On Mon, 14 Aug 2006 10:09:48 +0300, Jorn Baayen wrote: > > On Tue, 2006-08-08 at 10:46 -0700, Carl Worth wrote: > > > I'm planning to put new fixed<->floating-point conversion code into > > cairo this week. > > Any progress on this?
Nope. Didn't happen yet.
If someone wants to look at it, here are some details of what could be
done:
1) The current implementation has complete function-call
overhead. Could easily be reduced with inlining, (if the compiler's
not doing that automatically), or macros.
So that's the easy one that doesn't actually change the code at
all. Next is the stuff that will take a little more investigation:
2) There's some discussion of the correctness of the rounding of the
current code here. For any new implementation, I would like to see
comments indicating that the code respects the concerns raised
here:
https://bugs.freedesktop.org/show_bug.cgi?id=4846
(And better, than comments would be some test cases that ensure the
desired behavior is met.)
3) Finally, a couple of people have proposed much faster mechanisms
for implementing the conversion. First was Bill Spitzak who
provided some code here:
http://lists.freedesktop.org/archives/cairo/2005-June/004419.html
Then later, Tim Rowley independently provided a source explaining
the code along with a very similar implementation:
http://thread.gmane.org/gmane.comp.lib.cairo/5228/focus=5228
What I've been planning to do for a while was to write some
configure-time check to ensure that the assumptions made in this
code (IEEE floating-point) are valid and conditionally compile this
code only where we know it will work.
Thanks in advance for any work anyone might do in this area,
-Carl
pgpgZmKb0XeR5.pgp
Description: PGP signature
_______________________________________________ Performance-list mailing list [email protected] http://mail.gnome.org/mailman/listinfo/performance-list
