (ast_expression*)mid
 907         )
 908     );
 909     vec_push(midltexp->exprs,
 910         (ast_expression*)ast_binstore_new(
 911             intrin_ctx(intrin),
 912             INSTR_STORE_F,
 913             INSTR_MUL_F,
 914             (ast_expression*)accumulate,
 915             (ast_expression*)square
 916         )
 917     );
 918
 919     /*
 920      * <midltexpelse> = {
 921      *     high        = mid;
 922      *     accumulate *= (1.0 / square);
 923      * }
 924      */
 925     vec_push(midltexpelse->exprs,
 926         (ast_expression*)ast_store_new(
 927             intrin_ctx(intrin),
 928             INSTR_STORE_F,
 929             (ast_expression*)high,
 930             (ast_expression*)mid
 931         )
 932     );
 933     vec_push(midltexpelse->exprs,
 934         (ast_expression*)ast_binstore_new(
 935             intrin_ctx(intrin),
 936             INSTR_STORE_F,
 937             INSTR_MUL_F,
 938             (ast_expression*)accumulate,
 939             (ast_expression*)ast_binary_new(
 940                 intrin_ctx(intrin),
 941                 INSTR_DIV_F,
 942                 (ast_expression*)intrin->fold->imm_float[1],
 943                 (ast_expression*)square
 944             )
 945         )
 946     );
 947
 948     /*
 949      * <callsqrt2> = sqrt(square)
 950      */
 951     vec_push(callsqrt2->params, (ast_expression*)square);
 952
 953     /*
 954      * <whileblock> = {
 955      *     square = <callsqrt2>;
 956      *     if (mid < exp)
 957      *          <midltexp>;
 958      *     else
 959      *          <midltexpelse>;
 960      *
 961      *     mid = (low + high) / 2;
 962      * }
 963      */
 964     vec_push(whileblock->exprs,
 965         (ast_expression*)ast_store_new(
 966             intrin_ctx(intrin),
 967             INSTR_STORE_F,
 968             (ast_expression*)square,
 969             (ast_expression*)callsqrt2
 970         )
 971     );
 972     vec_push(whileblock->exprs,
 973         (ast_expression*)ast_ifthen_new(
 974             intrin_ctx(intrin),
 975             (ast_expression*)ast_binary_new(
 976                 intrin_ctx(intrin),
 977                 INSTR_LT,
 978                 (ast_expression*)mid,
 979                 (ast_expression*)exp
 980             ),
 981             (ast_expression*)midltexp,
 982             (ast_expression*)midltexpelse
 983         )
 984     );
 985     vec_push(whileblock->exprs,
 986         (ast_expression*)ast_store_new(
 987             intrin_ctx(intrin),
 988             INSTR_STORE_F,
 989             (ast_expression*)mid,
 990             (ast_expression*)ast_binary_new(
 991                 intrin_ctx(intrin),
 992                 INSTR_DIV_F,
 993                 (ast_expression*)ast_binary_new(
 994                     intrin_ctx(intrin),
 995                     INSTR_ADD_F,
 996                     (ast_expression*)low,
 997                     (ast_expression*)high
 998                 ),
 999                 (ast_expression*)fold_constgen_float(intrin->fold, 2.0f)
1000             )
1001         )
1002     );
1003
1004     /*
1005      * <callabs> = fabs(mid - exp)
1006      */
1007     vec_push(callfabs->params,
1008         (ast_expression*)ast_binary_new(
1009             intrin_ctx(intrin),
1010             INSTR_SUB_F,
1011             (ast_expression*)mid,
1012             (ast_expression*)exp
1013         )
1014     );
1015
1016     /*
1017      * while (<callfabs>  > epsilon)
1018      *     <whileblock>
1019      */
1020     vec_push(body->exprs,
1021         (ast_expression*)ast_loop_new(
1022             intrin_ctx(intrin),
1023             /* init */
1024             NULL,
1025             /* pre condition */
1026             (ast_expression*)ast_binary_new(
1027                 intrin_ctx(intrin),
1028                 INSTR_GT,
1029                 (ast_expression*)callfabs,
1030                 (ast_expression*)fold_constgen_float(intrin->fold, QC_POW_EPSILON)
1031             ),
1032             /* pre not */
1033             false,
1034             /* post condition */
1035             NULL,
1036             /* post not */
1037             false,
1038             /* increment expression */
1039             NULL,
1040             /* code block */
1041             (ast_expression*)whileblock
1042         )
1043     );
1044
1045     /* return accumulate */
1046     vec_push(body->exprs,
1047         (ast_expression*)ast_return_new(
1048             intrin_ctx(intrin),
1049             (ast_expression*)accumulate
1050         )
1051     );
1052
1053     /* } */
1054     vec_push(func->blocks, body);
1055
1056     intrin_reg(intrin, value, func);
1057     return (ast_expression*)value;
1058 }
1059
1060 static ast_expression *intrin_mod(intrin_t *intrin) {
1061     /*
1062      * float mod(float a, float b) {
1063      *     float div = a / b;
1064      *     float sign = (div < 0.0f) ? -1 : 1;
1065      *     return a - b * sign * floor(sign * div);
1066      * }
1067      */
1068     ast_value    *value = NULL;
1069     ast_call     *call  = ast_call_new (intrin_ctx(intrin), intrin_func_self(intrin, "floor", "mod"));
1070     ast_value    *a     = ast_value_new(intrin_ctx(intrin), "a",    TYPE_FLOAT);
1071     ast_value    *b     = ast_value_new(intrin_ctx(intrin), "b",    TYPE_FLOAT);
1072     ast_value    *div   = ast_value_new(intrin_ctx(intrin), "div",  TYPE_FLOAT);
1073     ast_value    *sign  = ast_value_new(intrin_ctx(intrin), "sign", TYPE_FLOAT);
1074     ast_block    *body  = ast_block_new(intrin_ctx(intrin));
1075     ast_function *func  = intrin_value(intrin, &value, "mod", TYPE_FLOAT);
1076
1077     vec_push(value->expression.params, a);
1078     vec_push(value->expression.params, b);
1079
1080     vec_push(body->locals, div);
1081     vec_push(body->locals, sign);
1082
1083     /* div = a / b; */
1084     vec_push(body->exprs,
1085         (ast_expression*)ast_store_new(
1086             intrin_ctx(intrin),
1087             INSTR_STORE_F,
1088             (ast_expression*)div,
1089             (ast_expression*)ast_binary_new(
1090                 intrin_ctx(intrin),
1091                 INSTR_DIV_F,
1092                 (ast_expression*)a,
1093                 (ast_expression*)b
1094             )
1095         )
1096     );
1097
1098     /* sign = (div < 0.0f) ? -1 : 1; */
1099     vec_push(body->exprs,
1100         (ast_expression*)ast_store_new(
1101             intrin_ctx(intrin),
1102             INSTR_STORE_F,
1103             (ast_expression*)sign,
1104             (ast_expression*)ast_ternary_new(
1105                 intrin_ctx(intrin),
1106                 (ast_expression*)ast_binary_new(
1107                     intrin_ctx(intrin),
1108                     INSTR_LT,
1109                     (ast_expression*)div,
1110                     (ast_expression*)intrin->fold->imm_float[0]
1111                 ),
1112                 (ast_expression*)intrin->fold->imm_float[2],
1113                 (ast_expression*)intrin->fold->imm_float[1]
1114             )
1115         )
1116     );
1117
1118     /* floor(sign * div) */
1119     vec_push(call->params,
1120         (ast_expression*)ast_binary_new(
1121             intrin_ctx(intrin),
1122             INSTR_MUL_F,
1123             (ast_expression*)sign,
1124             (ast_expression*)div
1125         )
1126     );
1127
1128     /* return a - b * sign * <call> */
1129     vec_push(body->exprs,
1130         (ast_expression*)ast_return_new(
1131             intrin_ctx(intrin),
1132             (ast_expression*)ast_binary_new(
1133                 intrin_ctx(intrin),
1134                 INSTR_SUB_F,
1135                 (ast_expression*)a,
1136                 (ast_expression*)ast_binary_new(
1137                     intrin_ctx(intrin),
1138                     INSTR_MUL_F,
1139                     (ast_expression*)b,
1140                     (ast_expression*)ast_binary_new(
1141                         intrin_ctx(intrin),
1142                         INSTR_MUL_F,
1143                         (ast_expression*)sign,
1144                         (ast_expression*)call
1145                     )
1146                 )
1147             )
1148         )
1149     );
1150
1151     vec_push(func->blocks, body);
1152     intrin_reg(intrin, value, func);
1153
1154     return (ast_expression*)value;
1155 }
1156
1157 static ast_expression *intrin_fabs(intrin_t *intrin) {
1158     /*
1159      * float fabs(float x) {
1160      *     return x < 0 ? -x : x;
1161      * }
1162      */
1163     ast_value    *value  = NULL;
1164     ast_value    *arg1   = ast_value_new(intrin_ctx(intrin), "x", TYPE_FLOAT);
1165     ast_block    *body   = ast_block_new(intrin_ctx(intrin));
1166     ast_function *func   = intrin_value(intrin, &value, "fabs", TYPE_FLOAT);
1167
1168     vec_push(body->exprs,
1169         (ast_expression*)ast_return_new(
1170             intrin_ctx(intrin),
1171             (ast_expression*)ast_ternary_new(
1172                 intrin_ctx(intrin),
1173                 (ast_expression*)ast_binary_new(
1174                     intrin_ctx(intrin),
1175                     INSTR_LE,
1176                     (ast_expression*)arg1,
1177                     (ast_expression*)intrin->fold->imm_float[0]
1178                 ),
1179                 (ast_expression*)ast_unary_new(
1180                     intrin_ctx(intrin),
1181                     VINSTR_NEG_F,
1182                     (ast_expression*)arg1
1183                 ),
1184                 (ast_expression*)arg1
1185             )
1186         )
1187     );
1188
1189     vec_push(value->expression.params, arg1);
1190     vec_push(func->blocks, body);
1191
1192     intrin_reg(intrin, value, func);
1193
1194     return (ast_expression*)value;
1195 }
1196
1197 /*
1198  * TODO: make static (and handle ast_type_string) here for the builtin
1199  * instead of in SYA parse close.
1200  */
1201 ast_expression *intrin_debug_typestring(intrin_t *intrin) {
1202     (void)intrin;
1203     return (ast_expression*)0x1;
1204 }
1205
1206 static const intrin_func_t intrinsics[] = {
1207     {&intrin_isfinite,         "__builtin_isfinite",         "isfinite", 1},
1208     {&intrin_isinf,            "__builtin_isinf",            "isinf",    1},
1209     {&intrin_isnan,            "__builtin_isnan",            "isnan",    1},
1210     {&intrin_isnormal,         "__builtin_isnormal",         "isnormal", 1},
1211     {&intrin_signbit,          "__builtin_signbit",          "signbit",  1},
1212     {&intrin_acosh,            "__builtin_acosh",            "acosh",    1},
1213     {&intrin_asinh,            "__builtin_asinh",            "asinh",    1},
1214     {&intrin_atanh,            "__builtin_atanh",            "atanh",    1},
1215     {&intrin_exp,              "__builtin_exp",              "exp",      1},
1216     {&intrin_exp2,             "__builtin_exp2",             "exp2",     1},
1217     {&intrin_expm1,            "__builtin_expm1",            "expm1",    1},
1218     {&intrin_mod,              "__builtin_mod",              "mod",      2},
1219     {&intrin_pow,              "__builtin_pow",              "pow",      2},
1220     {&intrin_fabs,             "__builtin_fabs",             "fabs",     1},
1221     {&intrin_debug_typestring, "__builtin_debug_typestring", "",         0},
1222
1223     {&intrin_nullfunc,         "#nullfunc",                  "",         0}
1224 };
1225
1226 static void intrin_error(intrin_t *intrin, const char *fmt, ...) {
1227     va_list ap;
1228     va_start(ap, fmt);
1229     vcompile_error(intrin->parser->lex->tok.ctx, fmt, ap);
1230     va_end(ap);
1231 }
1232
1233 /* exposed */
1234 intrin_t *intrin_init(parser_t *parser) {
1235     intrin_t *intrin = (intrin_t*)mem_a(sizeof(intrin_t));
1236     size_t    i;
1237
1238     intrin->parser     = parser;
1239     intrin->fold       = parser->fold;
1240     intrin->intrinsics = NULL;
1241     intrin->generated  = NULL;
1242
1243     vec_append(intrin->intrinsics, GMQCC_ARRAY_COUNT(intrinsics), intrinsics);
1244
1245     /* populate with null pointers for tracking generation */
1246     for (i = 0; i < GMQCC_ARRAY_COUNT(intrinsics); i++)
1247         vec_push(intrin->generated, NULL);
1248
1249     return intrin;
1250 }
1251
1252 void intrin_cleanup(intrin_t *intrin) {
1253     vec_free(intrin->intrinsics);
1254     vec_free(intrin->generated);
1255     mem_d(intrin);
1256 }
1257
1258 ast_expression *intrin_fold(intrin_t *intrin, ast_value *value, ast_expression **exprs) {
1259     size_t i;
1260     if (!value || !value->name)
1261         return NULL;
1262     for (i = 0; i < vec_size(intrin->intrinsics); i++)
1263         if (!strcmp(value->name, intrin->intrinsics[i].name))
1264             return (vec_size(exprs) != intrin->intrinsics[i].args)
1265                         ? NULL
1266                         : fold_intrin(intrin->fold, value->name + 10, exprs);
1267     return NULL;
1268 }
1269
1270 static GMQCC_INLINE ast_expression *intrin_func_try(intrin_t *intrin, size_t offset, const char *compare) {
1271     size_t i;
1272     for (i = 0; i < vec_size(intrin->intrinsics); i++) {
1273         if (strcmp(*(char **)((char *)&intrin->intrinsics[i] + offset), compare))
1274             continue;
1275         if (intrin->generated[i])
1276             return intrin->generated[i];
1277         return intrin->generated[i] = intrin->intrinsics[i].intrin(intrin);
1278     }
1279     return NULL;
1280 }
1281
1282 static ast_expression *intrin_func_self(intrin_t *intrin, const char *name, const char *from) {
1283     size_t           i;
1284     ast_expression  *find;
1285
1286     /* try current first */
1287     if ((find = parser_find_global(intrin->parser, name)) && ((ast_value*)find)->expression.vtype == TYPE_FUNCTION)
1288         for (i = 0; i < vec_size(intrin->parser->functions); ++i)
1289             if (((ast_value*)find)->name && !strcmp(intrin->parser->functions[i]->name, ((ast_value*)find)->name) && intrin->parser->functions[i]->builtin < 0)
1290                 return find;
1291     /* try name second */
1292     if ((find = intrin_func_try(intrin, offsetof(intrin_func_t, name),  name)))
1293         return find;
1294     /* try alias third */
1295     if ((find = intrin_func_try(intrin, offsetof(intrin_func_t, alias), name)))
1296         return find;
1297
1298     if (from) {
1299         intrin_error(intrin, "need function `%s', compiler depends on it for `__builtin_%s'", name, from);
1300         return intrin_func_self(intrin, "#nullfunc", NULL);
1301     }
1302     return NULL;
1303 }
1304
1305 ast_expression *intrin_func(intrin_t *intrin, const char *name) {
1306     return intrin_func_self(intrin, name, NULL);
1307 }