smash::TimeStampCounter Class Reference

#include <tsc.h>

A low-overhead timer for benchmarking small regions of code.

This is usually unused in SMASH, because it should only be temporarily used when benchmarking.

Definition at line 40 of file tsc.h.

Collaboration diagram for smash::TimeStampCounter:

Classes
union	Data
	Union that stores cycles,. More...

Public Member Functions
void	start ()
	Start the counter. More...
void	stop ()
	Stop the counter. More...
uint64_t	cycles () const

Private Attributes
Data	m_start
	Stores start of benchmarking. More...
Data	m_end
	Stores end of benchmarking. More...

Member Function Documentation

void smash::TimeStampCounter::start ( )

inline

Start the counter.

Definition at line 65 of file tsc.h.

                                    {
#ifdef VC_IMPL_MIC
  asm volatile("xor %%eax,%%eax\n\tcpuid\n\trdtsc"
               : "=a"(m_start.b[0]), "=d"(m_start.b[1])::"ebx", "ecx");
#elif defined _MSC_VER
  unsigned int tmp;
  m_start.a = __rdtscp(&tmp);
#else
  asm volatile("rdtscp" : "=a"(m_start.b[0]), "=d"(m_start.b[1])::"ecx");
#endif
}

void smash::TimeStampCounter::stop ( )

inline

Stop the counter.

Definition at line 77 of file tsc.h.

                                   {
#ifdef VC_IMPL_MIC
  asm volatile("xor %%eax,%%eax\n\tcpuid\n\trdtsc"
               : "=a"(m_end.b[0]), "=d"(m_end.b[1])::"ebx", "ecx");
#elif defined _MSC_VER
  unsigned int tmp;
  m_end.a = __rdtscp(&tmp);
#else
  asm volatile("rdtscp" : "=a"(m_end.b[0]), "=d"(m_end.b[1])::"ecx");
#endif
}

uint64_t smash::TimeStampCounter::cycles ( ) const

inline

Returns

Number of counted CPU cycles.

Definition at line 89 of file tsc.h.

{ return m_end.a - m_start.a; }

Here is the call graph for this function:

Here is the caller graph for this function:

Member Data Documentation

Data smash::TimeStampCounter::m_start

private

Stores start of benchmarking.

Definition at line 60 of file tsc.h.

Data smash::TimeStampCounter::m_end

private

Stores end of benchmarking.

Definition at line 62 of file tsc.h.

---

The documentation for this class was generated from the following file:

• src/include/smash/tsc.h