Created attachment 28320 [details]
Proposed patch

Hi,

In many places of httpd, we are skipping white spaces with code that looks like :
   while (*l && apr_isspace(*l)) {
       ++l;
   }

The first test against *l is IMO useless and could be removed in order to improve the generated code.
I.e. :
   while (apr_isspace(*l)) {
       ++l;
   }

apr_isspace is in fact turned to a call to isspace by the apr library and isspace(0) returns 0.


I also made some measurement.
The version with the test against *l is faster ONLY when the string to scan is EMPTY. In this case it is more or less 50% faster to completely avoid the call to isspace.
In ALL other cases, removing the first test is about 15% faster.


The proposed patch removes these, IMO, useless tests.
The modified files are :

 modules/cache/cache_storage.c     |    2 +-
 modules/cache/mod_cache_disk.c    |    2 +-
 modules/cache/mod_disk_cache.c    |    2 +-
 modules/filters/mod_proxy_html.c  |    2 +-
 modules/mappers/mod_imagemap.c    |    2 +-
 modules/mappers/mod_negotiation.c |    8 ++++----
 modules/mappers/mod_rewrite.c     |    2 +-
 modules/metadata/mod_cern_meta.c  |    2 +-
 modules/metadata/mod_headers.c    |    2 +-
 modules/metadata/mod_mime_magic.c |    2 +-
 modules/proxy/mod_proxy_http.c    |    2 +-
 server/util.c                     |    8 ++++----
 server/util_script.c              |    2 +-
 support/httxt2dbm.c               |    2 +-
 14 files changed, 20 insertions(+), 20 deletions(-)