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[chromium-blink-merge.git] / third_party / sqlite / sqlite-src-3080704 / src / hwtime.h
blobb8bc5a295be3fac8351fa9f08a77579d59c9a8e4
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.
11 ******************************************************************************
13 ** This file contains inline asm code for retrieving "high-performance"
14 ** counters for x86 class CPUs.
16 #ifndef _HWTIME_H_
17 #define _HWTIME_H_
20 ** The following routine only works on pentium-class (or newer) processors.
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.
25 #if (defined(__GNUC__) || defined(_MSC_VER)) && \
26 (defined(i386) || defined(__i386__) || defined(_M_IX86))
28 #if defined(__GNUC__)
30 __inline__ sqlite_uint64 sqlite3Hwtime(void){
31 unsigned int lo, hi;
32 __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
33 return (sqlite_uint64)hi << 32 | lo;
36 #elif defined(_MSC_VER)
38 __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){
39 __asm {
40 rdtsc
41 ret ; return value at EDX:EAX
45 #endif
47 #elif (defined(__GNUC__) && defined(__x86_64__))
49 __inline__ sqlite_uint64 sqlite3Hwtime(void){
50 unsigned long val;
51 __asm__ __volatile__ ("rdtsc" : "=A" (val));
52 return val;
55 #elif (defined(__GNUC__) && defined(__ppc__))
57 __inline__ sqlite_uint64 sqlite3Hwtime(void){
58 unsigned long long retval;
59 unsigned long junk;
60 __asm__ __volatile__ ("\n\
61 1: mftbu %1\n\
62 mftb %L0\n\
63 mftbu %0\n\
64 cmpw %0,%1\n\
65 bne 1b"
66 : "=r" (retval), "=r" (junk));
67 return retval;
70 #else
72 #error Need implementation of sqlite3Hwtime() for your platform.
75 ** To compile without implementing sqlite3Hwtime() for your platform,
76 ** you can remove the above #error and use the following
77 ** stub function. You will lose timing support for many
78 ** of the debugging and testing utilities, but it should at
79 ** least compile and run.
81 sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
83 #endif
85 #endif /* !defined(_HWTIME_H_) */