michael@0: /********************************************************************
michael@0:  *                                                                  *
michael@0:  * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE.   *
michael@0:  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
michael@0:  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
michael@0:  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
michael@0:  *                                                                  *
michael@0:  * THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2010                *
michael@0:  * by the Xiph.Org Foundation and contributors http://www.xiph.org/ *
michael@0:  *                                                                  *
michael@0:  ********************************************************************
michael@0: 
michael@0:  CPU capability detection for ARM processors.
michael@0: 
michael@0:  function:
michael@0:   last mod: $Id: cpu.c 17344 2010-07-21 01:42:18Z tterribe $
michael@0: 
michael@0:  ********************************************************************/
michael@0: 
michael@0: #include "armcpu.h"
michael@0: 
michael@0: #if !defined(OC_ARM_ASM)|| \
michael@0:  !defined(OC_ARM_ASM_EDSP)&&!defined(OC_ARM_ASM_ARMV6)&& \
michael@0:  !defined(OC_ARM_ASM_NEON)
michael@0: ogg_uint32_t oc_cpu_flags_get(void){
michael@0:   return 0;
michael@0: }
michael@0: 
michael@0: #elif defined(_MSC_VER)
michael@0: /*For GetExceptionCode() and EXCEPTION_ILLEGAL_INSTRUCTION.*/
michael@0: # define WIN32_LEAN_AND_MEAN
michael@0: # define WIN32_EXTRA_LEAN
michael@0: # include <windows.h>
michael@0: 
michael@0: ogg_uint32_t oc_cpu_flags_get(void){
michael@0:   ogg_uint32_t flags;
michael@0:   flags=0;
michael@0:   /*MSVC has no inline __asm support for ARM, but it does let you __emit
michael@0:      instructions via their assembled hex code.
michael@0:     All of these instructions should be essentially nops.*/
michael@0: # if defined(OC_ARM_ASM_EDSP)
michael@0:   __try{
michael@0:     /*PLD [r13]*/
michael@0:     __emit(0xF5DDF000);
michael@0:     flags|=OC_CPU_ARM_EDSP;
michael@0:   }
michael@0:   __except(GetExceptionCode()==EXCEPTION_ILLEGAL_INSTRUCTION){
michael@0:     /*Ignore exception.*/
michael@0:   }
michael@0: #  if defined(OC_ARM_ASM_MEDIA)
michael@0:   __try{
michael@0:     /*SHADD8 r3,r3,r3*/
michael@0:     __emit(0xE6333F93);
michael@0:     flags|=OC_CPU_ARM_MEDIA;
michael@0:   }
michael@0:   __except(GetExceptionCode()==EXCEPTION_ILLEGAL_INSTRUCTION){
michael@0:     /*Ignore exception.*/
michael@0:   }
michael@0: #   if defined(OC_ARM_ASM_NEON)
michael@0:   __try{
michael@0:     /*VORR q0,q0,q0*/
michael@0:     __emit(0xF2200150);
michael@0:     flags|=OC_CPU_ARM_NEON;
michael@0:   }
michael@0:   __except(GetExceptionCode()==EXCEPTION_ILLEGAL_INSTRUCTION){
michael@0:     /*Ignore exception.*/
michael@0:   }
michael@0: #   endif
michael@0: #  endif
michael@0: # endif
michael@0:   return flags;
michael@0: }
michael@0: 
michael@0: #elif defined(__linux__)
michael@0: # include <stdio.h>
michael@0: # include <stdlib.h>
michael@0: # include <string.h>
michael@0: 
michael@0: ogg_uint32_t oc_cpu_flags_get(void){
michael@0:   ogg_uint32_t  flags;
michael@0:   FILE         *fin;
michael@0:   flags=0;
michael@0:   /*Reading /proc/self/auxv would be easier, but that doesn't work reliably on
michael@0:      Android.
michael@0:     This also means that detection will fail in Scratchbox.*/
michael@0:   fin=fopen("/proc/cpuinfo","r");
michael@0:   if(fin!=NULL){
michael@0:     /*512 should be enough for anybody (it's even enough for all the flags that
michael@0:        x86 has accumulated... so far).*/
michael@0:     char buf[512];
michael@0:     while(fgets(buf,511,fin)!=NULL){
michael@0:       if(memcmp(buf,"Features",8)==0){
michael@0:         char *p;
michael@0:         p=strstr(buf," edsp");
michael@0:         if(p!=NULL&&(p[5]==' '||p[5]=='\n'))flags|=OC_CPU_ARM_EDSP;
michael@0:         p=strstr(buf," neon");
michael@0:         if(p!=NULL&&(p[5]==' '||p[5]=='\n'))flags|=OC_CPU_ARM_NEON;
michael@0:       }
michael@0:       if(memcmp(buf,"CPU architecture:",17)==0){
michael@0:         int version;
michael@0:         version=atoi(buf+17);
michael@0:         if(version>=6)flags|=OC_CPU_ARM_MEDIA;
michael@0:       }
michael@0:     }
michael@0:     fclose(fin);
michael@0:   }
michael@0:   return flags;
michael@0: }
michael@0: 
michael@0: #else
michael@0: /*The feature registers which can tell us what the processor supports are
michael@0:    accessible in priveleged modes only, so we can't have a general user-space
michael@0:    detection method like on x86.*/
michael@0: # error "Configured to use ARM asm but no CPU detection method available for " \
michael@0:  "your platform.  Reconfigure with --disable-asm (or send patches)."
michael@0: #endif