I'd like to get the sign of a `float` value as an `int` value of -1 or 1.
Avoiding conditionals is always a good idea in reducing computational cost. For instance, one way I can think of would be to use a fast `bit-shift` to get the sign:
float a = ...;
int sign = a >> 31; //0 for pos, 1 for neg
sign = ~sign; //1 for pos, 0 for neg
sign = sign << 1; //2 for pos, 0 for neg
sign -= 1; //-1 for pos, 1 for neg -- perfect.
Or more concisely:
int sign = (~(a >> 31) << 1) - 1;
1. Does this seem like a good approach?
2. Will this work for all platforms, given endianness concerns (as MSB holds sign)?