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 cell factor_vm::unbox_array_size_slow()
 217 {
 218         if(tagged<object>(ctx->peek()).type() == BIGNUM_TYPE)
 219         {
 220                 bignum *zero = untag<bignum>(bignum_zero);
 221                 bignum *max = cell_to_bignum(array_size_max);
 222                 bignum *n = untag<bignum>(ctx->peek());
 223                 if(bignum_compare(n,zero) != bignum_comparison_less
 224                         && bignum_compare(n,max) == bignum_comparison_less)
 225                 {
 226                         ctx->pop();
 227                         return bignum_to_cell(n);
 228                 }
 229         }
 230
 231         general_error(ERROR_ARRAY_SIZE,ctx->pop(),tag_fixnum(array_size_max));
 232         return 0; /* can't happen */
 233 }
 234
 235 void factor_vm::primitive_fixnum_to_float()
 236 {
 237         ctx->replace(allot_float(fixnum_to_float(ctx->peek())));
 238 }
 239
 240 void factor_vm::primitive_format_float()
 241 {
 242         byte_array *array = allot_byte_array(100);
 243         char *format = alien_offset(ctx->pop());
 244         double value = untag_float_check(ctx->pop());
 245         SNPRINTF(array->data<char>(),99,format,value);
 246         ctx->push(tag<byte_array>(array));
 247 }
 248
 249 #define POP_FLOATS(x,y) \
 250         double y = untag_float(ctx->pop()); \
 251         double x = untag_float(ctx->pop());
 252
 253 void factor_vm::primitive_float_eq()
 254 {
 255         POP_FLOATS(x,y);
 256         ctx->push(tag_boolean(x == y));
 257 }
 258
 259 void factor_vm::primitive_float_add()
 260 {
 261         POP_FLOATS(x,y);
 262         ctx->push(allot_float(x + y));
 263 }
 264
 265 void factor_vm::primitive_float_subtract()
 266 {
 267         POP_FLOATS(x,y);
 268         ctx->push(allot_float(x - y));
 269 }
 270
 271 void factor_vm::primitive_float_multiply()
 272 {
 273         POP_FLOATS(x,y);
 274         ctx->push(allot_float(x * y));
 275 }
 276
 277 void factor_vm::primitive_float_divfloat()
 278 {
 279         POP_FLOATS(x,y);
 280         ctx->push(allot_float(x / y));
 281 }
 282
 283 void factor_vm::primitive_float_less()
 284 {
 285         POP_FLOATS(x,y);
 286         ctx->push(tag_boolean(x < y));
 287 }
 288
 289 void factor_vm::primitive_float_lesseq()
 290 {
 291         POP_FLOATS(x,y);
 292         ctx->push(tag_boolean(x <= y));
 293 }
 294
 295 void factor_vm::primitive_float_greater()
 296 {
 297         POP_FLOATS(x,y);
 298         ctx->push(tag_boolean(x > y));
 299 }
 300
 301 void factor_vm::primitive_float_greatereq()
 302 {
 303         POP_FLOATS(x,y);
 304         ctx->push(tag_boolean(x >= y));
 305 }
 306
 307 void factor_vm::primitive_float_bits()
 308 {
 309         ctx->push(from_unsigned_cell(float_bits((float)untag_float_check(ctx->pop()))));
 310 }
 311
 312 void factor_vm::primitive_bits_float()
 313 {
 314         ctx->push(allot_float(bits_float((u32)to_cell(ctx->pop()))));
 315 }
 316
 317 void factor_vm::primitive_double_bits()
 318 {
 319         ctx->push(from_unsigned_8(double_bits(untag_float_check(ctx->pop()))));
 320 }
 321
 322 void factor_vm::primitive_bits_double()
 323 {
 324         ctx->push(allot_float(bits_double(to_unsigned_8(ctx->pop()))));
 325 }
 326
 327 /* Cannot allocate */
 328 fixnum factor_vm::to_fixnum(cell tagged)
 329 {
 330         switch(TAG(tagged))
 331         {
 332         case FIXNUM_TYPE:
 333                 return untag_fixnum(tagged);
 334         case BIGNUM_TYPE:
 335                 return bignum_to_fixnum(untag<bignum>(tagged));
 336         default:
 337                 type_error(FIXNUM_TYPE,tagged);
 338                 return 0; /* can't happen */
 339         }
 340 }
 341
 342 VM_C_API fixnum to_fixnum(cell tagged, factor_vm *parent)
 343 {
 344         return parent->to_fixnum(tagged);
 345 }
 346
 347 cell factor_vm::to_cell(cell tagged)
 348 {
 349         return (cell)to_fixnum(tagged);
 350 }
 351
 352 VM_C_API cell to_cell(cell tagged, factor_vm *parent)
 353 {
 354         return parent->to_cell(tagged);
 355 }
 356
 357 VM_C_API cell from_signed_cell(fixnum integer, factor_vm *parent)
 358 {
 359         return parent->from_signed_cell(integer);
 360 }
 361
 362 VM_C_API cell from_unsigned_cell(cell integer, factor_vm *parent)
 363 {
 364         return parent->from_unsigned_cell(integer);
 365 }
 366
 367 cell factor_vm::from_signed_8(s64 n)
 368 {
 369         if(n < fixnum_min || n > fixnum_max)
 370                 return tag<bignum>(long_long_to_bignum(n));
 371         else
 372                 return tag_fixnum((fixnum)n);
 373 }
 374
 375 VM_C_API cell from_signed_8(s64 n, factor_vm *parent)
 376 {
 377         return parent->from_signed_8(n);
 378 }
 379
 380 /* Cannot allocate */
 381 s64 factor_vm::to_signed_8(cell obj)
 382 {
 383         switch(tagged<object>(obj).type())
 384         {
 385         case FIXNUM_TYPE:
 386                 return untag_fixnum(obj);
 387         case BIGNUM_TYPE:
 388                 return bignum_to_long_long(untag<bignum>(obj));
 389         default:
 390                 type_error(BIGNUM_TYPE,obj);
 391                 return 0;
 392         }
 393 }
 394
 395 VM_C_API s64 to_signed_8(cell obj, factor_vm *parent)
 396 {
 397         return parent->to_signed_8(obj);
 398 }
 399
 400 cell factor_vm::from_unsigned_8(u64 n)
 401 {
 402         if(n > (u64)fixnum_max)
 403                 return tag<bignum>(ulong_long_to_bignum(n));
 404         else
 405                 return tag_fixnum((fixnum)n);
 406 }
 407
 408 VM_C_API cell from_unsigned_8(u64 n, factor_vm *parent)
 409 {
 410         return parent->from_unsigned_8(n);
 411 }
 412
 413 /* Cannot allocate */
 414 u64 factor_vm::to_unsigned_8(cell obj)
 415 {
 416         switch(tagged<object>(obj).type())
 417         {
 418         case FIXNUM_TYPE:
 419                 return untag_fixnum(obj);
 420         case BIGNUM_TYPE:
 421                 return bignum_to_ulong_long(untag<bignum>(obj));
 422         default:
 423                 type_error(BIGNUM_TYPE,obj);
 424                 return 0;
 425         }
 426 }
 427
 428 VM_C_API u64 to_unsigned_8(cell obj, factor_vm *parent)
 429 {
 430         return parent->to_unsigned_8(obj);
 431 }
 432
 433 /* Cannot allocate */
 434 float factor_vm::to_float(cell value)
 435 {
 436         return (float)untag_float_check(value);
 437 }
 438
 439 /* Cannot allocate */
 440 double factor_vm::to_double(cell value)
 441 {
 442         return untag_float_check(value);
 443 }
 444
 445 /* The fixnum+, fixnum- and fixnum* primitives are defined in cpu_*.S. On
 446 overflow, they call these functions. */
 447 inline void factor_vm::overflow_fixnum_add(fixnum x, fixnum y)
 448 {
 449         ctx->replace(tag<bignum>(fixnum_to_bignum(
 450                 untag_fixnum(x) + untag_fixnum(y))));
 451 }
 452
 453 VM_C_API void overflow_fixnum_add(fixnum x, fixnum y, factor_vm *parent)
 454 {
 455         parent->overflow_fixnum_add(x,y);
 456 }
 457
 458 inline void factor_vm::overflow_fixnum_subtract(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_subtract(fixnum x, fixnum y, factor_vm *parent)
 465 {
 466         parent->overflow_fixnum_subtract(x,y);
 467 }
 468
 469 inline void factor_vm::overflow_fixnum_multiply(fixnum x, fixnum y)
 470 {
 471         bignum *bx = fixnum_to_bignum(x);
 472         GC_BIGNUM(bx);
 473         bignum *by = fixnum_to_bignum(y);
 474         GC_BIGNUM(by);
 475         ctx->replace(tag<bignum>(bignum_multiply(bx,by)));
 476 }
 477
 478 VM_C_API void overflow_fixnum_multiply(fixnum x, fixnum y, factor_vm *parent)
 479 {
 480         parent->overflow_fixnum_multiply(x,y);
 481 }
 482
 483 }