comments on KDE performance tips
Maks Orlovich
kde-optimize@mail.kde.org
Fri, 17 Jan 2003 20:27:55 -0500
>
> c. Use QString as it first compares the location of the string before
> doing the actual char by char comparison.
It _does_ use QString (actually two QString's and some ints in a structure;
but this is all academic, since KConfig exposes so much of its internal
storage that changing it isn't possible before KDE4; at least I don't see a
way). And this doesn't help you for doing less-than equals comparisons, which
is what is needed for tree insertions and lookups.
<snip stuff I really can't comment on>
> * found a little optimization opportunity in QString.
>
> bool operator!=( const char *s1, const QString &s2 )
> { return !(s1==s2); }
>
> Should return !(s2==s1) instead since (s1==s2) will match
> ==(const char *, const QString &) in its turn.
Yeah, I think so, good catch.
> A compiler with automatic inlining will help...
gcc-3.x inlines quite a bit by default with -O2.