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glibc/stdio-common/_itowa.c
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/* Internal function for converting integers to ASCII. | |
Copyright (C) 1994-2016 Free Software Foundation, Inc. | |
This file is part of the GNU C Library. | |
Contributed by Torbjorn Granlund <tege@matematik.su.se> | |
and Ulrich Drepper <drepper@gnu.org>. | |
The GNU C Library is free software; you can redistribute it and/or | |
modify it under the terms of the GNU Lesser General Public | |
License as published by the Free Software Foundation; either | |
version 2.1 of the License, or (at your option) any later version. | |
The GNU C Library is distributed in the hope that it will be useful, | |
but WITHOUT ANY WARRANTY; without even the implied warranty of | |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
Lesser General Public License for more details. | |
You should have received a copy of the GNU Lesser General Public | |
License along with the GNU C Library; if not, see | |
<http://www.gnu.org/licenses/>. */ | |
#include <gmp-mparam.h> | |
#include <gmp.h> | |
#include <limits.h> | |
#include <stdlib/gmp-impl.h> | |
#include <stdlib/longlong.h> | |
#include <_itowa.h> | |
/* Canonize environment. For some architectures not all values might | |
be defined in the GMP header files. */ | |
#ifndef UMUL_TIME | |
# define UMUL_TIME 1 | |
#endif | |
#ifndef UDIV_TIME | |
# define UDIV_TIME 3 | |
#endif | |
/* Control memory layout. */ | |
#ifdef PACK | |
# undef PACK | |
# define PACK __attribute__ ((packed)) | |
#else | |
# define PACK | |
#endif | |
/* Declare local types. */ | |
struct base_table_t | |
{ | |
#if (UDIV_TIME > 2 * UMUL_TIME) | |
mp_limb_t base_multiplier; | |
#endif | |
char flag; | |
char post_shift; | |
#if BITS_PER_MP_LIMB == 32 | |
struct | |
{ | |
char normalization_steps; | |
char ndigits; | |
mp_limb_t base PACK; | |
#if UDIV_TIME > 2 * UMUL_TIME | |
mp_limb_t base_ninv PACK; | |
#endif | |
} big; | |
#endif | |
}; | |
/* To reduce the memory needed we include some fields of the tables | |
only conditionally. */ | |
#if UDIV_TIME > 2 * UMUL_TIME | |
# define SEL1(X) X, | |
# define SEL2(X) ,X | |
#else | |
# define SEL1(X) | |
# define SEL2(X) | |
#endif | |
/* Factor table for the different bases. */ | |
extern const struct base_table_t _itoa_base_table[] attribute_hidden; | |
/* Lower-case digits. */ | |
extern const wchar_t _itowa_lower_digits[] attribute_hidden; | |
/* Upper-case digits. */ | |
extern const wchar_t _itowa_upper_digits[] attribute_hidden; | |
#if _ITOA_NEEDED | |
wchar_t * | |
_itowa (unsigned long long int value, wchar_t *buflim, unsigned int base, | |
int upper_case) | |
{ | |
const wchar_t *digits = (upper_case | |
? _itowa_upper_digits : _itowa_lower_digits); | |
wchar_t *bp = buflim; | |
const struct base_table_t *brec = &_itoa_base_table[base - 2]; | |
switch (base) | |
{ | |
# define RUN_2N(BITS) \ | |
do \ | |
{ \ | |
/* `unsigned long long int' always has 64 bits. */ \ | |
mp_limb_t work_hi = value >> (64 - BITS_PER_MP_LIMB); \ | |
\ | |
if (BITS_PER_MP_LIMB == 32) \ | |
{ \ | |
if (work_hi != 0) \ | |
{ \ | |
mp_limb_t work_lo; \ | |
int cnt; \ | |
\ | |
work_lo = value & 0xfffffffful; \ | |
for (cnt = BITS_PER_MP_LIMB / BITS; cnt > 0; --cnt) \ | |
{ \ | |
*--bp = digits[work_lo & ((1ul << BITS) - 1)]; \ | |
work_lo >>= BITS; \ | |
} \ | |
if (BITS_PER_MP_LIMB % BITS != 0) \ | |
{ \ | |
work_lo \ | |
|= ((work_hi \ | |
& ((1 << (BITS - BITS_PER_MP_LIMB%BITS)) \ | |
- 1)) \ | |
<< BITS_PER_MP_LIMB % BITS); \ | |
work_hi >>= BITS - BITS_PER_MP_LIMB % BITS; \ | |
if (work_hi == 0) \ | |
work_hi = work_lo; \ | |
else \ | |
*--bp = digits[work_lo]; \ | |
} \ | |
} \ | |
else \ | |
work_hi = value & 0xfffffffful; \ | |
} \ | |
do \ | |
{ \ | |
*--bp = digits[work_hi & ((1 << BITS) - 1)]; \ | |
work_hi >>= BITS; \ | |
} \ | |
while (work_hi != 0); \ | |
} \ | |
while (0) | |
case 8: | |
RUN_2N (3); | |
break; | |
case 16: | |
RUN_2N (4); | |
break; | |
default: | |
{ | |
# if BITS_PER_MP_LIMB == 64 | |
mp_limb_t base_multiplier = brec->base_multiplier; | |
if (brec->flag) | |
while (value != 0) | |
{ | |
mp_limb_t quo, rem, x; | |
mp_limb_t dummy __attribute__ ((unused)); | |
umul_ppmm (x, dummy, value, base_multiplier); | |
quo = (x + ((value - x) >> 1)) >> (brec->post_shift - 1); | |
rem = value - quo * base; | |
*--bp = digits[rem]; | |
value = quo; | |
} | |
else | |
while (value != 0) | |
{ | |
mp_limb_t quo, rem, x; | |
mp_limb_t dummy __attribute__ ((unused)); | |
umul_ppmm (x, dummy, value, base_multiplier); | |
quo = x >> brec->post_shift; | |
rem = value - quo * base; | |
*--bp = digits[rem]; | |
value = quo; | |
} | |
# endif | |
# if BITS_PER_MP_LIMB == 32 | |
mp_limb_t t[3]; | |
int n; | |
/* First convert x0 to 1-3 words in base s->big.base. | |
Optimize for frequent cases of 32 bit numbers. */ | |
if ((mp_limb_t) (value >> 32) >= 1) | |
{ | |
# if UDIV_TIME > 2 * UMUL_TIME || UDIV_NEEDS_NORMALIZATION | |
int big_normalization_steps = brec->big.normalization_steps; | |
mp_limb_t big_base_norm | |
= brec->big.base << big_normalization_steps; | |
# endif | |
if ((mp_limb_t) (value >> 32) >= brec->big.base) | |
{ | |
mp_limb_t x1hi, x1lo, r; | |
/* If you want to optimize this, take advantage of | |
that the quotient in the first udiv_qrnnd will | |
always be very small. It might be faster just to | |
subtract in a tight loop. */ | |
# if UDIV_TIME > 2 * UMUL_TIME | |
mp_limb_t x, xh, xl; | |
if (big_normalization_steps == 0) | |
xh = 0; | |
else | |
xh = (mp_limb_t) (value >> (64 - big_normalization_steps)); | |
xl = (mp_limb_t) (value >> (32 - big_normalization_steps)); | |
udiv_qrnnd_preinv (x1hi, r, xh, xl, big_base_norm, | |
brec->big.base_ninv); | |
xl = ((mp_limb_t) value) << big_normalization_steps; | |
udiv_qrnnd_preinv (x1lo, x, r, xl, big_base_norm, | |
brec->big.base_ninv); | |
t[2] = x >> big_normalization_steps; | |
if (big_normalization_steps == 0) | |
xh = x1hi; | |
else | |
xh = ((x1hi << big_normalization_steps) | |
| (x1lo >> (32 - big_normalization_steps))); | |
xl = x1lo << big_normalization_steps; | |
udiv_qrnnd_preinv (t[0], x, xh, xl, big_base_norm, | |
brec->big.base_ninv); | |
t[1] = x >> big_normalization_steps; | |
# elif UDIV_NEEDS_NORMALIZATION | |
mp_limb_t x, xh, xl; | |
if (big_normalization_steps == 0) | |
xh = 0; | |
else | |
xh = (mp_limb_t) (value >> 64 - big_normalization_steps); | |
xl = (mp_limb_t) (value >> 32 - big_normalization_steps); | |
udiv_qrnnd (x1hi, r, xh, xl, big_base_norm); | |
xl = ((mp_limb_t) value) << big_normalization_steps; | |
udiv_qrnnd (x1lo, x, r, xl, big_base_norm); | |
t[2] = x >> big_normalization_steps; | |
if (big_normalization_steps == 0) | |
xh = x1hi; | |
else | |
xh = ((x1hi << big_normalization_steps) | |
| (x1lo >> 32 - big_normalization_steps)); | |
xl = x1lo << big_normalization_steps; | |
udiv_qrnnd (t[0], x, xh, xl, big_base_norm); | |
t[1] = x >> big_normalization_steps; | |
# else | |
udiv_qrnnd (x1hi, r, 0, (mp_limb_t) (value >> 32), | |
brec->big.base); | |
udiv_qrnnd (x1lo, t[2], r, (mp_limb_t) value, brec->big.base); | |
udiv_qrnnd (t[0], t[1], x1hi, x1lo, brec->big.base); | |
# endif | |
n = 3; | |
} | |
else | |
{ | |
# if UDIV_TIME > 2 * UMUL_TIME | |
mp_limb_t x; | |
value <<= brec->big.normalization_steps; | |
udiv_qrnnd_preinv (t[0], x, (mp_limb_t) (value >> 32), | |
(mp_limb_t) value, big_base_norm, | |
brec->big.base_ninv); | |
t[1] = x >> brec->big.normalization_steps; | |
# elif UDIV_NEEDS_NORMALIZATION | |
mp_limb_t x; | |
value <<= big_normalization_steps; | |
udiv_qrnnd (t[0], x, (mp_limb_t) (value >> 32), | |
(mp_limb_t) value, big_base_norm); | |
t[1] = x >> big_normalization_steps; | |
# else | |
udiv_qrnnd (t[0], t[1], (mp_limb_t) (value >> 32), | |
(mp_limb_t) value, brec->big.base); | |
# endif | |
n = 2; | |
} | |
} | |
else | |
{ | |
t[0] = value; | |
n = 1; | |
} | |
/* Convert the 1-3 words in t[], word by word, to ASCII. */ | |
do | |
{ | |
mp_limb_t ti = t[--n]; | |
int ndig_for_this_limb = 0; | |
# if UDIV_TIME > 2 * UMUL_TIME | |
mp_limb_t base_multiplier = brec->base_multiplier; | |
if (brec->flag) | |
while (ti != 0) | |
{ | |
mp_limb_t quo, rem, x; | |
mp_limb_t dummy __attribute__ ((unused)); | |
umul_ppmm (x, dummy, ti, base_multiplier); | |
quo = (x + ((ti - x) >> 1)) >> (brec->post_shift - 1); | |
rem = ti - quo * base; | |
*--bp = digits[rem]; | |
ti = quo; | |
++ndig_for_this_limb; | |
} | |
else | |
while (ti != 0) | |
{ | |
mp_limb_t quo, rem, x; | |
mp_limb_t dummy __attribute__ ((unused)); | |
umul_ppmm (x, dummy, ti, base_multiplier); | |
quo = x >> brec->post_shift; | |
rem = ti - quo * base; | |
*--bp = digits[rem]; | |
ti = quo; | |
++ndig_for_this_limb; | |
} | |
# else | |
while (ti != 0) | |
{ | |
mp_limb_t quo, rem; | |
quo = ti / base; | |
rem = ti % base; | |
*--bp = digits[rem]; | |
ti = quo; | |
++ndig_for_this_limb; | |
} | |
# endif | |
/* If this wasn't the most significant word, pad with zeros. */ | |
if (n != 0) | |
while (ndig_for_this_limb < brec->big.ndigits) | |
{ | |
*--bp = '0'; | |
++ndig_for_this_limb; | |
} | |
} | |
while (n != 0); | |
# endif | |
} | |
break; | |
} | |
return bp; | |
} | |
#endif |