Update NOTES.opensolaris with scheduling details
[kopensolaris-gnu/glibc.git] / 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