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FS#7889 - Midi optimization

Attached to Project: Rockbox
Opened by Nils Wallménius (nls) - Thursday, 04 October 2007, 12:52 GMT+2
Last edited by Nils Wallménius (nls) - Thursday, 04 October 2007, 21:37 GMT+2
Task Type Patches
Category Plugins
Status Closed
Assigned To No-one
Player Type SW-codec
Severity Low
Priority Normal
Reported Version Daily build (which?)
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Private No

Details

This patch changes the loop in synthSample to use fewer multiplications and memory accesses, it also moves sample shifting out of the loop which gives slightly better accuracy. I have tested on my h300 with cpu boosting disabled and the number of buffer misses dropped 12%. To get the number of buffer misses I used the midi_bench.diff also posted below. As I don't have any other players I am interested in benchmarks for those.

Edit, fixed minor mistake in midi_bench.diff should now build fine :-)
   synthSample_opt.diff (4.4 KiB) 
 apps/plugins/midi/midiutil.c  |    3 +--
 apps/plugins/midi/synth.c     |    5 ++---
 apps/plugins/midi/midiutil.h  |    3 +--
 apps/plugins/midi/sequencer.c |   11 +----------
 apps/plugins/midi/synth.h     |   23 ++++++++++++++---------
 5 files changed, 19 insertions(+), 26 deletions(-)

   midi_bench.diff (1.3 KiB) 
 apps/plugins/midi/midiplay.c |   20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

This task depends upon

Closed by  Nils Wallménius (nls)
Thursday, 04 October 2007, 21:37 GMT+2
Reason for closing:  Accepted
Additional comments about closing:  comitted

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