Strength reduction
Strength reduction is a program optimization technique that replaces more expensive operations with cheaper ones.
A few examples of strength reduction:
| Expensive operation | Cheaper operation | |
|---|---|---|
| Division by a power of 2 | a / 2**n | a >> n |
| Modulo by a power of 2 | a % 2**n | a & (2**n - 1) |
Replacement of pow | pow(a, 0.5) | sqrt(a) |
pow(a, 1.5) | a * sqrt(a) | |
pow(a, -1.5) | 1.0 / (a * sqrt(a)) |