Xref:	news2.mv.net comp.os.msdos.djgpp:5009
From:	Erik Max Francis <max AT alcyone DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Speed optimization: memcpy() or for loop ??
Date:	Fri, 14 Jun 1996 23:26:05 -0700
Organization:	Alcyone Systems
Lines:	31
Message-ID:	<31C2577D.22FD99BD@alcyone.com>
References:	<4pmlrp$p7u AT crc-news DOT doc DOT ca>
NNTP-Posting-Host:	newton.alcyone.com
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Richard Young wrote:

> A question for the optimization experts:
> 
> For moving data, is it faster to use
> 
> a) memcpy(x,y,n*sizeof(x[0]))
> 
> or
> 
> b) for (i = 0; i < n; i++) x[i] = y[i];
> 
> or are they basically the same speed.

Use the standard library function.

The whole idea behind having such a function is that it is supposed to be a
good implementation of the operation you're interested in.  And, furthermore,
it knows which platform it's running under, so to speak, and so it can do the
right thing.

> With C++ is it better code practice to use b) over a)?

Same thing.

-- 
Erik Max Francis &tSftDotIotE && http://www.alcyone.com/max && max AT alcyone DOT com
San Jose, California, U.S.A. && 37 20 07 N 121 53 38 W && the 4th R is respect
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