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, write to the Free
  20    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  21    02111-1307 USA.  */
  22
  23 #include <gmp-mparam.h>
  24 #include <gmp.h>
  25 #include <limits.h>
  26 #include <stdlib/gmp-impl.h>
  27 #include <stdlib/longlong.h>
  28
  29 #include "_itoa.h"
  30
  31
  32 /* Canonize environment.  For some architectures not all values might
  33    be defined in the GMP header files.  */
  34 #ifndef UMUL_TIME
  35 # define UMUL_TIME 1
  36 #endif
  37 #ifndef UDIV_TIME
  38 # define UDIV_TIME 3
  39 #endif
  40
  41 /* Control memory layout.  */
  42 #ifdef PACK
  43 # undef PACK
  44 # define PACK __attribute__ ((packed))
  45 #else
  46 # define PACK
  47 #endif
  48
  49
  50 /* Declare local types.  */
  51 struct base_table_t
  52 {
  53 #if (UDIV_TIME > 2 * UMUL_TIME)
  54   mp_limb_t base_multiplier;
  55 #endif
  56   char flag;
  57   char post_shift;
  58 #if BITS_PER_MP_LIMB == 32
  59   struct
  60     {
  61       char normalization_steps;
  62       char ndigits;
  63       mp_limb_t base PACK;
  64 #if UDIV_TIME > 2 * UMUL_TIME
  65       mp_limb_t base_ninv PACK;
  66 #endif
  67     } big;
  68 #endif
  69 };
  70
  71 /* To reduce the memory needed we include some fields of the tables
  72    only conditionally.  */
  73 #if UDIV_TIME > 2 * UMUL_TIME
  74 # define SEL1(X) X,
  75 # define SEL2(X) ,X
  76 #else
  77 # define SEL1(X)
  78 # define SEL2(X)
  79 #endif
  80
  81
  82 /* We do not compile _itoa if we always can use _itoa_word.  */
  83 #if LLONG_MAX != LONG_MAX
  84 /* Local variables.  */
  85 const struct base_table_t _itoa_base_table[] attribute_hidden =
  86 {
  87 # if BITS_PER_MP_LIMB == 64
  88   /*  2 */ {SEL1(0ull) 1, 1},
  89   /*  3 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 1},
  90   /*  4 */ {SEL1(0ull) 1, 2},
  91   /*  5 */ {SEL1(0xcccccccccccccccdull) 0, 2},
  92   /*  6 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 2},
  93   /*  7 */ {SEL1(0x2492492492492493ull) 1, 3},
  94   /*  8 */ {SEL1(0ull) 1, 3},
  95   /*  9 */ {SEL1(0xe38e38e38e38e38full) 0, 3},
  96   /* 10 */ {SEL1(0xcccccccccccccccdull) 0, 3},
  97   /* 11 */ {SEL1(0x2e8ba2e8ba2e8ba3ull) 0, 1},
  98   /* 12 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 3},
  99   /* 13 */ {SEL1(0x4ec4ec4ec4ec4ec5ull) 0, 2},
 100   /* 14 */ {SEL1(0x2492492492492493ull) 1, 4},
 101   /* 15 */ {SEL1(0x8888888888888889ull) 0, 3},
 102   /* 16 */ {SEL1(0ull) 1, 4},
 103   /* 17 */ {SEL1(0xf0f0f0f0f0f0f0f1ull) 0, 4},
 104   /* 18 */ {SEL1(0xe38e38e38e38e38full) 0, 4},
 105   /* 19 */ {SEL1(0xd79435e50d79435full) 0, 4},
 106   /* 20 */ {SEL1(0xcccccccccccccccdull) 0, 4},
 107   /* 21 */ {SEL1(0x8618618618618619ull) 1, 5},
 108   /* 22 */ {SEL1(0x2e8ba2e8ba2e8ba3ull) 0, 2},
 109   /* 23 */ {SEL1(0x642c8590b21642c9ull) 1, 5},
 110   /* 24 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 4},
 111   /* 25 */ {SEL1(0x47ae147ae147ae15ull) 1, 5},
 112   /* 26 */ {SEL1(0x4ec4ec4ec4ec4ec5ull) 0, 3},
 113   /* 27 */ {SEL1(0x97b425ed097b425full) 0, 4},
 114   /* 28 */ {SEL1(0x2492492492492493ull) 1, 5},
 115   /* 29 */ {SEL1(0x1a7b9611a7b9611bull) 1, 5},
 116   /* 30 */ {SEL1(0x8888888888888889ull) 0, 4},
 117   /* 31 */ {SEL1(0x0842108421084211ull) 1, 5},
 118   /* 32 */ {SEL1(0ull) 1, 5},
 119   /* 33 */ {SEL1(0x0f83e0f83e0f83e1ull) 0, 1},
 120   /* 34 */ {SEL1(0xf0f0f0f0f0f0f0f1ull) 0, 5},
 121   /* 35 */ {SEL1(0xea0ea0ea0ea0ea0full) 0, 5},
 122   /* 36 */ {SEL1(0xe38e38e38e38e38full) 0, 5}
 123 # endif
 124 # if BITS_PER_MP_LIMB == 32
 125   /*  2 */ {SEL1(0ul) 1, 1, {0, 31, 0x80000000ul SEL2(0xfffffffful)}},
 126   /*  3 */ {SEL1(0xaaaaaaabul) 0, 1, {0, 20, 0xcfd41b91ul SEL2(0x3b563c24ul)}},
 127   /*  4 */ {SEL1(0ul) 1, 2, {1, 15, 0x40000000ul SEL2(0xfffffffful)}},
 128   /*  5 */ {SEL1(0xcccccccdul) 0, 2, {1, 13, 0x48c27395ul SEL2(0xc25c2684ul)}},
 129   /*  6 */ {SEL1(0xaaaaaaabul) 0, 2, {0, 12, 0x81bf1000ul SEL2(0xf91bd1b6ul)}},
 130   /*  7 */ {SEL1(0x24924925ul) 1, 3, {1, 11, 0x75db9c97ul SEL2(0x1607a2cbul)}},
 131   /*  8 */ {SEL1(0ul) 1, 3, {1, 10, 0x40000000ul SEL2(0xfffffffful)}},
 132   /*  9 */ {SEL1(0x38e38e39ul) 0, 1, {0, 10, 0xcfd41b91ul SEL2(0x3b563c24ul)}},
 133   /* 10 */ {SEL1(0xcccccccdul) 0, 3, {2, 9, 0x3b9aca00ul SEL2(0x12e0be82ul)}},
 134   /* 11 */ {SEL1(0xba2e8ba3ul) 0, 3, {0, 9, 0x8c8b6d2bul SEL2(0xd24cde04ul)}},
 135   /* 12 */ {SEL1(0xaaaaaaabul) 0, 3, {3, 8, 0x19a10000ul SEL2(0x3fa39ab5ul)}},
 136   /* 13 */ {SEL1(0x4ec4ec4ful) 0, 2, {2, 8, 0x309f1021ul SEL2(0x50f8ac5ful)}},
 137   /* 14 */ {SEL1(0x24924925ul) 1, 4, {1, 8, 0x57f6c100ul SEL2(0x74843b1eul)}},
 138   /* 15 */ {SEL1(0x88888889ul) 0, 3, {0, 8, 0x98c29b81ul SEL2(0xad0326c2ul)}},
 139   /* 16 */ {SEL1(0ul) 1, 4, {3, 7, 0x10000000ul SEL2(0xfffffffful)}},
 140   /* 17 */ {SEL1(0xf0f0f0f1ul) 0, 4, {3, 7, 0x18754571ul SEL2(0x4ef0b6bdul)}},
 141   /* 18 */ {SEL1(0x38e38e39ul) 0, 2, {2, 7, 0x247dbc80ul SEL2(0xc0fc48a1ul)}},
 142   /* 19 */ {SEL1(0xaf286bcbul) 1, 5, {2, 7, 0x3547667bul SEL2(0x33838942ul)}},
 143   /* 20 */ {SEL1(0xcccccccdul) 0, 4, {1, 7, 0x4c4b4000ul SEL2(0xad7f29abul)}},
 144   /* 21 */ {SEL1(0x86186187ul) 1, 5, {1, 7, 0x6b5a6e1dul SEL2(0x313c3d15ul)}},
 145   /* 22 */ {SEL1(0xba2e8ba3ul) 0, 4, {0, 7, 0x94ace180ul SEL2(0xb8cca9e0ul)}},
 146   /* 23 */ {SEL1(0xb21642c9ul) 0, 4, {0, 7, 0xcaf18367ul SEL2(0x42ed6de9ul)}},
 147   /* 24 */ {SEL1(0xaaaaaaabul) 0, 4, {4, 6, 0x0b640000ul SEL2(0x67980e0bul)}},
 148   /* 25 */ {SEL1(0x51eb851ful) 0, 3, {4, 6, 0x0e8d4a51ul SEL2(0x19799812ul)}},
 149   /* 26 */ {SEL1(0x4ec4ec4ful) 0, 3, {3, 6, 0x1269ae40ul SEL2(0xbce85396ul)}},
 150   /* 27 */ {SEL1(0x2f684bdbul) 1, 5, {3, 6, 0x17179149ul SEL2(0x62c103a9ul)}},
 151   /* 28 */ {SEL1(0x24924925ul) 1, 5, {3, 6, 0x1cb91000ul SEL2(0x1d353d43ul)}},
 152   /* 29 */ {SEL1(0x8d3dcb09ul) 0, 4, {2, 6, 0x23744899ul SEL2(0xce1deceaul)}},
 153   /* 30 */ {SEL1(0x88888889ul) 0, 4, {2, 6, 0x2b73a840ul SEL2(0x790fc511ul)}},
 154   /* 31 */ {SEL1(0x08421085ul) 1, 5, {2, 6, 0x34e63b41ul SEL2(0x35b865a0ul)}},
 155   /* 32 */ {SEL1(0ul) 1, 5, {1, 6, 0x40000000ul SEL2(0xfffffffful)}},
 156   /* 33 */ {SEL1(0x3e0f83e1ul) 0, 3, {1, 6, 0x4cfa3cc1ul SEL2(0xa9aed1b3ul)}},
 157   /* 34 */ {SEL1(0xf0f0f0f1ul) 0, 5, {1, 6, 0x5c13d840ul SEL2(0x63dfc229ul)}},
 158   /* 35 */ {SEL1(0xd41d41d5ul) 1, 6, {1, 6, 0x6d91b519ul SEL2(0x2b0fee30ul)}},
 159   /* 36 */ {SEL1(0x38e38e39ul) 0, 3, {0, 6, 0x81bf1000ul SEL2(0xf91bd1b6ul)}}
 160 # endif
 161 };
 162 #endif
 163
 164 /* Lower-case digits.  */
 165 extern const char _itoa_lower_digits[];
 166 extern const char _itoa_lower_digits_internal[] attribute_hidden;
 167 /* Upper-case digits.  */
 168 extern const char _itoa_upper_digits[];
 169 extern const char _itoa_upper_digits_internal[] attribute_hidden;
 170
 171
 172 char *
 173 _itoa_word (unsigned long value, char *buflim,
 174             unsigned int base, int upper_case)
 175 {
 176   const char *digits = (upper_case
 177 #if !defined NOT_IN_libc || defined IS_IN_rtld
 178                         ? INTUSE(_itoa_upper_digits)
 179                         : INTUSE(_itoa_lower_digits)
 180 #else
 181                         ? _itoa_upper_digits
 182                         : _itoa_lower_digits
 183 #endif
 184                        );
 185
 186   switch (base)
 187     {
 188 #define SPECIAL(Base)                                                         \
 189     case Base:                                                                \
 190       do                                                                      \
 191         *--buflim = digits[value % Base];                                     \
 192       while ((value /= Base) != 0);                                           \
 193       break
 194
 195       SPECIAL (10);
 196       SPECIAL (16);
 197       SPECIAL (8);
 198     default:
 199       do
 200         *--buflim = digits[value % base];
 201       while ((value /= base) != 0);
 202     }
 203   return buflim;
 204 }
 205 #undef SPECIAL
 206
 207
 208 #if LLONG_MAX != LONG_MAX
 209 char *
 210 _itoa (value, buflim, base, upper_case)
 211      unsigned long long int value;
 212      char *buflim;
 213      unsigned int base;
 214      int upper_case;
 215 {
 216   const char *digits = (upper_case
 217                         ? INTUSE(_itoa_upper_digits)
 218                         : INTUSE(_itoa_lower_digits));
 219   const struct base_table_t *brec = &_itoa_base_table[base - 2];
 220
 221   switch (base)
 222     {
 223 # define RUN_2N(BITS) \
 224       do                                                                      \
 225         {                                                                     \
 226           /* `unsigned long long int' always has 64 bits.  */                 \
 227           mp_limb_t work_hi = value >> (64 - BITS_PER_MP_LIMB);               \
 228                                                                               \
 229           if (BITS_PER_MP_LIMB == 32)                                         \
 230             {                                                                 \
 231               if (work_hi != 0)                                               \
 232                 {                                                             \
 233                   mp_limb_t work_lo;                                          \
 234                   int cnt;                                                    \
 235                                                                               \
 236                   work_lo = value & 0xfffffffful;                             \
 237                   for (cnt = BITS_PER_MP_LIMB / BITS; cnt > 0; --cnt)         \
 238                     {                                                         \
 239                       *--buflim = digits[work_lo & ((1ul << BITS) - 1)];      \
 240                       work_lo >>= BITS;                                       \
 241                     }                                                         \
 242                   if (BITS_PER_MP_LIMB % BITS != 0)                           \
 243                     {                                                         \
 244                       work_lo                                                 \
 245                         |= ((work_hi                                          \
 246                              & ((1 << (BITS - BITS_PER_MP_LIMB%BITS))         \
 247                                 - 1))                                         \
 248                             << BITS_PER_MP_LIMB % BITS);                      \
 249                       work_hi >>= BITS - BITS_PER_MP_LIMB % BITS;             \
 250                       if (work_hi == 0)                                       \
 251                         work_hi = work_lo;                                    \
 252                       else                                                    \
 253                         *--buflim = digits[work_lo];                          \
 254                     }                                                         \
 255                 }                                                             \
 256               else                                                            \
 257                 work_hi = value & 0xfffffffful;                               \
 258             }                                                                 \
 259           do                                                                  \
 260             {                                                                 \
 261               *--buflim = digits[work_hi & ((1 << BITS) - 1)];                \
 262               work_hi >>= BITS;                                               \
 263             }                                                                 \
 264           while (work_hi != 0);                                               \
 265         }                                                                     \
 266       while (0)
 267     case 8:
 268       RUN_2N (3);
 269       break;
 270
 271     case 16:
 272       RUN_2N (4);
 273       break;
 274
 275     default:
 276       {
 277         char *bufend = buflim;
 278 # if BITS_PER_MP_LIMB == 64
 279         mp_limb_t base_multiplier = brec->base_multiplier;
 280         if (brec->flag)
 281           while (value != 0)
 282             {
 283               mp_limb_t quo, rem, x, dummy;
 284
 285               umul_ppmm (x, dummy, value, base_multiplier);
 286               quo = (x + ((value - x) >> 1)) >> (brec->post_shift - 1);
 287               rem = value - quo * base;
 288               *--buflim = digits[rem];
 289               value = quo;
 290             }
 291         else
 292           while (value != 0)
 293             {
 294               mp_limb_t quo, rem, x, dummy;
 295
 296               umul_ppmm (x, dummy, value, base_multiplier);
 297               quo = x >> brec->post_shift;
 298               rem = value - quo * base;
 299               *--buflim = digits[rem];
 300               value = quo;
 301             }
 302 # endif
 303 # if BITS_PER_MP_LIMB == 32
 304         mp_limb_t t[3];
 305         int n;
 306
 307         /* First convert x0 to 1-3 words in base s->big.base.
 308            Optimize for frequent cases of 32 bit numbers.  */
 309         if ((mp_limb_t) (value >> 32) >= 1)
 310           {
 311 #  if UDIV_TIME > 2 * UMUL_TIME || UDIV_NEEDS_NORMALIZATION
 312             int big_normalization_steps = brec->big.normalization_steps;
 313             mp_limb_t big_base_norm
 314               = brec->big.base << big_normalization_steps;
 315 #  endif
 316             if ((mp_limb_t) (value >> 32) >= brec->big.base)
 317               {
 318                 mp_limb_t x1hi, x1lo, r;
 319                 /* If you want to optimize this, take advantage of
 320                    that the quotient in the first udiv_qrnnd will
 321                    always be very small.  It might be faster just to
 322                    subtract in a tight loop.  */
 323
 324 #  if UDIV_TIME > 2 * UMUL_TIME
 325                 mp_limb_t x, xh, xl;
 326
 327                 if (big_normalization_steps == 0)
 328                   xh = 0;
 329                 else
 330                   xh = (mp_limb_t) (value >> (64 - big_normalization_steps));
 331                 xl = (mp_limb_t) (value >> (32 - big_normalization_steps));
 332                 udiv_qrnnd_preinv (x1hi, r, xh, xl, big_base_norm,
 333                                    brec->big.base_ninv);
 334
 335                 xl = ((mp_limb_t) value) << big_normalization_steps;
 336                 udiv_qrnnd_preinv (x1lo, x, r, xl, big_base_norm,
 337                                    brec->big.base_ninv);
 338                 t[2] = x >> big_normalization_steps;
 339
 340                 if (big_normalization_steps == 0)
 341                   xh = x1hi;
 342                 else
 343                   xh = ((x1hi << big_normalization_steps)
 344                         | (x1lo >> (32 - big_normalization_steps)));
 345                 xl = x1lo << big_normalization_steps;
 346                 udiv_qrnnd_preinv (t[0], x, xh, xl, big_base_norm,
 347                                    brec->big.base_ninv);
 348                 t[1] = x >> big_normalization_steps;
 349 #  elif UDIV_NEEDS_NORMALIZATION
 350                 mp_limb_t x, xh, xl;
 351
 352                 if (big_normalization_steps == 0)
 353                   xh = 0;
 354                 else
 355                   xh = (mp_limb_t) (value >> 64 - big_normalization_steps);
 356                 xl = (mp_limb_t) (value >> 32 - big_normalization_steps);
 357                 udiv_qrnnd (x1hi, r, xh, xl, big_base_norm);
 358
 359                 xl = ((mp_limb_t) value) << big_normalization_steps;
 360                 udiv_qrnnd (x1lo, x, r, xl, big_base_norm);
 361                 t[2] = x >> big_normalization_steps;
 362
 363                 if (big_normalization_steps == 0)
 364                   xh = x1hi;
 365                 else
 366                   xh = ((x1hi << big_normalization_steps)
 367                         | (x1lo >> 32 - big_normalization_steps));
 368                 xl = x1lo << big_normalization_steps;
 369                 udiv_qrnnd (t[0], x, xh, xl, big_base_norm);
 370                 t[1] = x >> big_normalization_steps;
 371 #  else
 372                 udiv_qrnnd (x1hi, r, 0, (mp_limb_t) (value >> 32),
 373                             brec->big.base);
 374                 udiv_qrnnd (x1lo, t[2], r, (mp_limb_t) value, brec->big.base);
 375                 udiv_qrnnd (t[0], t[1], x1hi, x1lo, brec->big.base);
 376 #  endif
 377                 n = 3;
 378               }
 379             else
 380               {
 381 #  if UDIV_TIME > 2 * UMUL_TIME
 382                 mp_limb_t x;
 383
 384                 value <<= brec->big.normalization_steps;
 385                 udiv_qrnnd_preinv (t[0], x, (mp_limb_t) (value >> 32),
 386                                    (mp_limb_t) value, big_base_norm,
 387                                    brec->big.base_ninv);
 388                 t[1] = x >> brec->big.normalization_steps;
 389 #  elif UDIV_NEEDS_NORMALIZATION
 390                 mp_limb_t x;
 391
 392                 value <<= big_normalization_steps;
 393                 udiv_qrnnd (t[0], x, (mp_limb_t) (value >> 32),
 394                             (mp_limb_t) value, big_base_norm);
 395                 t[1] = x >> big_normalization_steps;
 396 #  else
 397                 udiv_qrnnd (t[0], t[1], (mp_limb_t) (value >> 32),
 398                             (mp_limb_t) value, brec->big.base);
 399 #  endif
 400                 n = 2;
 401               }
 402           }
 403         else
 404           {
 405             t[0] = value;
 406             n = 1;
 407           }
 408
 409         /* Convert the 1-3 words in t[], word by word, to ASCII.  */
 410         do
 411           {
 412             mp_limb_t ti = t[--n];
 413             int ndig_for_this_limb = 0;
 414
 415 #  if UDIV_TIME > 2 * UMUL_TIME
 416             mp_limb_t base_multiplier = brec->base_multiplier;
 417             if (brec->flag)
 418               while (ti != 0)
 419                 {
 420                   mp_limb_t quo, rem, x, dummy;
 421
 422                   umul_ppmm (x, dummy, ti, base_multiplier);
 423                   quo = (x + ((ti - x) >> 1)) >> (brec->post_shift - 1);
 424                   rem = ti - quo * base;
 425                   *--buflim = digits[rem];
 426                   ti = quo;
 427                   ++ndig_for_this_limb;
 428                 }
 429             else
 430               while (ti != 0)
 431                 {
 432                   mp_limb_t quo, rem, x, dummy;
 433
 434                   umul_ppmm (x, dummy, ti, base_multiplier);
 435                   quo = x >> brec->post_shift;
 436                   rem = ti - quo * base;
 437                   *--buflim = digits[rem];
 438                   ti = quo;
 439                   ++ndig_for_this_limb;
 440                 }
 441 #  else
 442             while (ti != 0)
 443               {
 444                 mp_limb_t quo, rem;
 445
 446                 quo = ti / base;
 447                 rem = ti % base;
 448                 *--buflim = digits[rem];
 449                 ti = quo;
 450                 ++ndig_for_this_limb;
 451               }
 452 #  endif
 453             /* If this wasn't the most significant word, pad with zeros.  */
 454             if (n != 0)
 455               while (ndig_for_this_limb < brec->big.ndigits)
 456                 {
 457                   *--buflim = '0';
 458                   ++ndig_for_this_limb;
 459                 }
 460           }
 461         while (n != 0);
 462 # endif
 463         if (buflim == bufend)
 464           *--buflim = '0';
 465       }
 466       break;
 467     }
 468
 469   return buflim;
 470 }
 471 #endif
 472
 473 char *
 474 _fitoa_word (unsigned long value, char *buf, unsigned int base, int upper_case)
 475 {
 476   char tmpbuf[sizeof (value) * 4];            /* Worst case length: base 2.  */
 477   char *cp = _itoa_word (value, tmpbuf + sizeof (value) * 4, base, upper_case);
 478   while (cp < tmpbuf + sizeof (value) * 4)
 479     *buf++ = *cp++;
 480   return buf;
 481 }
 482
 483 #if LLONG_MAX != LONG_MAX
 484 char *
 485 _fitoa (unsigned long long value, char *buf, unsigned int base, int upper_case)
 486 {
 487   char tmpbuf[sizeof (value) * 4];            /* Worst case length: base 2.  */
 488   char *cp = _itoa (value, tmpbuf + sizeof (value) * 4, base, upper_case);
 489   while (cp < tmpbuf + sizeof (value) * 4)
 490     *buf++ = *cp++;
 491   return buf;
 492 }
 493 #endif