diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 9fc59d94b5bcfa66a4515ece5b73440e29b7378b..aea6f284c28d5660a44097c4d533ed62043ed0c1 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,13 @@
+2006-05-27 Paolo Carlini <pcarlini@suse.de>
+
+ * configure.host: If the CPU provides atomic builtins select
+ generic/atomic_builtins/atomicity.h.
+ * config/cpu/generic/atomic_builtins/atomicity.h: Add.
+ * config/cpu/powerpc/atomicity.h: Remove.
+ * config/cpu/ia64/atomicity.h: Likewise.
+ * config/cpu/alpha/atomicity.h: Likewise.
+ * config/cpu/s390/atomicity.h: Likewise.
+
2006-05-26 Carlos O'Donell <carlos@codesourcery.com>
* Makefile.am: Add install-html target. Add install-html to .PHONY
diff --git a/libstdc++-v3/config/cpu/alpha/atomicity.h b/libstdc++-v3/config/cpu/alpha/atomicity.h
deleted file mode 100644
index d288483621af9727a3d187e1eb0a6def873c2e1f..0000000000000000000000000000000000000000
--- a/libstdc++-v3/config/cpu/alpha/atomicity.h
+++ /dev/null
@@ -1,46 +0,0 @@
-// Low-level functions for atomic operations: Alpha version -*- C++ -*-
-
-// Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005
-// Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library. This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 2, or (at your option)
-// any later version.
-
-// This 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 General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING. If not, write to the Free
-// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
-// USA.
-
-// As a special exception, you may use this file as part of a free software
-// library without restriction. Specifically, if other files instantiate
-// templates or use macros or inline functions from this file, or you compile
-// this file and link it with other files to produce an executable, this
-// file does not by itself cause the resulting executable to be covered by
-// the GNU General Public License. This exception does not however
-// invalidate any other reasons why the executable file might be covered by
-// the GNU General Public License.
-
-#include <bits/atomicity.h>
-
-_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
-
- _Atomic_word
- __attribute__ ((__unused__))
- __exchange_and_add(volatile _Atomic_word* __mem, int __val)
- { return __sync_fetch_and_add(__mem, __val); }
-
- void
- __attribute__ ((__unused__))
- __atomic_add(volatile _Atomic_word* __mem, int __val)
- { __sync_fetch_and_add(__mem, __val); }
-
-_GLIBCXX_END_NAMESPACE
-
diff --git a/libstdc++-v3/config/cpu/ia64/atomicity.h b/libstdc++-v3/config/cpu/generic/atomic_builtins/atomicity.h
similarity index 91%
rename from libstdc++-v3/config/cpu/ia64/atomicity.h
rename to libstdc++-v3/config/cpu/generic/atomic_builtins/atomicity.h
index baabeddadedd344d4ebe83e970d07f7a6e547f10..c6cf812c8f8c31a226e8d57456c9bf3c82b37845 100644
--- a/libstdc++-v3/config/cpu/ia64/atomicity.h
+++ b/libstdc++-v3/config/cpu/generic/atomic_builtins/atomicity.h
@@ -1,7 +1,7 @@
-// Low-level functions for atomic operations: IA64 version -*- C++ -*-
+// Low-level functions for atomic operations: version for CPUs providing
+// atomic builtins -*- C++ -*-
-// Copyright (C) 2000, 2001, 2003, 2004, 2005
-// Free Software Foundation, Inc.
+// Copyright (C) 2006 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
diff --git a/libstdc++-v3/config/cpu/powerpc/atomicity.h b/libstdc++-v3/config/cpu/powerpc/atomicity.h
deleted file mode 100644
index dbd859208a36c575cd92efcc0754e7cee66e942a..0000000000000000000000000000000000000000
--- a/libstdc++-v3/config/cpu/powerpc/atomicity.h
+++ /dev/null
@@ -1,45 +0,0 @@
-// Low-level functions for atomic operations: PowerPC version -*- C++ -*-
-
-// Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005
-// Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library. This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 2, or (at your option)
-// any later version.
-
-// This 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 General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING. If not, write to the Free
-// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
-// USA.
-
-// As a special exception, you may use this file as part of a free software
-// library without restriction. Specifically, if other files instantiate
-// templates or use macros or inline functions from this file, or you compile
-// this file and link it with other files to produce an executable, this
-// file does not by itself cause the resulting executable to be covered by
-// the GNU General Public License. This exception does not however
-// invalidate any other reasons why the executable file might be covered by
-// the GNU General Public License.
-
-#include <bits/atomicity.h>
-
-_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
-
- _Atomic_word
- __attribute__ ((__unused__))
- __exchange_and_add(volatile _Atomic_word* __mem, int __val)
- { return __sync_fetch_and_add(__mem, __val); }
-
- void
- __attribute__ ((__unused__))
- __atomic_add(volatile _Atomic_word* __mem, int __val)
- { __sync_fetch_and_add(__mem, __val); }
-
-_GLIBCXX_END_NAMESPACE
diff --git a/libstdc++-v3/config/cpu/s390/atomicity.h b/libstdc++-v3/config/cpu/s390/atomicity.h
deleted file mode 100644
index 631795eb23af7ba55f71d1118f7a14c6d597bb68..0000000000000000000000000000000000000000
--- a/libstdc++-v3/config/cpu/s390/atomicity.h
+++ /dev/null
@@ -1,44 +0,0 @@
-// Low-level functions for atomic operations: S/390 version -*- C++ -*-
-
-// Copyright (C) 2001, 2003, 2004, 2005 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library. This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 2, or (at your option)
-// any later version.
-
-// This 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 General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING. If not, write to the Free
-// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
-// USA.
-
-// As a special exception, you may use this file as part of a free software
-// library without restriction. Specifically, if other files instantiate
-// templates or use macros or inline functions from this file, or you compile
-// this file and link it with other files to produce an executable, this
-// file does not by itself cause the resulting executable to be covered by
-// the GNU General Public License. This exception does not however
-// invalidate any other reasons why the executable file might be covered by
-// the GNU General Public License.
-
-#include <bits/atomicity.h>
-
-_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
-
- _Atomic_word
- __attribute__ ((__unused__))
- __exchange_and_add(volatile _Atomic_word* __mem, int __val)
- { return __sync_fetch_and_add(__mem, __val); }
-
- void
- __attribute__ ((__unused__))
- __atomic_add(volatile _Atomic_word* __mem, int __val)
- { __sync_fetch_and_add(__mem, __val); }
-
-_GLIBCXX_END_NAMESPACE
diff --git a/libstdc++-v3/configure.host b/libstdc++-v3/configure.host
index 477e4d8bb13521901eee535081518d058070698b..9dd98372c7ff0cd8d7ac5d8f7077929839d0984b 100644
--- a/libstdc++-v3/configure.host
+++ b/libstdc++-v3/configure.host
@@ -142,11 +142,18 @@ cpu_include_dir=cpu/${try_cpu}
abi_baseline_pair=${try_cpu}-${host_os}
unset try_cpu
-if test -f ${glibcxx_srcdir}/config/${cpu_include_dir}/atomicity.h ; then
- atomicity_dir=$cpu_include_dir
-else
- atomicity_dir="cpu/generic"
-fi
+case "${host_cpu}" in
+ alpha* | ia64 | powerpc* | rs6000 | s390*)
+ atomicity_dir="cpu/generic/atomic_builtins"
+ ;;
+ *)
+ if test -f ${glibcxx_srcdir}/config/${cpu_include_dir}/atomicity.h ; then
+ atomicity_dir=$cpu_include_dir
+ else
+ atomicity_dir="cpu/generic"
+ fi
+ ;;
+esac
if test -f ${glibcxx_srcdir}/config/${cpu_include_dir}/cxxabi_tweaks.h ; then
abi_tweaks_dir=$cpu_include_dir