CODEWITHSUNDEEP
cfloating-pointnan
kp11
kp11

Reputation: 2125

Denormalized float number is detected as NaN. Why?

Currently, I am transmitting a denormalized float number = 0x00300000. Before this value is set for another variable, inequality (var != var) check is done i.e. check for NaN. The inequality check fails for the denormalized number and the number is detected as NaN.

Could you please tell me what I am doing wrong here? My code is in C.

Thanks.

Upvotes: 0

Views: 1008

Answers (1)

paxdiablo
paxdiablo

Reputation: 882806

The equality check seems fine on my system:

#include <stdio.h>
#include <string.h>

int main(void) {
    int i = 0x00300000;
    float f = 0;
    if (sizeof(f) != sizeof(i)) {
        printf ("Urk!\n");
        return 1;
    }
    memcpy (&f, &i, sizeof(f));
    printf ("%.50f\n", f);
    if (f == f)
        puts ("Equal");
    else
        puts ("Not equal");
    return 0;
}

This outputs:

0.00000000000000000000000000000000000000440810381558
Equal

Upvotes: 2

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