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