[Mplayer-cvslog] CVS: main/TOOLS fastmemcpybench.c,1.3,1.4

Michael Niedermayer michael at mplayer.dev.hu
Thu Nov 22 20:22:51 CET 2001


Update of /cvsroot/mplayer/main/TOOLS
In directory mplayer:/var/tmp.root/cvs-serv7865

Modified Files:
	fastmemcpybench.c 
Log Message:
newly allocated memory seems to point to only 1 zero filled 4k page or something so there is a near 100% cache hit rate ... not very realistic, writeing something in the source array fixes that so the benchmark scores are meaningfull now


Index: fastmemcpybench.c
===================================================================
RCS file: /cvsroot/mplayer/main/TOOLS/fastmemcpybench.c,v
retrieving revision 1.3
retrieving revision 1.4
diff -u -r1.3 -r1.4
--- fastmemcpybench.c	2 May 2001 14:48:35 -0000	1.3
+++ fastmemcpybench.c	22 Nov 2001 19:22:49 -0000	1.4
@@ -95,7 +95,7 @@
   return retval;
 }
 
-unsigned char arr1[ARR_SIZE],arr2[ARR_SIZE];
+unsigned char  __attribute__((aligned(4096)))arr1[ARR_SIZE],arr2[ARR_SIZE];
 
 int main( void )
 {
@@ -107,9 +107,12 @@
   mga_init();
   marr1 = &frame[3];
 #else
-  marr1 = &arr1[3];
+  marr1 = &arr1[0];
 #endif
-  marr2 = &arr2[9];
+  marr2 = &arr2[0];
+
+  for(i=0; i<ARR_SIZE; i++) marr1[i] = marr2[i] = i;
+
   t=GetTimer();
   v1 = read_tsc();
   for(i=0;i<100;i++) memcpy(marr1,marr2,ARR_SIZE-16);




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