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From: srs!matt@uunet.uu.net (Matt Goheen)
Newsgroups: comp.sys.sun
Subject: Moving data in/out of memory on a Sparc
Keywords: SunOS
Message-ID: <759@brazos.Rice.edu>
Date: 31 Jul 89 19:02:36 GMT
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Organization: Sun-Spots
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X-Sun-Spots-Digest: Volume 8, Issue 93, message 9 of 16

Put simply, what is the FASTEST way to move data in/out of a Sparc chip's
registers?

Put complexly and in much detail:

We need to fill as many registers as are available with 32 bit integers
from memory.  The data in memory can be laid out in whatever way is
necessary to speed access (most likely contiguously but perhaps not).
>From my limited experience with Sparc assembly, it would seem that on the
4/110, there are 8 global, 8 local, 8 input and 8 output registers.  Can
we use them all from an assembly routine as long as we restore the
necessary ones before we return?  It looks to me that loading double words
into register pairs using inline code is the fastest method (using the ldd
instruction), am I wrong (probably)?  This would be for a 4/110, would
anything change if it were for a Sparcstation (different memory
subsystem)?  How about other Sun Sparc systems?

Thanks to any and all respondents, your assistance is greatly appreciated,


Matt Goheen	matt@srs.uucp	matt%srs.uucp@harvard.harvard.edu