81 lines
1.5 KiB
C
81 lines
1.5 KiB
C
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// SPDX-License-Identifier: LGPL-3.0-or-later
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/**
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* \file numlib_itoa.c
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*
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* Integer to ASCII conversion.
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*
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* \copyright The DoubleFourteen Code Forge (C) All Rights Reserved
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* \author Lorenzo Cogotti
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*/
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#include "numlib.h"
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#include <string.h>
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// XXX(micia): benchmark memcpy()-less version, something with rep stos
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// amount of data copied over is very small, so it would probably pay off
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// leaving memcpy() out
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char *Utoa(unsigned long long x, char *dest)
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{
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char buf[DIGS(x) + 1];
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size_t n;
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char *p = buf + sizeof(buf);
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*--p = '\0';
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do {
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*--p = '0' + (x % 10);
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x /= 10;
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} while (x != 0);
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n = (buf + sizeof(buf)) - p;
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memcpy(dest, p, n);
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return dest + n - 1;
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}
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char *Itoa(long long x, char *dest)
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{
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char buf[1 + DIGS(x) + 1];
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unsigned long long ax; // NOTE keep this unsigned!
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size_t n;
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char *p = buf + sizeof(buf);
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ax = ABS(x); // also handles LLONG_MIN, ax being unsigned
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// NOTE: this is still a signed overflow, which is technically
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// undefined in standard C
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*--p = '\0';
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do {
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*--p = '0' + (ax % 10);
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ax /= 10;
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} while (ax != 0);
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if (x < 0)
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*--p = '-';
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n = (buf + sizeof(buf)) - p;
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memcpy(dest, p, n);
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return dest + n - 1;
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}
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char *Xtoa(unsigned long long x, char *dest)
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{
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char buf[XDIGS(x) + 1];
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size_t n;
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char *p = buf + sizeof(buf);
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*--p = '\0';
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do {
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*--p = "0123456789abcdef"[x & 0xf];
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x >>= 4;
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} while (x != 0);
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n = (buf + sizeof(buf)) - p;
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memcpy(dest, p, n);
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return dest + n - 1;
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}
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