Jack2  1.9.9
cycles.h
1 /*
2  Copyright (C) 2001 Paul Davis
3  Code derived from various headers from the Linux kernel
4 
5  This program is free software; you can redistribute it and/or modify
6  it under the terms of the GNU General Public License as published by
7  the Free Software Foundation; either version 2 of the License, or
8  (at your option) any later version.
9 
10  This program is distributed in the hope that it will be useful,
11  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  GNU General Public License for more details.
14 
15  You should have received a copy of the GNU General Public License
16  along with this program; if not, write to the Free Software
17  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 
19  $Id: cycles.h,v 1.4.2.1 2006/06/20 14:44:00 letz Exp $
20 */
21 
22 #ifndef __jack_cycles_h__
23 #define __jack_cycles_h__
24 
25 /*
26  * Standard way to access the cycle counter on i586+ CPUs.
27  * Currently only used on SMP.
28  *
29  * If you really have a SMP machine with i486 chips or older,
30  * compile for that, and this will just always return zero.
31  * That's ok, it just means that the nicer scheduling heuristics
32  * won't work for you.
33  *
34  * We only use the low 32 bits, and we'd simply better make sure
35  * that we reschedule before that wraps. Scheduling at least every
36  * four billion cycles just basically sounds like a good idea,
37  * regardless of how fast the machine is.
38  */
39 
40 #ifdef __x86_64__
41 
42 typedef unsigned long cycles_t;
43 extern cycles_t cacheflush_time;
44 
45 static inline unsigned long get_cycles(void)
46 {
47  unsigned int hi, lo;
48  __asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
49  return (((unsigned long)hi)<<32) | ((unsigned long)lo);
50 }
51 
52 #endif /* __x86_64__ */
53 
54 #ifdef __sparc_v9__
55 /* rd is V9 only */
56 static inline unsigned long long get_cycles(void)
57 {
58  unsigned long long res;
59  __asm__ __volatile__("rd %%tick, %0" : "=r"(res));
60  return res;
61 }
62 #endif /* __sparc_v9__ */
63 
64 #ifdef __PPC__
65 
66 /* PowerPC */
67 
68 #define CPU_FTR_601 0x00000100
69 
70 typedef unsigned long cycles_t;
71 
72 /* For the "cycle" counter we use the timebase lower half. */
73 
74 extern cycles_t cacheflush_time;
75 
76 static inline cycles_t get_cycles(void)
77 {
78  cycles_t ret = 0;
79 
80  __asm__ __volatile__(
81  "98: mftb %0\n"
82  "99:\n"
83  ".section __ftr_fixup,\"a\"\n"
84  " .long %1\n"
85  " .long 0\n"
86  " .long 98b\n"
87  " .long 99b\n"
88  ".previous"
89  : "=r" (ret) : "i" (CPU_FTR_601));
90  return ret;
91 }
92 
93 #endif /* __PPC__ */
94 
95 #ifdef __i386__
96 
97 typedef unsigned long long cycles_t;
98 
99 extern cycles_t cacheflush_time;
100 
101 #define rdtscll(val) \
102  __asm__ __volatile__("rdtsc" : "=A" (val))
103 
104 static inline cycles_t get_cycles (void)
105 {
106  unsigned long long ret;
107 
108  rdtscll(ret);
109  return ret;
110 }
111 
112 #endif /* __i386__ */
113 
114 /* everything else but x86, amd64, sparcv9 or ppc */
115 #if !defined (__PPC__) && !defined (__x86_64__) && !defined (__i386__) && !defined (__sparc_v9__)
116 
117 #warning No suitable get_cycles() implementation. Returning 0 instead
118 
119 typedef unsigned long long cycles_t;
120 
121 static inline cycles_t get_cycles(void)
122 {
123  return 0;
124 }
125 
126 #endif /* everything else but x86, amd64, sparcv9 or ppc */
127 
128 
129 #endif /* __jack_cycles_h__ */