kcpuinfo.cpp
/*
* This file is part of the KDE libraries
* Copyright (C) 2003 Fredrik Höglund <fredrik@kde.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <csignal>
#include <csetjmp>
#include <config.h>
#include "kcpuinfo.h"
#if defined(__GNUC__) || defined(__INTEL_COMPILER)
# define HAVE_GNU_INLINE_ASM
#endif
typedef void (*kde_sighandler_t) (int);
#ifdef __i386__
static jmp_buf env;
// Sighandler for the SSE OS support check
static void sighandler( int )
{
std::longjmp( env, 1 );
}
#endif
#ifdef __PPC__
static sigjmp_buf KDE_NO_EXPORT jmpbuf;
static sig_atomic_t KDE_NO_EXPORT canjump = 0;
static void KDE_NO_EXPORT sigill_handler( int sig )
{
if ( !canjump ) {
signal( sig, SIG_DFL );
raise( sig );
}
canjump = 0;
siglongjmp( jmpbuf, 1 );
}
#endif
static int getCpuFeatures()
{
volatile int features = 0;
#if defined( HAVE_GNU_INLINE_ASM )
#if defined( __i386__ )
bool haveCPUID = false;
bool have3DNOW = false;
int result = 0;
// First check if the CPU supports the CPUID instruction
__asm__ __volatile__(
// Try to toggle the CPUID bit in the EFLAGS register
"pushf \n\t" // Push the EFLAGS register onto the stack
"popl %%ecx \n\t" // Pop the value into ECX
"movl %%ecx, %%edx \n\t" // Copy ECX to EDX
"xorl $0x00200000, %%ecx \n\t" // Toggle bit 21 (CPUID) in ECX
"pushl %%ecx \n\t" // Push the modified value onto the stack
"popf \n\t" // Pop it back into EFLAGS
// Check if the CPUID bit was successfully toggled
"pushf \n\t" // Push EFLAGS back onto the stack
"popl %%ecx \n\t" // Pop the value into ECX
"xorl %%eax, %%eax \n\t" // Zero out the EAX register
"cmpl %%ecx, %%edx \n\t" // Compare ECX with EDX
"je .Lno_cpuid_support%= \n\t" // Jump if they're identical
"movl $1, %%eax \n\t" // Set EAX to true
".Lno_cpuid_support%=: \n\t"
: "=a"(haveCPUID) : : "%ecx", "%edx" );
// If we don't have CPUID we won't have the other extensions either
if ( ! haveCPUID )
return 0L;
// Execute CPUID with the feature request bit set
__asm__ __volatile__(
"pushl %%ebx \n\t" // Save EBX
"movl $1, %%eax \n\t" // Set EAX to 1 (features request)
"cpuid \n\t" // Call CPUID
"popl %%ebx \n\t" // Restore EBX
: "=d"(result) : : "%eax", "%ecx" );
// Test bit 23 (MMX support)
if ( result & 0x00800000 )
features |= KCPUInfo::IntelMMX;
__asm__ __volatile__(
"pushl %%ebx \n\t"
"movl $0x80000000, %%eax \n\t"
"cpuid \n\t"
"cmpl $0x80000000, %%eax \n\t"
"jbe .Lno_extended%= \n\t"
"movl $0x80000001, %%eax \n\t"
"cpuid \n\t"
"test $0x80000000, %%edx \n\t"
"jz .Lno_extended%= \n\t"
"movl $1, %%eax \n\t" // // Set EAX to true
".Lno_extended%=: \n\t"
"popl %%ebx \n\t" // Restore EBX
: "=a"(have3DNOW) : );
if ( have3DNOW )
features |= KCPUInfo::AMD3DNOW;
#ifdef HAVE_X86_SSE
// Test bit 25 (SSE support)
if ( result & 0x00200000 ) {
features |= KCPUInfo::IntelSSE;
// OS support test for SSE.
// Install our own sighandler for SIGILL.
kde_sighandler_t oldhandler = std::signal( SIGILL, sighandler );
// Try executing an SSE insn to see if we get a SIGILL
if ( setjmp( env ) )
features ^= KCPUInfo::IntelSSE; // The OS support test failed
else
__asm__ __volatile__("xorps %xmm0, %xmm0");
// Restore the default sighandler
std::signal( SIGILL, oldhandler );
// Test bit 26 (SSE2 support)
if ( (result & 0x00400000) && (features & KCPUInfo::IntelSSE) )
features |= KCPUInfo::IntelSSE2;
// Note: The OS requirements for SSE2 are the same as for SSE
// so we don't have to do any additional tests for that.
}
#endif // HAVE_X86_SSE
#elif defined __PPC__ && defined HAVE_PPC_ALTIVEC
signal( SIGILL, sigill_handler );
if ( sigsetjmp( jmpbuf, 1 ) ) {
signal( SIGILL, SIG_DFL );
} else {
canjump = 1;
__asm__ __volatile__( "mtspr 256, %0\n\t"
"vand %%v0, %%v0, %%v0"
: /* none */
: "r" (-1) );
signal( SIGILL, SIG_DFL );
features |= KCPUInfo::AltiVec;
}
#endif // __i386__
#endif //HAVE_GNU_INLINE_ASM
return features;
}
unsigned int KCPUInfo::s_features = getCpuFeatures();
KCPUInfo::IntelSSE
Intel's SSE instructions.
Definition: kcpuinfo.h:48
KCPUInfo::IntelMMX
Intel's MMX instructions.
Definition: kcpuinfo.h:47
KCPUInfo::IntelSSE2
Intel's SSE2 instructions.
Definition: kcpuinfo.h:49
KCPUInfo::AMD3DNOW
AMD 3DNOW instructions.
Definition: kcpuinfo.h:50
KCPUInfo::AltiVec
Motorola AltiVec instructions.
Definition: kcpuinfo.h:51

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