Path: utzoo!attcan!uunet!taumet!steve
From: steve@taumet.com (Stephen Clamage)
Newsgroups: comp.lang.c
Subject: Re: Efficient way to transform float to string
Message-ID: <537@taumet.com>
Date: 10 Dec 90 16:11:14 GMT
References: <QbLnB1u00WBMM53Wpp@andrew.cmu.edu> <5906@stpstn.UUCP>
Organization: Taumetric Corporation, San Diego
Lines: 15

lerman@stpstn.UUCP (Ken Lerman) writes:

>2 -- Rather than multiplying by 10, shift left two, add the original
>     and shift left again.  (A smart compiler might do this for you.)
>     [Some might say that a reasonable compiler should do this for you.]

Except that on some machines shifting is not cheap.  On some machines
an integer multiply by 10 is faster than two shifts and an add along
with creating an intermediate result.  A good rule is to leave it up to
the compiler until performance tests prove you must do low-level coding
like this.  In that case, be sure to conditionalize the code for the
particular compiler.
-- 

Steve Clamage, TauMetric Corp, steve@taumet.com