Re: SPARC code generation references

torek@elf.ee.lbl.gov (Chris Torek) writes:
>[You can `leaf crush' on the SPARC as long as there are enough
> registers: non-parameter (sp/ret-pc) `o' registers and 7 `g'
> registers.]


Be careful with this. According to the SPARC ABI (Applications Binary
Interface) standard, an ABI conforming program does something like:


%g0 is always zero
%g1 is a caller-save `very temp'
%g2..%g4 are reserved for application code and may not
be modified by libraries
%g5..%g7 may be read but not written by an application
(e.g., the analog of %g2..%g4 for libraries)


Eek!


I don't sit on the committee. I think some of this is useful but as
much as they've done is too much, since it potentially leaves (so to
speak :-) only one `very temp'. As an aside, you can't manually
spill/restore reserved `g' registers because they might be needed by
an asynchronous signal. Ah, omniscience by committee is just as hard
as any other time :-)


;-D on ( An opinion a day... ) Pardo
--

Return to the comp.compilers page.
Search the comp.compilers archives again.