src/os_timer.cpp

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file os_timer.cpp OS/compiler dependant real time tick sampling. */
  11
  12 #include "stdafx.h"
  13
  14 #undef RDTSC_AVAILABLE
  15
  16 /* rdtsc for MSC_VER, uses simple inline assembly, or _rdtsc
  17  * from external win64.asm because VS2005 does not support inline assembly */
  18 #if defined(_MSC_VER) && !defined(RDTSC_AVAILABLE) && !defined(WINCE)
  19 #include <intrin.h>
  20 uint64 ottd_rdtsc()
  21 {
  22         return __rdtsc();
  23 }
  24 #define RDTSC_AVAILABLE
  25 #endif
  26
  27 /* rdtsc for OS/2. Hopefully this works, who knows */
  28 #if defined (__WATCOMC__) && !defined(RDTSC_AVAILABLE)
  29 unsigned __int64 ottd_rdtsc();
  30 # pragma aux ottd_rdtsc = 0x0F 0x31 value [edx eax] parm nomemory modify exact [edx eax] nomemory;
  31 # define RDTSC_AVAILABLE
  32 #endif
  33
  34 /* rdtsc for all other *nix-en (hopefully). Use GCC syntax */
  35 #if (defined(__i386__) || defined(__x86_64__)) && !defined(__DJGPP__) && !defined(RDTSC_AVAILABLE)
  36 uint64 ottd_rdtsc()
  37 {
  38         uint32 high, low;
  39         __asm__ __volatile__ ("rdtsc" : "=a" (low), "=d" (high));
  40         return ((uint64)high << 32) | low;
  41 }
  42 # define RDTSC_AVAILABLE
  43 #endif
  44
  45 /* rdtsc for PPC which has this not */
  46 #if (defined(__POWERPC__) || defined(__powerpc__)) && !defined(RDTSC_AVAILABLE)
  47 uint64 ottd_rdtsc()
  48 {
  49         uint32 high = 0, high2 = 0, low;
  50         /* PPC does not have rdtsc, so we cheat by reading the two 32-bit time-counters
  51          * it has, 'Move From Time Base (Upper)'. Since these are two reads, in the
  52          * very unlikely event that the lower part overflows to the upper part while we
  53          * read it; we double-check and reread the registers */
  54         asm volatile (
  55                                   "mftbu %0\n"
  56                                   "mftb %1\n"
  57                                   "mftbu %2\n"
  58                                   "cmpw %3,%4\n"
  59                                   "bne- $-16\n"
  60                                   : "=r" (high), "=r" (low), "=r" (high2)
  61                                   : "0" (high), "2" (high2)
  62                                   );
  63         return ((uint64)high << 32) | low;
  64 }
  65 # define RDTSC_AVAILABLE
  66 #endif
  67
  68 /* In all other cases we have no support for rdtsc. No major issue,
  69  * you just won't be able to profile your code with TIC()/TOC() */
  70 #if !defined(RDTSC_AVAILABLE)
  71 /* MSVC (in case of WinCE) can't handle #warning */
  72 # if !defined(_MSC_VER)
  73 #warning "(non-fatal) No support for rdtsc(), you won't be able to profile with TIC/TOC"
  74 # endif
  75 uint64 ottd_rdtsc() {return 0;}
  76 #endif