Added local optimization: 0x7F...F - x -> x ^ 0x7F...F.
Improved local optimization.
Added local optimization: (x + 0x7F...F) ^ 0x7F...F -> -x.
Added local optimization: (x & 0x7F...F) - x -> x & 0x80...0.
Added local optimization: 0xF...FE - (x | 0x7F...F) -> x | 0x7F...F.