• Status Closed
  • Percent Complete
  • Task Type Patches
  • Category Codecs
  • Assigned To No-one
  • Operating System All players
  • Severity Low
  • Priority Very Low
  • Reported Version Release 3.4
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by Buschel - 2010-06-08
Last edited by Buschel - 2010-06-09

FS#11381 - eabi: flac with -O2

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.

Closed by  Buschel
2010-06-09 06:21
Reason for closing:  Accepted
Additional comments about closing:   Warning: Undefined array key "typography" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 371 Warning: Undefined array key "camelcase" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 407

Submitted with r26712

nls commented on 2010-06-08 14:13

O2 with gcc4.4 is faster on the gigabeast too

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.

Some test on Coldfire would be great! So, if you own one, please support :o)

fg commented on 2010-06-08 20:40

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

Thanks, Frank. So, we better leave -O1 for non-ARM targets. I will submit the attached v02-patch.


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