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/* Initialize CPU feature data.
This file is part of the GNU C Library.
Copyright (C) 2008, 2009 Free Software Foundation, Inc.
Contributed by Ulrich Drepper <drepper@redhat.com>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include "init-arch.h"
struct cpu_features __cpu_features attribute_hidden;
static void
get_common_indeces (void)
{
asm volatile ("cpuid"
: "=a" (__cpu_features.cpuid[COMMON_CPUID_INDEX_1].eax),
"=b" (__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ebx),
"=c" (__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ecx),
"=d" (__cpu_features.cpuid[COMMON_CPUID_INDEX_1].edx)
: "0" (1));
unsigned int eax = __cpu_features.cpuid[COMMON_CPUID_INDEX_1].eax;
__cpu_features.family = (eax >> 8) & 0x0f;
__cpu_features.model = (eax >> 4) & 0x0f;
}
void
__init_cpu_features (void)
{
unsigned int ebx;
unsigned int ecx;
unsigned int edx;
asm volatile ("cpuid"
: "=a" (__cpu_features.max_cpuid), "=b" (ebx), "=c" (ecx),
"=d" (edx)
: "0" (0));
/* This spells out "GenuineIntel". */
if (ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69)
{
__cpu_features.kind = arch_kind_intel;
get_common_indeces ();
unsigned int eax = __cpu_features.cpuid[COMMON_CPUID_INDEX_1].eax;
unsigned int extended_family = (eax >> 20) & 0xff;
unsigned int extended_model = (eax >> 12) & 0xf0;
if (__cpu_features.family == 0x0f)
{
__cpu_features.family += extended_family;
__cpu_features.model += extended_model;
}
else if (__cpu_features.family == 0x06)
{
__cpu_features.model += extended_model;
if (__cpu_features.model == 0x1c)
/* Avoid SSSE3 on Atom since it is slow. */
__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ecx &= ~(1 << 9);
}
}
/* This spells out "AuthenticAMD". */
else if (ebx == 0x68747541 && ecx == 0x444d4163 && edx == 0x69746e65)
{
__cpu_features.kind = arch_kind_amd;
get_common_indeces ();
}
else
__cpu_features.kind = arch_kind_other;
}
const struct cpu_features *
__get_cpu_features (void)
{
if (__cpu_features.kind == arch_kind_unknown)
__init_cpu_features ();
return &__cpu_features;
}
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