The Tor Browser: mozglue/build/SSE.cpp@97036ab72558

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 /* vim: set shiftwidth=4 tabstop=8 autoindent cindent expandtab: */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 /* compile-time and runtime tests for whether to use SSE instructions */

     8 #include "SSE.h"

    10 namespace {

    12 // SSE.h has parallel #ifs which declare MOZILLA_SSE_HAVE_CPUID_DETECTION.

    13 // We can't declare these functions in the header file, however, because

    14 // <intrin.h> conflicts with <windows.h> on MSVC 2005, and some files want to

    15 // include both SSE.h and <windows.h>.

    17 #ifdef HAVE_CPUID_H

    19 // cpuid.h is available on gcc 4.3 and higher on i386 and x86_64

    20 #include <cpuid.h>

    22 enum CPUIDRegister { eax = 0, ebx = 1, ecx = 2, edx = 3 };

    24 static bool

    25 has_cpuid_bit(unsigned int level, CPUIDRegister reg, unsigned int bit)

    26 {

    27   unsigned int regs[4];

    28   return __get_cpuid(level, &regs[0], &regs[1], &regs[2], &regs[3]) &&

    29          (regs[reg] & bit);

    30 }

    32 #elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_AMD64))

    34 // MSVC 2005 or newer on x86-32 or x86-64

    35 #include <intrin.h>

    37 enum CPUIDRegister { eax = 0, ebx = 1, ecx = 2, edx = 3 };

    39 static bool

    40 has_cpuid_bit(unsigned int level, CPUIDRegister reg, unsigned int bit)

    41 {

    42   // Check that the level in question is supported.

    43   int regs[4];

    44   __cpuid(regs, level & 0x80000000u);

    45   if (unsigned(regs[0]) < level)

    46     return false;

    48   __cpuid(regs, level);

    49   return !!(unsigned(regs[reg]) & bit);

    50 }

    52 #elif defined(__SUNPRO_CC) && (defined(__i386) || defined(__x86_64__))

    54 enum CPUIDRegister { eax = 0, ebx = 1, ecx = 2, edx = 3 };

    56 #ifdef __i386

    57 static void

    58 moz_cpuid(int CPUInfo[4], int InfoType)

    59 {

    60   asm (

    61     "xchg %esi, %ebx\n"

    62     "cpuid\n"

    63     "movl %eax, (%edi)\n"

    64     "movl %ebx, 4(%edi)\n"

    65     "movl %ecx, 8(%edi)\n"

    66     "movl %edx, 12(%edi)\n"

    67     "xchg %esi, %ebx\n"

    68     :

    69     : "a"(InfoType), // %eax

    70       "D"(CPUInfo) // %edi

    71     : "%ecx", "%edx", "%esi"

    72   );

    73 }

    74 #else

    75 static void

    76 moz_cpuid(int CPUInfo[4], int InfoType)

    77 {

    78   asm (

    79     "xchg %rsi, %rbx\n"

    80     "cpuid\n"

    81     "movl %eax, (%rdi)\n"

    82     "movl %ebx, 4(%rdi)\n"

    83     "movl %ecx, 8(%rdi)\n"

    84     "movl %edx, 12(%rdi)\n"

    85     "xchg %rsi, %rbx\n"

    86     :

    87     : "a"(InfoType), // %eax

    88       "D"(CPUInfo) // %rdi

    89     : "%ecx", "%edx", "%rsi"

    90   );

    91 }

    92 #endif

    94 static bool

    95 has_cpuid_bit(unsigned int level, CPUIDRegister reg, unsigned int bit)

    96 {

    97   // Check that the level in question is supported.

    98   volatile int regs[4];

    99   moz_cpuid((int *)regs, level & 0x80000000u);

   100   if (unsigned(regs[0]) < level)

   101     return false;

   103   moz_cpuid((int *)regs, level);

   104   return !!(unsigned(regs[reg]) & bit);

   105 }

   107 #endif // end CPUID declarations

   109 }

   111 namespace mozilla {

   113 namespace sse_private {

   115 #if defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)

   117 #if !defined(MOZILLA_PRESUME_MMX)

   118   bool mmx_enabled = has_cpuid_bit(1u, edx, (1u<<23));

   119 #endif

   121 #if !defined(MOZILLA_PRESUME_SSE)

   122   bool sse_enabled = has_cpuid_bit(1u, edx, (1u<<25));

   123 #endif

   125 #if !defined(MOZILLA_PRESUME_SSE2)

   126   bool sse2_enabled = has_cpuid_bit(1u, edx, (1u<<26));

   127 #endif

   129 #if !defined(MOZILLA_PRESUME_SSE3)

   130   bool sse3_enabled = has_cpuid_bit(1u, ecx, (1u<<0));

   131 #endif

   133 #if !defined(MOZILLA_PRESUME_SSSE3)

   134   bool ssse3_enabled = has_cpuid_bit(1u, ecx, (1u<<9));

   135 #endif

   137 #if !defined(MOZILLA_PRESUME_SSE4A)

   138   bool sse4a_enabled = has_cpuid_bit(0x80000001u, ecx, (1u<<6));

   139 #endif

   141 #if !defined(MOZILLA_PRESUME_SSE4_1)

   142   bool sse4_1_enabled = has_cpuid_bit(1u, ecx, (1u<<19));

   143 #endif

   145 #if !defined(MOZILLA_PRESUME_SSE4_2)

   146   bool sse4_2_enabled = has_cpuid_bit(1u, ecx, (1u<<20));

   147 #endif

   149 #endif

   151 } // namespace sse_private

   152 } // namespace mozilla

The Tor Browser / file revision

mozglue/build/SSE.cpp@97036ab72558

mozglue/build/SSE.cpp