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#include <stdio.h>
#include <math.h>
double
llong2double(unsigned long long int l)
{
union { double d; unsigned long long int l; } u;
/* l=(l >> 32) | (l << 32); */
u.l=l;
return u.d;
}
float
int2float(unsigned long int l)
{
union { float f; unsigned long int l; } u;
u.l = l;
return u.f;
}
void
printfloat(float f)
{
double d = f;
union { float f; unsigned int i; } u;
u.f = f;
if (isnan(d)) {
puts("NaN (float from int)");
} else {
printf("%f (float) = 0x%08X (int)\n", d, u.i);
}
}
void
printdouble(double d)
{
union { double d; unsigned long long int l; } u;
u.d = d;
if (isnan(d)) {
puts("NaN (double from long long int)");
} else {
printf("%f (double) = 0x%08X%08X (long long int)\n", d,
(unsigned int) (u.l / 0x100000000ULL),
(unsigned int) (u.l % 0x100000000ULL));
}
}
int
main(int ac, char *av[])
{
printfloat(int2float(0x7f800000UL));
printfloat(int2float(0xff800000UL));
printfloat(int2float(0x7f800001UL));
printfloat(int2float(0x7fffffffUL));
printfloat(int2float(0xff800001UL));
printfloat(int2float(0xffffffffUL));
printfloat(int2float(0x00000000UL));
printfloat(int2float(0x80000000UL));
printdouble(llong2double(0x7ff0000000000000ULL));
printdouble(llong2double(0xfff0000000000000ULL));
printdouble(llong2double(0x7ff0000000000001ULL));
printdouble(llong2double(0x7fffffffffffffffULL));
printdouble(llong2double(0xfff0000000000001ULL));
printdouble(llong2double(0xffffffffffffffffULL));
printdouble(llong2double(0x0000000000000000ULL));
printdouble(llong2double(0x8000000000000000ULL));
return 0;
}
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