glibc/stdio-common/_itoa.c
Siddhesh Poyarekar 30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30

478 lines
14 KiB
C

/* Internal function for converting integers to ASCII.
Copyright (C) 1994-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#include <gmp-mparam.h>
#include <gmp.h>
#include <limits.h>
#include <stdlib/gmp-impl.h>
#include <stdlib/longlong.h>
#include <_itoa.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
/* We do not compile _itoa if we always can use _itoa_word. */
#if _ITOA_NEEDED
/* Local variables. */
const struct base_table_t _itoa_base_table[] attribute_hidden =
{
# if BITS_PER_MP_LIMB == 64
/* 2 */ {SEL1(0ull) 1, 1},
/* 3 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 1},
/* 4 */ {SEL1(0ull) 1, 2},
/* 5 */ {SEL1(0xcccccccccccccccdull) 0, 2},
/* 6 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 2},
/* 7 */ {SEL1(0x2492492492492493ull) 1, 3},
/* 8 */ {SEL1(0ull) 1, 3},
/* 9 */ {SEL1(0xe38e38e38e38e38full) 0, 3},
/* 10 */ {SEL1(0xcccccccccccccccdull) 0, 3},
/* 11 */ {SEL1(0x2e8ba2e8ba2e8ba3ull) 0, 1},
/* 12 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 3},
/* 13 */ {SEL1(0x4ec4ec4ec4ec4ec5ull) 0, 2},
/* 14 */ {SEL1(0x2492492492492493ull) 1, 4},
/* 15 */ {SEL1(0x8888888888888889ull) 0, 3},
/* 16 */ {SEL1(0ull) 1, 4},
/* 17 */ {SEL1(0xf0f0f0f0f0f0f0f1ull) 0, 4},
/* 18 */ {SEL1(0xe38e38e38e38e38full) 0, 4},
/* 19 */ {SEL1(0xd79435e50d79435full) 0, 4},
/* 20 */ {SEL1(0xcccccccccccccccdull) 0, 4},
/* 21 */ {SEL1(0x8618618618618619ull) 1, 5},
/* 22 */ {SEL1(0x2e8ba2e8ba2e8ba3ull) 0, 2},
/* 23 */ {SEL1(0x642c8590b21642c9ull) 1, 5},
/* 24 */ {SEL1(0xaaaaaaaaaaaaaaabull) 0, 4},
/* 25 */ {SEL1(0x47ae147ae147ae15ull) 1, 5},
/* 26 */ {SEL1(0x4ec4ec4ec4ec4ec5ull) 0, 3},
/* 27 */ {SEL1(0x97b425ed097b425full) 0, 4},
/* 28 */ {SEL1(0x2492492492492493ull) 1, 5},
/* 29 */ {SEL1(0x1a7b9611a7b9611bull) 1, 5},
/* 30 */ {SEL1(0x8888888888888889ull) 0, 4},
/* 31 */ {SEL1(0x0842108421084211ull) 1, 5},
/* 32 */ {SEL1(0ull) 1, 5},
/* 33 */ {SEL1(0x0f83e0f83e0f83e1ull) 0, 1},
/* 34 */ {SEL1(0xf0f0f0f0f0f0f0f1ull) 0, 5},
/* 35 */ {SEL1(0xea0ea0ea0ea0ea0full) 0, 5},
/* 36 */ {SEL1(0xe38e38e38e38e38full) 0, 5}
# endif
# if BITS_PER_MP_LIMB == 32
/* 2 */ {SEL1(0ul) 1, 1, {0, 31, 0x80000000ul SEL2(0xfffffffful)}},
/* 3 */ {SEL1(0xaaaaaaabul) 0, 1, {0, 20, 0xcfd41b91ul SEL2(0x3b563c24ul)}},
/* 4 */ {SEL1(0ul) 1, 2, {1, 15, 0x40000000ul SEL2(0xfffffffful)}},
/* 5 */ {SEL1(0xcccccccdul) 0, 2, {1, 13, 0x48c27395ul SEL2(0xc25c2684ul)}},
/* 6 */ {SEL1(0xaaaaaaabul) 0, 2, {0, 12, 0x81bf1000ul SEL2(0xf91bd1b6ul)}},
/* 7 */ {SEL1(0x24924925ul) 1, 3, {1, 11, 0x75db9c97ul SEL2(0x1607a2cbul)}},
/* 8 */ {SEL1(0ul) 1, 3, {1, 10, 0x40000000ul SEL2(0xfffffffful)}},
/* 9 */ {SEL1(0x38e38e39ul) 0, 1, {0, 10, 0xcfd41b91ul SEL2(0x3b563c24ul)}},
/* 10 */ {SEL1(0xcccccccdul) 0, 3, {2, 9, 0x3b9aca00ul SEL2(0x12e0be82ul)}},
/* 11 */ {SEL1(0xba2e8ba3ul) 0, 3, {0, 9, 0x8c8b6d2bul SEL2(0xd24cde04ul)}},
/* 12 */ {SEL1(0xaaaaaaabul) 0, 3, {3, 8, 0x19a10000ul SEL2(0x3fa39ab5ul)}},
/* 13 */ {SEL1(0x4ec4ec4ful) 0, 2, {2, 8, 0x309f1021ul SEL2(0x50f8ac5ful)}},
/* 14 */ {SEL1(0x24924925ul) 1, 4, {1, 8, 0x57f6c100ul SEL2(0x74843b1eul)}},
/* 15 */ {SEL1(0x88888889ul) 0, 3, {0, 8, 0x98c29b81ul SEL2(0xad0326c2ul)}},
/* 16 */ {SEL1(0ul) 1, 4, {3, 7, 0x10000000ul SEL2(0xfffffffful)}},
/* 17 */ {SEL1(0xf0f0f0f1ul) 0, 4, {3, 7, 0x18754571ul SEL2(0x4ef0b6bdul)}},
/* 18 */ {SEL1(0x38e38e39ul) 0, 2, {2, 7, 0x247dbc80ul SEL2(0xc0fc48a1ul)}},
/* 19 */ {SEL1(0xaf286bcbul) 1, 5, {2, 7, 0x3547667bul SEL2(0x33838942ul)}},
/* 20 */ {SEL1(0xcccccccdul) 0, 4, {1, 7, 0x4c4b4000ul SEL2(0xad7f29abul)}},
/* 21 */ {SEL1(0x86186187ul) 1, 5, {1, 7, 0x6b5a6e1dul SEL2(0x313c3d15ul)}},
/* 22 */ {SEL1(0xba2e8ba3ul) 0, 4, {0, 7, 0x94ace180ul SEL2(0xb8cca9e0ul)}},
/* 23 */ {SEL1(0xb21642c9ul) 0, 4, {0, 7, 0xcaf18367ul SEL2(0x42ed6de9ul)}},
/* 24 */ {SEL1(0xaaaaaaabul) 0, 4, {4, 6, 0x0b640000ul SEL2(0x67980e0bul)}},
/* 25 */ {SEL1(0x51eb851ful) 0, 3, {4, 6, 0x0e8d4a51ul SEL2(0x19799812ul)}},
/* 26 */ {SEL1(0x4ec4ec4ful) 0, 3, {3, 6, 0x1269ae40ul SEL2(0xbce85396ul)}},
/* 27 */ {SEL1(0x2f684bdbul) 1, 5, {3, 6, 0x17179149ul SEL2(0x62c103a9ul)}},
/* 28 */ {SEL1(0x24924925ul) 1, 5, {3, 6, 0x1cb91000ul SEL2(0x1d353d43ul)}},
/* 29 */ {SEL1(0x8d3dcb09ul) 0, 4, {2, 6, 0x23744899ul SEL2(0xce1deceaul)}},
/* 30 */ {SEL1(0x88888889ul) 0, 4, {2, 6, 0x2b73a840ul SEL2(0x790fc511ul)}},
/* 31 */ {SEL1(0x08421085ul) 1, 5, {2, 6, 0x34e63b41ul SEL2(0x35b865a0ul)}},
/* 32 */ {SEL1(0ul) 1, 5, {1, 6, 0x40000000ul SEL2(0xfffffffful)}},
/* 33 */ {SEL1(0x3e0f83e1ul) 0, 3, {1, 6, 0x4cfa3cc1ul SEL2(0xa9aed1b3ul)}},
/* 34 */ {SEL1(0xf0f0f0f1ul) 0, 5, {1, 6, 0x5c13d840ul SEL2(0x63dfc229ul)}},
/* 35 */ {SEL1(0xd41d41d5ul) 1, 6, {1, 6, 0x6d91b519ul SEL2(0x2b0fee30ul)}},
/* 36 */ {SEL1(0x38e38e39ul) 0, 3, {0, 6, 0x81bf1000ul SEL2(0xf91bd1b6ul)}}
# endif
};
#endif
char *
_itoa_word (_ITOA_WORD_TYPE value, char *buflim,
unsigned int base, int upper_case)
{
const char *digits = (upper_case
? _itoa_upper_digits
: _itoa_lower_digits);
switch (base)
{
#define SPECIAL(Base) \
case Base: \
do \
*--buflim = digits[value % Base]; \
while ((value /= Base) != 0); \
break
SPECIAL (10);
SPECIAL (16);
SPECIAL (8);
default:
do
*--buflim = digits[value % base];
while ((value /= base) != 0);
}
return buflim;
}
#undef SPECIAL
#if _ITOA_NEEDED
char *
_itoa (unsigned long long int value, char *buflim, unsigned int base,
int upper_case)
{
const char *digits = (upper_case
? _itoa_upper_digits
: _itoa_lower_digits);
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) \
{ \
*--buflim = 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 \
*--buflim = digits[work_lo]; \
} \
} \
else \
work_hi = value & 0xfffffffful; \
} \
do \
{ \
*--buflim = 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:
{
char *bufend = buflim;
# 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;
*--buflim = 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;
*--buflim = 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;
*--buflim = 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;
*--buflim = digits[rem];
ti = quo;
++ndig_for_this_limb;
}
# else
while (ti != 0)
{
mp_limb_t quo, rem;
quo = ti / base;
rem = ti % base;
*--buflim = 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)
{
*--buflim = '0';
++ndig_for_this_limb;
}
}
while (n != 0);
# endif
if (buflim == bufend)
*--buflim = '0';
}
break;
}
return buflim;
}
#endif
char *
_fitoa_word (_ITOA_WORD_TYPE value, char *buf, unsigned int base,
int upper_case)
{
char tmpbuf[sizeof (value) * 4]; /* Worst case length: base 2. */
char *cp = _itoa_word (value, tmpbuf + sizeof (value) * 4, base, upper_case);
while (cp < tmpbuf + sizeof (value) * 4)
*buf++ = *cp++;
return buf;
}
#if _ITOA_NEEDED
char *
_fitoa (unsigned long long value, char *buf, unsigned int base, int upper_case)
{
char tmpbuf[sizeof (value) * 4]; /* Worst case length: base 2. */
char *cp = _itoa (value, tmpbuf + sizeof (value) * 4, base, upper_case);
while (cp < tmpbuf + sizeof (value) * 4)
*buf++ = *cp++;
return buf;
}
#endif