Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!cs.uoregon.edu!ns.uoregon.edu!milton!uw-beaver!mit-eddie!bbn.com!papaya.bbn.com!rsalz
From: rsalz@bbn.com (Rich Salz)
Newsgroups: comp.lang.c
Subject: Re: Efficient STRing CoMPares?
Message-ID: <3401@litchi.bbn.com>
Date: 19 Mar 91 06:24:43 GMT
References: <1991Mar15.142821@mars.mpr.ca> <15486@smoke.brl.mil> <1193@caslon.cs.arizona.edu> <15496@smoke.brl.mil> <1991Mar18.174207.7377@bingvaxu.cc.binghamton.edu>
Organization: BBN Systems and Technology, Inc.
Lines: 18

In <1991Mar18.174207.7377@bingvaxu.cc.binghamton.edu> consp06@bingsuns.cc.binghamton.edu (Robert Konigsberg) writes:
|  Wouldn't it be good then, to include in the macro,
|something to compare the actual POINTERS?  If the pointers are the
|same then the two strings have no CHOICE but to be equivelant.  This
|would really cut down the time under certain situations.
If you're careful about the circumstances under which you use it, you might
want to do something like this:
    #define EQ(p, q)                \
	    ((p) == (q) || ((p)[0] == (q)[0] && strcmp((p), (q)) == 0))
I did this in Coda ("File distribution alternative to rdist", comp.sources.unix
Volume 21) which builds lots of structures with shared strings.  I got a slight
performance gain (1 or 2%, I think).

It's the difference between (eq ... ) and (equal ...), right-p?
	/r$
-- 
Please send comp.sources.unix-related mail to rsalz@uunet.uu.net.
Use a domain-based address or give alternate paths, or you may lose out.