cosmopolitan/libc/fmt/itoa128radix10.greg.c

55 lines
2.7 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program 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 │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/alg/reverse.h"
#include "libc/fmt/conv.h"
#include "libc/fmt/itoa.h"
#include "libc/limits.h"
uint128_t __udivmodti4(uint128_t, uint128_t, uint128_t *);
/**
* Converts unsigned 128-bit integer to string.
* @param a needs at least 40 bytes
* @return bytes written w/o nul
*/
noinline size_t uint128toarray_radix10(uint128_t i, char *a) {
size_t j;
uint128_t rem;
j = 0;
do {
i = __udivmodti4(i, 10, &rem);
a[j++] = rem + '0';
} while (i > 0);
a[j] = '\0';
reverse(a, j);
return j;
}
/**
* Converts signed 128-bit integer to string.
* @param a needs at least 41 bytes
* @return bytes written w/o nul
*/
size_t int128toarray_radix10(int128_t i, char *a) {
if (i >= 0) return uint128toarray_radix10(i, a);
*a++ = '-';
return 1 + uint128toarray_radix10(-i, a);
}