[fpc-devel] Re. z370 Cross Compilation, Pass 2 of ....

[Hans-Peter Diettrich]

Mark Morgan Lloyd schrieb:
> Hans-Peter Diettrich wrote:
>> Mark Morgan Lloyd schrieb:

>>> Question (to save me digging into the manuals right now): where a 
>>> recent machine uses the dedicated stack instructions, is the stack 
>>> pointer one of the standard registers? In other words, can push/pop 
>>> operations be trivially and exactly simulated for older hardware?
>>
>> You mean thread safety?
> 
> No, I meant that Bernd suggested R1 earlier as a simulated stack 
> pointer. Does IBM use R1 for this on variants of the architecture that 
> have push/pop opcodes, or some other general-purpose register, or a 
> dedicated register?

Dunno, sorry. Perhaps a new register has been introduced with the new 
instructions?

>> As long as only one thread is running, the push/pop instructions must 
>> not be atomic.
> 
> I hate to correct language usage, but "/need/ not be atomic" would be 
> clearer.

Much appreciated :-)

DoDi