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d28797e426
There will be more than one function which, in multiarch mode, wants to use SSSE3. We should not test in each of them for Atoms with slow SSSE3. Instead, disable the SSSE3 bit in the startup code for such machines.
89 lines
2.7 KiB
C
89 lines
2.7 KiB
C
/* Initialize CPU feature data.
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This file is part of the GNU C Library.
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Copyright (C) 2008, 2009 Free Software Foundation, Inc.
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Contributed by Ulrich Drepper <drepper@redhat.com>.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include "init-arch.h"
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struct cpu_features __cpu_features attribute_hidden;
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static void
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get_common_indeces (void)
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{
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asm volatile ("cpuid"
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: "=a" (__cpu_features.cpuid[COMMON_CPUID_INDEX_1].eax),
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"=b" (__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ebx),
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"=c" (__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ecx),
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"=d" (__cpu_features.cpuid[COMMON_CPUID_INDEX_1].edx)
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: "0" (1));
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unsigned int eax = __cpu_features.cpuid[COMMON_CPUID_INDEX_1].eax;
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__cpu_features.family = (eax >> 8) & 0x0f;
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__cpu_features.model = (eax >> 4) & 0x0f;
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}
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void
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__init_cpu_features (void)
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{
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unsigned int ebx;
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unsigned int ecx;
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unsigned int edx;
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asm volatile ("cpuid"
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: "=a" (__cpu_features.max_cpuid), "=b" (ebx), "=c" (ecx),
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"=d" (edx)
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: "0" (0));
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/* This spells out "GenuineIntel". */
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if (ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69)
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{
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__cpu_features.kind = arch_kind_intel;
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get_common_indeces ();
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unsigned int eax = __cpu_features.cpuid[COMMON_CPUID_INDEX_1].eax;
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unsigned int extended_family = (eax >> 20) & 0xff;
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unsigned int extended_model = (eax >> 12) & 0xf0;
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if (__cpu_features.family == 0x0f)
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{
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__cpu_features.family += extended_family;
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__cpu_features.model += extended_model;
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}
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else if (__cpu_features.family == 0x06)
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{
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__cpu_features.model += extended_model;
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if (__cpu_features.model == 0x1c)
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/* Avoid SSSE3 on Atom since it is slow. */
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__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ecx &= ~(1 << 9);
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}
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}
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/* This spells out "AuthenticAMD". */
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else if (ebx == 0x68747541 && ecx == 0x444d4163 && edx == 0x69746e65)
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{
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__cpu_features.kind = arch_kind_amd;
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get_common_indeces ();
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}
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else
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__cpu_features.kind = arch_kind_other;
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}
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