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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: comp.arch
Subject: Re: AM29000 Booleans
Message-ID: <8012@utzoo.UUCP>
Date: Sun, 10-May-87 15:00:01 EDT
Article-I.D.: utzoo.8012
Posted: Sun May 10 15:00:01 1987
Date-Received: Sun, 10-May-87 15:00:01 EDT
References: <1270@aw.sei.cmu.edu>
Organization: U of Toronto Zoology
Lines: 14

> The above from Am29000 user's manual page 7-10 for a 32 bit integer multiply.
> It takes 32 instructions to do it  (similar for divide).
> 
> Now, I can understand the advantages of a RISC processor but this is going
> to far.  Should I put 32 instructions in the processing stream each time
> I need to multiply two numbers?  Should I use a subroutine?

Many multiplies (at least in non-numerical code) are by small integer
constants.  For those, a sensible compiler will generate whatever small
number of steps is actually needed to do the particular multiply, as a
function of the binary representation of the constant.
-- 
"If you want PL/I, you know       Henry Spencer @ U of Toronto Zoology
where to find it." -- DMR         {allegra,ihnp4,decvax,pyramid}!utzoo!henry