Path: utzoo!attcan!uunet!seismo!sundc!pitstop!sun!amdcad!ames!vsi1!daver!mips!cprice
From: cprice@mips.COM (Charlie Price)
Newsgroups: comp.arch
Subject: Re: register save/restore
Message-ID: <7702@winchester.mips.COM>
Date: 5 Nov 88 02:27:45 GMT
References: <3300037@m.cs.uiuc.edu> <5938@killer.DALLAS.TX.US> <7580@aw.sei.cmu.edu> <1009@l.cc.purdue.edu>
Reply-To: cprice@winchester.UUCP (Charlie Price)
Organization: MIPS Computer Systems, Sunnyvale, CA
Lines: 23

In article <1009@l.cc.purdue.edu> cik@l.cc.purdue.edu (Herman Rubin) writes:
>In article <7580@aw.sei.cmu.edu>, firth@sei.cmu.edu (Robert Firth) writes:
>> 	Register Saving across Procedure Calls
>> 	--------------------------------------
>> Which is better - caller saves or callee saves?
>> 
>> A. Is this the right question?
>
>It is, if library subroutines are to be used.  A compiler cannot change
>the procedure to be followed in this case.

Not necessarily.

MIPS has ucode libraries (an intermediate representation) available
and compiling C with -O4 optimization selected uses
these libraries and does interprocedural register allocation including
the library modules.  For some applications this is worth doing.

On the other hand, what about shared-library routines with
dynamic linkage at runtime?
-- 
Charlie Price    cprice@mips.com        (408) 720-1700
MIPS Computer Systems / 928 Arques Ave. / Sunnyvale, CA   94086