rdtsc.h

/*
    Copyright 2011, Spyros Blanas.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
 
#include <stdint.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
#if !defined(__i386__) && !defined(__x86_64__) && !defined(__sparc__)
#warning No supported architecture found -- timers will return junk.
#endif
 
static __inline__ uint64_t curtick() {
        uint64_t tick;
#if defined(__i386__)
        unsigned long lo, hi;
        __asm__ __volatile__ (".byte 0x0f, 0x31" : "=a" (lo), "=d" (hi));
        tick = (uint64_t) hi << 32 | lo;
#elif defined(__x86_64__)
        unsigned long lo, hi;
        __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
        tick = (uint64_t) hi << 32 | lo;
#elif defined(__sparc__)
        __asm__ __volatile__ ("rd %%tick, %0" : "=r" (tick));
#endif
        return tick;
}
 
static __inline__ void startTimer(uint64_t* t) {
        *t = curtick();
}
 
static __inline__ void stopTimer(uint64_t* t) {
        *t = curtick() - *t;
}
 
#ifdef __cplusplus
}
#endif