src/os_timer.c
author rubidium
Tue, 09 Jan 2007 14:48:21 +0000
changeset 5572 a98ffa55b19c
parent 5475 2e6990a8c7c4
permissions -rw-r--r--
(svn r8000) -Codechange: drop UDP packets when their internal size does not match the received size. If that is the case, the packet was not received in one piece (or got somehow mangled with another packet), which will cause us to drop the packet later on because we are (for example) trying to read beyond the end of the packet.
/* $Id$ */

#include "stdafx.h"

#undef RDTSC_AVAILABLE

/* rdtsc for MSC_VER, uses simple inline assembly, or _rdtsc
 * from external win64.asm because VS2005 does not support inline assembly */
#if defined(_MSC_VER) && !defined(RDTSC_AVAILABLE)
# if defined (_M_AMD64)
extern uint64 _rdtsc(void);
#	else
uint64 _declspec(naked) _rdtsc(void)
{
	_asm {
		rdtsc
		ret
	}
}
# endif
# define RDTSC_AVAILABLE
#endif

/* rdtsc for OS/2. Hopefully this works, who knows */
#if defined (__WATCOMC__) && !defined(RDTSC_AVAILABLE)
unsigned __int64 _rdtsc( void);
# pragma aux _rdtsc = 0x0F 0x31 value [edx eax] parm nomemory modify exact [edx eax] nomemory;
# define RDTSC_AVAILABLE
#endif

/* rdtsc for all other *nix-en (hopefully). Use GCC syntax */
#if defined(__i386__) || defined(__x86_64__) && !defined(RDTSC_AVAILABLE)
uint64 _rdtsc(void)
{
	uint32 high, low;
	__asm__ __volatile__ ("rdtsc" : "=a" (low), "=d" (high));
	return ((uint64)high << 32) | low;
}
# define RDTSC_AVAILABLE
#endif

/* rdtsc for PPC which has this not */
#if (defined(__POWERPC__) || defined(__powerpc__)) && !defined(RDTSC_AVAILABLE)
uint64 _rdtsc(void)
{
	uint32 high = 0, high2 = 0, low;
	/* PPC does not have rdtsc, so we cheat by reading the two 32-bit time-counters
	 * it has, 'Move From Time Base (Upper)'. Since these are two reads, in the
	 * very unlikely event that the lower part overflows to the upper part while we
	 * read it; we double-check and reread the registers */
	asm volatile (
				  "mftbu %0\n"
				  "mftb %1\n"
				  "mftbu %2\n"
				  "cmpw %3,%4\n"
				  "bne- $-16\n"
				  : "=r" (high), "=r" (low), "=r" (high2)
				  : "0" (high), "2" (high2)
				  );
	return ((uint64)high << 32) | low;
}
# define RDTSC_AVAILABLE
#endif

/* In all other cases we have no support for rdtsc. No major issue,
 * you just won't be able to profile your code with TIC()/TOC() */
#if !defined(RDTSC_AVAILABLE)
#warning "(non-fatal) No support for rdtsc(), you won't be able to profile with TIC/TOC"
uint64 _rdtsc(void) {return 0;}
#endif