gzdoom/snes_spc/demo/benchmark.c

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/* Measures performance of SPC emulator. Takes about 4 seconds.
NOTE: This assumes that the program is getting all processor time; you might need to
arrange for this or else the performance will be reported lower than it really is.
Usage: benchmark [test.spc]
*/
#include "snes_spc/spc.h"
#include "demo_util.h" /* error(), load_file() */
#include <time.h>
clock_t start_timing( int seconds );
int main( int argc, char** argv )
{
/* Load SPC */
long spc_size;
void* spc = load_file( (argc > 1) ? argv [1] : "test.spc", &spc_size );
SNES_SPC* snes_spc = spc_new();
if ( !snes_spc ) error( "Out of memory" );
spc_load_spc( snes_spc, spc, spc_size );
free( spc );
{
/* Repeatedly fill buffer for 4 seconds */
int const seconds = 4;
#define BUF_SIZE 4096
clock_t end = start_timing( seconds );
int count = 0;
while ( clock() < end )
{
static short buf [BUF_SIZE];
error( spc_play( snes_spc, BUF_SIZE, buf ) );
count++;
}
/* Report performance based on how many buffer fills were possible */
{
double rate = (double) count * BUF_SIZE / (spc_sample_rate * 2 * seconds);
printf( "Performance: %.3fx real-time, or %.0f%% CPU for normal rate\n",
rate, 100.0 / rate );
}
}
return 0;
}
/* Synchronizes with host clock and returns clock() time that is duration seconds from now */
clock_t start_timing( int duration )
{
clock_t clock_dur = duration * CLOCKS_PER_SEC;
clock_t time = clock();
while ( clock() == time ) { }
if ( clock() - time > clock_dur )
error( "Insufficient clock() time resolution" );
return clock() + clock_dur;
}