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Re: rawmemchr usage

From: Simon Josefsson
Subject: Re: rawmemchr usage
Date: Wed, 27 May 2009 07:14:39 +0200
User-agent: Gnus/5.110011 (No Gnus v0.11) Emacs/23.0.94 (gnu/linux)

Bruno Haible <address@hidden> writes:

> Eric Blake wrote:
>> +    strtok_r: use rawmemchr for speed.
>> +    * lib/strtok_r.c (__rawmemchr): Use faster rawmemchr.
>> +    * modules/strtok_r (Depends-on): Add rawmemchr.
>> ...
>> Likewise, what about these other modules that only use strchr to find the 
>> terminating byte of a known-terminated string, where rawmemchr could be the 
>> faster choice?
>> lib/argz.c:     entry = strchr (entry, '\0') + 1;
>> lib/argz.in.h:  __entry = strchr (__entry, '\0') + 1;
>> lib/canonicalize-lgpl.c:      dest = strchr (rpath, '\0');
>> lib/canonicalize.c:      dest = strchr (rname, '\0');
>> lib/glob.c:                 end_name = strchr (unescape, '\0');
> This time I'm with Sam Steingold's argumentation: We should avoid creeping
> additions of dependencies. rawmemchr is additional code to be compiled on
> all non-glibc platforms, whereas strchr() is present in libc on all systems.
> There is nothing wrong with the use of strchr(). I even doubt whether the
> code in lib/rawmemchr.c can beat assembly language code like the one glibc
> has for strchr. Furthermore, the code in lib/canonicalize*.c is certainly
> not speed relevant (since it mostly makes system calls).

I also prefer using strchr rather than rawmemchr here.  It is simpler to


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