Avoid an access violation if malloc failes.
[glibc.git] / stdio-common / _itowa.c
blob4c93b31e6bef2cc8110c50032861f2bc43c1daff
1 /* Internal function for converting integers to ASCII.
2 Copyright (C) 1994, 1995, 1996, 1999, 2000 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>.
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 <gmp.h>
24 #include <stdlib/gmp-impl.h>
25 #include <stdlib/longlong.h>
27 #include "_itowa.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
79 /* Factor table for the different bases. */
80 extern const struct base_table_t _itoa_base_table[];
82 /* Lower-case digits. */
83 extern const wchar_t _itowa_lower_digits[];
84 /* Upper-case digits. */
85 extern const wchar_t _itowa_upper_digits[];
88 wchar_t *
89 _itowa (value, buflim, base, upper_case)
90 unsigned long long int value;
91 wchar_t *buflim;
92 unsigned int base;
93 int upper_case;
95 const wchar_t *digits = (upper_case
96 ? _itowa_upper_digits : _itowa_lower_digits);
97 wchar_t *bp = buflim;
98 const struct base_table_t *brec = &_itoa_base_table[base - 2];
100 switch (base)
102 #define RUN_2N(BITS) \
103 do \
105 /* `unsigned long long int' always has 64 bits. */ \
106 mp_limb_t work_hi = value >> (64 - BITS_PER_MP_LIMB); \
108 if (BITS_PER_MP_LIMB == 32) \
110 if (work_hi != 0) \
112 mp_limb_t work_lo; \
113 int cnt; \
115 work_lo = value & 0xfffffffful; \
116 for (cnt = BITS_PER_MP_LIMB / BITS; cnt > 0; --cnt) \
118 *--bp = digits[work_lo & ((1ul << BITS) - 1)]; \
119 work_lo >>= BITS; \
121 if (BITS_PER_MP_LIMB % BITS != 0) \
123 work_lo \
124 |= ((work_hi \
125 & ((1 << (BITS - BITS_PER_MP_LIMB%BITS)) \
126 - 1)) \
127 << BITS_PER_MP_LIMB % BITS); \
128 work_hi >>= BITS - BITS_PER_MP_LIMB % BITS; \
129 if (work_hi == 0) \
130 work_hi = work_lo; \
131 else \
132 *--bp = digits[work_lo]; \
135 else \
136 work_hi = value & 0xfffffffful; \
138 do \
140 *--bp = digits[work_hi & ((1 << BITS) - 1)]; \
141 work_hi >>= BITS; \
143 while (work_hi != 0); \
145 while (0)
146 case 8:
147 RUN_2N (3);
148 break;
150 case 16:
151 RUN_2N (4);
152 break;
154 default:
156 #if BITS_PER_MP_LIMB == 64
157 mp_limb_t base_multiplier = brec->base_multiplier;
158 if (brec->flag)
159 while (value != 0)
161 mp_limb_t quo, rem, x, dummy;
163 umul_ppmm (x, dummy, value, base_multiplier);
164 quo = (x + ((value - x) >> 1)) >> (brec->post_shift - 1);
165 rem = value - quo * base;
166 *--bp = digits[rem];
167 value = quo;
169 else
170 while (value != 0)
172 mp_limb_t quo, rem, x, dummy;
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;
180 #endif
181 #if BITS_PER_MP_LIMB == 32
182 mp_limb_t t[3];
183 int n;
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)
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)
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. */
202 #if UDIV_TIME > 2 * UMUL_TIME
203 mp_limb_t x, xh, xl;
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);
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;
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;
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);
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;
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;
257 else
259 #if (UDIV_TIME > 2 * UMUL_TIME)
260 mp_limb_t x;
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;
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;
281 else
283 t[0] = value;
284 n = 1;
287 /* Convert the 1-3 words in t[], word by word, to ASCII. */
290 mp_limb_t ti = t[--n];
291 int ndig_for_this_limb = 0;
293 #if UDIV_TIME > 2 * UMUL_TIME
294 mp_limb_t base_multiplier = brec->base_multiplier;
295 if (brec->flag)
296 while (ti != 0)
298 mp_limb_t quo, rem, x, dummy;
300 umul_ppmm (x, dummy, ti, base_multiplier);
301 quo = (x + ((ti - x) >> 1)) >> (brec->post_shift - 1);
302 rem = ti - quo * base;
303 *--bp = digits[rem];
304 ti = quo;
305 ++ndig_for_this_limb;
307 else
308 while (ti != 0)
310 mp_limb_t quo, rem, x, dummy;
312 umul_ppmm (x, dummy, ti, base_multiplier);
313 quo = x >> brec->post_shift;
314 rem = ti - quo * base;
315 *--bp = digits[rem];
316 ti = quo;
317 ++ndig_for_this_limb;
319 #else
320 while (ti != 0)
322 mp_limb_t quo, rem;
324 quo = ti / base;
325 rem = ti % base;
326 *--bp = digits[rem];
327 ti = quo;
328 ++ndig_for_this_limb;
330 #endif
331 /* If this wasn't the most significant word, pad with zeros. */
332 if (n != 0)
333 while (ndig_for_this_limb < brec->big.ndigits)
335 *--bp = '0';
336 ++ndig_for_this_limb;
339 while (n != 0);
340 #endif
342 break;
345 return bp;