/*****************************************************************************/
/*                                                                           */
/*  Copyright (c) 2008, 2009, 2010                                           */
/*                         Computer Architecture Group (CAG)                 */
/*                         University of A Coruña, Spain                     */
/*                         (http://gac.des.udc.es)                           */
/*                         Galicia Supercomputing Center (CESGA)             */
/*                         (http://www.cesga.es)                             */
/*                         Hewlett-Packard Spain (HP)                        */
/*                         (http://www.hp.es)                                */
/*                                                                           */
/*  This file is part of UPC Operations Microbenchmarking Suite (UOMS).      */
/*                                                                           */
/*  UOMS is free software: you can redistribute it and/or modify             */
/*  it under the terms of the GNU Lesser General Public License as published */
/*  by the Free Software Foundation, either version 3 of the License, or     */
/*  (at your option) any later version.                                      */
/*                                                                           */
/*  UOMS 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 Lesser General Public License for more details.                      */
/*                                                                           */
/*  You should have received a copy of the GNU Lesser General Public License */
/*  along with UOMS.  If not, see <http://www.gnu.org/licenses/>.            */
/*                                                                           */
/*****************************************************************************/

/*****************************************************************************/
/*                                                                           */
/*    FUNDING: This development has been funded by Hewlett-Packard Spain     */
/*                                                                           */      
/*    Project Name:                                                          */
/*     UPCHACO (2008-2011)                                                   */
/*    Subproject:                                                            */
/*     Improving UPC Usability and  Performance in Constellation Systems:    */
/*     Implementation/Extensions of UPC Libraries.                           */
/*     (UPCPU­Project -> UPC Performance and Usability Project)               */
/*                                                                           */
/*****************************************************************************/

/*****************************************************************************

  For further documentation, see

  [1] Files under doc/

******************************************************************************/


#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

/* Get clock ticks */
uint64_t getTicks() {
#ifdef __ia64
	#ifdef __INTEL_COMPILER
		#include <ia64intrin.h>
		return (uint64_t)__getReg(_IA64_REG_AR_ITC);
	#else
		uint64_t ret = 0;
		__asm__ __volatile__("mov %0=ar.itc" : "=r"(ret) );
		return ret;	
  #endif
#else
	#ifdef __HP_UPC_VER
    return hpupc_ticks_now();
	#elif __BERKELEY_UPC__
    return bupc_ticks_now();
	#else
    uint64_t tstamp;
    struct timeval tv;
    if (gettimeofday(&tv, NULL)) {
        perror("gettimeofday");
        abort();
    }
    tstamp = (((uint64_t)tv.tv_sec) * 1000000 + tv.tv_usec)*1000;
    return tstamp;
	#endif
#endif
}

/* Ticks to nanoseconds */
uint64_t ticksToNS(uint64_t ticks) {
#ifdef __ia64
	#include <errno.h>
	double tick_rate_ns = 0;
	errno = 0;
	FILE *fp = fopen("/proc/cpuinfo","r");
	if (errno != 0){
		perror("*** Error opening /proc/cpuinfo: ");
		exit(-1);
	}
	char input[255];
	while (!feof(fp) && fgets(input, 255, fp)) {
		if (strstr(input,"itc MHz")) {
			char *p = strchr(input,':');
			double MHz = 0.0;
			if (p) MHz = atof(p+1);
			if(!(MHz > 1 && MHz < 100000)) /* ensure it looks reasonable */
				fprintf(stderr, "*** Warning: ITC frequency unreasonable: %f MHz\n*** Expect unexpected results\n",MHz);
			tick_rate_ns = 1000. / MHz;
			break;
		}
	}
	fclose(fp);
	return (ticks * tick_rate_ns);
#else
	#ifdef __HP_UPC_VER
    return hpupc_ticks_to_ns(ticks);
	#elif __BERKELEY_UPC__
    return bupc_ticks_to_ns(ticks);
	#else // if gettimeofday is used
    return ticks;
	#endif
#endif
}