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qsort documentation update
- To: libc-alpha Mailinglist <libc-alpha at sourceware dot cygnus dot com>
- Subject: qsort documentation update
- From: Andreas Jaeger <aj at suse dot de>
- Date: 15 May 2000 15:09:09 +0200
- Cc: Jeremy Buhler <jbuhler at cs dot washington dot edu>
Jeremy mentioned in an reply to PR libc/1611:
} On 28 Feb 2000, Andreas Jaeger wrote:
} > The following patch has now been added to the development version of
} > glibc 2.2. What do you think of it? It limits the memory to a
} > quarter of the physical memory.
} [snip]
}
} This is acceptable, but I think that the max allocation size could be
} reduced even more. As I mentioned in my previous message, merge sort
} isn't actually a performance win if the extra memory requirement is
} big enough.
}
} I know the standard doesn't require that qsort() be an in-place sort,
} but the extra allocation is sufficiently "surprising" that it might be
} worth mentioning in the libc documentation. I can imagine that
} someone building an embedded system will trip over this behavior in
} the future.
I'm appending a patch for the documentation. Is this ok?
Andreas
2000-05-15 Andreas Jaeger <aj@suse.de>
* manual/search.texi (Array Sort Function): Document that qsort is
not necessarily in-place.
============================================================
Index: manual/search.texi
--- manual/search.texi 2000/03/10 08:40:34 1.30
+++ manual/search.texi 2000/05/15 13:08:52
@@ -183,6 +183,10 @@
The @code{qsort} function derives its name from the fact that it was
originally implemented using the ``quick sort'' algorithm.
+
+The implementation of @code{qsort} in this library might not be an
+in-place sort and might thereby use an extra amount of memory to store
+the array.
@end deftypefun
@node Search/Sort Example
--
Andreas Jaeger
SuSE Labs aj@suse.de
private aj@arthur.inka.de