iLiad Some speedup ideas..

[henris42]

Hello everybody,

I just got myself an Iliad v2, and I immediately noticed the sluggishness...
even though it's a nice gadget overall.

Anycase, I though I ought to try to do something about it, so did some research - and recompiling.

As the Iliad's PXA255 CPU doesn't have an FPU, all floating point operations
are hideously slow, and should be avoided at all cost.. at least use
-ffast-math gcc option to minimize the impact.

Additionally, I noticed that poppler has an embedded fixed-point library,
so I compiled both ipdf (with jharker's alpha fullscreen patch) and
poppler again, and at least to my eyes the system seems a lot faster, especially when going back and forth.
(This means I/O is still quite a bottleneck - maybe a readahead cache?..;)

OK, this is what I did:

Makefile.am: (both) added

AM_CFLAGS='-O4 -ffast-math'
AM_CXXFLAGS='-O4 -ffast-math'

Popper configure flags:

./configure --host=arm-linux --build=i386 --prefix=/usr --enable-fixedpoint --disable-cairo-output --disable-gtk-te
st --disable-poppler-qt

Any case, this seemed worthawhile at least to my eye. I can attach
the ipdf and the lib if anyone wants to benchmark without compiling,
just let me know..;)

In any case, I'd love to hear you comments!

//HS

[rincewind]

I'd like to test the library, but don't have time to make the POS compile now (haven't maintained my build environment as well as I could have over the last upgradesit seems). I've also got a community version running (with gestures and such), but as far as I can see, floats seems to be used only in regards to zooming within ipdf itself. But I would guess that for rendering PDFs, there could be quite some speed gain! Well done!

It also seems that when I have PDFs that I scribble in on a memory card, it seems faster than if it's on internal memory. Saving scribbles is annoyingly slow, even if no scribbles have been changed...

/R

[daudi]

Originally Posted by rincewind

... I've also got a community version running (with gestures and such), but as far as I can see, floats seems to be used only in regards to zooming within ipdf itself. But I would guess that for rendering PDFs, there could be quite some speed gain! Well done!

On that note, I have finally put your version into the set of installers (I hope that's okay). Can you confirm that I have used the latest and greatest version of it?

Originally Posted by rincewind

It also seems that when I have PDFs that I scribble in on a memory card, it seems faster than if it's on internal memory. Saving scribbles is annoyingly slow, even if no scribbles have been changed...

/R

I find that the slow speed resulting from scribbles is a real problem for loading PDFs with scribbles. I have been using PDFs as notepads (mainly for navigation using hyperlinks) and have found that the scribble file gets quite large quite quickly and then causes the PDF to load very slowly indeed.