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                 fixnum z = x / y;
  47                 fixnum w = x % y;
  48                 *s1 = tag_fixnum(z);
  49                 *s0 = tag_fixnum(w);
  50         }
  51 }
  52
  53 /*
  54  * If we're shifting right by n bits, we won't overflow as long as none of the
  55  * high WORD_SIZE-TAG_BITS-n bits are set.
  56  */
  57 inline fixnum factor_vm::sign_mask(fixnum x)
  58 {
  59         return x >> (WORD_SIZE - 1);
  60 }
  61
  62 inline fixnum factor_vm::branchless_max(fixnum x, fixnum y)
  63 {
  64         return (x - ((x - y) & sign_mask(x - y)));
  65 }
  66
  67 inline fixnum factor_vm::branchless_abs(fixnum x)
  68 {
  69         return (x ^ sign_mask(x)) - sign_mask(x);
  70 }
  71
  72 void factor_vm::primitive_fixnum_shift()
  73 {
  74         fixnum y = untag_fixnum(ctx->pop());
  75         fixnum x = untag_fixnum(ctx->peek());
  76
  77         if(x == 0)
  78                 return;
  79         else if(y < 0)
  80         {
  81                 y = branchless_max(y,-WORD_SIZE + 1);
  82                 ctx->replace(tag_fixnum(x >> -y));
  83                 return;
  84         }
  85         else if(y < WORD_SIZE - TAG_BITS)
  86         {
  87                 fixnum mask = -((fixnum)1 << (WORD_SIZE - 1 - TAG_BITS - y));
  88                 if(!(branchless_abs(x) & mask))
  89                 {
  90                         ctx->replace(tag_fixnum(x << y));
  91                         return;
  92                 }
  93         }
  94
  95         ctx->replace(tag<bignum>(bignum_arithmetic_shift(
  96                 fixnum_to_bignum(x),y)));
  97 }
  98
  99 void factor_vm::primitive_fixnum_to_bignum()
 100 {
 101         ctx->replace(tag<bignum>(fixnum_to_bignum(untag_fixnum(ctx->peek()))));
 102 }
 103
 104 void factor_vm::primitive_float_to_bignum()
 105 {
 106         ctx->replace(tag<bignum>(float_to_bignum(ctx->peek())));
 107 }
 108
 109 #define POP_BIGNUMS(x,y) \
 110         bignum * y = untag<bignum>(ctx->pop()); \
 111         bignum * x = untag<bignum>(ctx->pop());
 112
 113 void factor_vm::primitive_bignum_eq()
 114 {
 115         POP_BIGNUMS(x,y);
 116         ctx->push(tag_boolean(bignum_equal_p(x,y)));
 117 }
 118
 119 void factor_vm::primitive_bignum_add()
 120 {
 121         POP_BIGNUMS(x,y);
 122         ctx->push(tag<bignum>(bignum_add(x,y)));
 123 }
 124
 125 void factor_vm::primitive_bignum_subtract()
 126 {
 127         POP_BIGNUMS(x,y);
 128         ctx->push(tag<bignum>(bignum_subtract(x,y)));
 129 }
 130
 131 void factor_vm::primitive_bignum_multiply()
 132 {
 133         POP_BIGNUMS(x,y);
 134         ctx->push(tag<bignum>(bignum_multiply(x,y)));
 135 }
 136
 137 void factor_vm::primitive_bignum_divint()
 138 {
 139         POP_BIGNUMS(x,y);
 140         ctx->push(tag<bignum>(bignum_quotient(x,y)));
 141 }
 142
 143 void factor_vm::primitive_bignum_divmod()
 144 {
 145         bignum *q, *r;
 146         POP_BIGNUMS(x,y);
 147         bignum_divide(x,y,&q,&r);
 148         ctx->push(tag<bignum>(q));
 149         ctx->push(tag<bignum>(r));
 150 }
 151
 152 void factor_vm::primitive_bignum_mod()
 153 {
 154         POP_BIGNUMS(x,y);
 155         ctx->push(tag<bignum>(bignum_remainder(x,y)));
 156 }
 157
 158 void factor_vm::primitive_bignum_gcd()
 159 {
 160         POP_BIGNUMS(x,y);
 161         ctx->push(tag<bignum>(bignum_gcd(x,y)));
 162 }
 163
 164 void factor_vm::primitive_bignum_and()
 165 {
 166         POP_BIGNUMS(x,y);
 167         ctx->push(tag<bignum>(bignum_bitwise_and(x,y)));
 168 }
 169
 170 void factor_vm::primitive_bignum_or()
 171 {
 172         POP_BIGNUMS(x,y);
 173         ctx->push(tag<bignum>(bignum_bitwise_ior(x,y)));
 174 }
 175
 176 void factor_vm::primitive_bignum_xor()
 177 {
 178         POP_BIGNUMS(x,y);
 179         ctx->push(tag<bignum>(bignum_bitwise_xor(x,y)));
 180 }
 181
 182 void factor_vm::primitive_bignum_shift()
 183 {
 184         fixnum y = untag_fixnum(ctx->pop());
 185         bignum* x = untag<bignum>(ctx->pop());
 186         ctx->push(tag<bignum>(bignum_arithmetic_shift(x,y)));
 187 }
 188
 189 void factor_vm::primitive_bignum_less()
 190 {
 191         POP_BIGNUMS(x,y);
 192         ctx->push(tag_boolean(bignum_compare(x,y) == bignum_comparison_less));
 193 }
 194
 195 void factor_vm::primitive_bignum_lesseq()
 196 {
 197         POP_BIGNUMS(x,y);
 198         ctx->push(tag_boolean(bignum_compare(x,y) != bignum_comparison_greater));
 199 }
 200
 201 void factor_vm::primitive_bignum_greater()
 202 {
 203         POP_BIGNUMS(x,y);
 204         ctx->push(tag_boolean(bignum_compare(x,y) == bignum_comparison_greater));
 205 }
 206
 207 void factor_vm::primitive_bignum_greatereq()
 208 {
 209         POP_BIGNUMS(x,y);
 210         ctx->push(tag_boolean(bignum_compare(x,y) != bignum_comparison_less));
 211 }
 212
 213 void factor_vm::primitive_bignum_not()
 214 {
 215         ctx->replace(tag<bignum>(bignum_bitwise_not(untag<bignum>(ctx->peek()))));
 216 }
 217
 218 void factor_vm::primitive_bignum_bitp()
 219 {
 220         int bit = (int)to_fixnum(ctx->pop());
 221         bignum *x = untag<bignum>(ctx->pop());
 222         ctx->push(tag_boolean(bignum_logbitp(bit,x)));
 223 }
 224
 225 void factor_vm::primitive_bignum_log2()
 226 {
 227         ctx->replace(tag<bignum>(bignum_integer_length(untag<bignum>(ctx->peek()))));
 228 }
 229
 230 /* allocates memory */
 231 cell factor_vm::unbox_array_size_slow()
 232 {
 233         if(tagged<object>(ctx->peek()).type() == BIGNUM_TYPE)
 234         {
 235                 bignum *zero = untag<bignum>(bignum_zero);
 236                 GC_BIGNUM(zero);
 237                 bignum *max = cell_to_bignum(array_size_max);
 238                 bignum *n = untag<bignum>(ctx->peek());
 239                 if(bignum_compare(n,zero) != bignum_comparison_less
 240                         && bignum_compare(n,max) == bignum_comparison_less)
 241                 {
 242                         ctx->pop();
 243                         return bignum_to_cell(n);
 244                 }
 245         }
 246
 247         general_error(ERROR_ARRAY_SIZE,ctx->pop(),tag_fixnum(array_size_max));
 248         return 0; /* can't happen */
 249 }
 250
 251 void factor_vm::primitive_fixnum_to_float()
 252 {
 253         ctx->replace(allot_float(fixnum_to_float(ctx->peek())));
 254 }
 255
 256 void factor_vm::primitive_format_float()
 257 {
 258         byte_array *array = allot_byte_array(100);
 259         char *format = alien_offset(ctx->pop());
 260         double value = untag_float_check(ctx->pop());
 261         SNPRINTF(array->data<char>(),99,format,value);
 262         ctx->push(tag<byte_array>(array));
 263 }
 264
 265 #define POP_FLOATS(x,y) \
 266         double y = untag_float(ctx->pop()); \
 267         double x = untag_float(ctx->pop());
 268
 269 void factor_vm::primitive_float_eq()
 270 {
 271         POP_FLOATS(x,y);
 272         ctx->push(tag_boolean(x == y));
 273 }
 274
 275 void factor_vm::primitive_float_add()
 276 {
 277         POP_FLOATS(x,y);
 278         ctx->push(allot_float(x + y));
 279 }
 280
 281 void factor_vm::primitive_float_subtract()
 282 {
 283         POP_FLOATS(x,y);
 284         ctx->push(allot_float(x - y));
 285 }
 286
 287 void factor_vm::primitive_float_multiply()
 288 {
 289         POP_FLOATS(x,y);
 290         ctx->push(allot_float(x * y));
 291 }
 292
 293 void factor_vm::primitive_float_divfloat()
 294 {
 295         POP_FLOATS(x,y);
 296         ctx->push(allot_float(x / y));
 297 }
 298
 299 void factor_vm::primitive_float_less()
 300 {
 301         POP_FLOATS(x,y);
 302         ctx->push(tag_boolean(x < y));
 303 }
 304
 305 void factor_vm::primitive_float_lesseq()
 306 {
 307         POP_FLOATS(x,y);
 308         ctx->push(tag_boolean(x <= y));
 309 }
 310
 311 void factor_vm::primitive_float_greater()
 312 {
 313         POP_FLOATS(x,y);
 314         ctx->push(tag_boolean(x > y));
 315 }
 316
 317 void factor_vm::primitive_float_greatereq()
 318 {
 319         POP_FLOATS(x,y);
 320         ctx->push(tag_boolean(x >= y));
 321 }
 322
 323 /* Allocates memory */
 324 void factor_vm::primitive_float_bits()
 325 {
 326         ctx->push(from_unsigned_cell(float_bits((float)untag_float_check(ctx->pop()))));
 327 }
 328
 329 /* Allocates memory */
 330 void factor_vm::primitive_bits_float()
 331 {
 332         ctx->push(allot_float(bits_float((u32)to_cell(ctx->pop()))));
 333 }
 334
 335 void factor_vm::primitive_double_bits()
 336 {
 337         ctx->push(from_unsigned_8(double_bits(untag_float_check(ctx->pop()))));
 338 }
 339
 340 void factor_vm::primitive_bits_double()
 341 {
 342         ctx->push(allot_float(bits_double(to_unsigned_8(ctx->pop()))));
 343 }
 344
 345 /* Cannot allocate */
 346 fixnum factor_vm::to_fixnum(cell tagged)
 347 {
 348         switch(TAG(tagged))
 349         {
 350         case FIXNUM_TYPE:
 351                 return untag_fixnum(tagged);
 352         case BIGNUM_TYPE:
 353                 return bignum_to_fixnum(untag<bignum>(tagged));
 354         default:
 355                 type_error(FIXNUM_TYPE,tagged);
 356                 return 0; /* can't happen */
 357         }
 358 }
 359
 360 VM_C_API fixnum to_fixnum(cell tagged, factor_vm *parent)
 361 {
 362         return parent->to_fixnum(tagged);
 363 }
 364
 365 cell factor_vm::to_cell(cell tagged)
 366 {
 367         return (cell)to_fixnum(tagged);
 368 }
 369
 370 VM_C_API cell to_cell(cell tagged, factor_vm *parent)
 371 {
 372         return parent->to_cell(tagged);
 373 }
 374
 375 /* Allocates memory */
 376 VM_C_API cell from_signed_cell(fixnum integer, factor_vm *parent)
 377 {
 378         return parent->from_signed_cell(integer);
 379 }
 380
 381 /* Allocates memory */
 382 VM_C_API cell from_unsigned_cell(cell integer, factor_vm *parent)
 383 {
 384         return parent->from_unsigned_cell(integer);
 385 }
 386
 387 /* Allocates memory */
 388 cell factor_vm::from_signed_8(s64 n)
 389 {
 390         if(n < fixnum_min || n > fixnum_max)
 391                 return tag<bignum>(long_long_to_bignum(n));
 392         else
 393                 return tag_fixnum((fixnum)n);
 394 }
 395
 396 VM_C_API cell from_signed_8(s64 n, factor_vm *parent)
 397 {
 398         return parent->from_signed_8(n);
 399 }
 400
 401 /* Cannot allocate */
 402 s64 factor_vm::to_signed_8(cell obj)
 403 {
 404         switch(tagged<object>(obj).type())
 405         {
 406         case FIXNUM_TYPE:
 407                 return untag_fixnum(obj);
 408         case BIGNUM_TYPE:
 409                 return bignum_to_long_long(untag<bignum>(obj));
 410         default:
 411                 type_error(BIGNUM_TYPE,obj);
 412                 return 0;
 413         }
 414 }
 415
 416 VM_C_API s64 to_signed_8(cell obj, factor_vm *parent)
 417 {
 418         return parent->to_signed_8(obj);
 419 }
 420
 421 cell factor_vm::from_unsigned_8(u64 n)
 422 {
 423         if(n > (u64)fixnum_max)
 424                 return tag<bignum>(ulong_long_to_bignum(n));
 425         else
 426                 return tag_fixnum((fixnum)n);
 427 }
 428
 429 VM_C_API cell from_unsigned_8(u64 n, factor_vm *parent)
 430 {
 431         return parent->from_unsigned_8(n);
 432 }
 433
 434 /* Cannot allocate */
 435 u64 factor_vm::to_unsigned_8(cell obj)
 436 {
 437         switch(tagged<object>(obj).type())
 438         {
 439         case FIXNUM_TYPE:
 440                 return untag_fixnum(obj);
 441         case BIGNUM_TYPE:
 442                 return bignum_to_ulong_long(untag<bignum>(obj));
 443         default:
 444                 type_error(BIGNUM_TYPE,obj);
 445                 return 0;
 446         }
 447 }
 448
 449 VM_C_API u64 to_unsigned_8(cell obj, factor_vm *parent)
 450 {
 451         return parent->to_unsigned_8(obj);
 452 }
 453
 454 /* Cannot allocate */
 455 float factor_vm::to_float(cell value)
 456 {
 457         return (float)untag_float_check(value);
 458 }
 459
 460 /* Cannot allocate */
 461 double factor_vm::to_double(cell value)
 462 {
 463         return untag_float_check(value);
 464 }
 465
 466 /* The fixnum+, fixnum- and fixnum* primitives are defined in cpu_*.S. On
 467 overflow, they call these functions. */
 468 inline void factor_vm::overflow_fixnum_add(fixnum x, fixnum y)
 469 {
 470         ctx->replace(tag<bignum>(fixnum_to_bignum(
 471                 untag_fixnum(x) + untag_fixnum(y))));
 472 }
 473
 474 VM_C_API void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *parent)
 475 {
 476         parent->overflow_fixnum_add(x,y);
 477 }
 478
 479 inline void factor_vm::overflow_fixnum_subtract(fixnum x, fixnum y)
 480 {
 481         ctx->replace(tag<bignum>(fixnum_to_bignum(
 482                 untag_fixnum(x) - untag_fixnum(y))));
 483 }
 484
 485 VM_C_API void overflow_fixnum_subtract(fixnum x, fixnum y, factor_vm *parent)
 486 {
 487         parent->overflow_fixnum_subtract(x,y);
 488 }
 489
 490 inline void factor_vm::overflow_fixnum_multiply(fixnum x, fixnum y)
 491 {
 492         bignum *bx = fixnum_to_bignum(x);
 493         GC_BIGNUM(bx);
 494         bignum *by = fixnum_to_bignum(y);
 495         GC_BIGNUM(by);
 496         ctx->replace(tag<bignum>(bignum_multiply(bx,by)));
 497 }
 498
 499 VM_C_API void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *parent)
 500 {
 501         parent->overflow_fixnum_multiply(x,y);
 502 }
 503
 504 }