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-rw-r--r--sysdeps/x86/Makefile11
-rw-r--r--sysdeps/x86/Versions5
-rw-r--r--sysdeps/x86/cpu-features-offsets.sym7
-rw-r--r--sysdeps/x86/cpu-features.c202
-rw-r--r--sysdeps/x86/cpu-features.h240
-rw-r--r--sysdeps/x86/dl-get-cpu-features.c27
-rw-r--r--sysdeps/x86/libc-start.c41
-rw-r--r--sysdeps/x86/rtld-global-offsets.sym7
-rw-r--r--sysdeps/x86/tst-get-cpu-features-static.c1
-rw-r--r--sysdeps/x86/tst-get-cpu-features.c31
10 files changed, 572 insertions, 0 deletions
diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index 19f5eca741..c262fdf487 100644
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -8,3 +8,14 @@ $(objpfx)tst-ld-sse-use.out: ../sysdeps/x86/tst-ld-sse-use.sh $(objpfx)ld.so
$(BASH) $< $(objpfx) '$(NM)' '$(OBJDUMP)' '$(READELF)' > $@; \
$(evaluate-test)
endif
+
+ifeq ($(subdir),csu)
+gen-as-const-headers += cpu-features-offsets.sym rtld-global-offsets.sym
+endif
+
+ifeq ($(subdir),elf)
+sysdep-dl-routines += dl-get-cpu-features
+
+tests += tst-get-cpu-features
+tests-static += tst-get-cpu-features-static
+endif
diff --git a/sysdeps/x86/Versions b/sysdeps/x86/Versions
new file mode 100644
index 0000000000..e02923708e
--- /dev/null
+++ b/sysdeps/x86/Versions
@@ -0,0 +1,5 @@
+ld {
+ GLIBC_PRIVATE {
+ __get_cpu_features;
+ }
+}
diff --git a/sysdeps/x86/cpu-features-offsets.sym b/sysdeps/x86/cpu-features-offsets.sym
new file mode 100644
index 0000000000..a9d53d195f
--- /dev/null
+++ b/sysdeps/x86/cpu-features-offsets.sym
@@ -0,0 +1,7 @@
+#define SHARED 1
+
+#include <ldsodefs.h>
+
+#define rtld_global_ro_offsetof(mem) offsetof (struct rtld_global_ro, mem)
+
+RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET rtld_global_ro_offsetof (_dl_x86_cpu_features)
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
new file mode 100644
index 0000000000..587080c1a4
--- /dev/null
+++ b/sysdeps/x86/cpu-features.c
@@ -0,0 +1,202 @@
+/* Initialize CPU feature data.
+ This file is part of the GNU C Library.
+ Copyright (C) 2008-2015 Free Software Foundation, Inc.
+
+ 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, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <cpuid.h>
+#include <cpu-features.h>
+
+static inline void
+get_common_indeces (struct cpu_features *cpu_features,
+ unsigned int *family, unsigned int *model)
+{
+ unsigned int eax;
+ __cpuid (1, eax, cpu_features->cpuid[COMMON_CPUID_INDEX_1].ebx,
+ cpu_features->cpuid[COMMON_CPUID_INDEX_1].ecx,
+ cpu_features->cpuid[COMMON_CPUID_INDEX_1].edx);
+ GLRO(dl_x86_cpu_features).cpuid[COMMON_CPUID_INDEX_1].eax = eax;
+ *family = (eax >> 8) & 0x0f;
+ *model = (eax >> 4) & 0x0f;
+}
+
+static inline void
+init_cpu_features (struct cpu_features *cpu_features)
+{
+ unsigned int ebx, ecx, edx;
+ unsigned int family = 0;
+ unsigned int model = 0;
+ enum cpu_features_kind kind;
+
+ __cpuid (0, cpu_features->max_cpuid, ebx, ecx, edx);
+
+ /* This spells out "GenuineIntel". */
+ if (ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69)
+ {
+ kind = arch_kind_intel;
+
+ get_common_indeces (cpu_features, &family, &model);
+
+ 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 (family == 0x0f)
+ {
+ family += extended_family;
+ model += extended_model;
+ }
+ else if (family == 0x06)
+ {
+ ecx = cpu_features->cpuid[COMMON_CPUID_INDEX_1].ecx;
+ model += extended_model;
+ switch (model)
+ {
+ case 0x1c:
+ case 0x26:
+ /* BSF is slow on Atom. */
+ cpu_features->feature[index_Slow_BSF] |= bit_Slow_BSF;
+ break;
+
+ case 0x37:
+ case 0x4a:
+ case 0x4d:
+ case 0x5a:
+ case 0x5d:
+ /* Unaligned load versions are faster than SSSE3
+ on Silvermont. */
+#if index_Fast_Unaligned_Load != index_Prefer_PMINUB_for_stringop
+# error index_Fast_Unaligned_Load != index_Prefer_PMINUB_for_stringop
+#endif
+#if index_Fast_Unaligned_Load != index_Slow_SSE4_2
+# error index_Fast_Unaligned_Load != index_Slow_SSE4_2
+#endif
+ cpu_features->feature[index_Fast_Unaligned_Load]
+ |= (bit_Fast_Unaligned_Load
+ | bit_Prefer_PMINUB_for_stringop
+ | bit_Slow_SSE4_2);
+ break;
+
+ default:
+ /* Unknown family 0x06 processors. Assuming this is one
+ of Core i3/i5/i7 processors if AVX is available. */
+ if ((ecx & bit_AVX) == 0)
+ break;
+
+ case 0x1a:
+ case 0x1e:
+ case 0x1f:
+ case 0x25:
+ case 0x2c:
+ case 0x2e:
+ case 0x2f:
+ /* Rep string instructions, copy backward, unaligned loads
+ and pminub are fast on Intel Core i3, i5 and i7. */
+#if index_Fast_Rep_String != index_Fast_Copy_Backward
+# error index_Fast_Rep_String != index_Fast_Copy_Backward
+#endif
+#if index_Fast_Rep_String != index_Fast_Unaligned_Load
+# error index_Fast_Rep_String != index_Fast_Unaligned_Load
+#endif
+#if index_Fast_Rep_String != index_Prefer_PMINUB_for_stringop
+# error index_Fast_Rep_String != index_Prefer_PMINUB_for_stringop
+#endif
+ cpu_features->feature[index_Fast_Rep_String]
+ |= (bit_Fast_Rep_String
+ | bit_Fast_Copy_Backward
+ | bit_Fast_Unaligned_Load
+ | bit_Prefer_PMINUB_for_stringop);
+ break;
+ }
+ }
+ }
+ /* This spells out "AuthenticAMD". */
+ else if (ebx == 0x68747541 && ecx == 0x444d4163 && edx == 0x69746e65)
+ {
+ kind = arch_kind_amd;
+
+ get_common_indeces (cpu_features, &family, &model);
+
+ ecx = cpu_features->cpuid[COMMON_CPUID_INDEX_1].ecx;
+
+ unsigned int eax;
+ __cpuid (0x80000000, eax, ebx, ecx, edx);
+ if (eax >= 0x80000001)
+ __cpuid (0x80000001,
+ cpu_features->cpuid[COMMON_CPUID_INDEX_80000001].eax,
+ cpu_features->cpuid[COMMON_CPUID_INDEX_80000001].ebx,
+ cpu_features->cpuid[COMMON_CPUID_INDEX_80000001].ecx,
+ cpu_features->cpuid[COMMON_CPUID_INDEX_80000001].edx);
+ }
+ else
+ kind = arch_kind_other;
+
+ if (cpu_features->max_cpuid >= 7)
+ __cpuid_count (7, 0,
+ cpu_features->cpuid[COMMON_CPUID_INDEX_7].eax,
+ cpu_features->cpuid[COMMON_CPUID_INDEX_7].ebx,
+ cpu_features->cpuid[COMMON_CPUID_INDEX_7].ecx,
+ cpu_features->cpuid[COMMON_CPUID_INDEX_7].edx);
+
+ /* Can we call xgetbv? */
+ if (HAS_CPU_FEATURE (OSXSAVE))
+ {
+ unsigned int xcrlow;
+ unsigned int xcrhigh;
+ asm ("xgetbv" : "=a" (xcrlow), "=d" (xcrhigh) : "c" (0));
+ /* Is YMM and XMM state usable? */
+ if ((xcrlow & (bit_YMM_state | bit_XMM_state)) ==
+ (bit_YMM_state | bit_XMM_state))
+ {
+ /* Determine if AVX is usable. */
+ if (HAS_CPU_FEATURE (AVX))
+ cpu_features->feature[index_AVX_Usable] |= bit_AVX_Usable;
+#if index_AVX2_Usable != index_AVX_Fast_Unaligned_Load
+# error index_AVX2_Usable != index_AVX_Fast_Unaligned_Load
+#endif
+ /* Determine if AVX2 is usable. Unaligned load with 256-bit
+ AVX registers are faster on processors with AVX2. */
+ if (HAS_CPU_FEATURE (AVX2))
+ cpu_features->feature[index_AVX2_Usable]
+ |= bit_AVX2_Usable | bit_AVX_Fast_Unaligned_Load;
+ /* Check if OPMASK state, upper 256-bit of ZMM0-ZMM15 and
+ ZMM16-ZMM31 state are enabled. */
+ if ((xcrlow & (bit_Opmask_state | bit_ZMM0_15_state
+ | bit_ZMM16_31_state)) ==
+ (bit_Opmask_state | bit_ZMM0_15_state | bit_ZMM16_31_state))
+ {
+ /* Determine if AVX512F is usable. */
+ if (HAS_CPU_FEATURE (AVX512F))
+ {
+ cpu_features->feature[index_AVX512F_Usable]
+ |= bit_AVX512F_Usable;
+ /* Determine if AVX512DQ is usable. */
+ if (HAS_CPU_FEATURE (AVX512DQ))
+ cpu_features->feature[index_AVX512DQ_Usable]
+ |= bit_AVX512DQ_Usable;
+ }
+ }
+ /* Determine if FMA is usable. */
+ if (HAS_CPU_FEATURE (FMA))
+ cpu_features->feature[index_FMA_Usable] |= bit_FMA_Usable;
+ /* Determine if FMA4 is usable. */
+ if (HAS_CPU_FEATURE (FMA4))
+ cpu_features->feature[index_FMA4_Usable] |= bit_FMA4_Usable;
+ }
+ }
+
+ cpu_features->family = family;
+ cpu_features->model = model;
+ cpu_features->kind = kind;
+}
diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h
new file mode 100644
index 0000000000..22e5abb919
--- /dev/null
+++ b/sysdeps/x86/cpu-features.h
@@ -0,0 +1,240 @@
+/* This file is part of the GNU C Library.
+ Copyright (C) 2008-2015 Free Software Foundation, Inc.
+
+ 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, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef cpu_features_h
+#define cpu_features_h
+
+#define bit_Fast_Rep_String (1 << 0)
+#define bit_Fast_Copy_Backward (1 << 1)
+#define bit_Slow_BSF (1 << 2)
+#define bit_Fast_Unaligned_Load (1 << 4)
+#define bit_Prefer_PMINUB_for_stringop (1 << 5)
+#define bit_AVX_Usable (1 << 6)
+#define bit_FMA_Usable (1 << 7)
+#define bit_FMA4_Usable (1 << 8)
+#define bit_Slow_SSE4_2 (1 << 9)
+#define bit_AVX2_Usable (1 << 10)
+#define bit_AVX_Fast_Unaligned_Load (1 << 11)
+#define bit_AVX512F_Usable (1 << 12)
+#define bit_AVX512DQ_Usable (1 << 13)
+
+/* CPUID Feature flags. */
+
+/* COMMON_CPUID_INDEX_1. */
+#define bit_SSE2 (1 << 26)
+#define bit_SSSE3 (1 << 9)
+#define bit_SSE4_1 (1 << 19)
+#define bit_SSE4_2 (1 << 20)
+#define bit_OSXSAVE (1 << 27)
+#define bit_AVX (1 << 28)
+#define bit_POPCOUNT (1 << 23)
+#define bit_FMA (1 << 12)
+#define bit_FMA4 (1 << 16)
+
+/* COMMON_CPUID_INDEX_7. */
+#define bit_RTM (1 << 11)
+#define bit_AVX2 (1 << 5)
+#define bit_AVX512F (1 << 16)
+#define bit_AVX512DQ (1 << 17)
+
+/* XCR0 Feature flags. */
+#define bit_XMM_state (1 << 1)
+#define bit_YMM_state (2 << 1)
+#define bit_Opmask_state (1 << 5)
+#define bit_ZMM0_15_state (1 << 6)
+#define bit_ZMM16_31_state (1 << 7)
+
+/* The integer bit array index for the first set of internal feature bits. */
+#define FEATURE_INDEX_1 0
+
+/* The current maximum size of the feature integer bit array. */
+#define FEATURE_INDEX_MAX 1
+
+#ifdef __ASSEMBLER__
+
+# include <ifunc-defines.h>
+# include <rtld-global-offsets.h>
+
+# define index_SSE2 COMMON_CPUID_INDEX_1*CPUID_SIZE+CPUID_EDX_OFFSET
+# define index_SSSE3 COMMON_CPUID_INDEX_1*CPUID_SIZE+CPUID_ECX_OFFSET
+# define index_SSE4_1 COMMON_CPUID_INDEX_1*CPUID_SIZE+CPUID_ECX_OFFSET
+# define index_SSE4_2 COMMON_CPUID_INDEX_1*CPUID_SIZE+CPUID_ECX_OFFSET
+# define index_AVX COMMON_CPUID_INDEX_1*CPUID_SIZE+CPUID_ECX_OFFSET
+# define index_AVX2 COMMON_CPUID_INDEX_7*CPUID_SIZE+CPUID_EBX_OFFSET
+
+# define index_Fast_Rep_String FEATURE_INDEX_1*FEATURE_SIZE
+# define index_Fast_Copy_Backward FEATURE_INDEX_1*FEATURE_SIZE
+# define index_Slow_BSF FEATURE_INDEX_1*FEATURE_SIZE
+# define index_Fast_Unaligned_Load FEATURE_INDEX_1*FEATURE_SIZE
+# define index_Prefer_PMINUB_for_stringop FEATURE_INDEX_1*FEATURE_SIZE
+# define index_AVX_Usable FEATURE_INDEX_1*FEATURE_SIZE
+# define index_FMA_Usable FEATURE_INDEX_1*FEATURE_SIZE
+# define index_FMA4_Usable FEATURE_INDEX_1*FEATURE_SIZE
+# define index_Slow_SSE4_2 FEATURE_INDEX_1*FEATURE_SIZE
+# define index_AVX2_Usable FEATURE_INDEX_1*FEATURE_SIZE
+# define index_AVX_Fast_Unaligned_Load FEATURE_INDEX_1*FEATURE_SIZE
+# define index_AVX512F_Usable FEATURE_INDEX_1*FEATURE_SIZE
+# define index_AVX512DQ_Usable FEATURE_INDEX_1*FEATURE_SIZE
+
+# if defined (_LIBC) && !IS_IN (nonlib)
+# ifdef __x86_64__
+# ifdef SHARED
+# if IS_IN (rtld)
+# define LOAD_RTLD_GLOBAL_RO_RDX
+# define HAS_FEATURE(offset, name) \
+ testl $(bit_##name), _rtld_local_ro+offset+(index_##name)(%rip)
+# else
+# define LOAD_RTLD_GLOBAL_RO_RDX \
+ mov _rtld_global_ro@GOTPCREL(%rip), %RDX_LP
+# define HAS_FEATURE(offset, name) \
+ testl $(bit_##name), \
+ RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET+offset+(index_##name)(%rdx)
+# endif
+# else /* SHARED */
+# define LOAD_RTLD_GLOBAL_RO_RDX
+# define HAS_FEATURE(offset, name) \
+ testl $(bit_##name), _dl_x86_cpu_features+offset+(index_##name)(%rip)
+# endif /* !SHARED */
+# else /* __x86_64__ */
+# ifdef SHARED
+# define LOAD_FUNC_GOT_EAX(func) \
+ leal func@GOTOFF(%edx), %eax
+# if IS_IN (rtld)
+# define LOAD_GOT_AND_RTLD_GLOBAL_RO \
+ LOAD_PIC_REG(dx)
+# define HAS_FEATURE(offset, name) \
+ testl $(bit_##name), offset+(index_##name)+_rtld_local_ro@GOTOFF(%edx)
+# else
+# define LOAD_GOT_AND_RTLD_GLOBAL_RO \
+ LOAD_PIC_REG(dx); \
+ mov _rtld_global_ro@GOT(%edx), %ecx
+# define HAS_FEATURE(offset, name) \
+ testl $(bit_##name), \
+ RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET+offset+(index_##name)(%ecx)
+# endif
+# else /* SHARED */
+# define LOAD_FUNC_GOT_EAX(func) \
+ leal func, %eax
+# define LOAD_GOT_AND_RTLD_GLOBAL_RO
+# define HAS_FEATURE(offset, name) \
+ testl $(bit_##name), _dl_x86_cpu_features+offset+(index_##name)
+# endif /* !SHARED */
+# endif /* !__x86_64__ */
+# else /* _LIBC && !nonlib */
+# error "Sorry, <cpu-features.h> is unimplemented for assembler"
+# endif /* !_LIBC || nonlib */
+
+/* HAS_* evaluates to true if we may use the feature at runtime. */
+# define HAS_CPU_FEATURE(name) HAS_FEATURE (CPUID_OFFSET, name)
+# define HAS_ARCH_FEATURE(name) HAS_FEATURE (FEATURE_OFFSET, name)
+
+#else /* __ASSEMBLER__ */
+
+enum
+ {
+ COMMON_CPUID_INDEX_1 = 0,
+ COMMON_CPUID_INDEX_7,
+ COMMON_CPUID_INDEX_80000001, /* for AMD */
+ /* Keep the following line at the end. */
+ COMMON_CPUID_INDEX_MAX
+ };
+
+struct cpu_features
+{
+ enum cpu_features_kind
+ {
+ arch_kind_unknown = 0,
+ arch_kind_intel,
+ arch_kind_amd,
+ arch_kind_other
+ } kind;
+ int max_cpuid;
+ struct cpuid_registers
+ {
+ unsigned int eax;
+ unsigned int ebx;
+ unsigned int ecx;
+ unsigned int edx;
+ } cpuid[COMMON_CPUID_INDEX_MAX];
+ unsigned int family;
+ unsigned int model;
+ unsigned int feature[FEATURE_INDEX_MAX];
+};
+
+/* Used from outside of glibc to get access to the CPU features
+ structure. */
+extern const struct cpu_features *__get_cpu_features (void)
+ __attribute__ ((const));
+
+# if defined (_LIBC) && !IS_IN (nonlib)
+/* Unused for x86. */
+# define INIT_ARCH()
+# define __get_cpu_features() (&GLRO(dl_x86_cpu_features))
+# endif
+
+
+/* HAS_* evaluates to true if we may use the feature at runtime. */
+# define HAS_CPU_FEATURE(name) \
+ ((__get_cpu_features ()->cpuid[index_##name].reg_##name & (bit_##name)) != 0)
+# define HAS_ARCH_FEATURE(name) \
+ ((__get_cpu_features ()->feature[index_##name] & (bit_##name)) != 0)
+
+# define index_SSE2 COMMON_CPUID_INDEX_1
+# define index_SSSE3 COMMON_CPUID_INDEX_1
+# define index_SSE4_1 COMMON_CPUID_INDEX_1
+# define index_SSE4_2 COMMON_CPUID_INDEX_1
+# define index_AVX COMMON_CPUID_INDEX_1
+# define index_AVX2 COMMON_CPUID_INDEX_7
+# define index_AVX512F COMMON_CPUID_INDEX_7
+# define index_AVX512DQ COMMON_CPUID_INDEX_7
+# define index_RTM COMMON_CPUID_INDEX_7
+# define index_FMA COMMON_CPUID_INDEX_1
+# define index_FMA4 COMMON_CPUID_INDEX_80000001
+# define index_POPCOUNT COMMON_CPUID_INDEX_1
+# define index_OSXSAVE COMMON_CPUID_INDEX_1
+
+# define reg_SSE2 edx
+# define reg_SSSE3 ecx
+# define reg_SSE4_1 ecx
+# define reg_SSE4_2 ecx
+# define reg_AVX ecx
+# define reg_AVX2 ebx
+# define reg_AVX512F ebx
+# define reg_AVX512DQ ebx
+# define reg_RTM ebx
+# define reg_FMA ecx
+# define reg_FMA4 ecx
+# define reg_POPCOUNT ecx
+# define reg_OSXSAVE ecx
+
+# define index_Fast_Rep_String FEATURE_INDEX_1
+# define index_Fast_Copy_Backward FEATURE_INDEX_1
+# define index_Slow_BSF FEATURE_INDEX_1
+# define index_Fast_Unaligned_Load FEATURE_INDEX_1
+# define index_Prefer_PMINUB_for_stringop FEATURE_INDEX_1
+# define index_AVX_Usable FEATURE_INDEX_1
+# define index_FMA_Usable FEATURE_INDEX_1
+# define index_FMA4_Usable FEATURE_INDEX_1
+# define index_Slow_SSE4_2 FEATURE_INDEX_1
+# define index_AVX2_Usable FEATURE_INDEX_1
+# define index_AVX_Fast_Unaligned_Load FEATURE_INDEX_1
+# define index_AVX512F_Usable FEATURE_INDEX_1
+# define index_AVX512DQ_Usable FEATURE_INDEX_1
+
+#endif /* !__ASSEMBLER__ */
+
+#endif /* cpu_features_h */
diff --git a/sysdeps/x86/dl-get-cpu-features.c b/sysdeps/x86/dl-get-cpu-features.c
new file mode 100644
index 0000000000..080e5e8532
--- /dev/null
+++ b/sysdeps/x86/dl-get-cpu-features.c
@@ -0,0 +1,27 @@
+/* This file is part of the GNU C Library.
+ Copyright (C) 2015 Free Software Foundation, Inc.
+
+ 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, see
+ <http://www.gnu.org/licenses/>. */
+
+
+#include <ldsodefs.h>
+
+#undef __get_cpu_features
+
+const struct cpu_features *
+__get_cpu_features (void)
+{
+ return &GLRO(dl_x86_cpu_features);
+}
diff --git a/sysdeps/x86/libc-start.c b/sysdeps/x86/libc-start.c
new file mode 100644
index 0000000000..9f0c0457c1
--- /dev/null
+++ b/sysdeps/x86/libc-start.c
@@ -0,0 +1,41 @@
+/* Copyright (C) 2015 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifdef SHARED
+# include <csu/libc-start.c>
+# else
+/* The main work is done in the generic function. */
+# define LIBC_START_DISABLE_INLINE
+# define LIBC_START_MAIN generic_start_main
+# include <csu/libc-start.c>
+# include <cpu-features.h>
+# include <cpu-features.c>
+
+extern struct cpu_features _dl_x86_cpu_features;
+
+int
+__libc_start_main (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
+ int argc, char **argv,
+ __typeof (main) init,
+ void (*fini) (void),
+ void (*rtld_fini) (void), void *stack_end)
+{
+ init_cpu_features (&_dl_x86_cpu_features);
+ return generic_start_main (main, argc, argv, init, fini, rtld_fini,
+ stack_end);
+}
+#endif
diff --git a/sysdeps/x86/rtld-global-offsets.sym b/sysdeps/x86/rtld-global-offsets.sym
new file mode 100644
index 0000000000..a9d53d195f
--- /dev/null
+++ b/sysdeps/x86/rtld-global-offsets.sym
@@ -0,0 +1,7 @@
+#define SHARED 1
+
+#include <ldsodefs.h>
+
+#define rtld_global_ro_offsetof(mem) offsetof (struct rtld_global_ro, mem)
+
+RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET rtld_global_ro_offsetof (_dl_x86_cpu_features)
diff --git a/sysdeps/x86/tst-get-cpu-features-static.c b/sysdeps/x86/tst-get-cpu-features-static.c
new file mode 100644
index 0000000000..03f59060c5
--- /dev/null
+++ b/sysdeps/x86/tst-get-cpu-features-static.c
@@ -0,0 +1 @@
+#include "tst-get-cpu-features.c"
diff --git a/sysdeps/x86/tst-get-cpu-features.c b/sysdeps/x86/tst-get-cpu-features.c
new file mode 100644
index 0000000000..c17060f5e1
--- /dev/null
+++ b/sysdeps/x86/tst-get-cpu-features.c
@@ -0,0 +1,31 @@
+/* Test case for x86 __get_cpu_features interface
+ Copyright (C) 2015 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <stdlib.h>
+#include <cpu-features.h>
+
+static int
+do_test (void)
+{
+ if (__get_cpu_features ()->kind == arch_kind_unknown)
+ abort ();
+ return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../../test-skeleton.c"