x86: Set dl_hwcap from CPU featureshjl/hwcap/master

On x86, the usage of AT_HWCAP in glibc is obsolete since addition of
dl_x86_cpu_features.  dl_hwcap, which was set from AT_HWCAP, is used by
dynamic linker to build an array of hardware capability names, which are
added to search path when loading shared object.  dl_hwcap was unused on
x86-64 and only SSE2 was used on i386.

This patch sets dl_hwcap with new hardware capabilities from CPU
features.  Currently, 2 capabilities, SSE2 and AVX2, are supported.
The maximum number of hardware capabilities is 64.  Since x86-64
includes SSE2, SSE2 is skipped on x86-64.  dl_x86_cap_flags is kepted
for i386 and is used by _dl_show_auxv.  dl_x86_hwcap_flags is added
for new hardware capabilities.

	* sysdeps/i386/dl-hwcap.h: New file.
	* sysdeps/x86/dl-hwcap.h: Likewise.
	* sysdeps/x86_64/dl-hwcap.h: Likewise.
	* sysdeps/x86_64/dl-procinfo.h: Likewise.
	* sysdeps/i386/dl-procinfo.c (_dl_x86_hwcap_flags): New.
	* sysdeps/i386/dl-procinfo.h: Include <dl-hwcap.h>.
	(_DL_HWCAP_COUNT): Removed.
	(HWCAP_I386_XXX): Likewise.
	(HWCAP_IMPORTANT): Likewise.
	(_dl_procinfo): Likewise.
	(_dl_hwcap_string): Likewise.
	(_dl_string_hwcap): Likewise.
	* sysdeps/unix/sysv/linux/i386/dl-procinfo.h (_dl_procinfo):
	Replace _DL_HWCAP_COUNT with 32.
	* sysdeps/unix/sysv/linux/x86_64/dl-procinfo.h [!IS_IN (ldconfig)]:
	Include <sysdeps/x86_64/dl-procinfo.h>.
	* sysdeps/x86/cpu-features.c: Include <dl-hwcap.h>.
	(init_cpu_features): Set dl_hwcap and dl_hwcap_mask.
	* sysdeps/x86_64/dl-procinfo.c (_dl_x86_hwcap_flags): New.

10 files changed, 170 insertions, 57 deletions

diff --git a/sysdeps/i386/dl-hwcap.h b/sysdeps/i386/dl-hwcap.h
new file mode 100644
index 0000000000..0e8d95f0cf
--- /dev/null
+++ b/sysdeps/i386/dl-hwcap.h
@@ -0,0 +1,25 @@
+/* i386 version of hardware capability information handling macros.
+   Copyright (C) 2017 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/>.  */
+
+#ifndef _DL_HWCAP_H
+#define _DL_HWCAP_H
+#include <sysdeps/x86/dl-hwcap.h>
+
+#define HWCAP_IMPORTANT		(HWCAP_X86_SSE2 | HWCAP_X86_AVX2)
+
+#endif /* dl-hwcap.h */
diff --git a/sysdeps/i386/dl-procinfo.c b/sysdeps/i386/dl-procinfo.c
index cec7dccfb8..acb800b342 100644
--- a/sysdeps/i386/dl-procinfo.c
+++ b/sysdeps/i386/dl-procinfo.c
@@ -79,6 +79,22 @@ PROCINFO_CLASS const char _dl_x86_cap_flags[32][8]
 #endif
 
 #if !defined PROCINFO_DECL && defined SHARED
+  ._dl_x86_hwcap_flags
+#else
+PROCINFO_CLASS const char _dl_x86_hwcap_flags[2][8]
+#endif
+#ifndef PROCINFO_DECL
+= {
+    "sse2", "avx2"
+  }
+#endif
+#if !defined SHARED || defined PROCINFO_DECL
+;
+#else
+,
+#endif
+
+#if !defined PROCINFO_DECL && defined SHARED
   ._dl_x86_platforms
 #else
 PROCINFO_CLASS const char _dl_x86_platforms[4][5]
diff --git a/sysdeps/i386/dl-procinfo.h b/sysdeps/i386/dl-procinfo.h
index 9c38846f0b..5b9bb4c070 100644
--- a/sysdeps/i386/dl-procinfo.h
+++ b/sysdeps/i386/dl-procinfo.h
@@ -20,8 +20,7 @@
 #ifndef _DL_PROCINFO_H
 #define _DL_PROCINFO_H	1
 #include <ldsodefs.h>
-
-#define _DL_HWCAP_COUNT 32
+#include <dl-hwcap.h>
 
 #define _DL_PLATFORMS_COUNT	4
 
@@ -31,59 +30,6 @@
 #define _DL_HWCAP_PLATFORM	(((1ULL << _DL_PLATFORMS_COUNT) - 1) \
 				 << _DL_FIRST_PLATFORM)
 
-enum
-{
-  HWCAP_I386_FPU   = 1 << 0,
-  HWCAP_I386_VME   = 1 << 1,
-  HWCAP_I386_DE    = 1 << 2,
-  HWCAP_I386_PSE   = 1 << 3,
-  HWCAP_I386_TSC   = 1 << 4,
-  HWCAP_I386_MSR   = 1 << 5,
-  HWCAP_I386_PAE   = 1 << 6,
-  HWCAP_I386_MCE   = 1 << 7,
-  HWCAP_I386_CX8   = 1 << 8,
-  HWCAP_I386_APIC  = 1 << 9,
-  HWCAP_I386_SEP   = 1 << 11,
-  HWCAP_I386_MTRR  = 1 << 12,
-  HWCAP_I386_PGE   = 1 << 13,
-  HWCAP_I386_MCA   = 1 << 14,
-  HWCAP_I386_CMOV  = 1 << 15,
-  HWCAP_I386_FCMOV = 1 << 16,
-  HWCAP_I386_MMX   = 1 << 23,
-  HWCAP_I386_OSFXSR = 1 << 24,
-  HWCAP_I386_XMM   = 1 << 25,
-  HWCAP_I386_XMM2  = 1 << 26,
-  HWCAP_I386_AMD3D = 1 << 31,
-
-  /* XXX Which others to add here?  */
-  HWCAP_IMPORTANT = (HWCAP_I386_XMM2)
-
-};
-
-/* We cannot provide a general printing function.  */
-#define _dl_procinfo(type, word) -1
-
-static inline const char *
-__attribute__ ((unused))
-_dl_hwcap_string (int idx)
-{
-  return GLRO(dl_x86_cap_flags)[idx];
-};
-
-static inline int
-__attribute__ ((unused, always_inline))
-_dl_string_hwcap (const char *str)
-{
-  int i;
-
-  for (i = 0; i < _DL_HWCAP_COUNT; i++)
-    {
-      if (strcmp (str, GLRO(dl_x86_cap_flags)[i]) == 0)
-	return i;
-    }
-  return -1;
-};
-
 static inline int
 __attribute__ ((unused, always_inline))
 _dl_string_platform (const char *str)
diff --git a/sysdeps/unix/sysv/linux/i386/dl-procinfo.h b/sysdeps/unix/sysv/linux/i386/dl-procinfo.h
index d49638c2e0..c8196a81dc 100644
--- a/sysdeps/unix/sysv/linux/i386/dl-procinfo.h
+++ b/sysdeps/unix/sysv/linux/i386/dl-procinfo.h
@@ -36,7 +36,7 @@ _dl_procinfo (unsigned int type, unsigned long int word)
 
   _dl_printf ("AT_HWCAP:   ");
 
-  for (i = 0; i < _DL_HWCAP_COUNT; ++i)
+  for (i = 0; i < 32; ++i)
     if (word & (1 << i))
       _dl_printf (" %s", GLRO(dl_x86_cap_flags)[i]);
 
diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-procinfo.h b/sysdeps/unix/sysv/linux/x86_64/dl-procinfo.h
index 7829e1cd67..dba5cc960f 100644
--- a/sysdeps/unix/sysv/linux/x86_64/dl-procinfo.h
+++ b/sysdeps/unix/sysv/linux/x86_64/dl-procinfo.h
@@ -1,5 +1,5 @@
 #if IS_IN (ldconfig)
 # include <sysdeps/unix/sysv/linux/i386/dl-procinfo.h>
 #else
-# include <sysdeps/generic/dl-procinfo.h>
+# include <sysdeps/x86_64/dl-procinfo.h>
 #endif
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index 33788ed323..10fe2f3f85 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -18,6 +18,7 @@
 
 #include <cpuid.h>
 #include <cpu-features.h>
+#include <dl-hwcap.h>
 
 static void
 get_common_indeces (struct cpu_features *cpu_features,
@@ -302,4 +303,12 @@ no_cpuid:
   cpu_features->family = family;
   cpu_features->model = model;
   cpu_features->kind = kind;
+
+  /* Reuse dl_hwcap and dl_hwcap_mask for x86.  */
+  GLRO(dl_hwcap) = 0;
+  if (CPU_FEATURES_CPU_P (cpu_features, SSE2))
+    GLRO(dl_hwcap) |= HWCAP_X86_SSE2;
+  if (CPU_FEATURES_ARCH_P (cpu_features, AVX2_Usable))
+    GLRO(dl_hwcap) |= HWCAP_X86_AVX2;
+  GLRO(dl_hwcap_mask) = HWCAP_IMPORTANT;
 }
diff --git a/sysdeps/x86/dl-hwcap.h b/sysdeps/x86/dl-hwcap.h
new file mode 100644
index 0000000000..13ff32a485
--- /dev/null
+++ b/sysdeps/x86/dl-hwcap.h
@@ -0,0 +1,48 @@
+/* x86 version of hardware capability information handling macros.
+   Copyright (C) 2017 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/>.  */
+
+#define _DL_HWCAP_COUNT 2
+
+enum
+{
+  HWCAP_X86_SSE2  = 1 << 0,
+  HWCAP_X86_AVX2  = 1 << 1
+};
+
+static inline const char *
+__attribute__ ((unused))
+_dl_hwcap_string (int idx)
+{
+  return GLRO(dl_x86_hwcap_flags)[idx];
+};
+
+static inline int
+__attribute__ ((unused, always_inline))
+_dl_string_hwcap (const char *str)
+{
+  int i;
+
+  for (i = 0; i < _DL_HWCAP_COUNT; i++)
+    {
+      if (strcmp (str, GLRO(dl_x86_hwcap_flags)[i]) == 0)
+	return i;
+    }
+  return -1;
+};
+
+/* We cannot provide a general printing function.  */
+#define _dl_procinfo(type, word) -1
diff --git a/sysdeps/x86_64/dl-hwcap.h b/sysdeps/x86_64/dl-hwcap.h
new file mode 100644
index 0000000000..6e31fa91be
--- /dev/null
+++ b/sysdeps/x86_64/dl-hwcap.h
@@ -0,0 +1,25 @@
+/* x86-64 version of hardware capability information handling macros.
+   Copyright (C) 2017 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/>.  */
+
+#ifndef _DL_HWCAP_H
+#define _DL_HWCAP_H
+#include <sysdeps/x86/dl-hwcap.h>
+
+#define HWCAP_IMPORTANT		(HWCAP_X86_AVX2)
+
+#endif /* dl-hwcap.h */
diff --git a/sysdeps/x86_64/dl-procinfo.c b/sysdeps/x86_64/dl-procinfo.c
index a76624fb06..5ccdb7fbc3 100644
--- a/sysdeps/x86_64/dl-procinfo.c
+++ b/sysdeps/x86_64/dl-procinfo.c
@@ -53,5 +53,21 @@ PROCINFO_CLASS struct cpu_features _dl_x86_cpu_features
 ,
 #endif
 
+#if !defined PROCINFO_DECL && defined SHARED
+  ._dl_x86_hwcap_flags
+#else
+PROCINFO_CLASS const char _dl_x86_hwcap_flags[2][8]
+#endif
+#ifndef PROCINFO_DECL
+= {
+    "sse2", "avx2"
+  }
+#endif
+#if !defined SHARED || defined PROCINFO_DECL
+;
+#else
+,
+#endif
+
 #undef PROCINFO_DECL
 #undef PROCINFO_CLASS
diff --git a/sysdeps/x86_64/dl-procinfo.h b/sysdeps/x86_64/dl-procinfo.h
new file mode 100644
index 0000000000..ddbde2d946
--- /dev/null
+++ b/sysdeps/x86_64/dl-procinfo.h
@@ -0,0 +1,28 @@
+/* x86-64 version of processor capability information handling macros.
+   Copyright (C) 2017 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/>.  */
+
+#ifndef _DL_PROCINFO_H
+#define _DL_PROCINFO_H	1
+#include <dl-hwcap.h>
+
+/* There're no platforms to filter out.  */
+#define _DL_HWCAP_PLATFORM	0
+
+#define _dl_string_platform(str) (-1)
+
+#endif /* dl-procinfo.h */