mono/utils/mono-hwcap-x86.c

   1 /*
   2  * mono-hwcap-x86.c: x86 hardware feature detection
   3  *
   4  * Authors:
   5  *    Alex Rønne Petersen (alexrp@xamarin.com)
   6  *    Elijah Taylor (elijahtaylor@google.com)
   7  *    Miguel de Icaza (miguel@xamarin.com)
   8  *    Neale Ferguson (Neale.Ferguson@SoftwareAG-usa.com)
   9  *    Paolo Molaro (lupus@xamarin.com)
  10  *    Rodrigo Kumpera (kumpera@gmail.com)
  11  *    Sebastien Pouliot (sebastien@xamarin.com)
  12  *    Zoltan Varga (vargaz@xamarin.com)
  13  *
  14  * Copyright 2003 Ximian, Inc.
  15  * Copyright 2003-2011 Novell, Inc
  16  * Copyright 2006 Broadcom
  17  * Copyright 2007-2008 Andreas Faerber
  18  * Copyright 2011-2013 Xamarin Inc
  19  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
  20  */
  21
  22 #include "mono/utils/mono-hwcap.h"
  23
  24 #if defined(HAVE_UNISTD_H)
  25 #include <unistd.h>
  26 #endif
  27 #if defined(_MSC_VER)
  28 #include <intrin.h>
  29 #endif
  30
  31 static gboolean
  32 cpuid (int id, int *p_eax, int *p_ebx, int *p_ecx, int *p_edx)
  33 {
  34 #if defined(_MSC_VER)
  35         int info [4];
  36 #endif
  37
  38         /* First, make sure we can use cpuid if we're on 32-bit. */
  39 #if defined(TARGET_X86)
  40         gboolean have_cpuid = FALSE;
  41
  42 #if defined(_MSC_VER)
  43         __asm {
  44                 pushfd
  45                 pop eax
  46                 mov edx, eax
  47                 xor eax, 0x200000
  48                 push eax
  49                 popfd
  50                 pushfd
  51                 pop eax
  52                 xor eax, edx
  53                 and eax, 0x200000
  54                 mov have_cpuid, eax
  55         }
  56 #else
  57         __asm__ __volatile__ (
  58                 "pushfl\n\t"
  59                 "popl\t%%eax\n\t"
  60                 "movl\t%%eax, %%edx\n\t"
  61                 "xorl\t$0x200000, %%eax\n\t"
  62                 "pushl\t%%eax\n\t"
  63                 "popfl\n\t"
  64                 "pushfl\n\t"
  65                 "popl\t%%eax\n\t"
  66                 "xorl\t%%edx, %%eax\n\t"
  67                 "andl\t$0x200000, %%eax\n\t"
  68                 "movl\t%%eax, %0\n\t"
  69                 : "=r" (have_cpuid)
  70                 :
  71                 : "%eax", "%edx"
  72         );
  73 #endif
  74
  75         if (!have_cpuid)
  76                 return FALSE;
  77 #endif
  78
  79         /* Now issue the actual cpuid instruction. We can use
  80            MSVC's __cpuid on both 32-bit and 64-bit. */
  81 #if defined(_MSC_VER)
  82         __cpuid (info, id);
  83         *p_eax = info [0];
  84         *p_ebx = info [1];
  85         *p_ecx = info [2];
  86         *p_edx = info [3];
  87 #elif defined(TARGET_X86)
  88         /* This complicated stuff is necessary because EBX
  89            may be used by the compiler in PIC mode. */
  90         __asm__ __volatile__ (
  91                 "xchgl\t%%ebx, %k1\n\t"
  92                 "cpuid\n\t"
  93                 "xchgl\t%%ebx, %k1\n\t"
  94                 : "=a" (*p_eax), "=&r" (*p_ebx), "=c" (*p_ecx), "=d" (*p_edx)
  95                 : "0" (id)
  96         );
  97 #else
  98         __asm__ __volatile__ (
  99                 "cpuid\n\t"
 100                 : "=a" (*p_eax), "=b" (*p_ebx), "=c" (*p_ecx), "=d" (*p_edx)
 101                 : "a" (id)
 102         );
 103 #endif
 104
 105         return TRUE;
 106 }
 107
 108 void
 109 mono_hwcap_arch_init (void)
 110 {
 111         int eax, ebx, ecx, edx;
 112
 113         if (cpuid (1, &eax, &ebx, &ecx, &edx)) {
 114                 if (edx & (1 << 15)) {
 115                         mono_hwcap_x86_has_cmov = TRUE;
 116
 117                         if (edx & 1)
 118                                 mono_hwcap_x86_has_fcmov = TRUE;
 119                 }
 120
 121                 if (edx & (1 << 25))
 122                         mono_hwcap_x86_has_sse1 = TRUE;
 123
 124                 if (edx & (1 << 26))
 125                         mono_hwcap_x86_has_sse2 = TRUE;
 126
 127                 if (ecx & (1 << 0))
 128                         mono_hwcap_x86_has_sse3 = TRUE;
 129
 130                 if (ecx & (1 << 9))
 131                         mono_hwcap_x86_has_ssse3 = TRUE;
 132
 133                 if (ecx & (1 << 19))
 134                         mono_hwcap_x86_has_sse41 = TRUE;
 135
 136                 if (ecx & (1 << 20))
 137                         mono_hwcap_x86_has_sse42 = TRUE;
 138         }
 139
 140         if (cpuid (0x80000000, &eax, &ebx, &ecx, &edx)) {
 141                 if ((unsigned int) eax >= 0x80000001 && ebx == 0x68747541 && ecx == 0x444D4163 && edx == 0x69746E65) {
 142                         if (cpuid (0x80000001, &eax, &ebx, &ecx, &edx)) {
 143                                 if (ecx & (1 << 6))
 144                                         mono_hwcap_x86_has_sse4a = TRUE;
 145                         }
 146                 }
 147         }
 148
 149 #if defined(HAVE_UNISTD_H)
 150         mono_hwcap_x86_is_xen = !access ("/proc/xen", F_OK);
 151 #endif
 152 }