lkml.org 
[lkml]   [2011]   [Sep]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[Question] FastFPE math emulation
Date
Hi,

I am playing around with a "friendlyarm mini2440" development board.
It's a system based on a 400 Mhz samsung s3c2440 CPU, which is itself
based on a ARM920T core.
This system does not have a FPU. (nor integer DSP instruction-set).


I want to experiment to use this board for audio-related application,
e.g. the codec2 vocoder.
The implementation of that codec is now based on floating-point math.

First tests indicate that, using default settings, the board is not fast
enough to do realtime encoding or decoding of codec2 . (encoding a 34
second audio-sample takes 42 seconds).


Yesterday, I noticed the kernel has an option "FastFPE math emulation"
but when I install a kernel with that option enabled, I see no
difference at all.

- does FastFPE work on this kind of CPU.
- Is there something that needs to be done to activate it? (setting,
option during compiling, ...?)


Info:
# uname -a
Linux FriendlyARM 2.6.32.2-FriendlyARM #9 Wed Sep 7 21:38:49 CEST 2011
armv4tl unknown

$ grep -i fpe .config
CONFIG_FPE_NWFPE=y
# CONFIG_FPE_NWFPE_XP is not set
CONFIG_FPE_FASTFPE=y


# cat /proc/cpuinfo
Processor : ARM920T rev 0 (v4l)
BogoMIPS : 201.93
Features : swp half
CPU implementer : 0x41
CPU architecture: 4T
CPU variant : 0x1
CPU part : 0x920
CPU revision : 0

Hardware : FriendlyARM Mini2440 development board
Revision : 0000
Serial : 0000000000000000



http://friendlyarm.net/products/mini2440?lang=en
http://codec2.org/


Cheerio!
Kr. Bonne.



\
 
 \ /
  Last update: 2011-09-08 12:47    [W:0.023 / U:0.260 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site