🚀 go-pugleaf

In article <4fcq34$fik@solutions.solon.com>, Colin McMahon
<engstad@funcom.no> writes
>Michael Smith (msmith@mpx.com.au) wrote:
>:      while (*src) *(dest++) = *(src++);
>
>Why don't you use: memcpy(dest, src, strlen(src))? On about all Intel 
>80x86 machines (I think Pentiums actually are faster without it), this 
>function is inlined to compile as a fast REP MOVSW.

Two reasons:

1. Other platforms don't necessarily have this type of instruction.

2. Using the above may seriously slow the code down.

Consider copying a "string" on a UNIX system which is 200 Kb in size.
You then have to:

 (a)  process 200K of characters to find the length of the string, then
 (b)  copy 200K from one buffer to another.

This is inevitably going to be slower as the original code only performs
one copy!


--
Graham Coles           |      e-mail: graham@scitec.demon.co.uk
Sci-Tec Software       |      flames: bill@microsoft.com     :)