workspace/ksplash/ksplashx/kcpuinfo.cpp

   1 /*
   2  * This file is part of the KDE libraries
   3  * Copyright (C) 2003 Fredrik Höglund <fredrik@kde.org>
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include <csignal>
  28 #include <csetjmp>
  29
  30 #include <config-workspace.h>
  31 #include "kcpuinfo.h"
  32
  33
  34 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
  35 #  define HAVE_GNU_INLINE_ASM
  36 #endif
  37
  38
  39 // Copied from kdecore/kglobal.h
  40 #if __GNUC__ - 0 > 3 || (__GNUC__ - 0 == 3 && __GNUC_MINOR__ - 0 > 2)
  41 #  define KDE_NO_EXPORT __attribute__ ((visibility("hidden")))
  42 #else
  43 #  define KDE_NO_EXPORT
  44 #endif
  45
  46 typedef void (*kde_sighandler_t) (int);
  47
  48 #ifdef __i386__
  49 #ifdef HAVE_X86_SSE
  50 static jmp_buf env;
  51
  52 // Sighandler for the SSE OS support check
  53 static void sighandler( int )
  54 {
  55     std::longjmp( env, 1 );
  56 }
  57 #endif
  58 #endif
  59
  60 #ifdef __PPC__
  61 static sigjmp_buf jmpbuf;
  62 static sig_atomic_t canjump = 0;
  63
  64 static void sigill_handler( int sig )
  65 {
  66     if ( !canjump ) {
  67         signal( sig, SIG_DFL );
  68         raise( sig );
  69     }
  70     canjump = 0;
  71     siglongjmp( jmpbuf, 1 );
  72 }
  73 #endif
  74
  75 static int getCpuFeatures()
  76 {
  77     volatile int features = 0;
  78
  79 #if defined( HAVE_GNU_INLINE_ASM )
  80 #if defined( __i386__ )
  81     bool haveCPUID = false;
  82     bool have3DNOW = false;
  83     int result = 0;
  84
  85     // First check if the CPU supports the CPUID instruction
  86     __asm__ __volatile__(
  87     // Try to toggle the CPUID bit in the EFLAGS register
  88     "pushf                      \n\t"   // Push the EFLAGS register onto the stack
  89     "popl   %%ecx               \n\t"   // Pop the value into ECX
  90     "movl   %%ecx, %%edx        \n\t"   // Copy ECX to EDX
  91     "xorl   $0x00200000, %%ecx  \n\t"   // Toggle bit 21 (CPUID) in ECX
  92     "pushl  %%ecx               \n\t"   // Push the modified value onto the stack
  93     "popf                       \n\t"   // Pop it back into EFLAGS
  94
  95     // Check if the CPUID bit was successfully toggled
  96     "pushf                      \n\t"   // Push EFLAGS back onto the stack
  97     "popl   %%ecx               \n\t"   // Pop the value into ECX
  98     "xorl   %%eax, %%eax        \n\t"   // Zero out the EAX register
  99     "cmpl   %%ecx, %%edx        \n\t"   // Compare ECX with EDX
 100     "je    .Lno_cpuid_support%= \n\t"   // Jump if they're identical
 101     "movl      $1, %%eax        \n\t"   // Set EAX to true
 102     ".Lno_cpuid_support%=:      \n\t"
 103     : "=a"(haveCPUID) : : "%ecx", "%edx" );
 104
 105     // If we don't have CPUID we won't have the other extensions either
 106     if ( ! haveCPUID )
 107         return 0L;
 108
 109     // Execute CPUID with the feature request bit set
 110     __asm__ __volatile__(
 111     "pushl  %%ebx               \n\t"   // Save EBX
 112     "movl      $1, %%eax        \n\t"   // Set EAX to 1 (features request)
 113     "cpuid                      \n\t"   // Call CPUID
 114     "popl   %%ebx               \n\t"   // Restore EBX
 115     : "=d"(result) : : "%eax", "%ecx" );
 116
 117     // Test bit 23 (MMX support)
 118     if ( result & 0x00800000 )
 119         features |= KCPUInfo::IntelMMX;
 120
 121     __asm__ __volatile__(
 122       "pushl %%ebx             \n\t"
 123       "movl $0x80000000, %%eax \n\t"
 124       "cpuid                   \n\t"
 125       "cmpl $0x80000000, %%eax \n\t"
 126       "jbe .Lno_extended%=     \n\t"
 127       "movl $0x80000001, %%eax \n\t"
 128       "cpuid                   \n\t"
 129       "test $0x80000000, %%edx \n\t"
 130       "jz .Lno_extended%=      \n\t"
 131       "movl      $1, %%eax     \n\t"   // // Set EAX to true
 132       ".Lno_extended%=:        \n\t"
 133       "popl   %%ebx            \n\t"   // Restore EBX
 134       : "=a"(have3DNOW) : );
 135
 136     if ( have3DNOW )
 137         features |= KCPUInfo::AMD3DNOW;
 138
 139 #ifdef HAVE_X86_SSE
 140     // Test bit 25 (SSE support)
 141     if ( result & 0x00200000 ) {
 142         features |= KCPUInfo::IntelSSE;
 143
 144         // OS support test for SSE.
 145         // Install our own sighandler for SIGILL.
 146         kde_sighandler_t oldhandler = std::signal( SIGILL, sighandler );
 147
 148         // Try executing an SSE insn to see if we get a SIGILL
 149         if ( setjmp( env ) )
 150             features ^= KCPUInfo::IntelSSE; // The OS support test failed
 151         else
 152             __asm__ __volatile__("xorps %xmm0, %xmm0");
 153
 154         // Restore the default sighandler
 155         std::signal( SIGILL, oldhandler );
 156
 157         // Test bit 26 (SSE2 support)
 158         if ( (result & 0x00400000) && (features & KCPUInfo::IntelSSE) )
 159             features |= KCPUInfo::IntelSSE2;
 160
 161         // Note: The OS requirements for SSE2 are the same as for SSE
 162         //       so we don't have to do any additional tests for that.
 163     }
 164 #endif // HAVE_X86_SSE
 165 #elif defined __PPC__ && defined HAVE_PPC_ALTIVEC
 166     signal( SIGILL, sigill_handler );
 167     if ( sigsetjmp( jmpbuf, 1 ) ) {
 168         signal( SIGILL, SIG_DFL );
 169     } else {
 170         canjump = 1;
 171         __asm__ __volatile__( "mtspr 256, %0\n\t"
 172                               "vand %%v0, %%v0, %%v0"
 173                               : /* none */
 174                               : "r" (-1) );
 175         signal( SIGILL, SIG_DFL );
 176         features |= KCPUInfo::AltiVec;
 177     }
 178 #endif // __i386__
 179 #endif //HAVE_GNU_INLINE_ASM
 180
 181     return features;
 182 }
 183
 184 unsigned int KCPUInfo::s_features = getCpuFeatures();
 185
 186