stdio-common/_itoa.c

   1 /* Internal function for converting integers to ASCII.
   2    Copyright (C) 1994, 1995, 1996, 1999, 2000, 2002, 2003
   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 <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 /* Local variables.  */
  82 const struct base_table_t _itoa_base_table[] attribute_hidden =
  83 {
  84 #if BITS_PER_MP_LIMB == 64
  85   /*  2 */ {SEL1(0ull) 1, 1},
  86   /*  3 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 1},
  87   /*  4 */ {SEL1(0ull) 1, 2},
  88   /*  5 */ {SEL1(0xcccccccccccccccdull) 0, 2},
  89   /*  6 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 2},
  90   /*  7 */ {SEL1(0x2492492492492493ull) 1, 3},
  91   /*  8 */ {SEL1(0ull) 1, 3},
  92   /*  9 */ {SEL1(0xe38e38e38e38e38full) 0, 3},
  93   /* 10 */ {SEL1(0xcccccccccccccccdull) 0, 3},
  94   /* 11 */ {SEL1(0x2e8ba2e8ba2e8ba3ull) 0, 1},
  95   /* 12 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 3},
  96   /* 13 */ {SEL1(0x4ec4ec4ec4ec4ec5ull) 0, 2},
  97   /* 14 */ {SEL1(0x2492492492492493ull) 1, 4},
  98   /* 15 */ {SEL1(0x8888888888888889ull) 0, 3},
  99   /* 16 */ {SEL1(0ull) 1, 4},
 100   /* 17 */ {SEL1(0xf0f0f0f0f0f0f0f1ull) 0, 4},
 101   /* 18 */ {SEL1(0xe38e38e38e38e38full) 0, 4},
 102   /* 19 */ {SEL1(0xd79435e50d79435full) 0, 4},
 103   /* 20 */ {SEL1(0xcccccccccccccccdull) 0, 4},
 104   /* 21 */ {SEL1(0x8618618618618619ull) 1, 5},
 105   /* 22 */ {SEL1(0x2e8ba2e8ba2e8ba3ull) 0, 2},
 106   /* 23 */ {SEL1(0x642c8590b21642c9ull) 1, 5},
 107   /* 24 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 4},
 108   /* 25 */ {SEL1(0x47ae147ae147ae15ull) 1, 5},
 109   /* 26 */ {SEL1(0x4ec4ec4ec4ec4ec5ull) 0, 3},
 110   /* 27 */ {SEL1(0x97b425ed097b425full) 0, 4},
 111   /* 28 */ {SEL1(0x2492492492492493ull) 1, 5},
 112   /* 29 */ {SEL1(0x1a7b9611a7b9611bull) 1, 5},
 113   /* 30 */ {SEL1(0x8888888888888889ull) 0, 4},
 114   /* 31 */ {SEL1(0x0842108421084211ull) 1, 5},
 115   /* 32 */ {SEL1(0ull) 1, 5},
 116   /* 33 */ {SEL1(0x0f83e0f83e0f83e1ull) 0, 1},
 117   /* 34 */ {SEL1(0xf0f0f0f0f0f0f0f1ull) 0, 5},
 118   /* 35 */ {SEL1(0xea0ea0ea0ea0ea0full) 0, 5},
 119   /* 36 */ {SEL1(0xe38e38e38e38e38full) 0, 5}
 120 #endif
 121 #if BITS_PER_MP_LIMB == 32
 122   /*  2 */ {SEL1(0ul) 1, 1, {0, 31, 0x80000000ul SEL2(0xfffffffful)}},
 123   /*  3 */ {SEL1(0xaaaaaaabul) 0, 1, {0, 20, 0xcfd41b91ul SEL2(0x3b563c24ul)}},
 124   /*  4 */ {SEL1(0ul) 1, 2, {1, 15, 0x40000000ul SEL2(0xfffffffful)}},
 125   /*  5 */ {SEL1(0xcccccccdul) 0, 2, {1, 13, 0x48c27395ul SEL2(0xc25c2684ul)}},
 126   /*  6 */ {SEL1(0xaaaaaaabul) 0, 2, {0, 12, 0x81bf1000ul SEL2(0xf91bd1b6ul)}},
 127   /*  7 */ {SEL1(0x24924925ul) 1, 3, {1, 11, 0x75db9c97ul SEL2(0x1607a2cbul)}},
 128   /*  8 */ {SEL1(0ul) 1, 3, {1, 10, 0x40000000ul SEL2(0xfffffffful)}},
 129   /*  9 */ {SEL1(0x38e38e39ul) 0, 1, {0, 10, 0xcfd41b91ul SEL2(0x3b563c24ul)}},
 130   /* 10 */ {SEL1(0xcccccccdul) 0, 3, {2, 9, 0x3b9aca00ul SEL2(0x12e0be82ul)}},
 131   /* 11 */ {SEL1(0xba2e8ba3ul) 0, 3, {0, 9, 0x8c8b6d2bul SEL2(0xd24cde04ul)}},
 132   /* 12 */ {SEL1(0xaaaaaaabul) 0, 3, {3, 8, 0x19a10000ul SEL2(0x3fa39ab5ul)}},
 133   /* 13 */ {SEL1(0x4ec4ec4ful) 0, 2, {2, 8, 0x309f1021ul SEL2(0x50f8ac5ful)}},
 134   /* 14 */ {SEL1(0x24924925ul) 1, 4, {1, 8, 0x57f6c100ul SEL2(0x74843b1eul)}},
 135   /* 15 */ {SEL1(0x88888889ul) 0, 3, {0, 8, 0x98c29b81ul SEL2(0xad0326c2ul)}},
 136   /* 16 */ {SEL1(0ul) 1, 4, {3, 7, 0x10000000ul SEL2(0xfffffffful)}},
 137   /* 17 */ {SEL1(0xf0f0f0f1ul) 0, 4, {3, 7, 0x18754571ul SEL2(0x4ef0b6bdul)}},
 138   /* 18 */ {SEL1(0x38e38e39ul) 0, 2, {2, 7, 0x247dbc80ul SEL2(0xc0fc48a1ul)}},
 139   /* 19 */ {SEL1(0xaf286bcbul) 1, 5, {2, 7, 0x3547667bul SEL2(0x33838942ul)}},
 140   /* 20 */ {SEL1(0xcccccccdul) 0, 4, {1, 7, 0x4c4b4000ul SEL2(0xad7f29abul)}},
 141   /* 21 */ {SEL1(0x86186187ul) 1, 5, {1, 7, 0x6b5a6e1dul SEL2(0x313c3d15ul)}},
 142   /* 22 */ {SEL1(0xba2e8ba3ul) 0, 4, {0, 7, 0x94ace180ul SEL2(0xb8cca9e0ul)}},
 143   /* 23 */ {SEL1(0xb21642c9ul) 0, 4, {0, 7, 0xcaf18367ul SEL2(0x42ed6de9ul)}},
 144   /* 24 */ {SEL1(0xaaaaaaabul) 0, 4, {4, 6, 0x0b640000ul SEL2(0x67980e0bul)}},
 145   /* 25 */ {SEL1(0x51eb851ful) 0, 3, {4, 6, 0x0e8d4a51ul SEL2(0x19799812ul)}},
 146   /* 26 */ {SEL1(0x4ec4ec4ful) 0, 3, {3, 6, 0x1269ae40ul SEL2(0xbce85396ul)}},
 147   /* 27 */ {SEL1(0x2f684bdbul) 1, 5, {3, 6, 0x17179149ul SEL2(0x62c103a9ul)}},
 148   /* 28 */ {SEL1(0x24924925ul) 1, 5, {3, 6, 0x1cb91000ul SEL2(0x1d353d43ul)}},
 149   /* 29 */ {SEL1(0x8d3dcb09ul) 0, 4, {2, 6, 0x23744899ul SEL2(0xce1deceaul)}},
 150   /* 30 */ {SEL1(0x88888889ul) 0, 4, {2, 6, 0x2b73a840ul SEL2(0x790fc511ul)}},
 151   /* 31 */ {SEL1(0x08421085ul) 1, 5, {2, 6, 0x34e63b41ul SEL2(0x35b865a0ul)}},
 152   /* 32 */ {SEL1(0ul) 1, 5, {1, 6, 0x40000000ul SEL2(0xfffffffful)}},
 153   /* 33 */ {SEL1(0x3e0f83e1ul) 0, 3, {1, 6, 0x4cfa3cc1ul SEL2(0xa9aed1b3ul)}},
 154   /* 34 */ {SEL1(0xf0f0f0f1ul) 0, 5, {1, 6, 0x5c13d840ul SEL2(0x63dfc229ul)}},
 155   /* 35 */ {SEL1(0xd41d41d5ul) 1, 6, {1, 6, 0x6d91b519ul SEL2(0x2b0fee30ul)}},
 156   /* 36 */ {SEL1(0x38e38e39ul) 0, 3, {0, 6, 0x81bf1000ul SEL2(0xf91bd1b6ul)}}
 157 #endif
 158 };
 159
 160 /* Lower-case digits.  */
 161 extern const char _itoa_lower_digits[];
 162 extern const char _itoa_lower_digits_internal[] attribute_hidden;
 163 /* Upper-case digits.  */
 164 extern const char _itoa_upper_digits[];
 165 extern const char _itoa_upper_digits_internal[] attribute_hidden;
 166
 167
 168 char *
 169 _itoa (value, buflim, base, upper_case)
 170      unsigned long long int value;
 171      char *buflim;
 172      unsigned int base;
 173      int upper_case;
 174 {
 175   const char *digits = (upper_case
 176                         ? INTUSE(_itoa_upper_digits)
 177                         : INTUSE(_itoa_lower_digits));
 178   const struct base_table_t *brec = &_itoa_base_table[base - 2];
 179
 180   switch (base)
 181     {
 182 #define RUN_2N(BITS) \
 183       do                                                                      \
 184         {                                                                     \
 185           /* `unsigned long long int' always has 64 bits.  */                 \
 186           mp_limb_t work_hi = value >> (64 - BITS_PER_MP_LIMB);               \
 187                                                                               \
 188           if (BITS_PER_MP_LIMB == 32)                                         \
 189             {                                                                 \
 190               if (work_hi != 0)                                               \
 191                 {                                                             \
 192                   mp_limb_t work_lo;                                          \
 193                   int cnt;                                                    \
 194                                                                               \
 195                   work_lo = value & 0xfffffffful;                             \
 196                   for (cnt = BITS_PER_MP_LIMB / BITS; cnt > 0; --cnt)         \
 197                     {                                                         \
 198                       *--buflim = digits[work_lo & ((1ul << BITS) - 1)];      \
 199                       work_lo >>= BITS;                                       \
 200                     }                                                         \
 201                   if (BITS_PER_MP_LIMB % BITS != 0)                           \
 202                     {                                                         \
 203                       work_lo                                                 \
 204                         |= ((work_hi                                          \
 205                              & ((1 << (BITS - BITS_PER_MP_LIMB%BITS))         \
 206                                 - 1))                                         \
 207                             << BITS_PER_MP_LIMB % BITS);                      \
 208                       work_hi >>= BITS - BITS_PER_MP_LIMB % BITS;             \
 209                       if (work_hi == 0)                                       \
 210                         work_hi = work_lo;                                    \
 211                       else                                                    \
 212                         *--buflim = digits[work_lo];                          \
 213                     }                                                         \
 214                 }                                                             \
 215               else                                                            \
 216                 work_hi = value & 0xfffffffful;                               \
 217             }                                                                 \
 218           do                                                                  \
 219             {                                                                 \
 220               *--buflim = digits[work_hi & ((1 << BITS) - 1)];                \
 221               work_hi >>= BITS;                                               \
 222             }                                                                 \
 223           while (work_hi != 0);                                               \
 224         }                                                                     \
 225       while (0)
 226     case 8:
 227       RUN_2N (3);
 228       break;
 229
 230     case 16:
 231       RUN_2N (4);
 232       break;
 233
 234     default:
 235       {
 236 #if BITS_PER_MP_LIMB == 64
 237         mp_limb_t base_multiplier = brec->base_multiplier;
 238         if (brec->flag)
 239           while (value != 0)
 240             {
 241               mp_limb_t quo, rem, x, dummy;
 242
 243               umul_ppmm (x, dummy, value, base_multiplier);
 244               quo = (x + ((value - x) >> 1)) >> (brec->post_shift - 1);
 245               rem = value - quo * base;
 246               *--buflim = digits[rem];
 247               value = quo;
 248             }
 249         else
 250           while (value != 0)
 251             {
 252               mp_limb_t quo, rem, x, dummy;
 253
 254               umul_ppmm (x, dummy, value, base_multiplier);
 255               quo = x >> brec->post_shift;
 256               rem = value - quo * base;
 257               *--buflim = digits[rem];
 258               value = quo;
 259             }
 260 #endif
 261 #if BITS_PER_MP_LIMB == 32
 262         mp_limb_t t[3];
 263         int n;
 264
 265         /* First convert x0 to 1-3 words in base s->big.base.
 266            Optimize for frequent cases of 32 bit numbers.  */
 267         if ((mp_limb_t) (value >> 32) >= 1)
 268           {
 269 #if UDIV_TIME > 2 * UMUL_TIME || UDIV_NEEDS_NORMALIZATION
 270             int big_normalization_steps = brec->big.normalization_steps;
 271             mp_limb_t big_base_norm
 272               = brec->big.base << big_normalization_steps;
 273 #endif
 274             if ((mp_limb_t) (value >> 32) >= brec->big.base)
 275               {
 276                 mp_limb_t x1hi, x1lo, r;
 277                 /* If you want to optimize this, take advantage of
 278                    that the quotient in the first udiv_qrnnd will
 279                    always be very small.  It might be faster just to
 280                    subtract in a tight loop.  */
 281
 282 #if UDIV_TIME > 2 * UMUL_TIME
 283                 mp_limb_t x, xh, xl;
 284
 285                 if (big_normalization_steps == 0)
 286                   xh = 0;
 287                 else
 288                   xh = (mp_limb_t) (value >> (64 - big_normalization_steps));
 289                 xl = (mp_limb_t) (value >> (32 - big_normalization_steps));
 290                 udiv_qrnnd_preinv (x1hi, r, xh, xl, big_base_norm,
 291                                    brec->big.base_ninv);
 292
 293                 xl = ((mp_limb_t) value) << big_normalization_steps;
 294                 udiv_qrnnd_preinv (x1lo, x, r, xl, big_base_norm,
 295                                    brec->big.base_ninv);
 296                 t[2] = x >> big_normalization_steps;
 297
 298                 if (big_normalization_steps == 0)
 299                   xh = x1hi;
 300                 else
 301                   xh = ((x1hi << big_normalization_steps)
 302                         | (x1lo >> (32 - big_normalization_steps)));
 303                 xl = x1lo << big_normalization_steps;
 304                 udiv_qrnnd_preinv (t[0], x, xh, xl, big_base_norm,
 305                                    brec->big.base_ninv);
 306                 t[1] = x >> big_normalization_steps;
 307 #elif UDIV_NEEDS_NORMALIZATION
 308                 mp_limb_t x, xh, xl;
 309
 310                 if (big_normalization_steps == 0)
 311                   xh = 0;
 312                 else
 313                   xh = (mp_limb_t) (value >> 64 - big_normalization_steps);
 314                 xl = (mp_limb_t) (value >> 32 - big_normalization_steps);
 315                 udiv_qrnnd (x1hi, r, xh, xl, big_base_norm);
 316
 317                 xl = ((mp_limb_t) value) << big_normalization_steps;
 318                 udiv_qrnnd (x1lo, x, r, xl, big_base_norm);
 319                 t[2] = x >> big_normalization_steps;
 320
 321                 if (big_normalization_steps == 0)
 322                   xh = x1hi;
 323                 else
 324                   xh = ((x1hi << big_normalization_steps)
 325                         | (x1lo >> 32 - big_normalization_steps));
 326                 xl = x1lo << big_normalization_steps;
 327                 udiv_qrnnd (t[0], x, xh, xl, big_base_norm);
 328                 t[1] = x >> big_normalization_steps;
 329 #else
 330                 udiv_qrnnd (x1hi, r, 0, (mp_limb_t) (value >> 32),
 331                             brec->big.base);
 332                 udiv_qrnnd (x1lo, t[2], r, (mp_limb_t) value, brec->big.base);
 333                 udiv_qrnnd (t[0], t[1], x1hi, x1lo, brec->big.base);
 334 #endif
 335                 n = 3;
 336               }
 337             else
 338               {
 339 #if (UDIV_TIME > 2 * UMUL_TIME)
 340                 mp_limb_t x;
 341
 342                 value <<= brec->big.normalization_steps;
 343                 udiv_qrnnd_preinv (t[0], x, (mp_limb_t) (value >> 32),
 344                                    (mp_limb_t) value, big_base_norm,
 345                                    brec->big.base_ninv);
 346                 t[1] = x >> brec->big.normalization_steps;
 347 #elif UDIV_NEEDS_NORMALIZATION
 348                 mp_limb_t x;
 349
 350                 value <<= big_normalization_steps;
 351                 udiv_qrnnd (t[0], x, (mp_limb_t) (value >> 32),
 352                             (mp_limb_t) value, big_base_norm);
 353                 t[1] = x >> big_normalization_steps;
 354 #else
 355                 udiv_qrnnd (t[0], t[1], (mp_limb_t) (value >> 32),
 356                             (mp_limb_t) value, brec->big.base);
 357 #endif
 358                 n = 2;
 359               }
 360           }
 361         else
 362           {
 363             t[0] = value;
 364             n = 1;
 365           }
 366
 367         /* Convert the 1-3 words in t[], word by word, to ASCII.  */
 368         do
 369           {
 370             mp_limb_t ti = t[--n];
 371             int ndig_for_this_limb = 0;
 372
 373 #if UDIV_TIME > 2 * UMUL_TIME
 374             mp_limb_t base_multiplier = brec->base_multiplier;
 375             if (brec->flag)
 376               while (ti != 0)
 377                 {
 378                   mp_limb_t quo, rem, x, dummy;
 379
 380                   umul_ppmm (x, dummy, ti, base_multiplier);
 381                   quo = (x + ((ti - x) >> 1)) >> (brec->post_shift - 1);
 382                   rem = ti - quo * base;
 383                   *--buflim = digits[rem];
 384                   ti = quo;
 385                   ++ndig_for_this_limb;
 386                 }
 387             else
 388               while (ti != 0)
 389                 {
 390                   mp_limb_t quo, rem, x, dummy;
 391
 392                   umul_ppmm (x, dummy, ti, base_multiplier);
 393                   quo = x >> brec->post_shift;
 394                   rem = ti - quo * base;
 395                   *--buflim = digits[rem];
 396                   ti = quo;
 397                   ++ndig_for_this_limb;
 398                 }
 399 #else
 400             while (ti != 0)
 401               {
 402                 mp_limb_t quo, rem;
 403
 404                 quo = ti / base;
 405                 rem = ti % base;
 406                 *--buflim = digits[rem];
 407                 ti = quo;
 408                 ++ndig_for_this_limb;
 409               }
 410 #endif
 411             /* If this wasn't the most significant word, pad with zeros.  */
 412             if (n != 0)
 413               while (ndig_for_this_limb < brec->big.ndigits)
 414                 {
 415                   *--buflim = '0';
 416                   ++ndig_for_this_limb;
 417                 }
 418           }
 419         while (n != 0);
 420 #endif
 421       }
 422       break;
 423     }
 424
 425   return buflim;
 426 }
 427
 428 char *
 429 _fitoa_word (unsigned long value, char *buf, unsigned int base, int upper_case)
 430 {
 431   char tmpbuf[sizeof (value) * 4];            /* Worst case length: base 2.  */
 432   char *cp = _itoa_word (value, tmpbuf + sizeof (value) * 4, base, upper_case);
 433   while (cp < tmpbuf + sizeof (value) * 4)
 434     *buf++ = *cp++;
 435   return buf;
 436 }
 437
 438 char *
 439 _fitoa (unsigned long long value, char *buf, unsigned int base, int upper_case)
 440 {
 441   char tmpbuf[sizeof (value) * 4];            /* Worst case length: base 2.  */
 442   char *cp = _itoa (value, tmpbuf + sizeof (value) * 4, base, upper_case);
 443   while (cp < tmpbuf + sizeof (value) * 4)
 444     *buf++ = *cp++;
 445   return buf;
 446 }