Jack2 1.9.7

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 __x86_64__
00041 
00042 typedef unsigned long cycles_t;
00043 extern cycles_t cacheflush_time;
00044 
00045 static inline unsigned long get_cycles(void)
00046 {
00047     unsigned int hi, lo;
00048     __asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
00049     return (((unsigned long)hi)<<32) | ((unsigned long)lo);
00050 }
00051 
00052 #endif /* __x86_64__ */
00053 
00054 #ifdef __sparc_v9__
00055 /* rd is V9 only */
00056 static inline unsigned long long get_cycles(void)
00057 {
00058         unsigned long long res;
00059         __asm__ __volatile__("rd %%tick, %0" : "=r"(res));
00060         return res;
00061 }
00062 #endif /* __sparc_v9__ */
00063 
00064 #ifdef __PPC__
00065 
00066 /* PowerPC */
00067 
00068 #define CPU_FTR_601                     0x00000100
00069 
00070 typedef unsigned long cycles_t;
00071 
00072 /* For the "cycle" counter we use the timebase lower half. */
00073 
00074 extern cycles_t cacheflush_time;
00075 
00076 static inline cycles_t get_cycles(void)
00077 {
00078     cycles_t ret = 0;
00079 
00080     __asm__ __volatile__(
00081         "98:    mftb %0\n"
00082         "99:\n"
00083         ".section __ftr_fixup,\"a\"\n"
00084         "       .long %1\n"
00085         "       .long 0\n"
00086         "       .long 98b\n"
00087         "       .long 99b\n"
00088         ".previous"
00089     : "=r" (ret) : "i" (CPU_FTR_601));
00090     return ret;
00091 }
00092 
00093 #endif /* __PPC__ */
00094 
00095 #ifdef __i386__
00096 
00097 typedef unsigned long long cycles_t;
00098 
00099 extern cycles_t cacheflush_time;
00100 
00101 #define rdtscll(val) \
00102      __asm__ __volatile__("rdtsc" : "=A" (val))
00103 
00104 static inline cycles_t get_cycles (void)
00105 {
00106     unsigned long long ret;
00107 
00108     rdtscll(ret);
00109     return ret;
00110 }
00111 
00112 #endif /* __i386__ */
00113 
00114 /* everything else but x86, amd64, sparcv9 or ppc */
00115 #if !defined (__PPC__) && !defined (__x86_64__) && !defined (__i386__) && !defined (__sparc_v9__)
00116 
00117 #warning No suitable get_cycles() implementation. Returning 0 instead
00118 
00119 typedef unsigned long long cycles_t;
00120 
00121 static inline cycles_t get_cycles(void)
00122 {
00123     return 0;
00124 }
00125 
00126 #endif /* everything else but x86, amd64, sparcv9 or ppc */
00127 
00128 
00129 #endif /* __jack_cycles_h__ */

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