[Dctrl-tools-devel] [SCM] Debian control file query tools branch, ajk/speed-optimizations, created. 2.12-6-g105f1bf

Antti-Juhani Kaijanaho ajk at debian.org
Wed Oct 31 22:10:26 UTC 2007


The branch, ajk/speed-optimizations has been created
        at  105f1bf474052af37b5c22d39b6b140c90cf7c99 (commit)

- Shortlog ------------------------------------------------------------
commit 105f1bf474052af37b5c22d39b6b140c90cf7c99
Author: Antti-Juhani Kaijanaho <ajk at debian.org>
Date:   Wed Oct 31 23:52:33 2007 +0200

    lib/paragraph.c (para_parse_next): Unobvious performance changes
    
    All of these changes have a measurable positive performance effect
    on my laptop, and several similar changes not made here had
    no measurable performance effect or had a measurable negative
    performance effect.  The difference between what works and
    what doesn't is completely unobvious to me.
    
    Signed-off-by: Antti-Juhani Kaijanaho <ajk at debian.org>

commit fcf129806c9e2002f0aa7d19d3587f12579bbfa4
Author: Antti-Juhani Kaijanaho <ajk at debian.org>
Date:   Wed Oct 31 21:15:58 2007 +0200

    lib/paragraph.c (para_parse_next): Use gotos, not a state variable
    
    On modern processors, unconditional jumps are always better than
    conditional jumps.  This rewrite eliminates a set of conditional
    jumps by encoding the states as goto targets and not using a
    while-switch strategy.
    
    My simple measurements show a 20 % speedup of a simple
    grep-dctrl run on my AMD64 laptop.
    
    Signed-off-by: Antti-Juhani Kaijanaho <ajk at debian.org>

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