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authorHans-Christoph Steiner <hans@eds.org>2012-03-30 20:42:12 -0400
committerHans-Christoph Steiner <hans@eds.org>2012-03-30 20:42:12 -0400
commit7bb481fda9ecb134804b49c2ce77ca28f7eea583 (patch)
tree31b520b9914d3e2453968abe375f2c102772c3dc /src/hwtime.h
Imported Upstream version 2.0.3
Diffstat (limited to 'src/hwtime.h')
-rw-r--r--src/hwtime.h85
1 files changed, 85 insertions, 0 deletions
diff --git a/src/hwtime.h b/src/hwtime.h
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+++ b/src/hwtime.h
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+/*
+** 2008 May 27
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains inline asm code for retrieving "high-performance"
+** counters for x86 class CPUs.
+*/
+#ifndef _HWTIME_H_
+#define _HWTIME_H_
+
+/*
+** The following routine only works on pentium-class (or newer) processors.
+** It uses the RDTSC opcode to read the cycle count value out of the
+** processor and returns that value. This can be used for high-res
+** profiling.
+*/
+#if (defined(__GNUC__) || defined(_MSC_VER)) && \
+ (defined(i386) || defined(__i386__) || defined(_M_IX86))
+
+ #if defined(__GNUC__)
+
+ __inline__ sqlite_uint64 sqlite3Hwtime(void){
+ unsigned int lo, hi;
+ __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
+ return (sqlite_uint64)hi << 32 | lo;
+ }
+
+ #elif defined(_MSC_VER)
+
+ __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){
+ __asm {
+ rdtsc
+ ret ; return value at EDX:EAX
+ }
+ }
+
+ #endif
+
+#elif (defined(__GNUC__) && defined(__x86_64__))
+
+ __inline__ sqlite_uint64 sqlite3Hwtime(void){
+ unsigned long val;
+ __asm__ __volatile__ ("rdtsc" : "=A" (val));
+ return val;
+ }
+
+#elif (defined(__GNUC__) && defined(__ppc__))
+
+ __inline__ sqlite_uint64 sqlite3Hwtime(void){
+ unsigned long long retval;
+ unsigned long junk;
+ __asm__ __volatile__ ("\n\
+ 1: mftbu %1\n\
+ mftb %L0\n\
+ mftbu %0\n\
+ cmpw %0,%1\n\
+ bne 1b"
+ : "=r" (retval), "=r" (junk));
+ return retval;
+ }
+
+#else
+
+ #error Need implementation of sqlite3Hwtime() for your platform.
+
+ /*
+ ** To compile without implementing sqlite3Hwtime() for your platform,
+ ** you can remove the above #error and use the following
+ ** stub function. You will lose timing support for many
+ ** of the debugging and testing utilities, but it should at
+ ** least compile and run.
+ */
+ sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
+
+#endif
+
+#endif /* !defined(_HWTIME_H_) */