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From: stolcke@ICSI.Berkeley.EDU (Andreas Stolcke)
Newsgroups: comp.sys.mips
Subject: pixie stats interpretation question
Keywords: pixie, instruction set stats
Message-ID: <1991Apr18.041605.26055@agate.berkeley.edu>
Date: 18 Apr 91 04:16:05 GMT
Sender: root@agate.berkeley.edu (Charlie Root)
Organization: International Computer Science Institute, Berkeley, CA
Lines: 20

I am having trouble understanding what the percentage for "spec" in
the both the dynamic and the static opcode distribution generated by
pixie refers to.  This item is invariably the one with the highest
frequency (in the 30% and 40%'s).

The MIPS assembler manual mentions "special instructions", but those
include things like exeception return and syscall.  The only explanation
I can come up with so far is that "spec" refers to exceptions inserted by
pixie itself for the purpose of stats collection.  But then I don't see
why these instruction are included in the stats at all, since they
could easily be factored out to give an accurate picture of the 
instruction set usage of the unpixified program.

Please reply by e-mail since I don't usually read this group.  Any
hints are welcome.

-- 
Andreas Stolcke					stolcke@icsi.berkeley.edu
International Computer Science Institute	stolcke@ucbicsi.bitnet
1957 Center St., Suite 600, Berkeley, CA 94704	(415) 642-4274 ext. 126