/****************************************************************************
DESCRIPTION:
Returns the speed of the processor in MHz.
HEADER:
cpuinfo.h
PARAMETERS:
accurate - True of the speed should be measured accurately
RETURNS:
Processor speed in MHz.
REMARKS:
This function returns the speed of the CPU in MHz. Note that if the speed
cannot be determined, this function will return 0.
If the accurate parameter is set to true, this function will spend longer
profiling the speed of the CPU, and will not round the CPU speed that is
reported. This is important for highly accurate timing using the Pentium
RDTSC instruction, but it does take a lot longer for the profiling to
produce accurate results.
SEE ALSO:
CPU_getProcessorSpeedInHz, CPU_getProcessorType, CPU_haveMMX,
CPU_getProcessorName
****************************************************************************/
ulong ZAPI CPU_getProcessorSpeed(
ibool accurate)
{
#if defined(__INTEL__)
/* Number of cycles needed to execute a single BSF instruction on i386+
* processors.
*/
u64 speed64;
ulong cpuSpeed;
uint i;
static ulong intel_cycles[] = {
115,47,43,
};
static ulong cyrix_cycles[] = {
38,38,52,52,
};
static ulong amd_cycles[] = {
49,
};
static ulong known_speeds[] = {
2000,1800,1700,1600,1500,1400,1300,1200,1100,1000,950,900,850,800,750,
700,650,600,550,500,450,433,400,350,333,300,266,233,200,166,150,133,
120,100,90,75,66,60,50,33,20,0,
};
if (CPU_haveRDTSC()) {
GetRDTSCCpuSpeed(accurate, &speed64);
PM_div64_32(speed64, speed64, 1000000);
cpuSpeed = PM_getlo32(speed64);
}
else {
int type = CPU_getProcessorType();
int processor = type & CPU_mask;
int vendor = type & CPU_familyMask;
if (vendor == CPU_Intel)
cpuSpeed = GetBSFCpuSpeed(ITERATIONS * intel_cycles[processor - CPU_i386]);
else if (vendor == CPU_Cyrix)
cpuSpeed = GetBSFCpuSpeed(ITERATIONS * cyrix_cycles[processor - CPU_Cyrix6x86]);
else if (vendor == CPU_AMD)
cpuSpeed = GetBSFCpuSpeed(ITERATIONS * amd_cycles[0]);
else
return 0;
}
/* Now normalise the results given known processors speeds, if the
* speed we measure is within 2MHz of the expected values
*/
if (!accurate) {
for (i = 0; known_speeds[i] != 0; i++) {
if (cpuSpeed >= (known_speeds[i]-3) && cpuSpeed <= (known_speeds[i]+3)) {
return known_speeds[i];
}
}
}
return cpuSpeed;
#else
return 0;
#endif
}
int main(void)
{
printf("Detecting processor information ...");
fflush(stdout);
printf("\n\n%s\n", CPU_getProcessorName());
if (CPU_haveRDTSC())
printf("\nProcessor supports Read Time Stamp Counter performance timer.\n");
return 0;
}
/****************************************************************************
DESCRIPTION:
Returns the speed of the processor in Hz.
HEADER:
ztimer.h
RETURNS:
Accurate processor speed in Hz.
REMARKS:
This function returns the accurate speed of the CPU in Hz. Note that if the
speed cannot be determined, this function will return 0.
This function is similar to the CPU_getProcessorSpeed function, except that
it attempts to accurately measure the CPU speed in Hz. This is used
internally in the Zen Timer libraries to provide accurate real world timing
information. This is important for highly accurate timing using the Pentium
RDTSC instruction, but it does take a lot longer for the profiling to
produce accurate results.
SEE ALSO:
CPU_getProcessorSpeed, CPU_getProcessorType, CPU_haveMMX,
CPU_getProcessorName
****************************************************************************/
ulong ZAPI CPU_getProcessorSpeedInHZ(
ibool accurate)
{
#if defined(__INTEL__)
if (CPU_haveRDTSC()) {
return GetRDTSCCpuSpeed(accurate);
}
return CPU_getProcessorSpeed(false) * 1000000;
#else
return 0;
#endif
}
/****************************************************************************
DESCRIPTION:
Returns the speed of the processor in Hz.
HEADER:
cpuinfo.h
RETURNS:
Accurate processor speed in Hz.
REMARKS:
This function returns the accurate speed of the CPU in Hz. Note that if the
speed cannot be determined, this function will return 0.
This function is similar to the CPU_getProcessorSpeed function, except that
it attempts to accurately measure the CPU speed in Hz. This is used
internally in the Zen Timer libraries to provide accurate real world timing
information. This is important for highly accurate timing using the Pentium
RDTSC instruction, but it does take a lot longer for the profiling to
produce accurate results.
SEE ALSO:
CPU_getProcessorSpeed, CPU_getProcessorType, CPU_haveMMX,
CPU_getProcessorName
****************************************************************************/
void ZAPI CPU_getProcessorSpeedInHZ(
ibool accurate,
CPU_largeInteger *speed)
{
#if defined(__INTEL__)
if (CPU_haveRDTSC()) {
u64 speed64;
GetRDTSCCpuSpeed(accurate, &speed64);
speed->low = PM_getlo32(speed64);
speed->high = PM_gethi32(speed64);
}
speed->low = CPU_getProcessorSpeed(false) * 1000000;
speed->high = 0;
#else
speed->low = 0;
speed->high = 0;
#endif
}
