How can I convert 4 bytes storing an IEEE 754 floating point number to a float value in C?

Question

My program reads into 4 bytes an IEEE 754 floating point number from a file. I need to portable convert those bytes to my C compilers float type. In other words I need a fun

Answer 1

If your implementation can guarantee correct endianness:

float raw2ieee(uint8_t *raw)
{
    // either
    union {
        uint8_t bytes[4];
        float fp;
    } un;
    memcpy(un.bytes, raw, 4);
    return un.fp;

    // or, as seen in the fast inverse square root:
    return *(float *)raw;
}