[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [aspell-devel] Does Anyone Compile Aspell with -DNDEBUG?

From: Kevin Atkinson
Subject: Re: [aspell-devel] Does Anyone Compile Aspell with -DNDEBUG?
Date: Sun, 1 Jun 2008 18:18:06 -0600 (MDT)

On Sun, 1 Jun 2008, Jose Da Silva wrote:

On June 1, 2008 03:46:16 pm Kevin Atkinson wrote:
On Sun, 1 Jun 2008, Jose Da Silva wrote:
This should shed some light on the subject using a self-contained
program. platform=linux, compiler = gcc, program=prezip.c

$ time ./prezip_asserted -c <wordlist.txt >wordlist.cwl
0.06user 0.00system 0:00.08elapsed 84%CPU (0avgtext+0avgdata
0maxresident)k 0inputs+0outputs (0major+132minor)pagefaults 0swaps
$ time ./prezip_debugged -c <wordlist.txt >wordlist.cwl
0.07user 0.00system 0:00.09elapsed 82%CPU (0avgtext+0avgdata
0maxresident)k 0inputs+0outputs (0major+132minor)pagefaults 0swaps

This test needs to run several times in order for the results to be

The test above spends an unknown amount of time in the program (in prezip),
and outside the program (file handling, passing values through stdin and
stdout). The stuff like stdin/stdout outside of prezip is basically
outside of your control and therefore not something you can tweak for
performance or debugging etc. I don't think you can get any significant
info running the test several times.

Let me put it another way, since the times are so close, this statement is meaningless:

user time increased from 0.06 to 0.07. This does not appear significant,
except you "do" need to to take account that a big portion of the 0.06user time is spent reading/writing stdin/stdout which means actual time within the prezip program may be a small value such as 0.01. If so, then a difference of 0.01 to 0.02 would be considered a big increase.

without running the tests multiple times. Since on the second run the numbers may become 0.07 0.06. There are a lot of things that can effect cpu time.

If you thing that the 0.01 difference is insignificant (thus running the tests again make no sense) than can I summarize your email as following:

  Coming prezip with -DNDEBUG or -g when combined with -O2 does not
  noticeably effect performance.

reply via email to

[Prev in Thread] Current Thread [Next in Thread]