stdio-common/_itoa.c

   1 /* Internal function for converting integers to ASCII.
   2    Copyright (C) 1994, 1995, 1996, 1999, 2000, 2002, 2003, 2004, 2007
   3    Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5    Contributed by Torbjorn Granlund <tege@matematik.su.se>
   6    and Ulrich Drepper <drepper@gnu.org>.
   7
   8    The GNU C Library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU Lesser General Public
  10    License as published by the Free Software Foundation; either
  11    version 2.1 of the License, or (at your option) any later version.
  12
  13    The GNU C Library is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16    Lesser General Public License for more details.
  17
  18    You should have received a copy of the GNU Lesser General Public
  19    License along with the GNU C Library; if not, see
  20    <http://www.gnu.org/licenses/>.  */
  21
  22 #include <gmp-mparam.h>
  23 #include <gmp.h>
  24 #include <limits.h>
  25 #include <stdlib/gmp-impl.h>
  26 #include <stdlib/longlong.h>
  27
  28 #include "_itoa.h"
  29
  30
  31 /* Canonize environment.  For some architectures not all values might
  32    be defined in the GMP header files.  */
  33 #ifndef UMUL_TIME
  34 # define UMUL_TIME 1
  35 #endif
  36 #ifndef UDIV_TIME
  37 # define UDIV_TIME 3
  38 #endif
  39
  40 /* Control memory layout.  */
  41 #ifdef PACK
  42 # undef PACK
  43 # define PACK __attribute__ ((packed))
  44 #else
  45 # define PACK
  46 #endif
  47
  48
  49 /* Declare local types.  */
  50 struct base_table_t
  51 {
  52 #if (UDIV_TIME > 2 * UMUL_TIME)
  53   mp_limb_t base_multiplier;
  54 #endif
  55   char flag;
  56   char post_shift;
  57 #if BITS_PER_MP_LIMB == 32
  58   struct
  59     {
  60       char normalization_steps;
  61       char ndigits;
  62       mp_limb_t base PACK;
  63 #if UDIV_TIME > 2 * UMUL_TIME
  64       mp_limb_t base_ninv PACK;
  65 #endif
  66     } big;
  67 #endif
  68 };
  69
  70 /* To reduce the memory needed we include some fields of the tables
  71    only conditionally.  */
  72 #if UDIV_TIME > 2 * UMUL_TIME
  73 # define SEL1(X) X,
  74 # define SEL2(X) ,X
  75 #else
  76 # define SEL1(X)
  77 # define SEL2(X)
  78 #endif
  79
  80
  81 /* We do not compile _itoa if we always can use _itoa_word.  */
  82 #if LLONG_MAX != LONG_MAX
  83 /* Local variables.  */
  84 const struct base_table_t _itoa_base_table[] attribute_hidden =
  85 {
  86 # if BITS_PER_MP_LIMB == 64
  87   /*  2 */ {SEL1(0ull) 1, 1},
  88   /*  3 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 1},
  89   /*  4 */ {SEL1(0ull) 1, 2},
  90   /*  5 */ {SEL1(0xcccccccccccccccdull) 0, 2},
  91   /*  6 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 2},
  92   /*  7 */ {SEL1(0x2492492492492493ull) 1, 3},
  93   /*  8 */ {SEL1(0ull) 1, 3},
  94   /*  9 */ {SEL1(0xe38e38e38e38e38full) 0, 3},
  95   /* 10 */ {SEL1(0xcccccccccccccccdull) 0, 3},
  96   /* 11 */ {SEL1(0x2e8ba2e8ba2e8ba3ull) 0, 1},
  97   /* 12 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 3},
  98   /* 13 */ {SEL1(0x4ec4ec4ec4ec4ec5ull) 0, 2},
  99   /* 14 */ {SEL1(0x2492492492492493ull) 1, 4},
 100   /* 15 */ {SEL1(0x8888888888888889ull) 0, 3},
 101   /* 16 */ {SEL1(0ull) 1, 4},
 102   /* 17 */ {SEL1(0xf0f0f0f0f0f0f0f1ull) 0, 4},
 103   /* 18 */ {SEL1(0xe38e38e38e38e38full) 0, 4},
 104   /* 19 */ {SEL1(0xd79435e50d79435full) 0, 4},
 105   /* 20 */ {SEL1(0xcccccccccccccccdull) 0, 4},
 106   /* 21 */ {SEL1(0x8618618618618619ull) 1, 5},
 107   /* 22 */ {SEL1(0x2e8ba2e8ba2e8ba3ull) 0, 2},
 108   /* 23 */ {SEL1(0x642c8590b21642c9ull) 1, 5},
 109   /* 24 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 4},
 110   /* 25 */ {SEL1(0x47ae147ae147ae15ull) 1, 5},
 111   /* 26 */ {SEL1(0x4ec4ec4ec4ec4ec5ull) 0, 3},
 112   /* 27 */ {SEL1(0x97b425ed097b425full) 0, 4},
 113   /* 28 */ {SEL1(0x2492492492492493ull) 1, 5},
 114   /* 29 */ {SEL1(0x1a7b9611a7b9611bull) 1, 5},
 115   /* 30 */ {SEL1(0x8888888888888889ull) 0, 4},
 116   /* 31 */ {SEL1(0x0842108421084211ull) 1, 5},
 117   /* 32 */ {SEL1(0ull) 1, 5},
 118   /* 33 */ {SEL1(0x0f83e0f83e0f83e1ull) 0, 1},
 119   /* 34 */ {SEL1(0xf0f0f0f0f0f0f0f1ull) 0, 5},
 120   /* 35 */ {SEL1(0xea0ea0ea0ea0ea0full) 0, 5},
 121   /* 36 */ {SEL1(0xe38e38e38e38e38full) 0, 5}
 122 # endif
 123 # if BITS_PER_MP_LIMB == 32
 124   /*  2 */ {SEL1(0ul) 1, 1, {0, 31, 0x80000000ul SEL2(0xfffffffful)}},
 125   /*  3 */ {SEL1(0xaaaaaaabul) 0, 1, {0, 20, 0xcfd41b91ul SEL2(0x3b563c24ul)}},
 126   /*  4 */ {SEL1(0ul) 1, 2, {1, 15, 0x40000000ul SEL2(0xfffffffful)}},
 127   /*  5 */ {SEL1(0xcccccccdul) 0, 2, {1, 13, 0x48c27395ul SEL2(0xc25c2684ul)}},
 128   /*  6 */ {SEL1(0xaaaaaaabul) 0, 2, {0, 12, 0x81bf1000ul SEL2(0xf91bd1b6ul)}},
 129   /*  7 */ {SEL1(0x24924925ul) 1, 3, {1, 11, 0x75db9c97ul SEL2(0x1607a2cbul)}},
 130   /*  8 */ {SEL1(0ul) 1, 3, {1, 10, 0x40000000ul SEL2(0xfffffffful)}},
 131   /*  9 */ {SEL1(0x38e38e39ul) 0, 1, {0, 10, 0xcfd41b91ul SEL2(0x3b563c24ul)}},
 132   /* 10 */ {SEL1(0xcccccccdul) 0, 3, {2, 9, 0x3b9aca00ul SEL2(0x12e0be82ul)}},
 133   /* 11 */ {SEL1(0xba2e8ba3ul) 0, 3, {0, 9, 0x8c8b6d2bul SEL2(0xd24cde04ul)}},
 134   /* 12 */ {SEL1(0xaaaaaaabul) 0, 3, {3, 8, 0x19a10000ul SEL2(0x3fa39ab5ul)}},
 135   /* 13 */ {SEL1(0x4ec4ec4ful) 0, 2, {2, 8, 0x309f1021ul SEL2(0x50f8ac5ful)}},
 136   /* 14 */ {SEL1(0x24924925ul) 1, 4, {1, 8, 0x57f6c100ul SEL2(0x74843b1eul)}},
 137   /* 15 */ {SEL1(0x88888889ul) 0, 3, {0, 8, 0x98c29b81ul SEL2(0xad0326c2ul)}},
 138   /* 16 */ {SEL1(0ul) 1, 4, {3, 7, 0x10000000ul SEL2(0xfffffffful)}},
 139   /* 17 */ {SEL1(0xf0f0f0f1ul) 0, 4, {3, 7, 0x18754571ul SEL2(0x4ef0b6bdul)}},
 140   /* 18 */ {SEL1(0x38e38e39ul) 0, 2, {2, 7, 0x247dbc80ul SEL2(0xc0fc48a1ul)}},
 141   /* 19 */ {SEL1(0xaf286bcbul) 1, 5, {2, 7, 0x3547667bul SEL2(0x33838942ul)}},
 142   /* 20 */ {SEL1(0xcccccccdul) 0, 4, {1, 7, 0x4c4b4000ul SEL2(0xad7f29abul)}},
 143   /* 21 */ {SEL1(0x86186187ul) 1, 5, {1, 7, 0x6b5a6e1dul SEL2(0x313c3d15ul)}},
 144   /* 22 */ {SEL1(0xba2e8ba3ul) 0, 4, {0, 7, 0x94ace180ul SEL2(0xb8cca9e0ul)}},
 145   /* 23 */ {SEL1(0xb21642c9ul) 0, 4, {0, 7, 0xcaf18367ul SEL2(0x42ed6de9ul)}},
 146   /* 24 */ {SEL1(0xaaaaaaabul) 0, 4, {4, 6, 0x0b640000ul SEL2(0x67980e0bul)}},
 147   /* 25 */ {SEL1(0x51eb851ful) 0, 3, {4, 6, 0x0e8d4a51ul SEL2(0x19799812ul)}},
 148   /* 26 */ {SEL1(0x4ec4ec4ful) 0, 3, {3, 6, 0x1269ae40ul SEL2(0xbce85396ul)}},
 149   /* 27 */ {SEL1(0x2f684bdbul) 1, 5, {3, 6, 0x17179149ul SEL2(0x62c103a9ul)}},
 150   /* 28 */ {SEL1(0x24924925ul) 1, 5, {3, 6, 0x1cb91000ul SEL2(0x1d353d43ul)}},
 151   /* 29 */ {SEL1(0x8d3dcb09ul) 0, 4, {2, 6, 0x23744899ul SEL2(0xce1deceaul)}},
 152   /* 30 */ {SEL1(0x88888889ul) 0, 4, {2, 6, 0x2b73a840ul SEL2(0x790fc511ul)}},
 153   /* 31 */ {SEL1(0x08421085ul) 1, 5, {2, 6, 0x34e63b41ul SEL2(0x35b865a0ul)}},
 154   /* 32 */ {SEL1(0ul) 1, 5, {1, 6, 0x40000000ul SEL2(0xfffffffful)}},
 155   /* 33 */ {SEL1(0x3e0f83e1ul) 0, 3, {1, 6, 0x4cfa3cc1ul SEL2(0xa9aed1b3ul)}},
 156   /* 34 */ {SEL1(0xf0f0f0f1ul) 0, 5, {1, 6, 0x5c13d840ul SEL2(0x63dfc229ul)}},
 157   /* 35 */ {SEL1(0xd41d41d5ul) 1, 6, {1, 6, 0x6d91b519ul SEL2(0x2b0fee30ul)}},
 158   /* 36 */ {SEL1(0x38e38e39ul) 0, 3, {0, 6, 0x81bf1000ul SEL2(0xf91bd1b6ul)}}
 159 # endif
 160 };
 161 #endif
 162
 163 /* Lower-case digits.  */
 164 extern const char _itoa_lower_digits[];
 165 extern const char _itoa_lower_digits_internal[] attribute_hidden;
 166 /* Upper-case digits.  */
 167 extern const char _itoa_upper_digits[];
 168 extern const char _itoa_upper_digits_internal[] attribute_hidden;
 169
 170
 171 char *
 172 _itoa_word (unsigned long value, char *buflim,
 173             unsigned int base, int upper_case)
 174 {
 175   const char *digits = (upper_case
 176 #if !defined NOT_IN_libc || defined IS_IN_rtld
 177                         ? INTUSE(_itoa_upper_digits)
 178                         : INTUSE(_itoa_lower_digits)
 179 #else
 180                         ? _itoa_upper_digits
 181                         : _itoa_lower_digits
 182 #endif
 183                        );
 184
 185   switch (base)
 186     {
 187 #define SPECIAL(Base)                                                         \
 188     case Base:                                                                \
 189       do                                                                      \
 190         *--buflim = digits[value % Base];                                     \
 191       while ((value /= Base) != 0);                                           \
 192       break
 193
 194       SPECIAL (10);
 195       SPECIAL (16);
 196       SPECIAL (8);
 197     default:
 198       do
 199         *--buflim = digits[value % base];
 200       while ((value /= base) != 0);
 201     }
 202   return buflim;
 203 }
 204 #undef SPECIAL
 205
 206
 207 #if LLONG_MAX != LONG_MAX
 208 char *
 209 _itoa (value, buflim, base, upper_case)
 210      unsigned long long int value;
 211      char *buflim;
 212      unsigned int base;
 213      int upper_case;
 214 {
 215   const char *digits = (upper_case
 216                         ? INTUSE(_itoa_upper_digits)
 217                         : INTUSE(_itoa_lower_digits));
 218   const struct base_table_t *brec = &_itoa_base_table[base - 2];
 219
 220   switch (base)
 221     {
 222 # define RUN_2N(BITS) \
 223       do                                                                      \
 224         {                                                                     \
 225           /* `unsigned long long int' always has 64 bits.  */                 \
 226           mp_limb_t work_hi = value >> (64 - BITS_PER_MP_LIMB);               \
 227                                                                               \
 228           if (BITS_PER_MP_LIMB == 32)                                         \
 229             {                                                                 \
 230               if (work_hi != 0)                                               \
 231                 {                                                             \
 232                   mp_limb_t work_lo;                                          \
 233                   int cnt;                                                    \
 234                                                                               \
 235                   work_lo = value & 0xfffffffful;                             \
 236                   for (cnt = BITS_PER_MP_LIMB / BITS; cnt > 0; --cnt)         \
 237                     {                                                         \
 238                       *--buflim = digits[work_lo & ((1ul << BITS) - 1)];      \
 239                       work_lo >>= BITS;                                       \
 240                     }                                                         \
 241                   if (BITS_PER_MP_LIMB % BITS != 0)                           \
 242                     {                                                         \
 243                       work_lo                                                 \
 244                         |= ((work_hi                                          \
 245                              & ((1 << (BITS - BITS_PER_MP_LIMB%BITS))         \
 246                                 - 1))                                         \
 247                             << BITS_PER_MP_LIMB % BITS);                      \
 248                       work_hi >>= BITS - BITS_PER_MP_LIMB % BITS;             \
 249                       if (work_hi == 0)                                       \
 250                         work_hi = work_lo;                                    \
 251                       else                                                    \
 252                         *--buflim = digits[work_lo];                          \
 253                     }                                                         \
 254                 }                                                             \
 255               else                                                            \
 256                 work_hi = value & 0xfffffffful;                               \
 257             }                                                                 \
 258           do                                                                  \
 259             {                                                                 \
 260               *--buflim = digits[work_hi & ((1 << BITS) - 1)];                \
 261               work_hi >>= BITS;                                               \
 262             }                                                                 \
 263           while (work_hi != 0);                                               \
 264         }                                                                     \
 265       while (0)
 266     case 8:
 267       RUN_2N (3);
 268       break;
 269
 270     case 16:
 271       RUN_2N (4);
 272       break;
 273
 274     default:
 275       {
 276         char *bufend = buflim;
 277 # if BITS_PER_MP_LIMB == 64
 278         mp_limb_t base_multiplier = brec->base_multiplier;
 279         if (brec->flag)
 280           while (value != 0)
 281             {
 282               mp_limb_t quo, rem, x, dummy;
 283
 284               umul_ppmm (x, dummy, value, base_multiplier);
 285               quo = (x + ((value - x) >> 1)) >> (brec->post_shift - 1);
 286               rem = value - quo * base;
 287               *--buflim = digits[rem];
 288               value = quo;
 289             }
 290         else
 291           while (value != 0)
 292             {
 293               mp_limb_t quo, rem, x, dummy;
 294
 295               umul_ppmm (x, dummy, value, base_multiplier);
 296               quo = x >> brec->post_shift;
 297               rem = value - quo * base;
 298               *--buflim = digits[rem];
 299               value = quo;
 300             }
 301 # endif
 302 # if BITS_PER_MP_LIMB == 32
 303         mp_limb_t t[3];
 304         int n;
 305
 306         /* First convert x0 to 1-3 words in base s->big.base.
 307            Optimize for frequent cases of 32 bit numbers.  */
 308         if ((mp_limb_t) (value >> 32) >= 1)
 309           {
 310 #  if UDIV_TIME > 2 * UMUL_TIME || UDIV_NEEDS_NORMALIZATION
 311             int big_normalization_steps = brec->big.normalization_steps;
 312             mp_limb_t big_base_norm
 313               = brec->big.base << big_normalization_steps;
 314 #  endif
 315             if ((mp_limb_t) (value >> 32) >= brec->big.base)
 316               {
 317                 mp_limb_t x1hi, x1lo, r;
 318                 /* If you want to optimize this, take advantage of
 319                    that the quotient in the first udiv_qrnnd will
 320                    always be very small.  It might be faster just to
 321                    subtract in a tight loop.  */
 322
 323 #  if UDIV_TIME > 2 * UMUL_TIME
 324                 mp_limb_t x, xh, xl;
 325
 326                 if (big_normalization_steps == 0)
 327                   xh = 0;
 328                 else
 329                   xh = (mp_limb_t) (value >> (64 - big_normalization_steps));
 330                 xl = (mp_limb_t) (value >> (32 - big_normalization_steps));
 331                 udiv_qrnnd_preinv (x1hi, r, xh, xl, big_base_norm,
 332                                    brec->big.base_ninv);
 333
 334                 xl = ((mp_limb_t) value) << big_normalization_steps;
 335                 udiv_qrnnd_preinv (x1lo, x, r, xl, big_base_norm,
 336                                    brec->big.base_ninv);
 337                 t[2] = x >> big_normalization_steps;
 338
 339                 if (big_normalization_steps == 0)
 340                   xh = x1hi;
 341                 else
 342                   xh = ((x1hi << big_normalization_steps)
 343                         | (x1lo >> (32 - big_normalization_steps)));
 344                 xl = x1lo << big_normalization_steps;
 345                 udiv_qrnnd_preinv (t[0], x, xh, xl, big_base_norm,
 346                                    brec->big.base_ninv);
 347                 t[1] = x >> big_normalization_steps;
 348 #  elif UDIV_NEEDS_NORMALIZATION
 349                 mp_limb_t x, xh, xl;
 350
 351                 if (big_normalization_steps == 0)
 352                   xh = 0;
 353                 else
 354                   xh = (mp_limb_t) (value >> 64 - big_normalization_steps);
 355                 xl = (mp_limb_t) (value >> 32 - big_normalization_steps);
 356                 udiv_qrnnd (x1hi, r, xh, xl, big_base_norm);
 357
 358                 xl = ((mp_limb_t) value) << big_normalization_steps;
 359                 udiv_qrnnd (x1lo, x, r, xl, big_base_norm);
 360                 t[2] = x >> big_normalization_steps;
 361
 362                 if (big_normalization_steps == 0)
 363                   xh = x1hi;
 364                 else
 365                   xh = ((x1hi << big_normalization_steps)
 366                         | (x1lo >> 32 - big_normalization_steps));
 367                 xl = x1lo << big_normalization_steps;
 368                 udiv_qrnnd (t[0], x, xh, xl, big_base_norm);
 369                 t[1] = x >> big_normalization_steps;
 370 #  else
 371                 udiv_qrnnd (x1hi, r, 0, (mp_limb_t) (value >> 32),
 372                             brec->big.base);
 373                 udiv_qrnnd (x1lo, t[2], r, (mp_limb_t) value, brec->big.base);
 374                 udiv_qrnnd (t[0], t[1], x1hi, x1lo, brec->big.base);
 375 #  endif
 376                 n = 3;
 377               }
 378             else
 379               {
 380 #  if UDIV_TIME > 2 * UMUL_TIME
 381                 mp_limb_t x;
 382
 383                 value <<= brec->big.normalization_steps;
 384                 udiv_qrnnd_preinv (t[0], x, (mp_limb_t) (value >> 32),
 385                                    (mp_limb_t) value, big_base_norm,
 386                                    brec->big.base_ninv);
 387                 t[1] = x >> brec->big.normalization_steps;
 388 #  elif UDIV_NEEDS_NORMALIZATION
 389                 mp_limb_t x;
 390
 391                 value <<= big_normalization_steps;
 392                 udiv_qrnnd (t[0], x, (mp_limb_t) (value >> 32),
 393                             (mp_limb_t) value, big_base_norm);
 394                 t[1] = x >> big_normalization_steps;
 395 #  else
 396                 udiv_qrnnd (t[0], t[1], (mp_limb_t) (value >> 32),
 397                             (mp_limb_t) value, brec->big.base);
 398 #  endif
 399                 n = 2;
 400               }
 401           }
 402         else
 403           {
 404             t[0] = value;
 405             n = 1;
 406           }
 407
 408         /* Convert the 1-3 words in t[], word by word, to ASCII.  */
 409         do
 410           {
 411             mp_limb_t ti = t[--n];
 412             int ndig_for_this_limb = 0;
 413
 414 #  if UDIV_TIME > 2 * UMUL_TIME
 415             mp_limb_t base_multiplier = brec->base_multiplier;
 416             if (brec->flag)
 417               while (ti != 0)
 418                 {
 419                   mp_limb_t quo, rem, x, dummy;
 420
 421                   umul_ppmm (x, dummy, ti, base_multiplier);
 422                   quo = (x + ((ti - x) >> 1)) >> (brec->post_shift - 1);
 423                   rem = ti - quo * base;
 424                   *--buflim = digits[rem];
 425                   ti = quo;
 426                   ++ndig_for_this_limb;
 427                 }
 428             else
 429               while (ti != 0)
 430                 {
 431                   mp_limb_t quo, rem, x, dummy;
 432
 433                   umul_ppmm (x, dummy, ti, base_multiplier);
 434                   quo = x >> brec->post_shift;
 435                   rem = ti - quo * base;
 436                   *--buflim = digits[rem];
 437                   ti = quo;
 438                   ++ndig_for_this_limb;
 439                 }
 440 #  else
 441             while (ti != 0)
 442               {
 443                 mp_limb_t quo, rem;
 444
 445                 quo = ti / base;
 446                 rem = ti % base;
 447                 *--buflim = digits[rem];
 448                 ti = quo;
 449                 ++ndig_for_this_limb;
 450               }
 451 #  endif
 452             /* If this wasn't the most significant word, pad with zeros.  */
 453             if (n != 0)
 454               while (ndig_for_this_limb < brec->big.ndigits)
 455                 {
 456                   *--buflim = '0';
 457                   ++ndig_for_this_limb;
 458                 }
 459           }
 460         while (n != 0);
 461 # endif
 462         if (buflim == bufend)
 463           *--buflim = '0';
 464       }
 465       break;
 466     }
 467
 468   return buflim;
 469 }
 470 #endif
 471
 472 char *
 473 _fitoa_word (unsigned long value, char *buf, unsigned int base, int upper_case)
 474 {
 475   char tmpbuf[sizeof (value) * 4];            /* Worst case length: base 2.  */
 476   char *cp = _itoa_word (value, tmpbuf + sizeof (value) * 4, base, upper_case);
 477   while (cp < tmpbuf + sizeof (value) * 4)
 478     *buf++ = *cp++;
 479   return buf;
 480 }
 481
 482 #if LLONG_MAX != LONG_MAX
 483 char *
 484 _fitoa (unsigned long long value, char *buf, unsigned int base, int upper_case)
 485 {
 486   char tmpbuf[sizeof (value) * 4];            /* Worst case length: base 2.  */
 487   char *cp = _itoa (value, tmpbuf + sizeof (value) * 4, base, upper_case);
 488   while (cp < tmpbuf + sizeof (value) * 4)
 489     *buf++ = *cp++;
 490   return buf;
 491 }
 492 #endif