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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 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Torbjorn Granlund <tege@matematik.su.se>
5 and Ulrich Drepper <drepper@gnu.ai.mit.edu>.
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Library General Public License as
9 published by the Free Software Foundation; either version 2 of the
10 License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Library General Public License for more details.
17 You should have received a copy of the GNU Library General Public
18 License along with the GNU C Library; see the file COPYING.LIB. If not,
19 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 #include <gmp-mparam.h>
23 #include <stdlib/gmp.h>
24 #include <stdlib/gmp-impl.h>
25 #include <stdlib/longlong.h>
27 #include "_itoa.h"
30 /* Canonize environment. For some architectures not all values might
31 be defined in the GMP header files. */
32 #ifndef UMUL_TIME
33 # define UMUL_TIME 1
34 #endif
35 #ifndef UDIV_TIME
36 # define UDIV_TIME 3
37 #endif
39 /* Control memory layout. */
40 #ifdef PACK
41 # undef PACK
42 # define PACK __attribute__ ((packed))
43 #else
44 # define PACK
45 #endif
48 /* Declare local types. */
49 struct base_table_t
51 #if (UDIV_TIME > 2 * UMUL_TIME)
52 mp_limb_t base_multiplier;
53 #endif
54 char flag;
55 char post_shift;
56 #if BITS_PER_MP_LIMB == 32
57 struct
59 char normalization_steps;
60 char ndigits;
61 mp_limb_t base PACK;
62 #if UDIV_TIME > 2 * UMUL_TIME
63 mp_limb_t base_ninv PACK;
64 #endif
65 } big;
66 #endif
69 /* To reduce the memory needed we include some fields of the tables
70 only conditionally. */
71 #if UDIV_TIME > 2 * UMUL_TIME
72 # define SEL1(X) X,
73 # define SEL2(X) ,X
74 #else
75 # define SEL1(X)
76 # define SEL2(X)
77 #endif
80 /* Local variables. */
81 static const struct base_table_t base_table[] =
83 #if BITS_PER_MP_LIMB == 64
84 /* 2 */ {SEL1(0ul) 1, 1},
85 /* 3 */ {SEL1(0xaaaaaaaaaaaaaaabul) 0, 1},
86 /* 4 */ {SEL1(0ul) 1, 2},
87 /* 5 */ {SEL1(0xcccccccccccccccdul) 0, 2},
88 /* 6 */ {SEL1(0xaaaaaaaaaaaaaaabul) 0, 2},
89 /* 7 */ {SEL1(0x2492492492492493ul) 1, 3},
90 /* 8 */ {SEL1(0ul) 1, 3},
91 /* 9 */ {SEL1(0xe38e38e38e38e38ful) 0, 3},
92 /* 10 */ {SEL1(0xcccccccccccccccdul) 0, 3},
93 /* 11 */ {SEL1(0x2e8ba2e8ba2e8ba3ul) 0, 1},
94 /* 12 */ {SEL1(0xaaaaaaaaaaaaaaabul) 0, 3},
95 /* 13 */ {SEL1(0x4ec4ec4ec4ec4ec5ul) 0, 2},
96 /* 14 */ {SEL1(0x2492492492492493ul) 1, 4},
97 /* 15 */ {SEL1(0x8888888888888889ul) 0, 3},
98 /* 16 */ {SEL1(0ul) 1, 4},
99 /* 17 */ {SEL1(0xf0f0f0f0f0f0f0f1ul) 0, 4},
100 /* 18 */ {SEL1(0xe38e38e38e38e38ful) 0, 4},
101 /* 19 */ {SEL1(0xd79435e50d79435ful) 0, 4},
102 /* 20 */ {SEL1(0xcccccccccccccccdul) 0, 4},
103 /* 21 */ {SEL1(0x8618618618618619ul) 1, 5},
104 /* 22 */ {SEL1(0x2e8ba2e8ba2e8ba3ul) 0, 2},
105 /* 23 */ {SEL1(0x642c8590b21642c9ul) 1, 5},
106 /* 24 */ {SEL1(0xaaaaaaaaaaaaaaabul) 0, 4},
107 /* 25 */ {SEL1(0x47ae147ae147ae15ul) 1, 5},
108 /* 26 */ {SEL1(0x4ec4ec4ec4ec4ec5ul) 0, 3},
109 /* 27 */ {SEL1(0x97b425ed097b425ful) 0, 4},
110 /* 28 */ {SEL1(0x2492492492492493ul) 1, 5},
111 /* 29 */ {SEL1(0x1a7b9611a7b9611bul) 1, 5},
112 /* 30 */ {SEL1(0x8888888888888889ul) 0, 4},
113 /* 31 */ {SEL1(0x0842108421084211ul) 1, 5},
114 /* 32 */ {SEL1(0ul) 1, 5},
115 /* 33 */ {SEL1(0x0f83e0f83e0f83e1ul) 0, 1},
116 /* 34 */ {SEL1(0xf0f0f0f0f0f0f0f1ul) 0, 5},
117 /* 35 */ {SEL1(0xea0ea0ea0ea0ea0ful) 0, 5},
118 /* 36 */ {SEL1(0xe38e38e38e38e38ful) 0, 5}
119 #endif
120 #if BITS_PER_MP_LIMB == 32
121 /* 2 */ {SEL1(0ul) 1, 1, {0, 31, 0x80000000ul SEL2(0xfffffffful)}},
122 /* 3 */ {SEL1(0xaaaaaaabul) 0, 1, {0, 20, 0xcfd41b91ul SEL2(0x3b563c24ul)}},
123 /* 4 */ {SEL1(0ul) 1, 2, {1, 15, 0x40000000ul SEL2(0xfffffffful)}},
124 /* 5 */ {SEL1(0xcccccccdul) 0, 2, {1, 13, 0x48c27395ul SEL2(0xc25c2684ul)}},
125 /* 6 */ {SEL1(0xaaaaaaabul) 0, 2, {0, 12, 0x81bf1000ul SEL2(0xf91bd1b6ul)}},
126 /* 7 */ {SEL1(0x24924925ul) 1, 3, {1, 11, 0x75db9c97ul SEL2(0x1607a2cbul)}},
127 /* 8 */ {SEL1(0ul) 1, 3, {1, 10, 0x40000000ul SEL2(0xfffffffful)}},
128 /* 9 */ {SEL1(0x38e38e39ul) 0, 1, {0, 10, 0xcfd41b91ul SEL2(0x3b563c24ul)}},
129 /* 10 */ {SEL1(0xcccccccdul) 0, 3, {2, 9, 0x3b9aca00ul SEL2(0x12e0be82ul)}},
130 /* 11 */ {SEL1(0xba2e8ba3ul) 0, 3, {0, 9, 0x8c8b6d2bul SEL2(0xd24cde04ul)}},
131 /* 12 */ {SEL1(0xaaaaaaabul) 0, 3, {3, 8, 0x19a10000ul SEL2(0x3fa39ab5ul)}},
132 /* 13 */ {SEL1(0x4ec4ec4ful) 0, 2, {2, 8, 0x309f1021ul SEL2(0x50f8ac5ful)}},
133 /* 14 */ {SEL1(0x24924925ul) 1, 4, {1, 8, 0x57f6c100ul SEL2(0x74843b1eul)}},
134 /* 15 */ {SEL1(0x88888889ul) 0, 3, {0, 8, 0x98c29b81ul SEL2(0xad0326c2ul)}},
135 /* 16 */ {SEL1(0ul) 1, 4, {3, 7, 0x10000000ul SEL2(0xfffffffful)}},
136 /* 17 */ {SEL1(0xf0f0f0f1ul) 0, 4, {3, 7, 0x18754571ul SEL2(0x4ef0b6bdul)}},
137 /* 18 */ {SEL1(0x38e38e39ul) 0, 2, {2, 7, 0x247dbc80ul SEL2(0xc0fc48a1ul)}},
138 /* 19 */ {SEL1(0xaf286bcbul) 1, 5, {2, 7, 0x3547667bul SEL2(0x33838942ul)}},
139 /* 20 */ {SEL1(0xcccccccdul) 0, 4, {1, 7, 0x4c4b4000ul SEL2(0xad7f29abul)}},
140 /* 21 */ {SEL1(0x86186187ul) 1, 5, {1, 7, 0x6b5a6e1dul SEL2(0x313c3d15ul)}},
141 /* 22 */ {SEL1(0xba2e8ba3ul) 0, 4, {0, 7, 0x94ace180ul SEL2(0xb8cca9e0ul)}},
142 /* 23 */ {SEL1(0xb21642c9ul) 0, 4, {0, 7, 0xcaf18367ul SEL2(0x42ed6de9ul)}},
143 /* 24 */ {SEL1(0xaaaaaaabul) 0, 4, {4, 6, 0x0b640000ul SEL2(0x67980e0bul)}},
144 /* 25 */ {SEL1(0x51eb851ful) 0, 3, {4, 6, 0x0e8d4a51ul SEL2(0x19799812ul)}},
145 /* 26 */ {SEL1(0x4ec4ec4ful) 0, 3, {3, 6, 0x1269ae40ul SEL2(0xbce85396ul)}},
146 /* 27 */ {SEL1(0x2f684bdbul) 1, 5, {3, 6, 0x17179149ul SEL2(0x62c103a9ul)}},
147 /* 28 */ {SEL1(0x24924925ul) 1, 5, {3, 6, 0x1cb91000ul SEL2(0x1d353d43ul)}},
148 /* 29 */ {SEL1(0x8d3dcb09ul) 0, 4, {2, 6, 0x23744899ul SEL2(0xce1deceaul)}},
149 /* 30 */ {SEL1(0x88888889ul) 0, 4, {2, 6, 0x2b73a840ul SEL2(0x790fc511ul)}},
150 /* 31 */ {SEL1(0x08421085ul) 1, 5, {2, 6, 0x34e63b41ul SEL2(0x35b865a0ul)}},
151 /* 32 */ {SEL1(0ul) 1, 5, {1, 6, 0x40000000ul SEL2(0xfffffffful)}},
152 /* 33 */ {SEL1(0x3e0f83e1ul) 0, 3, {1, 6, 0x4cfa3cc1ul SEL2(0xa9aed1b3ul)}},
153 /* 34 */ {SEL1(0xf0f0f0f1ul) 0, 5, {1, 6, 0x5c13d840ul SEL2(0x63dfc229ul)}},
154 /* 35 */ {SEL1(0xd41d41d5ul) 1, 6, {1, 6, 0x6d91b519ul SEL2(0x2b0fee30ul)}},
155 /* 36 */ {SEL1(0x38e38e39ul) 0, 3, {0, 6, 0x81bf1000ul SEL2(0xf91bd1b6ul)}}
156 #endif
159 /* Lower-case digits. */
160 extern const char _itoa_lower_digits[];
161 /* Upper-case digits. */
162 extern const char _itoa_upper_digits[];
165 char *
166 _itoa (value, buflim, base, upper_case)
167 unsigned long long int value;
168 char *buflim;
169 unsigned int base;
170 int upper_case;
172 const char *digits = upper_case ? _itoa_upper_digits : _itoa_lower_digits;
173 char *bp = buflim;
174 const struct base_table_t *brec = &base_table[base - 2];
176 switch (base)
178 #define RUN_2N(BITS) \
179 do \
181 /* `unsigned long long int' always has 64 bits. */ \
182 mp_limb_t work_hi = value >> (64 - BITS_PER_MP_LIMB); \
184 if (BITS_PER_MP_LIMB == 32) \
186 if (work_hi != 0) \
188 mp_limb_t work_lo; \
189 int cnt; \
191 work_lo = value & 0xfffffffful; \
192 for (cnt = BITS_PER_MP_LIMB / BITS; cnt > 0; --cnt) \
194 *--bp = digits[work_lo & ((1ul << BITS) - 1)]; \
195 work_lo >>= BITS; \
197 if (BITS_PER_MP_LIMB % BITS != 0) \
199 work_lo \
200 |= ((work_hi \
201 & ((1 << (BITS - BITS_PER_MP_LIMB%BITS)) \
202 - 1)) \
203 << BITS_PER_MP_LIMB % BITS); \
204 *--bp = digits[work_lo]; \
205 work_hi >>= BITS - BITS_PER_MP_LIMB % BITS; \
208 else \
209 work_hi = value & 0xfffffffful; \
211 do \
213 *--bp = digits[work_hi & ((1 << BITS) - 1)]; \
214 work_hi >>= BITS; \
216 while (work_hi != 0); \
218 while (0)
219 case 8:
220 RUN_2N (3);
221 break;
223 case 16:
224 RUN_2N (4);
225 break;
227 default:
229 #if BITS_PER_MP_LIMB == 64
230 mp_limb_t base_multiplier = brec->base_multiplier;
231 if (brec->flag)
232 while (value != 0)
234 mp_limb_t quo, rem, x, dummy;
236 umul_ppmm (x, dummy, value, base_multiplier);
237 quo = (x + ((value - x) >> 1)) >> (brec->post_shift - 1);
238 rem = value - quo * base;
239 *--bp = digits[rem];
240 value = quo;
242 else
243 while (value != 0)
245 mp_limb_t quo, rem, x, dummy;
247 umul_ppmm (x, dummy, value, base_multiplier);
248 quo = x >> brec->post_shift;
249 rem = value - quo * base;
250 *--bp = digits[rem];
251 value = quo;
253 #endif
254 #if BITS_PER_MP_LIMB == 32
255 mp_limb_t t[3];
256 int n;
258 /* First convert x0 to 1-3 words in base s->big.base.
259 Optimize for frequent cases of 32 bit numbers. */
260 if ((mp_limb_t) (value >> 32) >= 1)
262 #if UDIV_TIME > 2 * UMUL_TIME || UDIV_NEEDS_NORMALIZATION
263 int big_normalization_steps = brec->big.normalization_steps;
264 mp_limb_t big_base_norm
265 = brec->big.base << big_normalization_steps;
266 #endif
267 if ((mp_limb_t) (value >> 32) >= brec->big.base)
269 mp_limb_t x1hi, x1lo, r;
270 /* If you want to optimize this, take advantage of
271 that the quotient in the first udiv_qrnnd will
272 always be very small. It might be faster just to
273 subtract in a tight loop. */
275 #if UDIV_TIME > 2 * UMUL_TIME
276 mp_limb_t x, xh, xl;
278 if (big_normalization_steps == 0)
279 xh = 0;
280 else
281 xh = (mp_limb_t) (value >> (64 - big_normalization_steps));
282 xl = (mp_limb_t) (value >> (32 - big_normalization_steps));
283 udiv_qrnnd_preinv (x1hi, r, xh, xl, big_base_norm,
284 brec->big.base_ninv);
286 xl = ((mp_limb_t) value) << big_normalization_steps;
287 udiv_qrnnd_preinv (x1lo, x, r, xl, big_base_norm,
288 big_normalization_steps);
289 t[2] = x >> big_normalization_steps;
291 if (big_normalization_steps == 0)
292 xh = x1hi;
293 else
294 xh = ((x1hi << big_normalization_steps)
295 | (x1lo >> (32 - big_normalization_steps)));
296 xl = x1lo << big_normalization_steps;
297 udiv_qrnnd_preinv (t[0], x, xh, xl, big_base_norm,
298 big_normalization_steps);
299 t[1] = x >> big_normalization_steps;
300 #elif UDIV_NEEDS_NORMALIZATION
301 mp_limb_t x, xh, xl;
303 if (big_normalization_steps == 0)
304 xh = 0;
305 else
306 xh = (mp_limb_t) (value >> 64 - big_normalization_steps);
307 xl = (mp_limb_t) (value >> 32 - big_normalization_steps);
308 udiv_qrnnd (x1hi, r, xh, xl, big_base_norm);
310 xl = ((mp_limb_t) value) << big_normalization_steps;
311 udiv_qrnnd (x1lo, x, r, xl, big_base_norm);
312 t[2] = x >> big_normalization_steps;
314 if (big_normalization_steps == 0)
315 xh = x1hi;
316 else
317 xh = ((x1hi << big_normalization_steps)
318 | (x1lo >> 32 - big_normalization_steps));
319 xl = x1lo << big_normalization_steps;
320 udiv_qrnnd (t[0], x, xh, xl, big_base_norm);
321 t[1] = x >> big_normalization_steps;
322 #else
323 udiv_qrnnd (x1hi, r, 0, (mp_limb_t) (value >> 32),
324 brec->big.base);
325 udiv_qrnnd (x1lo, t[2], r, (mp_limb_t) value, brec->big.base);
326 udiv_qrnnd (t[0], t[1], x1hi, x1lo, brec->big.base);
327 #endif
328 n = 3;
330 else
332 #if (UDIV_TIME > 2 * UMUL_TIME)
333 mp_limb_t x;
335 value <<= brec->big.normalization_steps;
336 udiv_qrnnd_preinv (t[0], x, (mp_limb_t) (value >> 32),
337 (mp_limb_t) value, big_base_norm,
338 brec->big.base_ninv);
339 t[1] = x >> brec->big.normalization_steps;
340 #elif UDIV_NEEDS_NORMALIZATION
341 mp_limb_t x;
343 value <<= big_normalization_steps;
344 udiv_qrnnd (t[0], x, (mp_limb_t) (value >> 32),
345 (mp_limb_t) value, big_base_norm);
346 t[1] = x >> big_normalization_steps;
347 #else
348 udiv_qrnnd (t[0], t[1], (mp_limb_t) (value >> 32),
349 (mp_limb_t) value, brec->big.base);
350 #endif
351 n = 2;
354 else
356 t[0] = value;
357 n = 1;
360 /* Convert the 1-3 words in t[], word by word, to ASCII. */
363 mp_limb_t ti = t[--n];
364 int ndig_for_this_limb = 0;
366 #if UDIV_TIME > 2 * UMUL_TIME
367 mp_limb_t base_multiplier = brec->base_multiplier;
368 if (brec->flag)
369 while (ti != 0)
371 mp_limb_t quo, rem, x, dummy;
373 umul_ppmm (x, dummy, ti, base_multiplier);
374 quo = (x + ((ti - x) >> 1)) >> (brec->post_shift - 1);
375 rem = ti - quo * base;
376 *--bp = digits[rem];
377 ti = quo;
378 ++ndig_for_this_limb;
380 else
381 while (ti != 0)
383 mp_limb_t quo, rem, x, dummy;
385 umul_ppmm (x, dummy, ti, base_multiplier);
386 quo = x >> brec->post_shift;
387 rem = ti - quo * base;
388 *--bp = digits[rem];
389 ti = quo;
390 ++ndig_for_this_limb;
392 #else
393 while (ti != 0)
395 mp_limb_t quo, rem;
397 quo = ti / base;
398 rem = ti % base;
399 *--bp = digits[rem];
400 ti = quo;
401 ++ndig_for_this_limb;
403 #endif
404 /* If this wasn't the most significant word, pad with zeros. */
405 if (n != 0)
406 while (ndig_for_this_limb < brec->big.ndigits)
408 *--bp = '0';
409 ++ndig_for_this_limb;
412 while (n != 0);
413 #endif
415 break;
418 return bp;