Mercurial > spc_convert

     1 /* Measures performance of SPC emulator. Takes about 4 seconds.

     2 NOTE: This assumes that the program is getting all processor time; you might need to

     3 arrange for this or else the performance will be reported lower than it really is.

     4 

     5 Usage: benchmark [test.spc]

     6 */

     7 

     8 #include "snes_spc/spc.h"

     9 

    10 #include "demo_util.h" /* error(), load_file() */

    11 #include <time.h>

    12 

    13 clock_t start_timing( int seconds );

    14 

    15 int main( int argc, char** argv )

    16 {

    17 	/* Load SPC */

    18 	long spc_size;

    19 	void* spc = load_file( (argc > 1) ? argv [1] : "test.spc", &spc_size );

    20 	SNES_SPC* snes_spc = spc_new();

    21 	if ( !snes_spc ) error( "Out of memory" );

    22 	spc_load_spc( snes_spc, spc, spc_size );

    23 	free( spc );

    24 	

    25 	{

    26 		/* Repeatedly fill buffer for 4 seconds */

    27 		int const seconds = 4;

    28 		#define BUF_SIZE 4096

    29 		clock_t end = start_timing( seconds );

    30 		int count = 0;

    31 		while ( clock() < end )

    32 		{

    33 			static short buf [BUF_SIZE];

    34 			error( spc_play( snes_spc, BUF_SIZE, buf ) );

    35 			count++;

    36 		}

    37 		

    38 		/* Report performance based on how many buffer fills were possible */

    39 		{

    40 			double rate = (double) count * BUF_SIZE / (spc_sample_rate * 2 * seconds);

    41 			printf( "Performance: %.3fx real-time, or %.0f%% CPU for normal rate\n",

    42 					rate, 100.0 / rate );

    43 		}

    44 	}

    45 	

    46 	return 0;

    47 }

    48 

    49 /* Synchronizes with host clock and returns clock() time that is duration seconds from now */

    50 clock_t start_timing( int duration )

    51 {

    52 	clock_t clock_dur = duration * CLOCKS_PER_SEC;

    53 	clock_t time = clock();

    54 	while ( clock() == time ) { }

    55 	if ( clock() - time > clock_dur )

    56 		error( "Insufficient clock() time resolution" );

    57 	return clock() + clock_dur;

    58 }
author	Robert McIntyre <rlm@mit.edu>
date	Fri, 21 Oct 2011 05:53:11 -0700
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