database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-27 12:41:57 +03:00
Code Activity

Support fls().

Browse Source 
The immediate impetus for this is that Noah Misch's patch to elide
unnecessary table and index rebuilds when changing typmod for temporal
types uses it; and this is extracted from that patch, with some
further commentary by me.  But it seems logically separate from the
remainder of the patch, so I'm committing it separately; this is not
the first time someone has wanted fls() in the backend and probably
won't be the last.

If we end up using this in more performance-critical spots it may be
worthwhile to add some architecture-specific optimizations to our
src/port version of fls() - e.g. any x86 platform can implement this
using the assembly instruction BSRL.  But performance won't matter
a bit for assessing typmod changes, so I'm not worried about that
right now.
This commit is contained in:
Robert Haas
2012-02-07 13:45:46 -05:00
parent f7d7dade8a
commit 4f658dc851
5 changed files with 74 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
configure vendored
View File

@ -20833,7 +20833,8 @@ LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
for ac_func in crypt getopt getrusage inet_aton random rint srandom strdup strerror strlcat strlcpy strtol strtoul
for ac_func in crypt fls getopt getrusage inet_aton random rint srandom strdup strerror strlcat strlcpy strtol strtoul
do
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
{ $as_echo "$as_me:$LINENO: checking for $ac_func" >&5