Jack2 1.9.6

cycles.h

00001 /*
00002   Copyright (C) 2001 Paul Davis
00003   Code derived from various headers from the Linux kernel
00004 
00005   This program is free software; you can redistribute it and/or modify
00006   it under the terms of the GNU General Public License as published by
00007   the Free Software Foundation; either version 2 of the License, or
00008   (at your option) any later version.
00009 
00010   This program is distributed in the hope that it will be useful,
00011   but WITHOUT ANY WARRANTY; without even the implied warranty of
00012   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013   GNU General Public License for more details.
00014 
00015   You should have received a copy of the GNU General Public License
00016   along with this program; if not, write to the Free Software
00017   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00018 
00019   $Id: cycles.h,v 1.4.2.1 2006/06/20 14:44:00 letz Exp $
00020 */
00021 
00022 #ifndef __jack_cycles_h__
00023 #define __jack_cycles_h__
00024 
00025 /*
00026  * Standard way to access the cycle counter on i586+ CPUs.
00027  * Currently only used on SMP.
00028  *
00029  * If you really have a SMP machine with i486 chips or older,
00030  * compile for that, and this will just always return zero.
00031  * That's ok, it just means that the nicer scheduling heuristics
00032  * won't work for you.
00033  *
00034  * We only use the low 32 bits, and we'd simply better make sure
00035  * that we reschedule before that wraps. Scheduling at least every
00036  * four billion cycles just basically sounds like a good idea,
00037  * regardless of how fast the machine is.
00038  */
00039 
00040 #ifdef __linux__
00041 
00042 #ifdef __x86_64__
00043 
00044 typedef unsigned long cycles_t;
00045 extern cycles_t cacheflush_time;
00046 
00047 static inline unsigned long get_cycles(void)
00048 {
00049     unsigned int hi, lo;
00050     __asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
00051     return (((unsigned long)hi)<<32) | ((unsigned long)lo);
00052 }
00053 
00054 #endif /* __x86_64__ */
00055 
00056 #ifdef __sparc_v9__
00057 /* rd is V9 only */
00058 static inline unsigned long long get_cycles(void)
00059 {
00060         unsigned long long res;
00061         __asm__ __volatile__("rd %%tick, %0" : "=r"(res));
00062         return res;
00063 }
00064 #endif /* __sparc_v9__ */
00065 
00066 #ifdef __PPC__
00067 
00068 /* PowerPC */
00069 
00070 #define CPU_FTR_601                     0x00000100
00071 
00072 typedef unsigned long cycles_t;
00073 
00074 /* For the "cycle" counter we use the timebase lower half. */
00075 
00076 extern cycles_t cacheflush_time;
00077 
00078 static inline cycles_t get_cycles(void)
00079 {
00080     cycles_t ret = 0;
00081 
00082     __asm__ __volatile__(
00083         "98:    mftb %0\n"
00084         "99:\n"
00085         ".section __ftr_fixup,\"a\"\n"
00086         "       .long %1\n"
00087         "       .long 0\n"
00088         "       .long 98b\n"
00089         "       .long 99b\n"
00090         ".previous"
00091     : "=r" (ret) : "i" (CPU_FTR_601));
00092     return ret;
00093 }
00094 
00095 #endif /* __PPC__ */
00096 
00097 #ifdef __i386__
00098 
00099 typedef unsigned long long cycles_t;
00100 
00101 extern cycles_t cacheflush_time;
00102 
00103 #define rdtscll(val) \
00104      __asm__ __volatile__("rdtsc" : "=A" (val))
00105 
00106 static inline cycles_t get_cycles (void)
00107 {
00108     unsigned long long ret;
00109 
00110     rdtscll(ret);
00111     return ret;
00112 }
00113 
00114 #endif /* __i386__ */
00115 
00116 /* everything else but x86, amd64, sparcv9 or ppc */
00117 #if !defined (__PPC__) && !defined (__x86_64__) && !defined (__i386__) && !defined (__sparc_v9__)
00118 
00119 #warning No suitable get_cycles() implementation. Returning 0 instead
00120 
00121 typedef unsigned long long cycles_t;
00122 
00123 static inline cycles_t get_cycles(void)
00124 {
00125     return 0;
00126 }
00127 
00128 #endif /* everything else but x86, amd64, sparcv9 or ppc */
00129 
00130 #endif /* __linux__ */
00131 
00132 
00133 #if defined(__FreeBSD_kernel__)
00134 
00135 #warning No suitable get_cycles() implementation. Returning 0 instead
00136 
00137 typedef unsigned long long cycles_t;
00138 
00139 static inline cycles_t get_cycles(void)
00140 {
00141     return 0;
00142 }
00143 
00144 #endif /* __FreeBSD_kernel__ */
00145 
00146 
00147 #endif /* __jack_cycles_h__ */