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[glibc.git] / stdio-common / _itoa.c
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1 /* Internal function for converting integers to ASCII.
2 Copyright (C) 1994, 1995, 1996, 1999, 2000, 2002, 2003, 2004
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>.
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.
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.
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. */
23 #include <gmp-mparam.h>
24 #include <gmp.h>
25 #include <stdlib/gmp-impl.h>
26 #include <stdlib/longlong.h>
28 #include "_itoa.h"
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
40 /* Control memory layout. */
41 #ifdef PACK
42 # undef PACK
43 # define PACK __attribute__ ((packed))
44 #else
45 # define PACK
46 #endif
49 /* Declare local types. */
50 struct base_table_t
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
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
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
81 /* Local variables. */
82 const struct base_table_t _itoa_base_table[] attribute_hidden =
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
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;
168 char *
169 _itoa_word (unsigned long value, char *buflim,
170 unsigned int base, int upper_case)
172 const char *digits = (upper_case
173 #if !defined NOT_IN_libc || defined IS_IN_rtld
174 ? INTUSE(_itoa_upper_digits)
175 : INTUSE(_itoa_lower_digits)
176 #else
177 ? _itoa_upper_digits
178 : _itoa_lower_digits
179 #endif
182 switch (base)
184 #define SPECIAL(Base) \
185 case Base: \
186 do \
187 *--buflim = digits[value % Base]; \
188 while ((value /= Base) != 0); \
189 break
191 SPECIAL (10);
192 SPECIAL (16);
193 SPECIAL (8);
194 default:
196 *--buflim = digits[value % base];
197 while ((value /= base) != 0);
199 return buflim;
201 #undef SPECIAL
204 char *
205 _itoa (value, buflim, base, upper_case)
206 unsigned long long int value;
207 char *buflim;
208 unsigned int base;
209 int upper_case;
211 const char *digits = (upper_case
212 ? INTUSE(_itoa_upper_digits)
213 : INTUSE(_itoa_lower_digits));
214 const struct base_table_t *brec = &_itoa_base_table[base - 2];
216 switch (base)
218 #define RUN_2N(BITS) \
219 do \
221 /* `unsigned long long int' always has 64 bits. */ \
222 mp_limb_t work_hi = value >> (64 - BITS_PER_MP_LIMB); \
224 if (BITS_PER_MP_LIMB == 32) \
226 if (work_hi != 0) \
228 mp_limb_t work_lo; \
229 int cnt; \
231 work_lo = value & 0xfffffffful; \
232 for (cnt = BITS_PER_MP_LIMB / BITS; cnt > 0; --cnt) \
234 *--buflim = digits[work_lo & ((1ul << BITS) - 1)]; \
235 work_lo >>= BITS; \
237 if (BITS_PER_MP_LIMB % BITS != 0) \
239 work_lo \
240 |= ((work_hi \
241 & ((1 << (BITS - BITS_PER_MP_LIMB%BITS)) \
242 - 1)) \
243 << BITS_PER_MP_LIMB % BITS); \
244 work_hi >>= BITS - BITS_PER_MP_LIMB % BITS; \
245 if (work_hi == 0) \
246 work_hi = work_lo; \
247 else \
248 *--buflim = digits[work_lo]; \
251 else \
252 work_hi = value & 0xfffffffful; \
254 do \
256 *--buflim = digits[work_hi & ((1 << BITS) - 1)]; \
257 work_hi >>= BITS; \
259 while (work_hi != 0); \
261 while (0)
262 case 8:
263 RUN_2N (3);
264 break;
266 case 16:
267 RUN_2N (4);
268 break;
270 default:
272 #if BITS_PER_MP_LIMB == 64
273 mp_limb_t base_multiplier = brec->base_multiplier;
274 if (brec->flag)
275 while (value != 0)
277 mp_limb_t quo, rem, x, dummy;
279 umul_ppmm (x, dummy, value, base_multiplier);
280 quo = (x + ((value - x) >> 1)) >> (brec->post_shift - 1);
281 rem = value - quo * base;
282 *--buflim = digits[rem];
283 value = quo;
285 else
286 while (value != 0)
288 mp_limb_t quo, rem, x, dummy;
290 umul_ppmm (x, dummy, value, base_multiplier);
291 quo = x >> brec->post_shift;
292 rem = value - quo * base;
293 *--buflim = digits[rem];
294 value = quo;
296 #endif
297 #if BITS_PER_MP_LIMB == 32
298 mp_limb_t t[3];
299 int n;
301 /* First convert x0 to 1-3 words in base s->big.base.
302 Optimize for frequent cases of 32 bit numbers. */
303 if ((mp_limb_t) (value >> 32) >= 1)
305 #if UDIV_TIME > 2 * UMUL_TIME || UDIV_NEEDS_NORMALIZATION
306 int big_normalization_steps = brec->big.normalization_steps;
307 mp_limb_t big_base_norm
308 = brec->big.base << big_normalization_steps;
309 #endif
310 if ((mp_limb_t) (value >> 32) >= brec->big.base)
312 mp_limb_t x1hi, x1lo, r;
313 /* If you want to optimize this, take advantage of
314 that the quotient in the first udiv_qrnnd will
315 always be very small. It might be faster just to
316 subtract in a tight loop. */
318 #if UDIV_TIME > 2 * UMUL_TIME
319 mp_limb_t x, xh, xl;
321 if (big_normalization_steps == 0)
322 xh = 0;
323 else
324 xh = (mp_limb_t) (value >> (64 - big_normalization_steps));
325 xl = (mp_limb_t) (value >> (32 - big_normalization_steps));
326 udiv_qrnnd_preinv (x1hi, r, xh, xl, big_base_norm,
327 brec->big.base_ninv);
329 xl = ((mp_limb_t) value) << big_normalization_steps;
330 udiv_qrnnd_preinv (x1lo, x, r, xl, big_base_norm,
331 brec->big.base_ninv);
332 t[2] = x >> big_normalization_steps;
334 if (big_normalization_steps == 0)
335 xh = x1hi;
336 else
337 xh = ((x1hi << big_normalization_steps)
338 | (x1lo >> (32 - big_normalization_steps)));
339 xl = x1lo << big_normalization_steps;
340 udiv_qrnnd_preinv (t[0], x, xh, xl, big_base_norm,
341 brec->big.base_ninv);
342 t[1] = x >> big_normalization_steps;
343 #elif UDIV_NEEDS_NORMALIZATION
344 mp_limb_t x, xh, xl;
346 if (big_normalization_steps == 0)
347 xh = 0;
348 else
349 xh = (mp_limb_t) (value >> 64 - big_normalization_steps);
350 xl = (mp_limb_t) (value >> 32 - big_normalization_steps);
351 udiv_qrnnd (x1hi, r, xh, xl, big_base_norm);
353 xl = ((mp_limb_t) value) << big_normalization_steps;
354 udiv_qrnnd (x1lo, x, r, xl, big_base_norm);
355 t[2] = x >> big_normalization_steps;
357 if (big_normalization_steps == 0)
358 xh = x1hi;
359 else
360 xh = ((x1hi << big_normalization_steps)
361 | (x1lo >> 32 - big_normalization_steps));
362 xl = x1lo << big_normalization_steps;
363 udiv_qrnnd (t[0], x, xh, xl, big_base_norm);
364 t[1] = x >> big_normalization_steps;
365 #else
366 udiv_qrnnd (x1hi, r, 0, (mp_limb_t) (value >> 32),
367 brec->big.base);
368 udiv_qrnnd (x1lo, t[2], r, (mp_limb_t) value, brec->big.base);
369 udiv_qrnnd (t[0], t[1], x1hi, x1lo, brec->big.base);
370 #endif
371 n = 3;
373 else
375 #if (UDIV_TIME > 2 * UMUL_TIME)
376 mp_limb_t x;
378 value <<= brec->big.normalization_steps;
379 udiv_qrnnd_preinv (t[0], x, (mp_limb_t) (value >> 32),
380 (mp_limb_t) value, big_base_norm,
381 brec->big.base_ninv);
382 t[1] = x >> brec->big.normalization_steps;
383 #elif UDIV_NEEDS_NORMALIZATION
384 mp_limb_t x;
386 value <<= big_normalization_steps;
387 udiv_qrnnd (t[0], x, (mp_limb_t) (value >> 32),
388 (mp_limb_t) value, big_base_norm);
389 t[1] = x >> big_normalization_steps;
390 #else
391 udiv_qrnnd (t[0], t[1], (mp_limb_t) (value >> 32),
392 (mp_limb_t) value, brec->big.base);
393 #endif
394 n = 2;
397 else
399 t[0] = value;
400 n = 1;
403 /* Convert the 1-3 words in t[], word by word, to ASCII. */
406 mp_limb_t ti = t[--n];
407 int ndig_for_this_limb = 0;
409 #if UDIV_TIME > 2 * UMUL_TIME
410 mp_limb_t base_multiplier = brec->base_multiplier;
411 if (brec->flag)
412 while (ti != 0)
414 mp_limb_t quo, rem, x, dummy;
416 umul_ppmm (x, dummy, ti, base_multiplier);
417 quo = (x + ((ti - x) >> 1)) >> (brec->post_shift - 1);
418 rem = ti - quo * base;
419 *--buflim = digits[rem];
420 ti = quo;
421 ++ndig_for_this_limb;
423 else
424 while (ti != 0)
426 mp_limb_t quo, rem, x, dummy;
428 umul_ppmm (x, dummy, ti, base_multiplier);
429 quo = x >> brec->post_shift;
430 rem = ti - quo * base;
431 *--buflim = digits[rem];
432 ti = quo;
433 ++ndig_for_this_limb;
435 #else
436 while (ti != 0)
438 mp_limb_t quo, rem;
440 quo = ti / base;
441 rem = ti % base;
442 *--buflim = digits[rem];
443 ti = quo;
444 ++ndig_for_this_limb;
446 #endif
447 /* If this wasn't the most significant word, pad with zeros. */
448 if (n != 0)
449 while (ndig_for_this_limb < brec->big.ndigits)
451 *--buflim = '0';
452 ++ndig_for_this_limb;
455 while (n != 0);
456 #endif
458 break;
461 return buflim;
464 char *
465 _fitoa_word (unsigned long value, char *buf, unsigned int base, int upper_case)
467 char tmpbuf[sizeof (value) * 4]; /* Worst case length: base 2. */
468 char *cp = _itoa_word (value, tmpbuf + sizeof (value) * 4, base, upper_case);
469 while (cp < tmpbuf + sizeof (value) * 4)
470 *buf++ = *cp++;
471 return buf;
474 char *
475 _fitoa (unsigned long long value, char *buf, unsigned int base, int upper_case)
477 char tmpbuf[sizeof (value) * 4]; /* Worst case length: base 2. */
478 char *cp = _itoa (value, tmpbuf + sizeof (value) * 4, base, upper_case);
479 while (cp < tmpbuf + sizeof (value) * 4)
480 *buf++ = *cp++;
481 return buf;