DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (5b81998bb7ab)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152
/* vim: set shiftwidth=4 tabstop=8 autoindent cindent expandtab: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

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

#include "SSE.h"

namespace {

// SSE.h has parallel #ifs which declare MOZILLA_SSE_HAVE_CPUID_DETECTION.
// We can't declare these functions in the header file, however, because
// <intrin.h> conflicts with <windows.h> on MSVC 2005, and some files want to
// include both SSE.h and <windows.h>.

#ifdef HAVE_CPUID_H

// cpuid.h is available on gcc 4.3 and higher on i386 and x86_64
#include <cpuid.h>

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

static bool
has_cpuid_bit(unsigned int level, CPUIDRegister reg, unsigned int bit)
{
  unsigned int regs[4];
  return __get_cpuid(level, &regs[0], &regs[1], &regs[2], &regs[3]) &&
         (regs[reg] & bit);
}

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

// MSVC 2005 or newer on x86-32 or x86-64
#include <intrin.h>

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

static bool
has_cpuid_bit(unsigned int level, CPUIDRegister reg, unsigned int bit)
{
  // Check that the level in question is supported.
  int regs[4];
  __cpuid(regs, level & 0x80000000u);
  if (unsigned(regs[0]) < level)
    return false;

  __cpuid(regs, level);
  return !!(unsigned(regs[reg]) & bit);
}

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

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

#ifdef __i386
static void
moz_cpuid(int CPUInfo[4], int InfoType)
{
  asm (
    "xchg %esi, %ebx\n"
    "cpuid\n"
    "movl %eax, (%edi)\n"
    "movl %ebx, 4(%edi)\n"
    "movl %ecx, 8(%edi)\n"
    "movl %edx, 12(%edi)\n"
    "xchg %esi, %ebx\n"
    :
    : "a"(InfoType), // %eax
      "D"(CPUInfo) // %edi
    : "%ecx", "%edx", "%esi"
  );
}
#else
static void
moz_cpuid(int CPUInfo[4], int InfoType)
{
  asm (
    "xchg %rsi, %rbx\n"
    "cpuid\n"
    "movl %eax, (%rdi)\n"
    "movl %ebx, 4(%rdi)\n"
    "movl %ecx, 8(%rdi)\n"
    "movl %edx, 12(%rdi)\n"
    "xchg %rsi, %rbx\n"
    :
    : "a"(InfoType), // %eax
      "D"(CPUInfo) // %rdi
    : "%ecx", "%edx", "%rsi"
  );
}
#endif

static bool
has_cpuid_bit(unsigned int level, CPUIDRegister reg, unsigned int bit)
{
  // Check that the level in question is supported.
  volatile int regs[4];
  moz_cpuid((int *)regs, level & 0x80000000u);
  if (unsigned(regs[0]) < level)
    return false;

  moz_cpuid((int *)regs, level);
  return !!(unsigned(regs[reg]) & bit);
}

#endif // end CPUID declarations

}

namespace mozilla {

namespace sse_private {

#if defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)

#if !defined(MOZILLA_PRESUME_MMX)
  bool mmx_enabled = has_cpuid_bit(1u, edx, (1u<<23));
#endif

#if !defined(MOZILLA_PRESUME_SSE)
  bool sse_enabled = has_cpuid_bit(1u, edx, (1u<<25));
#endif

#if !defined(MOZILLA_PRESUME_SSE2)
  bool sse2_enabled = has_cpuid_bit(1u, edx, (1u<<26));
#endif

#if !defined(MOZILLA_PRESUME_SSE3)
  bool sse3_enabled = has_cpuid_bit(1u, ecx, (1u<<0));
#endif

#if !defined(MOZILLA_PRESUME_SSSE3)
  bool ssse3_enabled = has_cpuid_bit(1u, ecx, (1u<<9));
#endif

#if !defined(MOZILLA_PRESUME_SSE4A)
  bool sse4a_enabled = has_cpuid_bit(0x80000001u, ecx, (1u<<6));
#endif

#if !defined(MOZILLA_PRESUME_SSE4_1)
  bool sse4_1_enabled = has_cpuid_bit(1u, ecx, (1u<<19));
#endif

#if !defined(MOZILLA_PRESUME_SSE4_2)
  bool sse4_2_enabled = has_cpuid_bit(1u, ecx, (1u<<20));
#endif

#endif

} // namespace sse_private
} // namespace mozilla