////////////////////////////////////////////////////////////////////////////////

///

/// gcc version of the x86 CPU detect routine.

///

/// This file is to be compiled on any platform with the GNU C compiler.

/// Compiler. Please see 'cpu_detect_x86_win.cpp' for the x86 Windows version 

/// of this file.

///

/// Author        : Copyright (c) Olli Parviainen

/// Author e-mail : oparviai 'at' iki.fi

/// SoundTouch WWW: http://www.surina.net/soundtouch

///

////////////////////////////////////////////////////////////////////////////////

//

// Last changed  : $Date: 2009-01-11 13:36:36 +0200 (Sun, 11 Jan 2009) $

// File revision : $Revision: 4 $

//

// $Id: cpu_detect_x86_gcc.cpp 47 2009-01-11 11:36:36Z oparviai $

//

////////////////////////////////////////////////////////////////////////////////

//

// License :

//

//  SoundTouch audio processing library

//  Copyright (c) Olli Parviainen

//

//  This library is free software; you can redistribute it and/or

//  modify it under the terms of the GNU Lesser General Public

//  License as published by the Free Software Foundation; either

//  version 2.1 of the License, or (at your option) any later version.

//

//  This library 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.  See the GNU

//  Lesser General Public License for more details.

//

//  You should have received a copy of the GNU Lesser General Public

//  License along with this library; if not, write to the Free Software

//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

//

////////////////////////////////////////////////////////////////////////////////



#include <stdexcept>

#include <string>

#include "cpu_detect.h"

#include "STTypes.h"



#ifndef __GNUC__

#error wrong platform - this source code file is for the GNU C compiler.

#endif



using namespace std;



#include <stdio.h>

//////////////////////////////////////////////////////////////////////////////

//

// processor instructions extension detection routines

//

//////////////////////////////////////////////////////////////////////////////





// Flag variable indicating whick ISA extensions are disabled (for debugging)

static uint _dwDisabledISA = 0x00;      // 0xffffffff; //<- use this to disable all extensions



// Disables given set of instruction extensions. See SUPPORT_... defines.

void disableExtensions(uint dwDisableMask)

{

    _dwDisabledISA = dwDisableMask;

}







/// Checks which instruction set extensions are supported by the CPU.

uint detectCPUextensions(void)

{

#ifndef ALLOW_X86_OPTIMIZATIONS



    return 0; // always disable extensions on non-x86 platforms.



#else

    uint res = 0;



    if (_dwDisabledISA == 0xffffffff) return 0;



    asm volatile(

        "\n\txor     %%esi, %%esi"       // clear %%esi = result register

        // check if 'cpuid' instructions is available by toggling eflags bit 21



        "\n\tpushf"                      // save eflags to stack

        "\n\tpop     %%eax"              // load eax from stack (with eflags)

        "\n\tmovl    %%eax, %%ecx"       // save the original eflags values to ecx

        "\n\txor     $0x00200000, %%eax" // toggle bit 21

        "\n\tpush    %%eax"              // store toggled eflags to stack

        "\n\tpopf"                       // load eflags from stack

        "\n\tpushf"                      // save updated eflags to stack

        "\n\tpop     %%eax"              // load from stack

        "\n\txor     %%edx, %%edx"       // clear edx for defaulting no mmx

        "\n\tcmp     %%ecx, %%eax"       // compare to original eflags values

        "\n\tjz      end"                // jumps to 'end' if cpuid not present



        // cpuid instruction available, test for presence of mmx instructions



        "\n\tmovl    $1, %%eax"

        "\n\tcpuid"

//        movl       $0x00800000, %edx   // force enable MMX

        "\n\ttest    $0x00800000, %%edx"

        "\n\tjz      end"                // branch if MMX not available



        "\n\tor      $0x01, %%esi"       // otherwise add MMX support bit



        "\n\ttest    $0x02000000, %%edx"

        "\n\tjz      test3DNow"          // branch if SSE not available



        "\n\tor      $0x08, %%esi"       // otherwise add SSE support bit



    "\n\ttest3DNow:"

        // test for precense of AMD extensions

        "\n\tmov     $0x80000000, %%eax"

        "\n\tcpuid"

        "\n\tcmp     $0x80000000, %%eax"

        "\n\tjbe     end"                 // branch if no AMD extensions detected



        // test for precense of 3DNow! extension

        "\n\tmov     $0x80000001, %%eax"

        "\n\tcpuid"

        "\n\ttest    $0x80000000, %%edx"

        "\n\tjz      end"                  // branch if 3DNow! not detected



        "\n\tor      $0x02, %%esi"         // otherwise add 3DNow support bit



    "\n\tend:"



        "\n\tmov     %%esi, %0"



      : "=r" (res)

      : /* no inputs */

      : "%edx", "%eax", "%ecx", "%esi" );

      

    return res & ~_dwDisabledISA;

#endif

}