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//=============================================================================
/**
* @file Memcpy_Test.cpp
*
* $Id: Memcpy_Test.cpp 91813 2010-09-17 07:52:52Z johnnyw $
*
* @author Mike Marinez <mmartinez@oci.com>
*
* This test compares the performance of ACE_OS::memcpy with
* that of smemcpy which unrolls the memcpy loop upto size = 16.
* This test is also run via autoconf and if smemcpy is faster,
* ACE_HAS_MEMCPY_LOOP_UNROLL flag is set.
*
*/
//=============================================================================
#include "ace/OS_NS_string.h"
#include "ace/High_Res_Timer.h"
#include "test_config.h"
void *
smemcpy (void *dest, const void *src, const size_t n)
{
unsigned char *to = static_cast<unsigned char*> (dest);
const unsigned char *from = static_cast<const unsigned char*> (src);
// Unroll the loop...
switch (n) {
case 16: to[ 15] = from[ 15];
case 15: to[ 14] = from[ 14];
case 14: to[ 13] = from[ 13];
case 13: to[ 12] = from[ 12];
case 12: to[ 11] = from[ 11];
case 11: to[ 10] = from[ 10];
case 10: to[ 9] = from[ 9];
case 9: to[ 8] = from[ 8];
case 8: to[ 7] = from[ 7];
case 7: to[ 6] = from[ 6];
case 6: to[ 5] = from[ 5];
case 5: to[ 4] = from[ 4];
case 4: to[ 3] = from[ 3];
case 3: to[ 2] = from[ 2];
case 2: to[ 1] = from[ 1];
case 1: to[ 0] = from[ 0];
case 0: return dest;
default: return ACE_OS::memcpy (dest, src, n);
}
}
void
testit (int type)
{
char buffer[16];
size_t size = 16;
switch (type)
{
case 0: smemcpy ((void*)buffer, (void*)" THIS IS A TEST", size); break;
case 1: ACE_OS::memcpy ((void*)buffer, (void*)" THIS IS A TEST", size); break;
}
}
namespace { enum { ITERATIONS = 100000000 }; }
int
run_main (int, ACE_TCHAR *[])
{
ACE_START_TEST (ACE_TEXT ("Memcpy_Test"));
//ACE_Time_Value start, now;
struct timeval start, now;
for (int i = ITERATIONS; i > 0; --i)
testit (0);
start = ACE_High_Res_Timer::gettimeofday_hr ();
for (int j = ITERATIONS; j > 0; --j)
testit (0);
now = ACE_High_Res_Timer::gettimeofday_hr ();
double fast = 1000000 *(now.tv_sec - start.tv_sec) +
now.tv_usec - start.tv_usec;
ACE_DEBUG ((LM_DEBUG,
ACE_TEXT ("%f uSec per iteration for fast version.\n"),
fast / ITERATIONS));
start = ACE_High_Res_Timer::gettimeofday_hr ();
for (int k = ITERATIONS; k > 0; --k)
testit (1);
now = ACE_High_Res_Timer::gettimeofday_hr ();
double slow = 1000000 * (now.tv_sec-start.tv_sec) + now.tv_usec - start.tv_usec;
ACE_DEBUG ((LM_DEBUG,
ACE_TEXT ("%f uSec per iteration for slow version.\n"),
slow / ITERATIONS));
ACE_END_TEST;
return 0;
}
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