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 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                 bignum *max = cell_to_bignum(array_size_max);
 233                 bignum *n = untag<bignum>(ctx->peek());
 234                 if(bignum_compare(n,zero) != bignum_comparison_less
 235                         && bignum_compare(n,max) == bignum_comparison_less)
 236                 {
 237                         ctx->pop();
 238                         return bignum_to_cell(n);
 239                 }
 240         }
 241
 242         general_error(ERROR_ARRAY_SIZE,ctx->pop(),tag_fixnum(array_size_max));
 243         return 0; /* can't happen */
 244 }
 245
 246 void factor_vm::primitive_fixnum_to_float()
 247 {
 248         ctx->replace(allot_float(fixnum_to_float(ctx->peek())));
 249 }
 250
 251 void factor_vm::primitive_format_float()
 252 {
 253         byte_array *array = allot_byte_array(100);
 254         char *format = alien_offset(ctx->pop());
 255         double value = untag_float_check(ctx->pop());
 256         SNPRINTF(array->data<char>(),99,format,value);
 257         ctx->push(tag<byte_array>(array));
 258 }
 259
 260 #define POP_FLOATS(x,y) \
 261         double y = untag_float(ctx->pop()); \
 262         double x = untag_float(ctx->pop());
 263
 264 void factor_vm::primitive_float_eq()
 265 {
 266         POP_FLOATS(x,y);
 267         ctx->push(tag_boolean(x == y));
 268 }
 269
 270 void factor_vm::primitive_float_add()
 271 {
 272         POP_FLOATS(x,y);
 273         ctx->push(allot_float(x + y));
 274 }
 275
 276 void factor_vm::primitive_float_subtract()
 277 {
 278         POP_FLOATS(x,y);
 279         ctx->push(allot_float(x - y));
 280 }
 281
 282 void factor_vm::primitive_float_multiply()
 283 {
 284         POP_FLOATS(x,y);
 285         ctx->push(allot_float(x * y));
 286 }
 287
 288 void factor_vm::primitive_float_divfloat()
 289 {
 290         POP_FLOATS(x,y);
 291         ctx->push(allot_float(x / y));
 292 }
 293
 294 void factor_vm::primitive_float_less()
 295 {
 296         POP_FLOATS(x,y);
 297         ctx->push(tag_boolean(x < y));
 298 }
 299
 300 void factor_vm::primitive_float_lesseq()
 301 {
 302         POP_FLOATS(x,y);
 303         ctx->push(tag_boolean(x <= y));
 304 }
 305
 306 void factor_vm::primitive_float_greater()
 307 {
 308         POP_FLOATS(x,y);
 309         ctx->push(tag_boolean(x > y));
 310 }
 311
 312 void factor_vm::primitive_float_greatereq()
 313 {
 314         POP_FLOATS(x,y);
 315         ctx->push(tag_boolean(x >= y));
 316 }
 317
 318 void factor_vm::primitive_float_bits()
 319 {
 320         ctx->push(from_unsigned_cell(float_bits((float)untag_float_check(ctx->pop()))));
 321 }
 322
 323 void factor_vm::primitive_bits_float()
 324 {
 325         ctx->push(allot_float(bits_float((u32)to_cell(ctx->pop()))));
 326 }
 327
 328 void factor_vm::primitive_double_bits()
 329 {
 330         ctx->push(from_unsigned_8(double_bits(untag_float_check(ctx->pop()))));
 331 }
 332
 333 void factor_vm::primitive_bits_double()
 334 {
 335         ctx->push(allot_float(bits_double(to_unsigned_8(ctx->pop()))));
 336 }
 337
 338 /* Cannot allocate */
 339 fixnum factor_vm::to_fixnum(cell tagged)
 340 {
 341         switch(TAG(tagged))
 342         {
 343         case FIXNUM_TYPE:
 344                 return untag_fixnum(tagged);
 345         case BIGNUM_TYPE:
 346                 return bignum_to_fixnum(untag<bignum>(tagged));
 347         default:
 348                 type_error(FIXNUM_TYPE,tagged);
 349                 return 0; /* can't happen */
 350         }
 351 }
 352
 353 VM_C_API fixnum to_fixnum(cell tagged, factor_vm *parent)
 354 {
 355         return parent->to_fixnum(tagged);
 356 }
 357
 358 cell factor_vm::to_cell(cell tagged)
 359 {
 360         return (cell)to_fixnum(tagged);
 361 }
 362
 363 VM_C_API cell to_cell(cell tagged, factor_vm *parent)
 364 {
 365         return parent->to_cell(tagged);
 366 }
 367
 368 VM_C_API cell from_signed_cell(fixnum integer, factor_vm *parent)
 369 {
 370         return parent->from_signed_cell(integer);
 371 }
 372
 373 VM_C_API cell from_unsigned_cell(cell integer, factor_vm *parent)
 374 {
 375         return parent->from_unsigned_cell(integer);
 376 }
 377
 378 cell factor_vm::from_signed_8(s64 n)
 379 {
 380         if(n < fixnum_min || n > fixnum_max)
 381                 return tag<bignum>(long_long_to_bignum(n));
 382         else
 383                 return tag_fixnum((fixnum)n);
 384 }
 385
 386 VM_C_API cell from_signed_8(s64 n, factor_vm *parent)
 387 {
 388         return parent->from_signed_8(n);
 389 }
 390
 391 /* Cannot allocate */
 392 s64 factor_vm::to_signed_8(cell obj)
 393 {
 394         switch(tagged<object>(obj).type())
 395         {
 396         case FIXNUM_TYPE:
 397                 return untag_fixnum(obj);
 398         case BIGNUM_TYPE:
 399                 return bignum_to_long_long(untag<bignum>(obj));
 400         default:
 401                 type_error(BIGNUM_TYPE,obj);
 402                 return 0;
 403         }
 404 }
 405
 406 VM_C_API s64 to_signed_8(cell obj, factor_vm *parent)
 407 {
 408         return parent->to_signed_8(obj);
 409 }
 410
 411 cell factor_vm::from_unsigned_8(u64 n)
 412 {
 413         if(n > (u64)fixnum_max)
 414                 return tag<bignum>(ulong_long_to_bignum(n));
 415         else
 416                 return tag_fixnum((fixnum)n);
 417 }
 418
 419 VM_C_API cell from_unsigned_8(u64 n, factor_vm *parent)
 420 {
 421         return parent->from_unsigned_8(n);
 422 }
 423
 424 /* Cannot allocate */
 425 u64 factor_vm::to_unsigned_8(cell obj)
 426 {
 427         switch(tagged<object>(obj).type())
 428         {
 429         case FIXNUM_TYPE:
 430                 return untag_fixnum(obj);
 431         case BIGNUM_TYPE:
 432                 return bignum_to_ulong_long(untag<bignum>(obj));
 433         default:
 434                 type_error(BIGNUM_TYPE,obj);
 435                 return 0;
 436         }
 437 }
 438
 439 VM_C_API u64 to_unsigned_8(cell obj, factor_vm *parent)
 440 {
 441         return parent->to_unsigned_8(obj);
 442 }
 443
 444 /* Cannot allocate */
 445 float factor_vm::to_float(cell value)
 446 {
 447         return (float)untag_float_check(value);
 448 }
 449
 450 /* Cannot allocate */
 451 double factor_vm::to_double(cell value)
 452 {
 453         return untag_float_check(value);
 454 }
 455
 456 /* The fixnum+, fixnum- and fixnum* primitives are defined in cpu_*.S. On
 457 overflow, they call these functions. */
 458 inline void factor_vm::overflow_fixnum_add(fixnum x, fixnum y)
 459 {
 460         ctx->replace(tag<bignum>(fixnum_to_bignum(
 461                 untag_fixnum(x) + untag_fixnum(y))));
 462 }
 463
 464 VM_C_API void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *parent)
 465 {
 466         parent->overflow_fixnum_add(x,y);
 467 }
 468
 469 inline void factor_vm::overflow_fixnum_subtract(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_subtract(fixnum x, fixnum y, factor_vm *parent)
 476 {
 477         parent->overflow_fixnum_subtract(x,y);
 478 }
 479
 480 inline void factor_vm::overflow_fixnum_multiply(fixnum x, fixnum y)
 481 {
 482         bignum *bx = fixnum_to_bignum(x);
 483         GC_BIGNUM(bx);
 484         bignum *by = fixnum_to_bignum(y);
 485         GC_BIGNUM(by);
 486         ctx->replace(tag<bignum>(bignum_multiply(bx,by)));
 487 }
 488
 489 VM_C_API void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *parent)
 490 {
 491         parent->overflow_fixnum_multiply(x,y);
 492 }
 493
 494 }