Re: [Amforth] int_restore, etc.

[Enoch <ix...@ho...>]

Matthias Trute <mt...@we...> writes:

> Hi,
>
>> "-int" (int-off.asm) counterpart is "int_restore" (int-restore.asm). So,
>> why is this "int_restore" header commented out, i.e., not available to
>> the high level?
>
> uhm. yes. These words are one of very first ones, that fell out of
> scope later on.
>
>
>> Candidly, as "+int" (int-on.asm) is a simple SEI instruction (Set Global
>> Interrupt Flag) one would expect "-int" to be a simple CLI (Clear Global
>> Interrupt Flag) but this is not the case...
>> 
>> May I suggest:
>> 
>> +int → SEI
>> -int → CLI
>
> Thats fine.
>> int_suspend → ( -- SREG ) CLI
>> int_restore → ( SREG -- )
>
> These words are not really needed.
>
> \ get the I flag as a forth flag
> : int? SREG c@ SREG_I and 0> ;
>
> \ to be used in pairs within the same colon definition
> \ can be nested
> : critical[
>     int? r> swap >r >r \ keep the current state
>     -int \ turn interrupts off
>     drop \ currently the content of SREG.
> ;
>
> : ]critical
>     r> r> if +int then >r \ will crash if not matched
> ;
>
> \ test case. foo prints bar-1 baz0 qux-1
>
> : bar ." bar" int? . ;
> : baz ." baz" int? . ;
> : qux ." qux" int? . ;
>
> : foo
>   bar
>   critical[
>     \ nothing will disturb us here
>     baz
>   ]critical \ now interrupts or other things may happen again
>   qux ;

I like these "critical[" "]critical" words, much better than int_suspend
and int_restore, but I prefer their current asm code implementation
since one would like to keep the criticial code execution to the
minimum.

Thanks, Enoch.





















>
>
> ------------------------------------------------------------------------------
> The Go Parallel Website, sponsored by Intel - in partnership with Geeknet, 
> is your hub for all things parallel software development, from weekly thought 
> leadership blogs to news, videos, case studies, tutorials, tech docs, 
> whitepapers, evaluation guides, and opinion stories. Check out the most 
> recent posts - join the conversation now. http://goparallel.sourceforge.net/
> _______________________________________________
> Amforth-devel mailing list for http://amforth.sf.net/
> Amf...@li...
> https://lists.sourceforge.net/lists/listinfo/amforth-devel