gcc/libquadmath/quadmath_io.c

91 lines
1.7 KiB
C

#include "quadmath.h"
#include <stdio.h>
#include <string.h>
#define ABS(x) ((x) >= 0 ? (x) : -(x))
static void
format (char * res, const __float128 x, size_t n)
{
char buffer[1024];
char *p;
memset (buffer, 0, sizeof(buffer));
g_Qfmt (buffer, &x, n + 1, sizeof(buffer) - 3);
p = buffer + (*buffer == '-' ? 1 : 0);
// The sign is the easiest part
res[0] = (signbitq (x) ? '-' : '+');
if (*p == '.')
{
// We have a number smaller than 1, without exponent
int exp = 0;
char *c;
for (c = p+1; *c == '0'; c++)
exp++;
// We move the string "exp" characters left
size_t l = strlen (p+1+exp);
memcpy (res + 2, p + 1 + exp, l);
memset (res + 2 + l, '0', n - l + 1);
sprintf (res + n + 3, "e-%02d", exp + 1);
res[1] = res[2];
res[2] = '.';
return;
}
// Now, do we already have an exponent
char *c;
for (c = p; *c && *c != 'e'; c++)
;
if (*c)
{
int exp = strtol (c + 1, NULL, 10);
size_t l = c - p;
memcpy (res + 1, p, l);
if (l <= n + 1)
memset (res + 1 + l, '0', (int) n - l + 2);
sprintf (res + n + 3, "e%c%02d", exp >= 0 ? '+' : '-', ABS(exp));
return;
}
else
{
// If we have no exponent, normalize and add the exponent
for (c = p; *c && *c != '.'; c++)
;
res[1] = *p;
res[2] = '.';
size_t l = c - p;
memcpy (res + 3, p + 1, l);
size_t l2 = strlen (c + 1);
memcpy (res + 2 + l, c + 1, l2);
memset (res + 2 + l + l2, '0', n - (l + l2) + 1);
sprintf (res + n + 3, "e+%02d", l - 1);
return;
}
}
void
quadmath_dtoaq (char *s, size_t size, size_t n, __float128 x)
{
char buffer[1024];
memset (buffer, 0, sizeof(buffer));
format (buffer, x, n);
memcpy (s, buffer, size);
}