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chromium / external / github.com / sqlite / sqlite / HEAD / . / src / hwtime.h
blob: f808fa40eb9706405fe3abdf1c105d117100306e [file] [log] [blame]
shane9bcbdad2008-05-29 20:22:37[diff] [blame]1/*
2** 2008 May 27
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11******************************************************************************
12**
13** This file contains inline asm code for retrieving "high-performance"
drh594b1242019-11-20 12:07:40[diff] [blame]14** counters for x86 and x86_64 class CPUs.
shane9bcbdad2008-05-29 20:22:37[diff] [blame]15*/
drh43f58d62016-07-09 16:14:45[diff] [blame]16#ifndef SQLITE_HWTIME_H
17#define SQLITE_HWTIME_H
shane9bcbdad2008-05-29 20:22:37[diff] [blame]18
19/*
larrybrbc917382023-06-07 08:40:31[diff] [blame]20** The following routine only works on Pentium-class (or newer) processors.
shane9bcbdad2008-05-29 20:22:37[diff] [blame]21** It uses the RDTSC opcode to read the cycle count value out of the
22** processor and returns that value. This can be used for high-res
23** profiling.
24*/
drh594b1242019-11-20 12:07:40[diff] [blame]25#if !defined(__STRICT_ANSI__) && \
26 (defined(__GNUC__) || defined(_MSC_VER)) && \
27 (defined(i386) || defined(__i386__) || defined(_M_IX86))
shane9bcbdad2008-05-29 20:22:37[diff] [blame]28
29 #if defined(__GNUC__)
30
31 __inline__ sqlite_uint64 sqlite3Hwtime(void){
32 unsigned int lo, hi;
shane9bcbdad2008-05-29 20:22:37[diff] [blame]33 __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
34 return (sqlite_uint64)hi << 32 | lo;
35 }
36
37 #elif defined(_MSC_VER)
38
39 __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){
40 __asm {
41 rdtsc
42 ret ; return value at EDX:EAX
43 }
44 }
45
46 #endif
47
drh594b1242019-11-20 12:07:40[diff] [blame]48#elif !defined(__STRICT_ANSI__) && (defined(__GNUC__) && defined(__x86_64__))
shaneb08c1d02008-06-12 02:24:38[diff] [blame]49
50 __inline__ sqlite_uint64 sqlite3Hwtime(void){
dana3d0c152022-12-05 18:19:56[diff] [blame]51 unsigned int lo, hi;
52 __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
53 return (sqlite_uint64)hi << 32 | lo;
shaneb08c1d02008-06-12 02:24:38[diff] [blame]54 }
55
drh594b1242019-11-20 12:07:40[diff] [blame]56#elif !defined(__STRICT_ANSI__) && (defined(__GNUC__) && defined(__ppc__))
shane5cd89cf2008-08-01 14:33:15[diff] [blame]57
58 __inline__ sqlite_uint64 sqlite3Hwtime(void){
59 unsigned long long retval;
60 unsigned long junk;
61 __asm__ __volatile__ ("\n\
62 1: mftbu %1\n\
63 mftb %L0\n\
64 mftbu %0\n\
65 cmpw %0,%1\n\
66 bne 1b"
67 : "=r" (retval), "=r" (junk));
68 return retval;
69 }
70
shane9bcbdad2008-05-29 20:22:37[diff] [blame]71#else
72
shane9bcbdad2008-05-29 20:22:37[diff] [blame]73 /*
drh594b1242019-11-20 12:07:40[diff] [blame]74 ** asm() is needed for hardware timing support. Without asm(),
75 ** disable the sqlite3Hwtime() routine.
76 **
77 ** sqlite3Hwtime() is only used for some obscure debugging
78 ** and analysis configurations, not in any deliverable, so this
79 ** should not be a great loss.
shane9bcbdad2008-05-29 20:22:37[diff] [blame]80 */
81 sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
82
83#endif
84
drh43f58d62016-07-09 16:14:45[diff] [blame]85#endif /* !defined(SQLITE_HWTIME_H) */