On 04/12/2015 23:02, gareth wrote:
> OK, This is my interest.
>
> With the32-bit instruction set having conditional execuation based
> upon previously-set condition codes, what happens if there is a
> nested IF, if the conditions for execution are based upon the result
> of the outer IF?
>
> Presumably the outer IF has to be resolved by conditional branches
> and not by conditional execution?
Yes.
It my be possible to come up with inner and outer conditions based on
mutually exclusive flag combinations, but in modern ARMs with branch
prediction, a branch is going to be quicker than skipping large chunks
of not taken conditional instructions.
---druck