x86: Set dl_hwcap from CPU features hjl/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On x86, the usage of AT_HWCAP in glibc is obsolete since addition of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.

1 files changed, 16 insertions, 0 deletions

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]