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->peek());
 110
 111 void factor_vm::primitive_bignum_eq()
 112 {
 113         POP_BIGNUMS(x,y);
 114         ctx->replace(tag_boolean(bignum_equal_p(x,y)));
 115 }
 116
 117 void factor_vm::primitive_bignum_add()
 118 {
 119         POP_BIGNUMS(x,y);
 120         ctx->replace(tag<bignum>(bignum_add(x,y)));
 121 }
 122
 123 void factor_vm::primitive_bignum_subtract()
 124 {
 125         POP_BIGNUMS(x,y);
 126         ctx->replace(tag<bignum>(bignum_subtract(x,y)));
 127 }
 128
 129 void factor_vm::primitive_bignum_multiply()
 130 {
 131         POP_BIGNUMS(x,y);
 132         ctx->replace(tag<bignum>(bignum_multiply(x,y)));
 133 }
 134
 135 void factor_vm::primitive_bignum_divint()
 136 {
 137         POP_BIGNUMS(x,y);
 138         ctx->replace(tag<bignum>(bignum_quotient(x,y)));
 139 }
 140
 141 void factor_vm::primitive_bignum_divmod()
 142 {
 143         cell *s0 = (cell *)(ctx->datastack);
 144         cell *s1 = (cell *)(ctx->datastack - sizeof(cell));
 145         bignum *y = untag<bignum>(*s0);
 146         bignum *x = untag<bignum>(*s1);
 147         bignum *q, *r;
 148         bignum_divide(x, y, &q, &r);
 149         *s1 = tag<bignum>(q);
 150         *s0 = tag<bignum>(r);
 151 }
 152
 153 void factor_vm::primitive_bignum_mod()
 154 {
 155         POP_BIGNUMS(x,y);
 156         ctx->replace(tag<bignum>(bignum_remainder(x,y)));
 157 }
 158
 159 void factor_vm::primitive_bignum_gcd()
 160 {
 161         POP_BIGNUMS(x,y);
 162         ctx->replace(tag<bignum>(bignum_gcd(x,y)));
 163 }
 164
 165 void factor_vm::primitive_bignum_and()
 166 {
 167         POP_BIGNUMS(x,y);
 168         ctx->replace(tag<bignum>(bignum_bitwise_and(x,y)));
 169 }
 170
 171 void factor_vm::primitive_bignum_or()
 172 {
 173         POP_BIGNUMS(x,y);
 174         ctx->replace(tag<bignum>(bignum_bitwise_ior(x,y)));
 175 }
 176
 177 void factor_vm::primitive_bignum_xor()
 178 {
 179         POP_BIGNUMS(x,y);
 180         ctx->replace(tag<bignum>(bignum_bitwise_xor(x,y)));
 181 }
 182
 183 void factor_vm::primitive_bignum_shift()
 184 {
 185         fixnum y = untag_fixnum(ctx->pop());
 186         bignum* x = untag<bignum>(ctx->peek());
 187         ctx->replace(tag<bignum>(bignum_arithmetic_shift(x,y)));
 188 }
 189
 190 void factor_vm::primitive_bignum_less()
 191 {
 192         POP_BIGNUMS(x,y);
 193         ctx->replace(tag_boolean(bignum_compare(x,y) == bignum_comparison_less));
 194 }
 195
 196 void factor_vm::primitive_bignum_lesseq()
 197 {
 198         POP_BIGNUMS(x,y);
 199         ctx->replace(tag_boolean(bignum_compare(x,y) != bignum_comparison_greater));
 200 }
 201
 202 void factor_vm::primitive_bignum_greater()
 203 {
 204         POP_BIGNUMS(x,y);
 205         ctx->replace(tag_boolean(bignum_compare(x,y) == bignum_comparison_greater));
 206 }
 207
 208 void factor_vm::primitive_bignum_greatereq()
 209 {
 210         POP_BIGNUMS(x,y);
 211         ctx->replace(tag_boolean(bignum_compare(x,y) != bignum_comparison_less));
 212 }
 213
 214 void factor_vm::primitive_bignum_not()
 215 {
 216         ctx->replace(tag<bignum>(bignum_bitwise_not(untag<bignum>(ctx->peek()))));
 217 }
 218
 219 void factor_vm::primitive_bignum_bitp()
 220 {
 221         int bit = (int)to_fixnum(ctx->pop());
 222         bignum *x = untag<bignum>(ctx->pop());
 223         ctx->push(tag_boolean(bignum_logbitp(bit,x)));
 224 }
 225
 226 void factor_vm::primitive_bignum_log2()
 227 {
 228         ctx->replace(tag<bignum>(bignum_integer_length(untag<bignum>(ctx->peek()))));
 229 }
 230
 231 /* allocates memory */
 232 cell factor_vm::unbox_array_size_slow()
 233 {
 234         if(tagged<object>(ctx->peek()).type() == BIGNUM_TYPE)
 235         {
 236                 bignum *zero = untag<bignum>(bignum_zero);
 237                 GC_BIGNUM(zero);
 238                 bignum *max = cell_to_bignum(array_size_max);
 239                 bignum *n = untag<bignum>(ctx->peek());
 240                 if(bignum_compare(n,zero) != bignum_comparison_less
 241                         && bignum_compare(n,max) == bignum_comparison_less)
 242                 {
 243                         ctx->pop();
 244                         return bignum_to_cell(n);
 245                 }
 246         }
 247
 248         general_error(ERROR_ARRAY_SIZE,ctx->pop(),tag_fixnum(array_size_max));
 249         return 0; /* can't happen */
 250 }
 251
 252 void factor_vm::primitive_fixnum_to_float()
 253 {
 254         ctx->replace(allot_float(fixnum_to_float(ctx->peek())));
 255 }
 256
 257 void factor_vm::primitive_format_float()
 258 {
 259         byte_array *array = allot_byte_array(100);
 260         char *format = alien_offset(ctx->pop());
 261         double value = untag_float_check(ctx->pop());
 262         SNPRINTF(array->data<char>(),99,format,value);
 263         ctx->push(tag<byte_array>(array));
 264 }
 265
 266 #define POP_FLOATS(x,y) \
 267         double y = untag_float(ctx->pop()); \
 268         double x = untag_float(ctx->peek());
 269
 270 void factor_vm::primitive_float_eq()
 271 {
 272         POP_FLOATS(x,y);
 273         ctx->replace(tag_boolean(x == y));
 274 }
 275
 276 void factor_vm::primitive_float_add()
 277 {
 278         POP_FLOATS(x,y);
 279         ctx->replace(allot_float(x + y));
 280 }
 281
 282 void factor_vm::primitive_float_subtract()
 283 {
 284         POP_FLOATS(x,y);
 285         ctx->replace(allot_float(x - y));
 286 }
 287
 288 void factor_vm::primitive_float_multiply()
 289 {
 290         POP_FLOATS(x,y);
 291         ctx->replace(allot_float(x * y));
 292 }
 293
 294 void factor_vm::primitive_float_divfloat()
 295 {
 296         POP_FLOATS(x,y);
 297         ctx->replace(allot_float(x / y));
 298 }
 299
 300 void factor_vm::primitive_float_less()
 301 {
 302         POP_FLOATS(x,y);
 303         ctx->replace(tag_boolean(x < y));
 304 }
 305
 306 void factor_vm::primitive_float_lesseq()
 307 {
 308         POP_FLOATS(x,y);
 309         ctx->replace(tag_boolean(x <= y));
 310 }
 311
 312 void factor_vm::primitive_float_greater()
 313 {
 314         POP_FLOATS(x,y);
 315         ctx->replace(tag_boolean(x > y));
 316 }
 317
 318 void factor_vm::primitive_float_greatereq()
 319 {
 320         POP_FLOATS(x,y);
 321         ctx->replace(tag_boolean(x >= y));
 322 }
 323
 324 /* Allocates memory */
 325 void factor_vm::primitive_float_bits()
 326 {
 327         ctx->push(from_unsigned_cell(float_bits((float)untag_float_check(ctx->pop()))));
 328 }
 329
 330 /* Allocates memory */
 331 void factor_vm::primitive_bits_float()
 332 {
 333         ctx->push(allot_float(bits_float((u32)to_cell(ctx->pop()))));
 334 }
 335
 336 void factor_vm::primitive_double_bits()
 337 {
 338         ctx->push(from_unsigned_8(double_bits(untag_float_check(ctx->pop()))));
 339 }
 340
 341 void factor_vm::primitive_bits_double()
 342 {
 343         ctx->push(allot_float(bits_double(to_unsigned_8(ctx->pop()))));
 344 }
 345
 346 /* Cannot allocate */
 347 fixnum factor_vm::to_fixnum(cell tagged)
 348 {
 349         switch(TAG(tagged))
 350         {
 351         case FIXNUM_TYPE:
 352                 return untag_fixnum(tagged);
 353         case BIGNUM_TYPE:
 354                 return bignum_to_fixnum(untag<bignum>(tagged));
 355         default:
 356                 type_error(FIXNUM_TYPE,tagged);
 357                 return 0; /* can't happen */
 358         }
 359 }
 360
 361 VM_C_API fixnum to_fixnum(cell tagged, factor_vm *parent)
 362 {
 363         return parent->to_fixnum(tagged);
 364 }
 365
 366 cell factor_vm::to_cell(cell tagged)
 367 {
 368         return (cell)to_fixnum(tagged);
 369 }
 370
 371 VM_C_API cell to_cell(cell tagged, factor_vm *parent)
 372 {
 373         return parent->to_cell(tagged);
 374 }
 375
 376 /* Allocates memory */
 377 VM_C_API cell from_signed_cell(fixnum integer, factor_vm *parent)
 378 {
 379         return parent->from_signed_cell(integer);
 380 }
 381
 382 /* Allocates memory */
 383 VM_C_API cell from_unsigned_cell(cell integer, factor_vm *parent)
 384 {
 385         return parent->from_unsigned_cell(integer);
 386 }
 387
 388 /* Allocates memory */
 389 cell factor_vm::from_signed_8(s64 n)
 390 {
 391         if(n < fixnum_min || n > fixnum_max)
 392                 return tag<bignum>(long_long_to_bignum(n));
 393         else
 394                 return tag_fixnum((fixnum)n);
 395 }
 396
 397 VM_C_API cell from_signed_8(s64 n, factor_vm *parent)
 398 {
 399         return parent->from_signed_8(n);
 400 }
 401
 402 /* Cannot allocate */
 403 s64 factor_vm::to_signed_8(cell obj)
 404 {
 405         switch(tagged<object>(obj).type())
 406         {
 407         case FIXNUM_TYPE:
 408                 return untag_fixnum(obj);
 409         case BIGNUM_TYPE:
 410                 return bignum_to_long_long(untag<bignum>(obj));
 411         default:
 412                 type_error(BIGNUM_TYPE,obj);
 413                 return 0;
 414         }
 415 }
 416
 417 VM_C_API s64 to_signed_8(cell obj, factor_vm *parent)
 418 {
 419         return parent->to_signed_8(obj);
 420 }
 421
 422 cell factor_vm::from_unsigned_8(u64 n)
 423 {
 424         if(n > (u64)fixnum_max)
 425                 return tag<bignum>(ulong_long_to_bignum(n));
 426         else
 427                 return tag_fixnum((fixnum)n);
 428 }
 429
 430 VM_C_API cell from_unsigned_8(u64 n, factor_vm *parent)
 431 {
 432         return parent->from_unsigned_8(n);
 433 }
 434
 435 /* Cannot allocate */
 436 u64 factor_vm::to_unsigned_8(cell obj)
 437 {
 438         switch(tagged<object>(obj).type())
 439         {
 440         case FIXNUM_TYPE:
 441                 return untag_fixnum(obj);
 442         case BIGNUM_TYPE:
 443                 return bignum_to_ulong_long(untag<bignum>(obj));
 444         default:
 445                 type_error(BIGNUM_TYPE,obj);
 446                 return 0;
 447         }
 448 }
 449
 450 VM_C_API u64 to_unsigned_8(cell obj, factor_vm *parent)
 451 {
 452         return parent->to_unsigned_8(obj);
 453 }
 454
 455 /* Cannot allocate */
 456 float factor_vm::to_float(cell value)
 457 {
 458         return (float)untag_float_check(value);
 459 }
 460
 461 /* Cannot allocate */
 462 double factor_vm::to_double(cell value)
 463 {
 464         return untag_float_check(value);
 465 }
 466
 467 /* The fixnum+, fixnum- and fixnum* primitives are defined in cpu_*.S. On
 468 overflow, they call these functions. */
 469 inline void factor_vm::overflow_fixnum_add(fixnum x, fixnum y)
 470 {
 471         ctx->replace(tag<bignum>(fixnum_to_bignum(
 472                 untag_fixnum(x) + untag_fixnum(y))));
 473 }
 474
 475 VM_C_API void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *parent)
 476 {
 477         parent->overflow_fixnum_add(x,y);
 478 }
 479
 480 inline void factor_vm::overflow_fixnum_subtract(fixnum x, fixnum y)
 481 {
 482         ctx->replace(tag<bignum>(fixnum_to_bignum(
 483                 untag_fixnum(x) - untag_fixnum(y))));
 484 }
 485
 486 VM_C_API void overflow_fixnum_subtract(fixnum x, fixnum y, factor_vm *parent)
 487 {
 488         parent->overflow_fixnum_subtract(x,y);
 489 }
 490
 491 inline void factor_vm::overflow_fixnum_multiply(fixnum x, fixnum y)
 492 {
 493         bignum *bx = fixnum_to_bignum(x);
 494         GC_BIGNUM(bx);
 495         bignum *by = fixnum_to_bignum(y);
 496         GC_BIGNUM(by);
 497         ctx->replace(tag<bignum>(bignum_multiply(bx,by)));
 498 }
 499
 500 VM_C_API void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *parent)
 501 {
 502         parent->overflow_fixnum_multiply(x,y);
 503 }
 504
 505 }