vm/math.cpp

   1 #include "master.hpp"
   2
   3 namespace factor
   4 {
   5
   6 void factor_vm::primitive_bignum_to_fixnum()
   7 {
   8         ctx->replace(tag_fixnum(bignum_to_fixnum(untag<bignum>(ctx->peek()))));
   9 }
  10
  11 void factor_vm::primitive_float_to_fixnum()
  12 {
  13         ctx->replace(tag_fixnum(float_to_fixnum(ctx->peek())));
  14 }
  15
  16 /* Division can only overflow when we are dividing the most negative fixnum
  17 by -1. */
  18 void factor_vm::primitive_fixnum_divint()
  19 {
  20         fixnum y = untag_fixnum(ctx->pop()); \
  21         fixnum x = untag_fixnum(ctx->peek());
  22         fixnum result = x / y;
  23         if(result == -fixnum_min)
  24                 ctx->replace(from_signed_cell(-fixnum_min));
  25         else
  26                 ctx->replace(tag_fixnum(result));
  27 }
  28
  29 void factor_vm::primitive_fixnum_divmod()
  30 {
  31         cell y = ((cell *)ctx->datastack)[0];
  32         cell x = ((cell *)ctx->datastack)[-1];
  33         if(y == tag_fixnum(-1) && x == tag_fixnum(fixnum_min))
  34         {
  35                 ((cell *)ctx->datastack)[-1] = from_signed_cell(-fixnum_min);
  36                 ((cell *)ctx->datastack)[0] = tag_fixnum(0);
  37         }
  38         else
  39         {
  40                 ((cell *)ctx->datastack)[-1] = tag_fixnum(untag_fixnum(x) / untag_fixnum(y));
  41                 ((cell *)ctx->datastack)[0] = (fixnum)x % (fixnum)y;
  42         }
  43 }
  44
  45 /*
  46  * If we're shifting right by n bits, we won't overflow as long as none of the
  47  * high WORD_SIZE-TAG_BITS-n bits are set.
  48  */
  49 inline fixnum factor_vm::sign_mask(fixnum x)
  50 {
  51         return x >> (WORD_SIZE - 1);
  52 }
  53
  54 inline fixnum factor_vm::branchless_max(fixnum x, fixnum y)
  55 {
  56         return (x - ((x - y) & sign_mask(x - y)));
  57 }
  58
  59 inline fixnum factor_vm::branchless_abs(fixnum x)
  60 {
  61         return (x ^ sign_mask(x)) - sign_mask(x);
  62 }
  63
  64 void factor_vm::primitive_fixnum_shift()
  65 {
  66         fixnum y = untag_fixnum(ctx->pop());
  67         fixnum x = untag_fixnum(ctx->peek());
  68
  69         if(x == 0)
  70                 return;
  71         else if(y < 0)
  72         {
  73                 y = branchless_max(y,-WORD_SIZE + 1);
  74                 ctx->replace(tag_fixnum(x >> -y));
  75                 return;
  76         }
  77         else if(y < WORD_SIZE - TAG_BITS)
  78         {
  79                 fixnum mask = -((fixnum)1 << (WORD_SIZE - 1 - TAG_BITS - y));
  80                 if(!(branchless_abs(x) & mask))
  81                 {
  82                         ctx->replace(tag_fixnum(x << y));
  83                         return;
  84                 }
  85         }
  86
  87         ctx->replace(tag<bignum>(bignum_arithmetic_shift(
  88                 fixnum_to_bignum(x),y)));
  89 }
  90
  91 void factor_vm::primitive_fixnum_to_bignum()
  92 {
  93         ctx->replace(tag<bignum>(fixnum_to_bignum(untag_fixnum(ctx->peek()))));
  94 }
  95
  96 void factor_vm::primitive_float_to_bignum()
  97 {
  98         ctx->replace(tag<bignum>(float_to_bignum(ctx->peek())));
  99 }
 100
 101 #define POP_BIGNUMS(x,y) \
 102         bignum * y = untag<bignum>(ctx->pop()); \
 103         bignum * x = untag<bignum>(ctx->pop());
 104
 105 void factor_vm::primitive_bignum_eq()
 106 {
 107         POP_BIGNUMS(x,y);
 108         ctx->push(tag_boolean(bignum_equal_p(x,y)));
 109 }
 110
 111 void factor_vm::primitive_bignum_add()
 112 {
 113         POP_BIGNUMS(x,y);
 114         ctx->push(tag<bignum>(bignum_add(x,y)));
 115 }
 116
 117 void factor_vm::primitive_bignum_subtract()
 118 {
 119         POP_BIGNUMS(x,y);
 120         ctx->push(tag<bignum>(bignum_subtract(x,y)));
 121 }
 122
 123 void factor_vm::primitive_bignum_multiply()
 124 {
 125         POP_BIGNUMS(x,y);
 126         ctx->push(tag<bignum>(bignum_multiply(x,y)));
 127 }
 128
 129 void factor_vm::primitive_bignum_divint()
 130 {
 131         POP_BIGNUMS(x,y);
 132         ctx->push(tag<bignum>(bignum_quotient(x,y)));
 133 }
 134
 135 void factor_vm::primitive_bignum_divmod()
 136 {
 137         bignum *q, *r;
 138         POP_BIGNUMS(x,y);
 139         bignum_divide(x,y,&q,&r);
 140         ctx->push(tag<bignum>(q));
 141         ctx->push(tag<bignum>(r));
 142 }
 143
 144 void factor_vm::primitive_bignum_mod()
 145 {
 146         POP_BIGNUMS(x,y);
 147         ctx->push(tag<bignum>(bignum_remainder(x,y)));
 148 }
 149
 150 void factor_vm::primitive_bignum_and()
 151 {
 152         POP_BIGNUMS(x,y);
 153         ctx->push(tag<bignum>(bignum_bitwise_and(x,y)));
 154 }
 155
 156 void factor_vm::primitive_bignum_or()
 157 {
 158         POP_BIGNUMS(x,y);
 159         ctx->push(tag<bignum>(bignum_bitwise_ior(x,y)));
 160 }
 161
 162 void factor_vm::primitive_bignum_xor()
 163 {
 164         POP_BIGNUMS(x,y);
 165         ctx->push(tag<bignum>(bignum_bitwise_xor(x,y)));
 166 }
 167
 168 void factor_vm::primitive_bignum_shift()
 169 {
 170         fixnum y = untag_fixnum(ctx->pop());
 171         bignum* x = untag<bignum>(ctx->pop());
 172         ctx->push(tag<bignum>(bignum_arithmetic_shift(x,y)));
 173 }
 174
 175 void factor_vm::primitive_bignum_less()
 176 {
 177         POP_BIGNUMS(x,y);
 178         ctx->push(tag_boolean(bignum_compare(x,y) == bignum_comparison_less));
 179 }
 180
 181 void factor_vm::primitive_bignum_lesseq()
 182 {
 183         POP_BIGNUMS(x,y);
 184         ctx->push(tag_boolean(bignum_compare(x,y) != bignum_comparison_greater));
 185 }
 186
 187 void factor_vm::primitive_bignum_greater()
 188 {
 189         POP_BIGNUMS(x,y);
 190         ctx->push(tag_boolean(bignum_compare(x,y) == bignum_comparison_greater));
 191 }
 192
 193 void factor_vm::primitive_bignum_greatereq()
 194 {
 195         POP_BIGNUMS(x,y);
 196         ctx->push(tag_boolean(bignum_compare(x,y) != bignum_comparison_less));
 197 }
 198
 199 void factor_vm::primitive_bignum_not()
 200 {
 201         ctx->replace(tag<bignum>(bignum_bitwise_not(untag<bignum>(ctx->peek()))));
 202 }
 203
 204 void factor_vm::primitive_bignum_bitp()
 205 {
 206         int bit = (int)to_fixnum(ctx->pop());
 207         bignum *x = untag<bignum>(ctx->pop());
 208         ctx->push(tag_boolean(bignum_logbitp(bit,x)));
 209 }
 210
 211 void factor_vm::primitive_bignum_log2()
 212 {
 213         ctx->replace(tag<bignum>(bignum_integer_length(untag<bignum>(ctx->peek()))));
 214 }
 215
 216 unsigned int factor_vm::bignum_producer(unsigned int digit)
 217 {
 218         unsigned char *ptr = (unsigned char *)alien_offset(ctx->peek());
 219         return *(ptr + digit);
 220 }
 221
 222 unsigned int bignum_producer(unsigned int digit, factor_vm *parent)
 223 {
 224         return parent->bignum_producer(digit);
 225 }
 226
 227 void factor_vm::primitive_byte_array_to_bignum()
 228 {
 229         unsigned int n_digits = (unsigned int)array_capacity(untag_check<byte_array>(ctx->peek()));
 230         bignum * result = digit_stream_to_bignum(n_digits,factor::bignum_producer,0x100,0);
 231         ctx->replace(tag<bignum>(result));
 232 }
 233
 234 cell factor_vm::unbox_array_size_slow()
 235 {
 236         if(tagged<object>(ctx->peek()).type() == BIGNUM_TYPE)
 237         {
 238                 bignum *zero = untag<bignum>(bignum_zero);
 239                 bignum *max = cell_to_bignum(array_size_max);
 240                 bignum *n = untag<bignum>(ctx->peek());
 241                 if(bignum_compare(n,zero) != bignum_comparison_less
 242                         && bignum_compare(n,max) == bignum_comparison_less)
 243                 {
 244                         ctx->pop();
 245                         return bignum_to_cell(n);
 246                 }
 247         }
 248
 249         general_error(ERROR_ARRAY_SIZE,ctx->pop(),tag_fixnum(array_size_max));
 250         return 0; /* can't happen */
 251 }
 252
 253 void factor_vm::primitive_fixnum_to_float()
 254 {
 255         ctx->replace(allot_float(fixnum_to_float(ctx->peek())));
 256 }
 257
 258 void factor_vm::primitive_bignum_to_float()
 259 {
 260         ctx->replace(allot_float(bignum_to_float(ctx->peek())));
 261 }
 262
 263 void factor_vm::primitive_format_float()
 264 {
 265         byte_array *array = allot_byte_array(100);
 266         char *format = alien_offset(ctx->pop());
 267         double value = untag_float_check(ctx->pop());
 268         SNPRINTF(array->data<char>(),99,format,value);
 269         ctx->push(tag<byte_array>(array));
 270 }
 271
 272 #define POP_FLOATS(x,y) \
 273         double y = untag_float(ctx->pop()); \
 274         double x = untag_float(ctx->pop());
 275
 276 void factor_vm::primitive_float_eq()
 277 {
 278         POP_FLOATS(x,y);
 279         ctx->push(tag_boolean(x == y));
 280 }
 281
 282 void factor_vm::primitive_float_add()
 283 {
 284         POP_FLOATS(x,y);
 285         ctx->push(allot_float(x + y));
 286 }
 287
 288 void factor_vm::primitive_float_subtract()
 289 {
 290         POP_FLOATS(x,y);
 291         ctx->push(allot_float(x - y));
 292 }
 293
 294 void factor_vm::primitive_float_multiply()
 295 {
 296         POP_FLOATS(x,y);
 297         ctx->push(allot_float(x * y));
 298 }
 299
 300 void factor_vm::primitive_float_divfloat()
 301 {
 302         POP_FLOATS(x,y);
 303         ctx->push(allot_float(x / y));
 304 }
 305
 306 void factor_vm::primitive_float_mod()
 307 {
 308         POP_FLOATS(x,y);
 309         ctx->push(allot_float(fmod(x,y)));
 310 }
 311
 312 void factor_vm::primitive_float_less()
 313 {
 314         POP_FLOATS(x,y);
 315         ctx->push(tag_boolean(x < y));
 316 }
 317
 318 void factor_vm::primitive_float_lesseq()
 319 {
 320         POP_FLOATS(x,y);
 321         ctx->push(tag_boolean(x <= y));
 322 }
 323
 324 void factor_vm::primitive_float_greater()
 325 {
 326         POP_FLOATS(x,y);
 327         ctx->push(tag_boolean(x > y));
 328 }
 329
 330 void factor_vm::primitive_float_greatereq()
 331 {
 332         POP_FLOATS(x,y);
 333         ctx->push(tag_boolean(x >= y));
 334 }
 335
 336 void factor_vm::primitive_float_bits()
 337 {
 338         ctx->push(from_unsigned_cell(float_bits((float)untag_float_check(ctx->pop()))));
 339 }
 340
 341 void factor_vm::primitive_bits_float()
 342 {
 343         ctx->push(allot_float(bits_float((u32)to_cell(ctx->pop()))));
 344 }
 345
 346 void factor_vm::primitive_double_bits()
 347 {
 348         ctx->push(from_unsigned_8(double_bits(untag_float_check(ctx->pop()))));
 349 }
 350
 351 void factor_vm::primitive_bits_double()
 352 {
 353         ctx->push(allot_float(bits_double(to_unsigned_8(ctx->pop()))));
 354 }
 355
 356 /* Cannot allocate */
 357 fixnum factor_vm::to_fixnum(cell tagged)
 358 {
 359         switch(TAG(tagged))
 360         {
 361         case FIXNUM_TYPE:
 362                 return untag_fixnum(tagged);
 363         case BIGNUM_TYPE:
 364                 return bignum_to_fixnum(untag<bignum>(tagged));
 365         default:
 366                 type_error(FIXNUM_TYPE,tagged);
 367                 return 0; /* can't happen */
 368         }
 369 }
 370
 371 VM_C_API fixnum to_fixnum(cell tagged, factor_vm *parent)
 372 {
 373         return parent->to_fixnum(tagged);
 374 }
 375
 376 cell factor_vm::to_cell(cell tagged)
 377 {
 378         return (cell)to_fixnum(tagged);
 379 }
 380
 381 VM_C_API cell to_cell(cell tagged, factor_vm *parent)
 382 {
 383         return parent->to_cell(tagged);
 384 }
 385
 386 VM_C_API cell from_signed_cell(fixnum integer, factor_vm *parent)
 387 {
 388         return parent->from_signed_cell(integer);
 389 }
 390
 391 VM_C_API cell from_unsigned_cell(cell integer, factor_vm *parent)
 392 {
 393         return parent->from_unsigned_cell(integer);
 394 }
 395
 396 cell factor_vm::from_signed_8(s64 n)
 397 {
 398         if(n < fixnum_min || n > fixnum_max)
 399                 return tag<bignum>(long_long_to_bignum(n));
 400         else
 401                 return tag_fixnum((fixnum)n);
 402 }
 403
 404 VM_C_API cell from_signed_8(s64 n, factor_vm *parent)
 405 {
 406         return parent->from_signed_8(n);
 407 }
 408
 409 /* Cannot allocate */
 410 s64 factor_vm::to_signed_8(cell obj)
 411 {
 412         switch(tagged<object>(obj).type())
 413         {
 414         case FIXNUM_TYPE:
 415                 return untag_fixnum(obj);
 416         case BIGNUM_TYPE:
 417                 return bignum_to_long_long(untag<bignum>(obj));
 418         default:
 419                 type_error(BIGNUM_TYPE,obj);
 420                 return 0;
 421         }
 422 }
 423
 424 VM_C_API s64 to_signed_8(cell obj, factor_vm *parent)
 425 {
 426         return parent->to_signed_8(obj);
 427 }
 428
 429 cell factor_vm::from_unsigned_8(u64 n)
 430 {
 431         if(n > (u64)fixnum_max)
 432                 return tag<bignum>(ulong_long_to_bignum(n));
 433         else
 434                 return tag_fixnum((fixnum)n);
 435 }
 436
 437 VM_C_API cell from_unsigned_8(u64 n, factor_vm *parent)
 438 {
 439         return parent->from_unsigned_8(n);
 440 }
 441
 442 /* Cannot allocate */
 443 u64 factor_vm::to_unsigned_8(cell obj)
 444 {
 445         switch(tagged<object>(obj).type())
 446         {
 447         case FIXNUM_TYPE:
 448                 return untag_fixnum(obj);
 449         case BIGNUM_TYPE:
 450                 return bignum_to_ulong_long(untag<bignum>(obj));
 451         default:
 452                 type_error(BIGNUM_TYPE,obj);
 453                 return 0;
 454         }
 455 }
 456
 457 VM_C_API u64 to_unsigned_8(cell obj, factor_vm *parent)
 458 {
 459         return parent->to_unsigned_8(obj);
 460 }
 461
 462 /* Cannot allocate */
 463 float factor_vm::to_float(cell value)
 464 {
 465         return (float)untag_float_check(value);
 466 }
 467
 468 /* Cannot allocate */
 469 double factor_vm::to_double(cell value)
 470 {
 471         return untag_float_check(value);
 472 }
 473
 474 /* The fixnum+, fixnum- and fixnum* primitives are defined in cpu_*.S. On
 475 overflow, they call these functions. */
 476 inline void factor_vm::overflow_fixnum_add(fixnum x, fixnum y)
 477 {
 478         ctx->replace(tag<bignum>(fixnum_to_bignum(
 479                 untag_fixnum(x) + untag_fixnum(y))));
 480 }
 481
 482 VM_C_API void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *parent)
 483 {
 484         parent->overflow_fixnum_add(x,y);
 485 }
 486
 487 inline void factor_vm::overflow_fixnum_subtract(fixnum x, fixnum y)
 488 {
 489         ctx->replace(tag<bignum>(fixnum_to_bignum(
 490                 untag_fixnum(x) - untag_fixnum(y))));
 491 }
 492
 493 VM_C_API void overflow_fixnum_subtract(fixnum x, fixnum y, factor_vm *parent)
 494 {
 495         parent->overflow_fixnum_subtract(x,y);
 496 }
 497
 498 inline void factor_vm::overflow_fixnum_multiply(fixnum x, fixnum y)
 499 {
 500         bignum *bx = fixnum_to_bignum(x);
 501         GC_BIGNUM(bx);
 502         bignum *by = fixnum_to_bignum(y);
 503         GC_BIGNUM(by);
 504         ctx->replace(tag<bignum>(bignum_multiply(bx,by)));
 505 }
 506
 507 VM_C_API void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *parent)
 508 {
 509         parent->overflow_fixnum_multiply(x,y);
 510 }
 511
 512 }