sphtimer.h

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/*
 * Copyright (c) 2010-2014 IBM Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation, Steven Munroe      - initial API and implementation
 *     IBM Corporation, Adhemerval Zanella - bugfixes and documentation
 */

#ifndef __SPH_TIMER_H
#define __SPH_TIMER_H

#ifdef __cplusplus
#define __C__ "C"
#else
#define __C__
#endif

typedef unsigned long long int sphtimer_t;

#if defined(__powerpc64__)
#define __TIME_BASE(__time_v)                           \
  do {                                                  \
    sphtimer_t __t;                                     \
    __asm__ __volatile__ (                              \
      "mfspr %0,268"                                    \
      : "=r" (__t));                                    \
    __time_v = __t;                                     \
  } while (0)
#elif defined(__powerpc__)
#define __TIME_BASE(__time_v)                           \
  do {                                                  \
    unsigned long __tbu, __tbl, __tmp;                  \
    __asm__ volatile (                                  \
      "0:\n"                                            \
      "mftbu %0\n"                                      \
      "mftbl %1\n"                                      \
      "mftbu %2\n"                                      \
      "cmpw %0, %2\n"                                   \
      "bne- 0b"                                         \
      : "=r" (__tbu), "=r" (__tbl), "=r" (__tmp) );     \
    __time_v = (( (sphtimer_t) __tbu << 32) | __tbl);   \
  } while (0) 
#elif defined(__x86_64__) && defined(__x86_64_INVARIANT_TSC)
/* TODO: the accuracy might be susceptible to CPU clock throttling (mainly
 * due to CPU scaling. So we disable rdtsc unless the user explicitly defines
 * __x86_64_INVARIANT_TSC.
 */
#define __TIME_BASE(__time_v)                           \
  do {                                                  \
    unsigned int __t_hi, __t_lo;                        \
    __asm__ __volatile__ (                              \
      "rdtsc"                                           \
      : "=a" (__t_lo),                                  \
      "=d" (__t_hi));                                   \
    __time_v = ((sphtimer_t) __t_hi << 32) | __t_lo;    \
  } while (0)
#elif defined(__i386__) && defined(__x86_INVARIANT_TSC)
/* TODO: the accuracy might be susceptible to CPU clock throttling (mainly
 * due to CPU scaling. So we disable rdtsc unless the user explicitly defines
 * __x86_INVARIANT_TSC.
 */
#define __TIME_BASE(__time_v)                           \
  do {                                                  \
    unsigned int __t;                                   \
    __asm__ __volatile__ (                              \
      "rdtsc"                                           \
      : "=A" (__t));                                    \
    __time_v = __t;                                     \
  } while (0)
#else
#include <time.h>
#define __TIME_BASE(__time_v)                           \
  do {                                                  \
    struct timespec __ts;                                       \
    sphtimer_t __t;                                     \
    clock_gettime (CLOCK_MONOTONIC, &__ts);     \
    __t = ((sphtimer_t)__ts.tv_sec * 1000000000L)       \
        + (sphtimer_t)__ts.tv_nsec; \
    __time_v = __t;                                     \
  } while (0)

#endif
    
static inline sphtimer_t
sphgettimer (void)
{
  sphtimer_t t;
  __TIME_BASE (t);
  return t;
}

extern sphtimer_t sph_cpu_frequency;

extern __C__ sphtimer_t
sphgetcpufreq (void);

static inline sphtimer_t
sphfastcpufreq (void)
{
  sphtimer_t result = sph_cpu_frequency;

  if (__builtin_expect ((result == 0), 0))
    {
      result = sphgetcpufreq ();
    }
  return result;
}

#endif /* __SPH_TIMER_H */