The Tor Browser: media/libsoundtouch/src/cpu_detect

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 ////////////////////////////////////////////////////////////////////////////////

     2 ///

     3 /// Generic version of the x86 CPU extension detection routine.

     4 ///

     5 /// This file is for GNU & other non-Windows compilers, see 'cpu_detect_x86_win.cpp'

     6 /// for the Microsoft compiler version.

     7 ///

     8 /// Author        : Copyright (c) Olli Parviainen

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

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

    11 ///

    12 ////////////////////////////////////////////////////////////////////////////////

    13 //

    14 // Last changed  : $Date: 2014-01-07 12:24:28 -0600 (Tue, 07 Jan 2014) $

    15 // File revision : $Revision: 4 $

    16 //

    17 // $Id: cpu_detect_x86.cpp 183 2014-01-07 18:24:28Z oparviai $

    18 //

    19 ////////////////////////////////////////////////////////////////////////////////

    20 //

    21 // License :

    22 //

    23 //  SoundTouch audio processing library

    24 //  Copyright (c) Olli Parviainen

    25 //

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

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

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

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

    30 //

    31 //  This library is distributed in the hope that it will be useful,

    32 //  but WITHOUT ANY WARRANTY; without even the implied warranty of

    33 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    34 //  Lesser General Public License for more details.

    35 //

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

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

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

    39 //

    40 ////////////////////////////////////////////////////////////////////////////////

    42 #include "cpu_detect.h"

    43 #include "STTypes.h"

    46 #if defined(SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS)

    47    #if defined(__GNUC__) && defined(HAVE_CPUID_H)

    48        // gcc and clang

    49        #include "cpuid.h"

    50    #elif defined(_M_IX86)

    51        // windows non-gcc

    52        #include <intrin.h>

    53    #endif

    55    #define bit_MMX     (1 << 23)

    56    #define bit_SSE     (1 << 25)

    57    #define bit_SSE2    (1 << 26)

    58 #endif

    61 //////////////////////////////////////////////////////////////////////////////

    62 //

    63 // processor instructions extension detection routines

    64 //

    65 //////////////////////////////////////////////////////////////////////////////

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

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

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

    71 void disableExtensions(uint dwDisableMask)

    72 {

    73     _dwDisabledISA = dwDisableMask;

    74 }

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

    79 uint detectCPUextensions(void)

    80 {

    81 /// If building for a 64bit system (no Itanium) and the user wants optimizations.

    82 /// Return the OR of SUPPORT_{MMX,SSE,SSE2}. 11001 or 0x19.

    83 /// Keep the _dwDisabledISA test (2 more operations, could be eliminated).

    84 #if ((defined(__GNUC__) && defined(__x86_64__)) \

    85     || defined(_M_X64))  \

    86     && defined(SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS)

    87     return 0x19 & ~_dwDisabledISA;

    89 /// If building for a 32bit system and the user wants optimizations.

    90 /// Keep the _dwDisabledISA test (2 more operations, could be eliminated).

    91 #elif ((defined(__GNUC__) && defined(__i386__)) \

    92     || defined(_M_IX86))  \

    93     && defined(SOUNDTOUCH_ALLOW_X86_OPTIMIZATIONS)

    95     if (_dwDisabledISA == 0xffffffff) return 0;

    97     uint res = 0;

    99 #if !defined(__GNUC__)

   100     // Window / VS version of cpuid. Notice that Visual Studio 2005 or later required

   101     // for __cpuid intrinsic support.

   102     int reg[4] = {-1};

   104     // Check if no cpuid support.

   105     __cpuid(reg,0);

   106     if ((unsigned int)reg[0] == 0) return 0; // always disable extensions.

   108     __cpuid(reg,1);

   109     if ((unsigned int)reg[3] & bit_MMX)  res = res | SUPPORT_MMX;

   110     if ((unsigned int)reg[3] & bit_SSE)  res = res | SUPPORT_SSE;

   111     if ((unsigned int)reg[3] & bit_SSE2) res = res | SUPPORT_SSE2;

   112 #elif defined(HAVE_CPUID_H)

   113     // GCC version of cpuid. Requires GCC 4.3.0 or later for __cpuid intrinsic support.

   114     uint eax, ebx, ecx, edx;  // unsigned int is the standard type. uint is defined by the compiler and not guaranteed to be portable.

   116     // Check if no cpuid support.

   117     if (!__get_cpuid (1, &eax, &ebx, &ecx, &edx)) return 0; // always disable extensions.

   119     if (edx & bit_MMX)  res = res | SUPPORT_MMX;

   120     if (edx & bit_SSE)  res = res | SUPPORT_SSE;

   121     if (edx & bit_SSE2) res = res | SUPPORT_SSE2;

   122 #else

   123     // Compatible with GCC but no cpuid.h.

   124     return 0;

   125 #endif

   127     return res & ~_dwDisabledISA;

   129 #else

   131 /// One of these is true:

   132 /// 1) We don't want optimizations.

   133 /// 2) Using an unsupported compiler.

   134 /// 3) Running on a non-x86 platform.

   135     return 0;

   137 #endif

   138 }

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