[fpc-devel] Registers allocation technique

[Sergei Gorelkin]

30.09.2014 23:34, Sven Barth пишет:
> On 30.09.2014 18:37, Lag Programming wrote:
>> 1) "Unless a function calls another function, the function result
>> register will always be in rax. Calling for inlined functions doesn't
>> change this behaviour as it's not a real function call."
>
> RAX will only then be used for the function result when it is really needed (e.g. the last
> assignment in a function).

To somewhat clarify: the reqirement is to place result into RAX at the function exit point. This is 
unrelated to assignments to the 'result' variable in code.

 > Before that the compiler might reuse RAX as it pleases.
Likewise, the value of 'result' may be placed into any register or even to memory.

Regards,
Sergei