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 void factor_vm::primitive_byte_array_to_bignum()
 228 {
 229         unsigned int n_digits = (unsigned int)array_capacity(untag_check<byte_array>(ctx->peek()));
 230         bignum * result = digit_stream_to_bignum(n_digits,factor::bignum_producer,0x100,0);
 231         ctx->replace(tag<bignum>(result));
 232 }
 233
 234 cell factor_vm::unbox_array_size_slow()
 235 {
 236         if(tagged<object>(ctx->peek()).type() == BIGNUM_TYPE)
 237         {
 238                 bignum *zero = untag<bignum>(bignum_zero);
 239                 bignum *max = cell_to_bignum(array_size_max);
 240                 bignum *n = untag<bignum>(ctx->peek());
 241                 if(bignum_compare(n,zero) != bignum_comparison_less
 242                         && bignum_compare(n,max) == bignum_comparison_less)
 243                 {
 244                         ctx->pop();
 245                         return bignum_to_cell(n);
 246                 }
 247         }
 248
 249         general_error(ERROR_ARRAY_SIZE,ctx->pop(),tag_fixnum(array_size_max));
 250         return 0; /* can't happen */
 251 }
 252
 253 void factor_vm::primitive_fixnum_to_float()
 254 {
 255         ctx->replace(allot_float(fixnum_to_float(ctx->peek())));
 256 }
 257
 258 void factor_vm::primitive_format_float()
 259 {
 260         byte_array *array = allot_byte_array(100);
 261         char *format = alien_offset(ctx->pop());
 262         double value = untag_float_check(ctx->pop());
 263         SNPRINTF(array->data<char>(),99,format,value);
 264         ctx->push(tag<byte_array>(array));
 265 }
 266
 267 #define POP_FLOATS(x,y) \
 268         double y = untag_float(ctx->pop()); \
 269         double x = untag_float(ctx->pop());
 270
 271 void factor_vm::primitive_float_eq()
 272 {
 273         POP_FLOATS(x,y);
 274         ctx->push(tag_boolean(x == y));
 275 }
 276
 277 void factor_vm::primitive_float_add()
 278 {
 279         POP_FLOATS(x,y);
 280         ctx->push(allot_float(x + y));
 281 }
 282
 283 void factor_vm::primitive_float_subtract()
 284 {
 285         POP_FLOATS(x,y);
 286         ctx->push(allot_float(x - y));
 287 }
 288
 289 void factor_vm::primitive_float_multiply()
 290 {
 291         POP_FLOATS(x,y);
 292         ctx->push(allot_float(x * y));
 293 }
 294
 295 void factor_vm::primitive_float_divfloat()
 296 {
 297         POP_FLOATS(x,y);
 298         ctx->push(allot_float(x / y));
 299 }
 300
 301 void factor_vm::primitive_float_less()
 302 {
 303         POP_FLOATS(x,y);
 304         ctx->push(tag_boolean(x < y));
 305 }
 306
 307 void factor_vm::primitive_float_lesseq()
 308 {
 309         POP_FLOATS(x,y);
 310         ctx->push(tag_boolean(x <= y));
 311 }
 312
 313 void factor_vm::primitive_float_greater()
 314 {
 315         POP_FLOATS(x,y);
 316         ctx->push(tag_boolean(x > y));
 317 }
 318
 319 void factor_vm::primitive_float_greatereq()
 320 {
 321         POP_FLOATS(x,y);
 322         ctx->push(tag_boolean(x >= y));
 323 }
 324
 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 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 VM_C_API cell from_signed_cell(fixnum integer, factor_vm *parent)
 376 {
 377         return parent->from_signed_cell(integer);
 378 }
 379
 380 VM_C_API cell from_unsigned_cell(cell integer, factor_vm *parent)
 381 {
 382         return parent->from_unsigned_cell(integer);
 383 }
 384
 385 cell factor_vm::from_signed_8(s64 n)
 386 {
 387         if(n < fixnum_min || n > fixnum_max)
 388                 return tag<bignum>(long_long_to_bignum(n));
 389         else
 390                 return tag_fixnum((fixnum)n);
 391 }
 392
 393 VM_C_API cell from_signed_8(s64 n, factor_vm *parent)
 394 {
 395         return parent->from_signed_8(n);
 396 }
 397
 398 /* Cannot allocate */
 399 s64 factor_vm::to_signed_8(cell obj)
 400 {
 401         switch(tagged<object>(obj).type())
 402         {
 403         case FIXNUM_TYPE:
 404                 return untag_fixnum(obj);
 405         case BIGNUM_TYPE:
 406                 return bignum_to_long_long(untag<bignum>(obj));
 407         default:
 408                 type_error(BIGNUM_TYPE,obj);
 409                 return 0;
 410         }
 411 }
 412
 413 VM_C_API s64 to_signed_8(cell obj, factor_vm *parent)
 414 {
 415         return parent->to_signed_8(obj);
 416 }
 417
 418 cell factor_vm::from_unsigned_8(u64 n)
 419 {
 420         if(n > (u64)fixnum_max)
 421                 return tag<bignum>(ulong_long_to_bignum(n));
 422         else
 423                 return tag_fixnum((fixnum)n);
 424 }
 425
 426 VM_C_API cell from_unsigned_8(u64 n, factor_vm *parent)
 427 {
 428         return parent->from_unsigned_8(n);
 429 }
 430
 431 /* Cannot allocate */
 432 u64 factor_vm::to_unsigned_8(cell obj)
 433 {
 434         switch(tagged<object>(obj).type())
 435         {
 436         case FIXNUM_TYPE:
 437                 return untag_fixnum(obj);
 438         case BIGNUM_TYPE:
 439                 return bignum_to_ulong_long(untag<bignum>(obj));
 440         default:
 441                 type_error(BIGNUM_TYPE,obj);
 442                 return 0;
 443         }
 444 }
 445
 446 VM_C_API u64 to_unsigned_8(cell obj, factor_vm *parent)
 447 {
 448         return parent->to_unsigned_8(obj);
 449 }
 450
 451 /* Cannot allocate */
 452 float factor_vm::to_float(cell value)
 453 {
 454         return (float)untag_float_check(value);
 455 }
 456
 457 /* Cannot allocate */
 458 double factor_vm::to_double(cell value)
 459 {
 460         return untag_float_check(value);
 461 }
 462
 463 /* The fixnum+, fixnum- and fixnum* primitives are defined in cpu_*.S. On
 464 overflow, they call these functions. */
 465 inline void factor_vm::overflow_fixnum_add(fixnum x, fixnum y)
 466 {
 467         ctx->replace(tag<bignum>(fixnum_to_bignum(
 468                 untag_fixnum(x) + untag_fixnum(y))));
 469 }
 470
 471 VM_C_API void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *parent)
 472 {
 473         parent->overflow_fixnum_add(x,y);
 474 }
 475
 476 inline void factor_vm::overflow_fixnum_subtract(fixnum x, fixnum y)
 477 {
 478         ctx->replace(tag<bignum>(fixnum_to_bignum(
 479                 untag_fixnum(x) - untag_fixnum(y))));
 480 }
 481
 482 VM_C_API void overflow_fixnum_subtract(fixnum x, fixnum y, factor_vm *parent)
 483 {
 484         parent->overflow_fixnum_subtract(x,y);
 485 }
 486
 487 inline void factor_vm::overflow_fixnum_multiply(fixnum x, fixnum y)
 488 {
 489         bignum *bx = fixnum_to_bignum(x);
 490         GC_BIGNUM(bx);
 491         bignum *by = fixnum_to_bignum(y);
 492         GC_BIGNUM(by);
 493         ctx->replace(tag<bignum>(bignum_multiply(bx,by)));
 494 }
 495
 496 VM_C_API void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *parent)
 497 {
 498         parent->overflow_fixnum_multiply(x,y);
 499 }
 500
 501 }