From b971b5928749dc8ae893047bdfba15d20d25f06f Mon Sep 17 00:00:00 2001 From: Couriersud Date: Sun, 11 Oct 2009 17:32:38 +0000 Subject: [PATCH] A bottle of champaign to the person who explains the speed improvement in dkong from 1230% to 1470% due to this change (setting context->data to 0 in reset). Actually, it will avoid the first stream_update of buffer_stream when after approx. 11 samples the dac is written. Without setting data to 0, stream_update(buffer_stream) is called before stream_update(discrete_stream) is called. With the patch, the order is of the stream_updates is determined by streams.c. What makes this interesting is, that the startup order of the stream_updates determines the whole run-time of the game. When profiling, NODE_73 (Sallen-Key-Filter) needs 1066 cycles without the patch and under 135 with the patch, although it is the 4th node after DISCRETE_INPUT_BUFFER. All in all this looks like a caching issue, however I am currently clueless what in the end is causing it. --- src/emu/sound/disc_inp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/emu/sound/disc_inp.c b/src/emu/sound/disc_inp.c index 187a189fa19..83c89677aaf 100644 --- a/src/emu/sound/disc_inp.c +++ b/src/emu/sound/disc_inp.c @@ -34,9 +34,9 @@ struct dss_adjustment_context struct dss_input_context { stream_sample_t *ptr; /* current in ptr for stream */ - UINT8 data; /* data written */ double gain; /* node gain */ double offset; /* node offset */ + UINT8 data; /* data written */ UINT8 is_stream; UINT8 is_buffered; UINT32 stream_in_number; @@ -302,7 +302,7 @@ static DISCRETE_RESET(dss_input_stream) struct dss_input_context *context = (struct dss_input_context *)node->context; context->ptr = NULL; - //context->data = 0; + context->data = 0; } static DISCRETE_START(dss_input_stream)