4 ms·
Another very interesting characteristic of the arm instruction set is that MOV and AND have their opposite op (MVN and BIC). That means you can write MOV, r0,
by kalenx 9y ago
Another very interesting characteristic of the arm instruction set is that MOV and AND have their opposite op (MVN and BIC).
That means you can write MOV, r0, #-1 (equivalent to #0xFFFFFFFF) and the assembler will emit a MVN r0, #0 to fulfill your needs. This increases the number of constants that can be directly assigned.
- acqq 9y agoThe MVN and BIC are not the "opposite ops", they are the same operations but they do "binary not" over every bit of the parameter which is easy to implement in hardware. It's true this also allows for better code density.