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 /* does not allocate, even though from_signed_cell can allocate */
  17 /* Division can only overflow when we are dividing the most negative fixnum
  18 by -1. */
  19 void factor_vm::primitive_fixnum_divint()
  20 {
  21         fixnum y = untag_fixnum(ctx->pop());
  22         fixnum x = untag_fixnum(ctx->peek());
  23         fixnum result = x / y;
  24         if(result == -fixnum_min)
  25                 /* Does not allocate */
  26                 ctx->replace(from_signed_cell(-fixnum_min));
  27         else
  28                 ctx->replace(tag_fixnum(result));
  29 }
  30
  31 /* does not allocate, even though from_signed_cell can allocate */
  32 void factor_vm::primitive_fixnum_divmod()
  33 {
  34         cell *s0 = (cell *)(ctx->datastack);
  35         cell *s1 = (cell *)(ctx->datastack - sizeof(cell));
  36         fixnum y = untag_fixnum(*s0);
  37         fixnum x = untag_fixnum(*s1);
  38         if(y == -1 && x == fixnum_min)
  39         {
  40                 /* Does not allocate */
  41                 *s1 = from_signed_cell(-fixnum_min);
  42                 *s0 = tag_fixnum(0);
  43         }
  44         else
  45         {
  46                 *s1 = tag_fixnum(x / y);
  47                 *s0 = tag_fixnum(x % y);
  48         }
  49 }
  50
  51 /*
  52  * If we're shifting right by n bits, we won't overflow as long as none of the
  53  * high WORD_SIZE-TAG_BITS-n bits are set.
  54  */
  55 inline fixnum factor_vm::sign_mask(fixnum x)
  56 {
  57         return x >> (WORD_SIZE - 1);
  58 }
  59
  60 inline fixnum factor_vm::branchless_max(fixnum x, fixnum y)
  61 {
  62         return (x - ((x - y) & sign_mask(x - y)));
  63 }
  64
  65 inline fixnum factor_vm::branchless_abs(fixnum x)
  66 {
  67         return (x ^ sign_mask(x)) - sign_mask(x);
  68 }
  69
  70 void factor_vm::primitive_fixnum_shift()
  71 {
  72         fixnum y = untag_fixnum(ctx->pop());
  73         fixnum x = untag_fixnum(ctx->peek());
  74
  75         if(x == 0)
  76                 return;
  77         else if(y < 0)
  78         {
  79                 y = branchless_max(y,-WORD_SIZE + 1);
  80                 ctx->replace(tag_fixnum(x >> -y));
  81                 return;
  82         }
  83         else if(y < WORD_SIZE - TAG_BITS)
  84         {
  85                 fixnum mask = -((fixnum)1 << (WORD_SIZE - 1 - TAG_BITS - y));
  86                 if(!(branchless_abs(x) & mask))
  87                 {
  88                         ctx->replace(tag_fixnum(x << y));
  89                         return;
  90                 }
  91         }
  92
  93         ctx->replace(tag<bignum>(bignum_arithmetic_shift(
  94                 fixnum_to_bignum(x),y)));
  95 }
  96
  97 void factor_vm::primitive_fixnum_to_bignum()
  98 {
  99         ctx->replace(tag<bignum>(fixnum_to_bignum(untag_fixnum(ctx->peek()))));
 100 }
 101
 102 void factor_vm::primitive_float_to_bignum()
 103 {
 104         ctx->replace(tag<bignum>(float_to_bignum(ctx->peek())));
 105 }
 106
 107 #define POP_BIGNUMS(x,y) \
 108         bignum * y = untag<bignum>(ctx->pop()); \
 109         bignum * x = untag<bignum>(ctx->pop());
 110
 111 void factor_vm::primitive_bignum_eq()
 112 {
 113         POP_BIGNUMS(x,y);
 114         ctx->push(tag_boolean(bignum_equal_p(x,y)));
 115 }
 116
 117 void factor_vm::primitive_bignum_add()
 118 {
 119         POP_BIGNUMS(x,y);
 120         ctx->push(tag<bignum>(bignum_add(x,y)));
 121 }
 122
 123 void factor_vm::primitive_bignum_subtract()
 124 {
 125         POP_BIGNUMS(x,y);
 126         ctx->push(tag<bignum>(bignum_subtract(x,y)));
 127 }
 128
 129 void factor_vm::primitive_bignum_multiply()
 130 {
 131         POP_BIGNUMS(x,y);
 132         ctx->push(tag<bignum>(bignum_multiply(x,y)));
 133 }
 134
 135 void factor_vm::primitive_bignum_divint()
 136 {
 137         POP_BIGNUMS(x,y);
 138         ctx->push(tag<bignum>(bignum_quotient(x,y)));
 139 }
 140
 141 void factor_vm::primitive_bignum_divmod()
 142 {
 143         bignum *q, *r;
 144         POP_BIGNUMS(x,y);
 145         bignum_divide(x,y,&q,&r);
 146         ctx->push(tag<bignum>(q));
 147         ctx->push(tag<bignum>(r));
 148 }
 149
 150 void factor_vm::primitive_bignum_mod()
 151 {
 152         POP_BIGNUMS(x,y);
 153         ctx->push(tag<bignum>(bignum_remainder(x,y)));
 154 }
 155
 156 void factor_vm::primitive_bignum_gcd()
 157 {
 158         POP_BIGNUMS(x,y);
 159         ctx->push(tag<bignum>(bignum_gcd(x,y)));
 160 }
 161
 162 void factor_vm::primitive_bignum_and()
 163 {
 164         POP_BIGNUMS(x,y);
 165         ctx->push(tag<bignum>(bignum_bitwise_and(x,y)));
 166 }
 167
 168 void factor_vm::primitive_bignum_or()
 169 {
 170         POP_BIGNUMS(x,y);
 171         ctx->push(tag<bignum>(bignum_bitwise_ior(x,y)));
 172 }
 173
 174 void factor_vm::primitive_bignum_xor()
 175 {
 176         POP_BIGNUMS(x,y);
 177         ctx->push(tag<bignum>(bignum_bitwise_xor(x,y)));
 178 }
 179
 180 void factor_vm::primitive_bignum_shift()
 181 {
 182         fixnum y = untag_fixnum(ctx->pop());
 183         bignum* x = untag<bignum>(ctx->pop());
 184         ctx->push(tag<bignum>(bignum_arithmetic_shift(x,y)));
 185 }
 186
 187 void factor_vm::primitive_bignum_less()
 188 {
 189         POP_BIGNUMS(x,y);
 190         ctx->push(tag_boolean(bignum_compare(x,y) == bignum_comparison_less));
 191 }
 192
 193 void factor_vm::primitive_bignum_lesseq()
 194 {
 195         POP_BIGNUMS(x,y);
 196         ctx->push(tag_boolean(bignum_compare(x,y) != bignum_comparison_greater));
 197 }
 198
 199 void factor_vm::primitive_bignum_greater()
 200 {
 201         POP_BIGNUMS(x,y);
 202         ctx->push(tag_boolean(bignum_compare(x,y) == bignum_comparison_greater));
 203 }
 204
 205 void factor_vm::primitive_bignum_greatereq()
 206 {
 207         POP_BIGNUMS(x,y);
 208         ctx->push(tag_boolean(bignum_compare(x,y) != bignum_comparison_less));
 209 }
 210
 211 void factor_vm::primitive_bignum_not()
 212 {
 213         ctx->replace(tag<bignum>(bignum_bitwise_not(untag<bignum>(ctx->peek()))));
 214 }
 215
 216 void factor_vm::primitive_bignum_bitp()
 217 {
 218         int bit = (int)to_fixnum(ctx->pop());
 219         bignum *x = untag<bignum>(ctx->pop());
 220         ctx->push(tag_boolean(bignum_logbitp(bit,x)));
 221 }
 222
 223 void factor_vm::primitive_bignum_log2()
 224 {
 225         ctx->replace(tag<bignum>(bignum_integer_length(untag<bignum>(ctx->peek()))));
 226 }
 227
 228 /* allocates memory */
 229 cell factor_vm::unbox_array_size_slow()
 230 {
 231         if(tagged<object>(ctx->peek()).type() == BIGNUM_TYPE)
 232         {
 233                 bignum *zero = untag<bignum>(bignum_zero);
 234                 GC_BIGNUM(zero);
 235                 bignum *max = cell_to_bignum(array_size_max);
 236                 bignum *n = untag<bignum>(ctx->peek());
 237                 if(bignum_compare(n,zero) != bignum_comparison_less
 238                         && bignum_compare(n,max) == bignum_comparison_less)
 239                 {
 240                         ctx->pop();
 241                         return bignum_to_cell(n);
 242                 }
 243         }
 244
 245         general_error(ERROR_ARRAY_SIZE,ctx->pop(),tag_fixnum(array_size_max));
 246         return 0; /* can't happen */
 247 }
 248
 249 void factor_vm::primitive_fixnum_to_float()
 250 {
 251         ctx->replace(allot_float(fixnum_to_float(ctx->peek())));
 252 }
 253
 254 void factor_vm::primitive_format_float()
 255 {
 256         byte_array *array = allot_byte_array(100);
 257         char *format = alien_offset(ctx->pop());
 258         double value = untag_float_check(ctx->pop());
 259         SNPRINTF(array->data<char>(),99,format,value);
 260         ctx->push(tag<byte_array>(array));
 261 }
 262
 263 #define POP_FLOATS(x,y) \
 264         double y = untag_float(ctx->pop()); \
 265         double x = untag_float(ctx->pop());
 266
 267 void factor_vm::primitive_float_eq()
 268 {
 269         POP_FLOATS(x,y);
 270         ctx->push(tag_boolean(x == y));
 271 }
 272
 273 void factor_vm::primitive_float_add()
 274 {
 275         POP_FLOATS(x,y);
 276         ctx->push(allot_float(x + y));
 277 }
 278
 279 void factor_vm::primitive_float_subtract()
 280 {
 281         POP_FLOATS(x,y);
 282         ctx->push(allot_float(x - y));
 283 }
 284
 285 void factor_vm::primitive_float_multiply()
 286 {
 287         POP_FLOATS(x,y);
 288         ctx->push(allot_float(x * y));
 289 }
 290
 291 void factor_vm::primitive_float_divfloat()
 292 {
 293         POP_FLOATS(x,y);
 294         ctx->push(allot_float(x / y));
 295 }
 296
 297 void factor_vm::primitive_float_less()
 298 {
 299         POP_FLOATS(x,y);
 300         ctx->push(tag_boolean(x < y));
 301 }
 302
 303 void factor_vm::primitive_float_lesseq()
 304 {
 305         POP_FLOATS(x,y);
 306         ctx->push(tag_boolean(x <= y));
 307 }
 308
 309 void factor_vm::primitive_float_greater()
 310 {
 311         POP_FLOATS(x,y);
 312         ctx->push(tag_boolean(x > y));
 313 }
 314
 315 void factor_vm::primitive_float_greatereq()
 316 {
 317         POP_FLOATS(x,y);
 318         ctx->push(tag_boolean(x >= y));
 319 }
 320
 321 /* Allocates memory */
 322 void factor_vm::primitive_float_bits()
 323 {
 324         ctx->push(from_unsigned_cell(float_bits((float)untag_float_check(ctx->pop()))));
 325 }
 326
 327 /* Allocates memory */
 328 void factor_vm::primitive_bits_float()
 329 {
 330         ctx->push(allot_float(bits_float((u32)to_cell(ctx->pop()))));
 331 }
 332
 333 void factor_vm::primitive_double_bits()
 334 {
 335         ctx->push(from_unsigned_8(double_bits(untag_float_check(ctx->pop()))));
 336 }
 337
 338 void factor_vm::primitive_bits_double()
 339 {
 340         ctx->push(allot_float(bits_double(to_unsigned_8(ctx->pop()))));
 341 }
 342
 343 /* Cannot allocate */
 344 fixnum factor_vm::to_fixnum(cell tagged)
 345 {
 346         switch(TAG(tagged))
 347         {
 348         case FIXNUM_TYPE:
 349                 return untag_fixnum(tagged);
 350         case BIGNUM_TYPE:
 351                 return bignum_to_fixnum(untag<bignum>(tagged));
 352         default:
 353                 type_error(FIXNUM_TYPE,tagged);
 354                 return 0; /* can't happen */
 355         }
 356 }
 357
 358 VM_C_API fixnum to_fixnum(cell tagged, factor_vm *parent)
 359 {
 360         return parent->to_fixnum(tagged);
 361 }
 362
 363 cell factor_vm::to_cell(cell tagged)
 364 {
 365         return (cell)to_fixnum(tagged);
 366 }
 367
 368 VM_C_API cell to_cell(cell tagged, factor_vm *parent)
 369 {
 370         return parent->to_cell(tagged);
 371 }
 372
 373 /* Allocates memory */
 374 VM_C_API cell from_signed_cell(fixnum integer, factor_vm *parent)
 375 {
 376         return parent->from_signed_cell(integer);
 377 }
 378
 379 /* Allocates memory */
 380 VM_C_API cell from_unsigned_cell(cell integer, factor_vm *parent)
 381 {
 382         return parent->from_unsigned_cell(integer);
 383 }
 384
 385 /* Allocates memory */
 386 cell factor_vm::from_signed_8(s64 n)
 387 {
 388         if(n < fixnum_min || n > fixnum_max)
 389                 return tag<bignum>(long_long_to_bignum(n));
 390         else
 391                 return tag_fixnum((fixnum)n);
 392 }
 393
 394 VM_C_API cell from_signed_8(s64 n, factor_vm *parent)
 395 {
 396         return parent->from_signed_8(n);
 397 }
 398
 399 /* Cannot allocate */
 400 s64 factor_vm::to_signed_8(cell obj)
 401 {
 402         switch(tagged<object>(obj).type())
 403         {
 404         case FIXNUM_TYPE:
 405                 return untag_fixnum(obj);
 406         case BIGNUM_TYPE:
 407                 return bignum_to_long_long(untag<bignum>(obj));
 408         default:
 409                 type_error(BIGNUM_TYPE,obj);
 410                 return 0;
 411         }
 412 }
 413
 414 VM_C_API s64 to_signed_8(cell obj, factor_vm *parent)
 415 {
 416         return parent->to_signed_8(obj);
 417 }
 418
 419 cell factor_vm::from_unsigned_8(u64 n)
 420 {
 421         if(n > (u64)fixnum_max)
 422                 return tag<bignum>(ulong_long_to_bignum(n));
 423         else
 424                 return tag_fixnum((fixnum)n);
 425 }
 426
 427 VM_C_API cell from_unsigned_8(u64 n, factor_vm *parent)
 428 {
 429         return parent->from_unsigned_8(n);
 430 }
 431
 432 /* Cannot allocate */
 433 u64 factor_vm::to_unsigned_8(cell obj)
 434 {
 435         switch(tagged<object>(obj).type())
 436         {
 437         case FIXNUM_TYPE:
 438                 return untag_fixnum(obj);
 439         case BIGNUM_TYPE:
 440                 return bignum_to_ulong_long(untag<bignum>(obj));
 441         default:
 442                 type_error(BIGNUM_TYPE,obj);
 443                 return 0;
 444         }
 445 }
 446
 447 VM_C_API u64 to_unsigned_8(cell obj, factor_vm *parent)
 448 {
 449         return parent->to_unsigned_8(obj);
 450 }
 451
 452 /* Cannot allocate */
 453 float factor_vm::to_float(cell value)
 454 {
 455         return (float)untag_float_check(value);
 456 }
 457
 458 /* Cannot allocate */
 459 double factor_vm::to_double(cell value)
 460 {
 461         return untag_float_check(value);
 462 }
 463
 464 /* The fixnum+, fixnum- and fixnum* primitives are defined in cpu_*.S. On
 465 overflow, they call these functions. */
 466 inline void factor_vm::overflow_fixnum_add(fixnum x, fixnum y)
 467 {
 468         ctx->replace(tag<bignum>(fixnum_to_bignum(
 469                 untag_fixnum(x) + untag_fixnum(y))));
 470 }
 471
 472 VM_C_API void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *parent)
 473 {
 474         parent->overflow_fixnum_add(x,y);
 475 }
 476
 477 inline void factor_vm::overflow_fixnum_subtract(fixnum x, fixnum y)
 478 {
 479         ctx->replace(tag<bignum>(fixnum_to_bignum(
 480                 untag_fixnum(x) - untag_fixnum(y))));
 481 }
 482
 483 VM_C_API void overflow_fixnum_subtract(fixnum x, fixnum y, factor_vm *parent)
 484 {
 485         parent->overflow_fixnum_subtract(x,y);
 486 }
 487
 488 inline void factor_vm::overflow_fixnum_multiply(fixnum x, fixnum y)
 489 {
 490         bignum *bx = fixnum_to_bignum(x);
 491         GC_BIGNUM(bx);
 492         bignum *by = fixnum_to_bignum(y);
 493         GC_BIGNUM(by);
 494         ctx->replace(tag<bignum>(bignum_multiply(bx,by)));
 495 }
 496
 497 VM_C_API void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *parent)
 498 {
 499         parent->overflow_fixnum_multiply(x,y);
 500 }
 501
 502 }