Update.

2004-03-12  Ulrich Drepper  <drepper@redhat.com>

	* posix/getconf.c (vars): Add _SC_ values for cache information.
	* sysdeps/generic/bits/confname.h: Add _SC_* values for cache
	information.
	* sysdeps/unix/sysv/linux/sysconf.c (__sysconf): Reorganize to
	allow yet another sysconf function to include the one in this file.
	* sysdeps/unix/sysv/linux/i386/sysconf.c: New file.
	* sysdeps/generic/sysconf.c: Add default handling for cache line info.

7 files changed, 453 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index 2508ca43ae..accae8f842 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2004-03-12  Ulrich Drepper  <drepper@redhat.com>
+
+	* posix/getconf.c (vars): Add _SC_ values for cache information.
+	* sysdeps/generic/bits/confname.h: Add _SC_* values for cache
+	information.
+	* sysdeps/unix/sysv/linux/sysconf.c (__sysconf): Reorganize to
+	allow yet another sysconf function to include the one in this file.
+	* sysdeps/unix/sysv/linux/i386/sysconf.c: New file.
+	* sysdeps/generic/sysconf.c: Add default handling for cache line info.
+
 2004-03-11  Ulrich Drepper  <drepper@redhat.com>
 
 	* sysdeps/posix/sysconf.c (__sysconf): Add missing support for
diff --git a/bits/confname.h b/bits/confname.h
index a12edab698..d097a4ba1a 100644
--- a/bits/confname.h
+++ b/bits/confname.h
@@ -1,5 +1,6 @@
 /* `sysconf', `pathconf', and `confstr' NAME values.  Generic version.
-   Copyright (C) 1993,1995-1998,2000,2001,2003 Free Software Foundation, Inc.
+   Copyright (C) 1993,1995-1998,2000,2001,2003,2004
+   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
@@ -460,8 +461,40 @@ enum
 #define _SC_TRACE_EVENT_FILTER		_SC_TRACE_EVENT_FILTER
     _SC_TRACE_INHERIT,
 #define _SC_TRACE_INHERIT		_SC_TRACE_INHERIT
-    _SC_TRACE_LOG
+    _SC_TRACE_LOG,
 #define _SC_TRACE_LOG			_SC_TRACE_LOG
+
+    _SC_LEVEL1_ICACHE_SIZE,
+#define _SC_LEVEL1_ICACHE_SIZE		_SC_LEVEL1_ICACHE_SIZE
+    _SC_LEVEL1_ICACHE_ASSOC,
+#define _SC_LEVEL1_ICACHE_ASSOC		_SC_LEVEL1_ICACHE_ASSOC
+    _SC_LEVEL1_ICACHE_LINESIZE,
+#define _SC_LEVEL1_ICACHE_LINESIZE	_SC_LEVEL1_ICACHE_LINESIZE
+    _SC_LEVEL1_DCACHE_SIZE,
+#define _SC_LEVEL1_DCACHE_SIZE		_SC_LEVEL1_DCACHE_SIZE
+    _SC_LEVEL1_DCACHE_ASSOC,
+#define _SC_LEVEL1_DCACHE_ASSOC		_SC_LEVEL1_DCACHE_ASSOC
+    _SC_LEVEL1_DCACHE_LINESIZE,
+#define _SC_LEVEL1_DCACHE_LINESIZE	_SC_LEVEL1_DCACHE_LINESIZE
+    _SC_LEVEL2_CACHE_SIZE,
+#define _SC_LEVEL2_CACHE_SIZE		_SC_LEVEL2_CACHE_SIZE
+    _SC_LEVEL2_CACHE_ASSOC,
+#define _SC_LEVEL2_CACHE_ASSOC		_SC_LEVEL2_CACHE_ASSOC
+    _SC_LEVEL2_CACHE_LINESIZE,
+#define _SC_LEVEL2_CACHE_LINESIZE	_SC_LEVEL2_CACHE_LINESIZE
+    _SC_LEVEL3_CACHE_SIZE,
+#define _SC_LEVEL3_CACHE_SIZE		_SC_LEVEL3_CACHE_SIZE
+    _SC_LEVEL3_CACHE_ASSOC,
+#define _SC_LEVEL3_CACHE_ASSOC		_SC_LEVEL3_CACHE_ASSOC
+    _SC_LEVEL3_CACHE_LINESIZE,
+#define _SC_LEVEL3_CACHE_LINESIZE	_SC_LEVEL3_CACHE_LINESIZE
+    _SC_LEVEL4_CACHE_SIZE,
+#define _SC_LEVEL4_CACHE_SIZE		_SC_LEVEL4_CACHE_SIZE
+    _SC_LEVEL4_CACHE_ASSOC,
+#define _SC_LEVEL4_CACHE_ASSOC		_SC_LEVEL4_CACHE_ASSOC
+    _SC_LEVEL4_CACHE_LINESIZE
+#define _SC_LEVEL4_CACHE_LINESIZE	_SC_LEVEL4_CACHE_LINESIZE
+    /* Leave room here, maybe we need a few more cache levels some day.  */
   };
 
 /* Values for the NAME argument to `confstr'.  */
diff --git a/posix/getconf.c b/posix/getconf.c
index 47c5931627..2f68003ff3 100644
--- a/posix/getconf.c
+++ b/posix/getconf.c
@@ -869,6 +869,50 @@ static const struct conf vars[] =
     { "POSIX2_SYMLINKS", _PC_2_SYMLINKS, PATHCONF },
 #endif
 
+#ifdef _SC_LEVEL1_ICACHE_SIZE
+    { "LEVEL1_ICACHE_SIZE", _SC_LEVEL1_ICACHE_SIZE, SYSCONF },
+#endif
+#ifdef _SC_LEVEL1_ICACHE_ASSOC
+    { "LEVEL1_ICACHE_ASSOC", _SC_LEVEL1_ICACHE_ASSOC, SYSCONF },
+#endif
+#ifdef _SC_LEVEL1_ICACHE_LINESIZE
+    { "LEVEL1_ICACHE_LINESIZE", _SC_LEVEL1_ICACHE_LINESIZE, SYSCONF },
+#endif
+#ifdef _SC_LEVEL1_DCACHE_SIZE
+    { "LEVEL1_DCACHE_SIZE", _SC_LEVEL1_DCACHE_SIZE, SYSCONF },
+#endif
+#ifdef _SC_LEVEL1_DCACHE_ASSOC
+    { "LEVEL1_DCACHE_ASSOC", _SC_LEVEL1_DCACHE_ASSOC, SYSCONF },
+#endif
+#ifdef _SC_LEVEL1_DCACHE_LINESIZE
+    { "LEVEL1_DCACHE_LINESIZE", _SC_LEVEL1_DCACHE_LINESIZE, SYSCONF },
+#endif
+#ifdef _SC_LEVEL2_CACHE_SIZE
+    { "LEVEL2_CACHE_SIZE", _SC_LEVEL2_CACHE_SIZE, SYSCONF },
+#endif
+#ifdef _SC_LEVEL2_CACHE_ASSOC
+    { "LEVEL2_CACHE_ASSOC", _SC_LEVEL2_CACHE_ASSOC, SYSCONF },
+#endif
+#ifdef _SC_LEVEL2_CACHE_LINESIZE
+    { "LEVEL2_CACHE_LINESIZE", _SC_LEVEL2_CACHE_LINESIZE, SYSCONF },
+#endif
+#ifdef _SC_LEVEL3_CACHE_SIZE
+    { "LEVEL3_CACHE_SIZE", _SC_LEVEL3_CACHE_SIZE, SYSCONF },
+#endif
+#ifdef _SC_LEVEL3_CACHE_ASSOC
+    { "LEVEL3_CACHE_ASSOC", _SC_LEVEL3_CACHE_ASSOC, SYSCONF },
+#endif
+#ifdef _SC_LEVEL3_CACHE_LINESIZE
+    { "LEVEL3_CACHE_LINESIZE", _SC_LEVEL3_CACHE_LINESIZE, SYSCONF },
+#endif
+#ifdef _SC_LEVEL4_CACHE_SIZE
+    { "LEVEL4_CACHE_SIZE", _SC_LEVEL4_CACHE_SIZE, SYSCONF },
+#endif
+#ifdef _SC_LEVEL4_CACHE_ASSOC
+    { "LEVEL4_CACHE_ASSOC", _SC_LEVEL4_CACHE_ASSOC, SYSCONF },
+#endif
+
+
     { NULL, 0, SYSCONF }
   };
 
diff --git a/sysdeps/generic/bits/confname.h b/sysdeps/generic/bits/confname.h
index a12edab698..d097a4ba1a 100644
--- a/sysdeps/generic/bits/confname.h
+++ b/sysdeps/generic/bits/confname.h
@@ -1,5 +1,6 @@
 /* `sysconf', `pathconf', and `confstr' NAME values.  Generic version.
-   Copyright (C) 1993,1995-1998,2000,2001,2003 Free Software Foundation, Inc.
+   Copyright (C) 1993,1995-1998,2000,2001,2003,2004
+   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
@@ -460,8 +461,40 @@ enum
 #define _SC_TRACE_EVENT_FILTER		_SC_TRACE_EVENT_FILTER
     _SC_TRACE_INHERIT,
 #define _SC_TRACE_INHERIT		_SC_TRACE_INHERIT
-    _SC_TRACE_LOG
+    _SC_TRACE_LOG,
 #define _SC_TRACE_LOG			_SC_TRACE_LOG
+
+    _SC_LEVEL1_ICACHE_SIZE,
+#define _SC_LEVEL1_ICACHE_SIZE		_SC_LEVEL1_ICACHE_SIZE
+    _SC_LEVEL1_ICACHE_ASSOC,
+#define _SC_LEVEL1_ICACHE_ASSOC		_SC_LEVEL1_ICACHE_ASSOC
+    _SC_LEVEL1_ICACHE_LINESIZE,
+#define _SC_LEVEL1_ICACHE_LINESIZE	_SC_LEVEL1_ICACHE_LINESIZE
+    _SC_LEVEL1_DCACHE_SIZE,
+#define _SC_LEVEL1_DCACHE_SIZE		_SC_LEVEL1_DCACHE_SIZE
+    _SC_LEVEL1_DCACHE_ASSOC,
+#define _SC_LEVEL1_DCACHE_ASSOC		_SC_LEVEL1_DCACHE_ASSOC
+    _SC_LEVEL1_DCACHE_LINESIZE,
+#define _SC_LEVEL1_DCACHE_LINESIZE	_SC_LEVEL1_DCACHE_LINESIZE
+    _SC_LEVEL2_CACHE_SIZE,
+#define _SC_LEVEL2_CACHE_SIZE		_SC_LEVEL2_CACHE_SIZE
+    _SC_LEVEL2_CACHE_ASSOC,
+#define _SC_LEVEL2_CACHE_ASSOC		_SC_LEVEL2_CACHE_ASSOC
+    _SC_LEVEL2_CACHE_LINESIZE,
+#define _SC_LEVEL2_CACHE_LINESIZE	_SC_LEVEL2_CACHE_LINESIZE
+    _SC_LEVEL3_CACHE_SIZE,
+#define _SC_LEVEL3_CACHE_SIZE		_SC_LEVEL3_CACHE_SIZE
+    _SC_LEVEL3_CACHE_ASSOC,
+#define _SC_LEVEL3_CACHE_ASSOC		_SC_LEVEL3_CACHE_ASSOC
+    _SC_LEVEL3_CACHE_LINESIZE,
+#define _SC_LEVEL3_CACHE_LINESIZE	_SC_LEVEL3_CACHE_LINESIZE
+    _SC_LEVEL4_CACHE_SIZE,
+#define _SC_LEVEL4_CACHE_SIZE		_SC_LEVEL4_CACHE_SIZE
+    _SC_LEVEL4_CACHE_ASSOC,
+#define _SC_LEVEL4_CACHE_ASSOC		_SC_LEVEL4_CACHE_ASSOC
+    _SC_LEVEL4_CACHE_LINESIZE
+#define _SC_LEVEL4_CACHE_LINESIZE	_SC_LEVEL4_CACHE_LINESIZE
+    /* Leave room here, maybe we need a few more cache levels some day.  */
   };
 
 /* Values for the NAME argument to `confstr'.  */
diff --git a/sysdeps/posix/sysconf.c b/sysdeps/posix/sysconf.c
index 584a44fb41..66f978ba3b 100644
--- a/sysdeps/posix/sysconf.c
+++ b/sysdeps/posix/sysconf.c
@@ -1164,6 +1164,25 @@ __sysconf (name)
 #else
       return -1;
 #endif
+
+    case _SC_LEVEL1_ICACHE_SIZE:
+    case _SC_LEVEL1_ICACHE_ASSOC:
+    case _SC_LEVEL1_ICACHE_LINESIZE:
+    case _SC_LEVEL1_DCACHE_SIZE:
+    case _SC_LEVEL1_DCACHE_ASSOC:
+    case _SC_LEVEL1_DCACHE_LINESIZE:
+    case _SC_LEVEL2_CACHE_SIZE:
+    case _SC_LEVEL2_CACHE_ASSOC:
+    case _SC_LEVEL2_CACHE_LINESIZE:
+    case _SC_LEVEL3_CACHE_SIZE:
+    case _SC_LEVEL3_CACHE_ASSOC:
+    case _SC_LEVEL3_CACHE_LINESIZE:
+    case _SC_LEVEL4_CACHE_SIZE:
+    case _SC_LEVEL4_CACHE_ASSOC:
+      /* In general we cannot determine these values.  Therefore we
+	 return zero which indicates that no information is
+	 available.  */
+      return 0;
     }
 }
 
diff --git a/sysdeps/unix/sysv/linux/i386/sysconf.c b/sysdeps/unix/sysv/linux/i386/sysconf.c
new file mode 100644
index 0000000000..067c752924
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/i386/sysconf.c
@@ -0,0 +1,304 @@
+/* Get file-specific information about a file.  Linux version.
+   Copyright (C) 2003, 2004 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+
+static long int linux_sysconf (int name);
+
+
+static long int
+handle_i486 (int name)
+{
+  /* The processor only has a unified level 1 cache of 8k.  */
+  switch (name)
+    {
+    case _SC_LEVEL1_ICACHE_SIZE:
+    case _SC_LEVEL1_DCACHE_SIZE:
+      return 8 * 1024;
+
+    case _SC_LEVEL1_ICACHE_ASSOC:
+    case _SC_LEVEL1_DCACHE_ASSOC:
+      // XXX Anybody know this?
+      return 0;
+
+    case _SC_LEVEL1_ICACHE_LINESIZE:
+    case _SC_LEVEL1_DCACHE_LINESIZE:
+      // XXX Anybody know for sure?
+      return 16;
+
+    case _SC_LEVEL2_CACHE_SIZE:
+    case _SC_LEVEL2_CACHE_ASSOC:
+    case _SC_LEVEL2_CACHE_LINESIZE:
+    case _SC_LEVEL3_CACHE_SIZE:
+    case _SC_LEVEL3_CACHE_ASSOC:
+    case _SC_LEVEL3_CACHE_LINESIZE:
+    case _SC_LEVEL4_CACHE_SIZE:
+    case _SC_LEVEL4_CACHE_ASSOC:
+      /* Not available.  */
+      break;
+
+    default:
+      assert (! "cannot happen");
+    }
+
+  return -1;
+}
+
+
+static struct intel_02_cache_info
+{
+  unsigned int idx;
+  int name;
+  long int size;
+  long int assoc;
+  long int linesize;
+} intel_02_known[] =
+  {
+    { 0x06, _SC_LEVEL1_ICACHE_SIZE, 8192, 4, 32 },
+    { 0x08, _SC_LEVEL1_ICACHE_SIZE, 16384, 4, 32 },
+    { 0x0a, _SC_LEVEL1_DCACHE_SIZE, 8192, 2, 32 },
+    { 0x0c, _SC_LEVEL1_DCACHE_SIZE, 16384, 4, 32 },
+    { 0x22, _SC_LEVEL3_CACHE_SIZE, 524288, 4, 64 },
+    { 0x23, _SC_LEVEL3_CACHE_SIZE, 1048576, 8, 64 },
+    { 0x25, _SC_LEVEL3_CACHE_SIZE, 2097152, 8, 64 },
+    { 0x29, _SC_LEVEL3_CACHE_SIZE, 4194304, 8, 64 },
+    { 0x2c, _SC_LEVEL1_DCACHE_SIZE, 32768, 8, 64 },
+    { 0x30, _SC_LEVEL1_ICACHE_SIZE, 32768, 8, 64 },
+    { 0x41, _SC_LEVEL2_CACHE_SIZE, 131072, 4, 32 },
+    { 0x42, _SC_LEVEL2_CACHE_SIZE, 262144, 4, 32 },
+    { 0x43, _SC_LEVEL2_CACHE_SIZE, 524288, 4, 32 },
+    { 0x44, _SC_LEVEL2_CACHE_SIZE, 1048576, 4, 32 },
+    { 0x45, _SC_LEVEL2_CACHE_SIZE, 2097152, 4, 32 },
+    { 0x60, _SC_LEVEL1_DCACHE_SIZE, 16384, 8, 64 },
+    { 0x66, _SC_LEVEL1_DCACHE_SIZE, 8192, 4, 64 },
+    { 0x67, _SC_LEVEL1_DCACHE_SIZE, 16384, 4, 64 },
+    { 0x68, _SC_LEVEL1_DCACHE_SIZE, 32768, 4, 64 },
+    { 0x78, _SC_LEVEL2_CACHE_SIZE, 1048576, 8, 64 },
+    { 0x79, _SC_LEVEL2_CACHE_SIZE, 131072, 8, 64 },
+    { 0x7a, _SC_LEVEL2_CACHE_SIZE, 262144, 8, 64 },
+    { 0x7b, _SC_LEVEL2_CACHE_SIZE, 524288, 8, 64 },
+    { 0x7c, _SC_LEVEL2_CACHE_SIZE, 1048576, 8, 64 },
+    { 0x7d, _SC_LEVEL2_CACHE_SIZE, 2097152, 8, 64 },
+    { 0x82, _SC_LEVEL2_CACHE_SIZE, 262144, 8, 32 },
+    { 0x83, _SC_LEVEL2_CACHE_SIZE, 524288, 8, 32 },
+    { 0x84, _SC_LEVEL2_CACHE_SIZE, 1048576, 8, 32 },
+    { 0x85, _SC_LEVEL2_CACHE_SIZE, 2097152, 8, 32 },
+    { 0x86, _SC_LEVEL2_CACHE_SIZE, 524288, 4, 64 },
+    { 0x87, _SC_LEVEL2_CACHE_SIZE, 1048576, 8, 64 },
+  };
+#define nintel_02_known (sizeof (intel_02_known) / sizeof (intel_02_known[0]))
+
+
+static int
+intel_02_known_compare (const void *p1, const void *p2)
+{
+  const struct intel_02_cache_info *i1;
+  const struct intel_02_cache_info *i2;
+
+  i1 = (const struct intel_02_cache_info *) p1;
+  i2 = (const struct intel_02_cache_info *) p2;
+
+  if (i1->idx == i2->idx)
+    return 0;
+
+  return i1->idx < i2->idx ? -1 : 1;
+}
+
+
+static long int
+intel_check_word (int name, unsigned int value, bool *has_level_2,
+		  bool *no_level_2_or_3)
+{
+  if ((value & 0x80000000) != 0)
+    /* The register value is reserved.  */
+    return 0;
+
+  /* Fold the name.  The _SC_ constants are always in the order SIZE,
+     ASSOC, LINESIZE.  */
+  int folded_name = (_SC_LEVEL1_ICACHE_SIZE
+		     + ((name - _SC_LEVEL1_ICACHE_SIZE) / 3) * 3);
+
+  while (value != 0)
+    {
+      unsigned int byte = value & 0xff;
+
+      if (byte == 0x40)
+	*no_level_2_or_3 = true;
+      else
+	{
+	  struct intel_02_cache_info *found;
+	  struct intel_02_cache_info search;
+
+	  search.idx = byte;
+	  found = bsearch (&search, intel_02_known, nintel_02_known,
+			   sizeof (intel_02_known[0]), intel_02_known_compare);
+	  if (found != NULL)
+	    {
+	      if (found->name == folded_name)
+		{
+		  unsigned int offset = name - folded_name;
+
+		  if (offset == 0)
+		    /* Cache size.  */
+		    return found->size;
+		  if (offset == 1)
+		    return found->assoc;
+
+		  assert (offset == 2);
+		  return found->linesize;
+		}
+
+	      if (found->name == _SC_LEVEL2_CACHE_SIZE)
+		*has_level_2 = true;
+	    }
+	}
+
+      /* Next byte for the next round.  */
+      value >>= 8;
+    }
+
+  /* Nothing found.  */
+  return 0;
+}
+
+
+static long int
+handle_intel (int name, unsigned int maxidx)
+{
+  if (maxidx < 2)
+    {
+      // XXX Do such processors exist?  When we know we can fill in some
+      // values.
+      return 0;
+    }
+
+  /* OK, we can use the CPUID instruction to get all info about the
+     caches.  */
+  unsigned int cnt = 0;
+  unsigned int max = 1;
+  long int result = 0;
+  bool no_level_2_or_3 = false;
+  bool has_level_2 = false;
+  while (cnt++ < max)
+    {
+      unsigned int eax;
+      unsigned int ebx;
+      unsigned int ecx;
+      unsigned int edx;
+      asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
+		    : "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx)
+		    : "0" (2));
+
+      /* The low byte of EAX in the first round contain the number of
+	 rounds we have to make.  At least one, the one we are already
+	 doing.  */
+      if (cnt == 1)
+	{
+	  max = eax & 0xff;
+	  eax &= 0xffffff00;
+	}
+
+      /* Process the individual registers' value.  */
+      result = intel_check_word (name, eax, &has_level_2, &no_level_2_or_3);
+      if (result != 0)
+	return result;
+
+      result = intel_check_word (name, ebx, &has_level_2, &no_level_2_or_3);
+      if (result != 0)
+	return result;
+
+      result = intel_check_word (name, ecx, &has_level_2, &no_level_2_or_3);
+      if (result != 0)
+	return result;
+
+      result = intel_check_word (name, edx, &has_level_2, &no_level_2_or_3);
+      if (result != 0)
+	return result;
+    }
+
+  if (name >= _SC_LEVEL2_CACHE_SIZE && name <= _SC_LEVEL3_CACHE_LINESIZE
+      && no_level_2_or_3)
+    return -1;
+
+  return 0;
+}
+
+
+/* Get the value of the system variable NAME.  */
+long int
+__sysconf (int name)
+{
+  /* We only handle the cache information here (for now).  */
+  if (name < _SC_LEVEL1_ICACHE_SIZE || name > _SC_LEVEL4_CACHE_ASSOC)
+    return linux_sysconf (name);
+
+  /* Recognize i386 and compatible.  These don't have any cache on
+     board.  */
+  int eflags;
+  int ac;
+  asm volatile ("pushfl;\n\t"
+		"popl %0;\n\t"
+		"movl $0x240000, %1;\n\t"
+		"xorl %0, %1;\n\t"
+		"pushl %1;\n\t"
+		"popfl;\n\t"
+		"pushfl;\n\t"
+		"popl %1;\n\t"
+		"xorl %0, %1;\n\t"
+		"pushl %0;\n\t"
+		"popfl"
+		: "=r" (eflags), "=r" (ac));
+  if (ac == 0)
+    /* This is an i386.  */
+    // XXX Is this true for all brands?
+    return -1;
+
+  /* Detect i486, the last Intel processor without CPUID.  */
+  if ((ac & (1 << 21)) == 0)
+    {
+      /* No CPUID.  */
+      // XXX Fill in info about other brands.  For now only Intel.
+      return handle_i486 (name);
+    }
+
+  /* Find out what brand of processor.  */
+  unsigned int eax;
+  unsigned int ebx;
+  unsigned int ecx;
+  unsigned int edx;
+  asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
+		: "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx)
+		: "0" (0));
+
+  if (ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69)
+    return handle_intel (name, eax);
+  // XXX Fill in more vendors.
+
+  /* CPU not known, we have no information.  */
+  return 0;
+}
+
+/* Now the generic Linux version.  */
+#undef __sysconf
+#define __sysconf static linux_sysconf
+#include "../sysconf.c"
diff --git a/sysdeps/unix/sysv/linux/sysconf.c b/sysdeps/unix/sysv/linux/sysconf.c
index 61e9865dce..6fae5590f5 100644
--- a/sysdeps/unix/sysv/linux/sysconf.c
+++ b/sysdeps/unix/sysv/linux/sysconf.c
@@ -17,6 +17,7 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
+#include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>
 #include <sysdep.h>
@@ -26,10 +27,6 @@
 
 static long int posix_sysconf (int name);
 
-/* Define this first, so it can be inlined.  */
-#define __sysconf static posix_sysconf
-#include <sysdeps/posix/sysconf.c>
-
 
 /* Get the value of the system variable NAME.  */
 long int
@@ -83,3 +80,8 @@ __sysconf (int name)
     }
   return posix_sysconf (name);
 }
+
+/* Now the POSIX version.  */
+#undef __sysconf
+#define __sysconf static posix_sysconf
+#include <sysdeps/posix/sysconf.c>