kdefx Library API Documentation

kcpuinfo.cpp

00001 /*
00002  * This file is part of the KDE libraries
00003  * Copyright (C) 2003 Fredrik Höglund <fredrik@kde.org>
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions
00007  * are met:
00008  *
00009  * 1. Redistributions of source code must retain the above copyright
00010  *    notice, this list of conditions and the following disclaimer.
00011  * 2. Redistributions in binary form must reproduce the above copyright
00012  *    notice, this list of conditions and the following disclaimer in the
00013  *    documentation and/or other materials provided with the distribution.
00014  *
00015  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
00016  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00017  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
00018  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
00019  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
00020  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
00021  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
00022  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
00023  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
00024  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00025  */
00026 
00027 #include <csignal>
00028 #include <csetjmp>
00029 
00030 #include <config.h>
00031 #include "kcpuinfo.h"
00032 
00033 
00034 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
00035 #  define HAVE_GNU_INLINE_ASM
00036 #endif
00037 
00038 
00039 // Copied from kdecore/kdemacros.h
00040 #if __GNUC__ - 0 > 3 || (__GNUC__ - 0 == 3 && __GNUC_MINOR__ - 0 > 4)
00041 #  define KDE_NO_EXPORT __attribute__ ((visibility("hidden")))
00042 #else
00043 #  define KDE_NO_EXPORT
00044 #endif
00045 
00046 typedef void (*kde_sighandler_t) (int);
00047 
00048 #ifdef __i386__
00049 static jmp_buf env;
00050 
00051 // Sighandler for the SSE OS support check
00052 static void sighandler( int )
00053 {
00054     std::longjmp( env, 1 );
00055 }
00056 #endif
00057 
00058 #ifdef __PPC__
00059 static sigjmp_buf KDE_NO_EXPORT jmpbuf;
00060 static sig_atomic_t KDE_NO_EXPORT canjump = 0;
00061 
00062 static void KDE_NO_EXPORT sigill_handler( int sig )
00063 {
00064     if ( !canjump ) {
00065         signal( sig, SIG_DFL );
00066         raise( sig );
00067     }
00068     canjump = 0;
00069     siglongjmp( jmpbuf, 1 );
00070 }
00071 #endif
00072 
00073 static int getCpuFeatures()
00074 {
00075     int features = 0;
00076 
00077 #if defined( HAVE_GNU_INLINE_ASM )
00078 #if defined( __i386__ )
00079     bool haveCPUID = false;
00080     bool have3DNOW = false;
00081     int result = 0;
00082 
00083     // First check if the CPU supports the CPUID instruction
00084     __asm__ __volatile__(
00085     // Try to toggle the CPUID bit in the EFLAGS register
00086     "pushf                      \n\t"   // Push the EFLAGS register onto the stack
00087     "popl   %%ecx               \n\t"   // Pop the value into ECX
00088     "movl   %%ecx, %%edx        \n\t"   // Copy ECX to EDX
00089     "xorl   $0x00200000, %%ecx  \n\t"   // Toggle bit 21 (CPUID) in ECX
00090     "pushl  %%ecx               \n\t"   // Push the modified value onto the stack
00091     "popf                       \n\t"   // Pop it back into EFLAGS
00092 
00093     // Check if the CPUID bit was successfully toggled
00094     "pushf                      \n\t"   // Push EFLAGS back onto the stack
00095     "popl   %%ecx               \n\t"   // Pop the value into ECX
00096     "xorl   %%eax, %%eax        \n\t"   // Zero out the EAX register
00097     "cmpl   %%ecx, %%edx        \n\t"   // Compare ECX with EDX
00098     "je    .Lno_cpuid_support%= \n\t"   // Jump if they're identical
00099     "movl      $1, %%eax        \n\t"   // Set EAX to true
00100     ".Lno_cpuid_support%=:      \n\t"
00101     : "=a"(haveCPUID) : : "%ecx", "%edx" );
00102 
00103     // If we don't have CPUID we won't have the other extensions either
00104     if ( ! haveCPUID )
00105         return 0L;
00106 
00107     // Execute CPUID with the feature request bit set
00108     __asm__ __volatile__(
00109     "pushl  %%ebx               \n\t"   // Save EBX
00110     "movl      $1, %%eax        \n\t"   // Set EAX to 1 (features request)
00111     "cpuid                      \n\t"   // Call CPUID
00112     "popl   %%ebx               \n\t"   // Restore EBX
00113     : "=d"(result) : : "%eax", "%ecx" );
00114 
00115     // Test bit 23 (MMX support)
00116     if ( result & 0x00800000 )
00117         features |= KCPUInfo::IntelMMX;
00118 
00119     __asm__ __volatile__(
00120       "pushl %%ebx             \n\t"
00121       "movl $0x80000000, %%eax \n\t"
00122       "cpuid                   \n\t"
00123       "cmpl $0x80000000, %%eax \n\t"
00124       "jbe .Lno_extended%=     \n\t"
00125       "movl $0x80000001, %%eax \n\t"
00126       "cpuid                   \n\t"
00127       "test $0x80000000, %%edx \n\t"
00128       "jz .Lno_extended%=      \n\t"
00129       "movl      $1, %%eax     \n\t"   // // Set EAX to true
00130       ".Lno_extended%=:        \n\t"
00131       "popl   %%ebx            \n\t"   // Restore EBX
00132       : "=a"(have3DNOW) : );
00133 
00134     if ( have3DNOW )
00135         features |= KCPUInfo::AMD3DNOW;
00136 
00137 #ifdef HAVE_X86_SSE
00138     // Test bit 25 (SSE support)
00139     if ( result & 0x00200000 ) {
00140         features |= KCPUInfo::IntelSSE;
00141 
00142         // OS support test for SSE.
00143         // Install our own sighandler for SIGILL.
00144         kde_sighandler_t oldhandler = std::signal( SIGILL, sighandler );
00145 
00146         // Try executing an SSE insn to see if we get a SIGILL
00147         if ( setjmp( env ) )
00148             features ^= KCPUInfo::IntelSSE; // The OS support test failed
00149         else
00150             __asm__ __volatile__("xorps %xmm0, %xmm0");
00151 
00152         // Restore the default sighandler
00153         std::signal( SIGILL, oldhandler );
00154 
00155         // Test bit 26 (SSE2 support)
00156         if ( (result & 0x00400000) && (features & KCPUInfo::IntelSSE) )
00157             features |= KCPUInfo::IntelSSE2;
00158 
00159         // Note: The OS requirements for SSE2 are the same as for SSE
00160         //       so we don't have to do any additional tests for that.
00161     }
00162 #endif // HAVE_X86_SSE
00163 #elif defined __PPC__ && defined HAVE_PPC_ALTIVEC
00164     signal( SIGILL, sigill_handler );
00165     if ( sigsetjmp( jmpbuf, 1 ) ) {
00166         signal( SIGILL, SIG_DFL );
00167     } else {
00168         canjump = 1;
00169         __asm__ __volatile__( "mtspr 256, %0\n\t"
00170                               "vand %%v0, %%v0, %%v0"
00171                               : /* none */
00172                               : "r" (-1) );
00173         signal( SIGILL, SIG_DFL );
00174         features |= KCPUInfo::AltiVec;
00175     }
00176 #endif // __i386__
00177 #endif //HAVE_GNU_INLINE_ASM
00178 
00179     return features;
00180 }
00181 
00182 unsigned int KCPUInfo::s_features = getCpuFeatures();
00183 
00184 
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This file is part of the documentation for kdefx Library Version 3.4.3.
Documentation copyright © 1996-2004 the KDE developers.
Generated on Sun Oct 9 07:53:38 2005 by doxygen 1.4.4 written by Dimitri van Heesch, © 1997-2003