1/* Internal function for converting integers to ASCII.
2 Copyright (C) 1994-2020 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.org>.
6
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
11
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 Lesser General Public License for more details.
16
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, see
19 <https://www.gnu.org/licenses/>. */
20
21#include <gmp-mparam.h>
22#include <gmp.h>
23#include <limits.h>
24#include <stdlib/gmp-impl.h>
25#include <stdlib/longlong.h>
26
27#include <_itowa.h>
28
29
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
38
39/* Control memory layout. */
40#ifdef PACK
41# undef PACK
42# define PACK __attribute__ ((packed))
43#else
44# define PACK
45#endif
46
47
48/* Declare local types. */
49struct base_table_t
50{
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
58 {
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
67};
68
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
78
79/* Factor table for the different bases. */
80extern const struct base_table_t _itoa_base_table[] attribute_hidden;
81
82/* Lower-case digits. */
83extern const wchar_t _itowa_lower_digits[] attribute_hidden;
84/* Upper-case digits. */
85extern const wchar_t _itowa_upper_digits[] attribute_hidden;
86
87
88#if _ITOA_NEEDED
89wchar_t *
90_itowa (unsigned long long int value, wchar_t *buflim, unsigned int base,
91 int upper_case)
92{
93 const wchar_t *digits = (upper_case
94 ? _itowa_upper_digits : _itowa_lower_digits);
95 wchar_t *bp = buflim;
96 const struct base_table_t *brec = &_itoa_base_table[base - 2];
97
98 switch (base)
99 {
100# define RUN_2N(BITS) \
101 do \
102 { \
103 /* `unsigned long long int' always has 64 bits. */ \
104 mp_limb_t work_hi = value >> (64 - BITS_PER_MP_LIMB); \
105 \
106 if (BITS_PER_MP_LIMB == 32) \
107 { \
108 if (work_hi != 0) \
109 { \
110 mp_limb_t work_lo; \
111 int cnt; \
112 \
113 work_lo = value & 0xfffffffful; \
114 for (cnt = BITS_PER_MP_LIMB / BITS; cnt > 0; --cnt) \
115 { \
116 *--bp = digits[work_lo & ((1ul << BITS) - 1)]; \
117 work_lo >>= BITS; \
118 } \
119 if (BITS_PER_MP_LIMB % BITS != 0) \
120 { \
121 work_lo \
122 |= ((work_hi \
123 & ((1 << (BITS - BITS_PER_MP_LIMB%BITS)) \
124 - 1)) \
125 << BITS_PER_MP_LIMB % BITS); \
126 work_hi >>= BITS - BITS_PER_MP_LIMB % BITS; \
127 if (work_hi == 0) \
128 work_hi = work_lo; \
129 else \
130 *--bp = digits[work_lo]; \
131 } \
132 } \
133 else \
134 work_hi = value & 0xfffffffful; \
135 } \
136 do \
137 { \
138 *--bp = digits[work_hi & ((1 << BITS) - 1)]; \
139 work_hi >>= BITS; \
140 } \
141 while (work_hi != 0); \
142 } \
143 while (0)
144 case 8:
145 RUN_2N (3);
146 break;
147
148 case 16:
149 RUN_2N (4);
150 break;
151
152 default:
153 {
154# if BITS_PER_MP_LIMB == 64
155 mp_limb_t base_multiplier = brec->base_multiplier;
156 if (brec->flag)
157 while (value != 0)
158 {
159 mp_limb_t quo, rem, x;
160 mp_limb_t dummy __attribute__ ((unused));
161
162 umul_ppmm (x, dummy, value, base_multiplier);
163 quo = (x + ((value - x) >> 1)) >> (brec->post_shift - 1);
164 rem = value - quo * base;
165 *--bp = digits[rem];
166 value = quo;
167 }
168 else
169 while (value != 0)
170 {
171 mp_limb_t quo, rem, x;
172 mp_limb_t dummy __attribute__ ((unused));
173
174 umul_ppmm (x, dummy, value, base_multiplier);
175 quo = x >> brec->post_shift;
176 rem = value - quo * base;
177 *--bp = digits[rem];
178 value = quo;
179 }
180# endif
181# if BITS_PER_MP_LIMB == 32
182 mp_limb_t t[3];
183 int n;
184
185 /* First convert x0 to 1-3 words in base s->big.base.
186 Optimize for frequent cases of 32 bit numbers. */
187 if ((mp_limb_t) (value >> 32) >= 1)
188 {
189# if UDIV_TIME > 2 * UMUL_TIME || UDIV_NEEDS_NORMALIZATION
190 int big_normalization_steps = brec->big.normalization_steps;
191 mp_limb_t big_base_norm
192 = brec->big.base << big_normalization_steps;
193# endif
194 if ((mp_limb_t) (value >> 32) >= brec->big.base)
195 {
196 mp_limb_t x1hi, x1lo, r;
197 /* If you want to optimize this, take advantage of
198 that the quotient in the first udiv_qrnnd will
199 always be very small. It might be faster just to
200 subtract in a tight loop. */
201
202# if UDIV_TIME > 2 * UMUL_TIME
203 mp_limb_t x, xh, xl;
204
205 if (big_normalization_steps == 0)
206 xh = 0;
207 else
208 xh = (mp_limb_t) (value >> (64 - big_normalization_steps));
209 xl = (mp_limb_t) (value >> (32 - big_normalization_steps));
210 udiv_qrnnd_preinv (x1hi, r, xh, xl, big_base_norm,
211 brec->big.base_ninv);
212
213 xl = ((mp_limb_t) value) << big_normalization_steps;
214 udiv_qrnnd_preinv (x1lo, x, r, xl, big_base_norm,
215 brec->big.base_ninv);
216 t[2] = x >> big_normalization_steps;
217
218 if (big_normalization_steps == 0)
219 xh = x1hi;
220 else
221 xh = ((x1hi << big_normalization_steps)
222 | (x1lo >> (32 - big_normalization_steps)));
223 xl = x1lo << big_normalization_steps;
224 udiv_qrnnd_preinv (t[0], x, xh, xl, big_base_norm,
225 brec->big.base_ninv);
226 t[1] = x >> big_normalization_steps;
227# elif UDIV_NEEDS_NORMALIZATION
228 mp_limb_t x, xh, xl;
229
230 if (big_normalization_steps == 0)
231 xh = 0;
232 else
233 xh = (mp_limb_t) (value >> 64 - big_normalization_steps);
234 xl = (mp_limb_t) (value >> 32 - big_normalization_steps);
235 udiv_qrnnd (x1hi, r, xh, xl, big_base_norm);
236
237 xl = ((mp_limb_t) value) << big_normalization_steps;
238 udiv_qrnnd (x1lo, x, r, xl, big_base_norm);
239 t[2] = x >> big_normalization_steps;
240
241 if (big_normalization_steps == 0)
242 xh = x1hi;
243 else
244 xh = ((x1hi << big_normalization_steps)
245 | (x1lo >> 32 - big_normalization_steps));
246 xl = x1lo << big_normalization_steps;
247 udiv_qrnnd (t[0], x, xh, xl, big_base_norm);
248 t[1] = x >> big_normalization_steps;
249# else
250 udiv_qrnnd (x1hi, r, 0, (mp_limb_t) (value >> 32),
251 brec->big.base);
252 udiv_qrnnd (x1lo, t[2], r, (mp_limb_t) value, brec->big.base);
253 udiv_qrnnd (t[0], t[1], x1hi, x1lo, brec->big.base);
254# endif
255 n = 3;
256 }
257 else
258 {
259# if UDIV_TIME > 2 * UMUL_TIME
260 mp_limb_t x;
261
262 value <<= brec->big.normalization_steps;
263 udiv_qrnnd_preinv (t[0], x, (mp_limb_t) (value >> 32),
264 (mp_limb_t) value, big_base_norm,
265 brec->big.base_ninv);
266 t[1] = x >> brec->big.normalization_steps;
267# elif UDIV_NEEDS_NORMALIZATION
268 mp_limb_t x;
269
270 value <<= big_normalization_steps;
271 udiv_qrnnd (t[0], x, (mp_limb_t) (value >> 32),
272 (mp_limb_t) value, big_base_norm);
273 t[1] = x >> big_normalization_steps;
274# else
275 udiv_qrnnd (t[0], t[1], (mp_limb_t) (value >> 32),
276 (mp_limb_t) value, brec->big.base);
277# endif
278 n = 2;
279 }
280 }
281 else
282 {
283 t[0] = value;
284 n = 1;
285 }
286
287 /* Convert the 1-3 words in t[], word by word, to ASCII. */
288 do
289 {
290 mp_limb_t ti = t[--n];
291 int ndig_for_this_limb = 0;
292
293# if UDIV_TIME > 2 * UMUL_TIME
294 mp_limb_t base_multiplier = brec->base_multiplier;
295 if (brec->flag)
296 while (ti != 0)
297 {
298 mp_limb_t quo, rem, x;
299 mp_limb_t dummy __attribute__ ((unused));
300
301 umul_ppmm (x, dummy, ti, base_multiplier);
302 quo = (x + ((ti - x) >> 1)) >> (brec->post_shift - 1);
303 rem = ti - quo * base;
304 *--bp = digits[rem];
305 ti = quo;
306 ++ndig_for_this_limb;
307 }
308 else
309 while (ti != 0)
310 {
311 mp_limb_t quo, rem, x;
312 mp_limb_t dummy __attribute__ ((unused));
313
314 umul_ppmm (x, dummy, ti, base_multiplier);
315 quo = x >> brec->post_shift;
316 rem = ti - quo * base;
317 *--bp = digits[rem];
318 ti = quo;
319 ++ndig_for_this_limb;
320 }
321# else
322 while (ti != 0)
323 {
324 mp_limb_t quo, rem;
325
326 quo = ti / base;
327 rem = ti % base;
328 *--bp = digits[rem];
329 ti = quo;
330 ++ndig_for_this_limb;
331 }
332# endif
333 /* If this wasn't the most significant word, pad with zeros. */
334 if (n != 0)
335 while (ndig_for_this_limb < brec->big.ndigits)
336 {
337 *--bp = '0';
338 ++ndig_for_this_limb;
339 }
340 }
341 while (n != 0);
342# endif
343 }
344 break;
345 }
346
347 return bp;
348}
349#endif
350