Can Bitwise Operations Be Performed on Floating-Point Numbers in C/C ?

Bitwise Operations with Floating-Point Values

In C/C , bitwise operations can only be performed on integers, not on floating-point numbers. This is because floating-point numbers use a binary representation that is not compatible with bitwise operations.

For instance, when trying to perform a bitwise operation on a floating-point number a, such as a = a & (1 << 3), the compiler will produce an error. This is because the operand of the bitwise operator & must be an integer.

Casting the floating-point number a to an integer, as in a = (int)a & (1 << 3), allows the bitwise operation to be performed. However, this approach has a limitation. The operation is performed on the integer representation of a after rounding off the floating-point value.

Another attempt to cast the value to a void pointer, a = (void*)a & (1 << 3), is also invalid. This is because the type of the operand of the bitwise operator & must be the same as that of its operands. While void* has a larger representation than int, it cannot be used as an operand for bitwise operations.

The only way to perform a bitwise operation on a floating-point number is to analyze the bit content of the raw memory occupied by the value. This can be done using a union:

union FloatToInt {
    float f;
    int i;
};

FloatToInt fi;
fi.f = 1.4123;
fi.i = fi.i & (1 << 3);

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