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glibc/stdio-common/_itoa.c
Ulrich Drepper 4f8dbcb126 Update. 
* stdio-common/_itoa.c (_itoa): Fix special 32bit platform case
	with specific bases and only few bits set in second word.
1999-05-05 17:08:26 +00:00

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/* Internal function for converting integers to ASCII.
Copyright (C) 1994, 1995, 1996, 1999 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <gmp-mparam.h>
#include <stdlib/gmp.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
/* Local variables. */
static const struct base_table_t base_table[] =
{
#if BITS_PER_MP_LIMB == 64
/* 2 */ {SEL1(0ul) 1, 1},
/* 3 */ {SEL1(0xaaaaaaaaaaaaaaabul) 0, 1},
/* 4 */ {SEL1(0ul) 1, 2},
/* 5 */ {SEL1(0xcccccccccccccccdul) 0, 2},
/* 6 */ {SEL1(0xaaaaaaaaaaaaaaabul) 0, 2},
/* 7 */ {SEL1(0x2492492492492493ul) 1, 3},
/* 8 */ {SEL1(0ul) 1, 3},
/* 9 */ {SEL1(0xe38e38e38e38e38ful) 0, 3},
/* 10 */ {SEL1(0xcccccccccccccccdul) 0, 3},
/* 11 */ {SEL1(0x2e8ba2e8ba2e8ba3ul) 0, 1},
/* 12 */ {SEL1(0xaaaaaaaaaaaaaaabul) 0, 3},
/* 13 */ {SEL1(0x4ec4ec4ec4ec4ec5ul) 0, 2},
/* 14 */ {SEL1(0x2492492492492493ul) 1, 4},
/* 15 */ {SEL1(0x8888888888888889ul) 0, 3},
/* 16 */ {SEL1(0ul) 1, 4},
/* 17 */ {SEL1(0xf0f0f0f0f0f0f0f1ul) 0, 4},
/* 18 */ {SEL1(0xe38e38e38e38e38ful) 0, 4},
/* 19 */ {SEL1(0xd79435e50d79435ful) 0, 4},
/* 20 */ {SEL1(0xcccccccccccccccdul) 0, 4},
/* 21 */ {SEL1(0x8618618618618619ul) 1, 5},
/* 22 */ {SEL1(0x2e8ba2e8ba2e8ba3ul) 0, 2},
/* 23 */ {SEL1(0x642c8590b21642c9ul) 1, 5},
/* 24 */ {SEL1(0xaaaaaaaaaaaaaaabul) 0, 4},
/* 25 */ {SEL1(0x47ae147ae147ae15ul) 1, 5},
/* 26 */ {SEL1(0x4ec4ec4ec4ec4ec5ul) 0, 3},
/* 27 */ {SEL1(0x97b425ed097b425ful) 0, 4},
/* 28 */ {SEL1(0x2492492492492493ul) 1, 5},
/* 29 */ {SEL1(0x1a7b9611a7b9611bul) 1, 5},
/* 30 */ {SEL1(0x8888888888888889ul) 0, 4},
/* 31 */ {SEL1(0x0842108421084211ul) 1, 5},
/* 32 */ {SEL1(0ul) 1, 5},
/* 33 */ {SEL1(0x0f83e0f83e0f83e1ul) 0, 1},
/* 34 */ {SEL1(0xf0f0f0f0f0f0f0f1ul) 0, 5},
/* 35 */ {SEL1(0xea0ea0ea0ea0ea0ful) 0, 5},
/* 36 */ {SEL1(0xe38e38e38e38e38ful) 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
};
/* Lower-case digits. */
extern const char _itoa_lower_digits[];
/* Upper-case digits. */
extern const char _itoa_upper_digits[];
char *
_itoa (value, buflim, base, upper_case)
unsigned long long int value;
char *buflim;
unsigned int base;
int upper_case;
{
const char *digits = upper_case ? _itoa_upper_digits : _itoa_lower_digits;
char *bp = buflim;
const struct base_table_t *brec = &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, dummy;
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, dummy;
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, dummy;
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, dummy;
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;
}
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