Daniël Mantione wrote:
Op Tue, 26 Feb 2008, schreef Bernd Mueller:
Daniël Mantione wrote:
Op Tue, 26 Feb 2008, schreef Florian Klaempfl:
Daniël Mantione schrieb:
Op Tue, 26 Feb 2008, schreef Vincent Snijders:
Bernd Mueller schreef:
Hello,
the attached patch avoids misaligned data access (bus errors),
during
font rendering (with the graph unit) on Arm-Linux devices.
Instead of testing for arm cpu, you could use
FPC_REQUIRES_PROPER_ALIGNMENT too. So it is fixed for sparc as well.
Well, packed records are usually used when speed is unimportant. If
the
Isn't this used to read a font file?
You are right. Therefore, the "unaligned" pseudo function is the
proper solution.
the main affected routines are unpack and decode. Both routines were
called for every single character (only for a stroked font) via
OutTextXYDefault. So speed is not unimportant ;-)
Loosing a few clock cycles per character is completely acceptable, and
even the right engineering decision regarding size/memory trade-off. It
would be different if it would be a few clock cycles per pixel. Anyway,
the BGI font file format cannot be changed, so in such case the internal
data structures would need to be different from the ones on disk. Not
worth the effort.
The affected TStroke-Record has nothing to do with the BGI font file
format. I would not consider this a patch BTW, if you have to change the
CHR font file format to make it work.
I usually make my engineering decisions on facts and benchmarks. The
(very unexpected) result of this benchmark is, that a version with
leaving the TStroke-Record packed, is about 13 % faster than the
original patch. I am going to send a new patch soon.
Regards, Bernd.
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