mozglue/build/SSE.cpp

   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/. */
   5
   6 /* compile-time and runtime tests for whether to use SSE instructions */
   7
   8 #include "SSE.h"
   9
  10 namespace {
  11
  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>.
  16
  17 #ifdef HAVE_CPUID_H
  18
  19 // cpuid.h is available on gcc 4.3 and higher on i386 and x86_64
  20 #include <cpuid.h>
  21
  22 enum CPUIDRegister { eax = 0, ebx = 1, ecx = 2, edx = 3 };
  23
  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 }
  31
  32 #elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_AMD64))
  33
  34 // MSVC 2005 or newer on x86-32 or x86-64
  35 #include <intrin.h>
  36
  37 enum CPUIDRegister { eax = 0, ebx = 1, ecx = 2, edx = 3 };
  38
  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;
  47
  48   __cpuid(regs, level);
  49   return !!(unsigned(regs[reg]) & bit);
  50 }
  51
  52 #elif defined(__SUNPRO_CC) && (defined(__i386) || defined(__x86_64__))
  53
  54 enum CPUIDRegister { eax = 0, ebx = 1, ecx = 2, edx = 3 };
  55
  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
  93
  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;
 102
 103   moz_cpuid((int *)regs, level);
 104   return !!(unsigned(regs[reg]) & bit);
 105 }
 106
 107 #endif // end CPUID declarations
 108
 109 }
 110
 111 namespace mozilla {
 112
 113 namespace sse_private {
 114
 115 #if defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)
 116
 117 #if !defined(MOZILLA_PRESUME_MMX)
 118   bool mmx_enabled = has_cpuid_bit(1u, edx, (1u<<23));
 119 #endif
 120
 121 #if !defined(MOZILLA_PRESUME_SSE)
 122   bool sse_enabled = has_cpuid_bit(1u, edx, (1u<<25));
 123 #endif
 124
 125 #if !defined(MOZILLA_PRESUME_SSE2)
 126   bool sse2_enabled = has_cpuid_bit(1u, edx, (1u<<26));
 127 #endif
 128
 129 #if !defined(MOZILLA_PRESUME_SSE3)
 130   bool sse3_enabled = has_cpuid_bit(1u, ecx, (1u<<0));
 131 #endif
 132
 133 #if !defined(MOZILLA_PRESUME_SSSE3)
 134   bool ssse3_enabled = has_cpuid_bit(1u, ecx, (1u<<9));
 135 #endif
 136
 137 #if !defined(MOZILLA_PRESUME_SSE4A)
 138   bool sse4a_enabled = has_cpuid_bit(0x80000001u, ecx, (1u<<6));
 139 #endif
 140
 141 #if !defined(MOZILLA_PRESUME_SSE4_1)
 142   bool sse4_1_enabled = has_cpuid_bit(1u, ecx, (1u<<19));
 143 #endif
 144
 145 #if !defined(MOZILLA_PRESUME_SSE4_2)
 146   bool sse4_2_enabled = has_cpuid_bit(1u, ecx, (1u<<20));
 147 #endif
 148
 149 #endif
 150
 151 } // namespace sse_private
 152 } // namespace mozilla