Rockbox

Tasklist

FS#11381 - eabi: flac with -O2

Attached to Project: Rockbox
Opened by Andree Buschmann (Buschel) - Tuesday, 08 June 2010, 06:31 GMT
Last edited by Andree Buschmann (Buschel) - Wednesday, 09 June 2010, 06:21 GMT
Task Type Patches
Category Codecs
Status Closed
Assigned To No-one
Operating System All players
Severity Low
Priority Normal
Reported Version Release 3.4
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No

Details

As known flac decoding speed will slow down by ~8% when switching to the eabi tool chain. Thomas Martitz reported on irc that building with -O2 solves this problem. This patch enables -O2 for flac. As a result the decoder is faster than current svn.

Tested on arm7tdmi (iPod Video):
eabi, -O1 => ~13,5 MHz
eabi, -O2 => ~11,7 MHz

Could this please be retested on other targets and CPU's as well? Please report the speeds in this flyspray entry.
This task depends upon

Closed by  Andree Buschmann (Buschel)
Wednesday, 09 June 2010, 06:21 GMT
Reason for closing:  Accepted
Additional comments about closing:  Submitted with r26712
Comment by Nils Wallménius (nls) - Tuesday, 08 June 2010, 14:13 GMT
O2 with gcc4.4 is faster on the gigabeast too
Comment by Andree Buschmann (Buschel) - Tuesday, 08 June 2010, 18:28 GMT
Some more measurements on arm7tdmi:

svn, -O1 => ~12.7 MHz
svn, -O2 => ~12.3 MHz

So, even when using the standard toolchain -O2 is reasonable faster. As soon as we use eabi there is further major speed-up.
Comment by Andree Buschmann (Buschel) - Tuesday, 08 June 2010, 20:01 GMT
Some test on Coldfire would be great! So, if you own one, please support :o)
Comment by Frank Gevaerts (fg) - Tuesday, 08 June 2010, 20:40 GMT
h320
flac_5.flac, svn, 19.21MHz
flac_5.flac, this patch, 19.85MHz

flac_8.flac, svn, 19.67MHz
flac_8.flac, this patch, 20.36MHz
Comment by Andree Buschmann (Buschel) - Wednesday, 09 June 2010, 06:21 GMT
Thanks, Frank. So, we better leave -O1 for non-ARM targets. I will submit the attached v02-patch.

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