Steve Smith wrote:
The doc isn't "wrong", it's just a bit overstated. It's a good idea
to follow normal linkage conventions (well normal from 1970) and
they're encouraging that. This is an ancient facility, and for all I
know it may have been a more vital requirement in the past.
Also, I have no insider's knowledge of how the system works (like
Mulder & Relson). It's conceivable that things could change to where
you'll fail somehow if you don't preserve the registers.
I would (and do) just follow normal saving and restoring conventions
in an ETXR. It certainly won't hurt.
sas
Hence my question... the "normal saving" from the Assembler
Services doc says that R14, R15, R0 and R1 don't need to be preserved,
*unless* documented otherwise.
The ATTACH doc says that the called function is responsible
for "saving and restoring the registers."
Does that mean "all" the registers - or the "normal" ones; is that
sentence documentation that all the registers need to be saved/restored;
or that the system doesn't care about saving R14, R15, R0 and R1
and only R2-R13 needs to be saved/restored?
The doc seems ambiguous to me; which leads me down this path
of doing funky save-area machinations to ensure that all registers
are saved - not just the "normal" ones.
- Dave Rivers-
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