Add _dl_x86_cpu_features to rtld_global

This patch adds _dl_x86_cpu_features to rtld_global in x86 ld.so
and initializes it early before __libc_start_main is called so that
cpu_features is always available when it is used and we can avoid
calling __init_cpu_features in IFUNC selectors.

	* sysdeps/i386/dl-machine.h: Include <cpu-features.c>.
	(dl_platform_init): Call init_cpu_features.
	* sysdeps/i386/dl-procinfo.c (_dl_x86_cpu_features): New.
	* sysdeps/i386/i686/cacheinfo.c
	(DISABLE_PREFERRED_MEMORY_INSTRUCTION): Removed.
	* sysdeps/i386/i686/multiarch/Makefile (aux): Remove init-arch.
	* sysdeps/i386/i686/multiarch/Versions: Removed.
	* sysdeps/i386/i686/multiarch/ifunc-defines.sym (KIND_OFFSET):
	Removed.
	* sysdeps/i386/ldsodefs.h: Include <cpu-features.h>.
	* sysdeps/unix/sysv/linux/x86/Makefile
	(libpthread-sysdep_routines): Remove init-arch.
	* sysdeps/unix/sysv/linux/x86_64/dl-procinfo.c: Include
	<sysdeps/x86_64/dl-procinfo.c> instead of
	sysdeps/generic/dl-procinfo.c>.
	* sysdeps/x86/Makefile [$(subdir) == csu] (gen-as-const-headers):
	Add cpu-features-offsets.sym and rtld-global-offsets.sym.
	[$(subdir) == elf] (sysdep-dl-routines): Add dl-get-cpu-features.
	[$(subdir) == elf] (tests): Add tst-get-cpu-features.
	[$(subdir) == elf] (tests-static): Add
	tst-get-cpu-features-static.
	* sysdeps/x86/Versions: New file.
	* sysdeps/x86/cpu-features-offsets.sym: Likewise.
	* sysdeps/x86/cpu-features.c: Likewise.
	* sysdeps/x86/cpu-features.h: Likewise.
	* sysdeps/x86/dl-get-cpu-features.c: Likewise.
	* sysdeps/x86/libc-start.c: Likewise.
	* sysdeps/x86/rtld-global-offsets.sym: Likewise.
	* sysdeps/x86/tst-get-cpu-features-static.c: Likewise.
	* sysdeps/x86/tst-get-cpu-features.c: Likewise.
	* sysdeps/x86_64/dl-procinfo.c: Likewise.
	* sysdeps/x86_64/cacheinfo.c (__cpuid_count): Removed.
	Assume USE_MULTIARCH is defined and don't check it.
	(is_intel): Replace __cpu_features with GLRO(dl_x86_cpu_features).
	(is_amd): Likewise.
	(max_cpuid): Likewise.
	(intel_check_word): Likewise.
	(__cache_sysconf): Don't call __init_cpu_features.
	(__x86_preferred_memory_instruction): Removed.
	(init_cacheinfo): Don't call __init_cpu_features. Replace
	__cpu_features with GLRO(dl_x86_cpu_features).
	* sysdeps/x86_64/dl-machine.h: <cpu-features.c>.
	(dl_platform_init): Call init_cpu_features.
	* sysdeps/x86_64/ldsodefs.h: Include <cpu-features.h>.
	* sysdeps/x86_64/multiarch/Makefile (aux): Remove init-arch.
	* sysdeps/x86_64/multiarch/Versions: Removed.
	* sysdeps/x86_64/multiarch/cacheinfo.c: Likewise.
	* sysdeps/x86_64/multiarch/init-arch.c: Likewise.
	* sysdeps/x86_64/multiarch/ifunc-defines.sym (KIND_OFFSET):
	Removed.
	* sysdeps/x86_64/multiarch/init-arch.h: Rewrite.

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"