diff mbox

libstdc++: Allow using <future> without lock free atomic int

Message ID 20170103153224.GF895@redhat.com
State New
Headers show

Commit Message

Jonathan Wakely Jan. 3, 2017, 3:32 p.m. UTC 
On 19/12/16 17:52 +0000, Jonathan Wakely wrote:
>On 16/12/16 17:52 +0000, Jonathan Wakely wrote:

>>On 09/11/16 23:26 +0200, Pauli wrote:

>>>Compiling programs using std::future for old arm processors fails. The

>>>problem is caused by preprocessor check for atomic lock free int.

>>>

>>>Future can be changed to work correctly without lock free atomics with

>>>minor changes to exception_ptr implementation.

>>>

>>>Without lock free atomics there is question if deadlock can happen. But

>>>atomic operations can't call outside code preventing any ABBA or

>>>recursive mutex acquiring deadlocks.

>>>Deadlock could happen if throwing an exception or access

>>>is_lock_free() == false atomic from asynchronous signal handler.

>>>Throwing from signal handler is undefined behavior. I don't know about

>>>accessing atomics from asynchronous signal handler but that feels like

>>>undefined behavior if is_lock_free returns false.

>>>

>>>Bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64735

>>>

>>>differences to current if atomic builtins available:

>>>* Race detector annotations that are empty by default

>>>* Check for __gthread_active_p

>>>* Generate x86 code uses xadd instead of xsub

>>>This makes code a bit worse. But problem is duplicated to any other user

>>>of __exchange_and_add. The internal API implementation should be fixed

>>>to generate better code for all cases. But that is a follow up patch.

>>

>>I'd prefer to do it so we don't change anything for the targets that

>>already work. Your follow-up patch missed the deadline for GCC 7 and

>>so will have to wait for GCC 8 now, and we don't want to pessimize

>>x86.

>>

>>Also, I think your patch actually breaks some GNU/Linux targets,

>>because you removed the <atomic_lockfree_defines.h> header from

>><exception>, which means that in libsupc++/guard.cc the macro

>>ATOMIC_INT_LOCK_FREE is no longer defined, and so _GLIBCXX_USE_FUTEX

>>doesn't get defined. Now arguably guard.cc should have been including

>>the header directly, but it still shows why such an invasive patch is

>>a bad idea at this stage of the GCC 7 process.

>>

>>The attached patch attempts to make exception propagation work for all

>>targets, without changing anything if it already works.

>>

>>Do you see any problems with this alternative approach?

>>Could you please test it for armv5te?

>>

>>It passes all tests for x86_64-linux and ppc64le-linux.

>>

>>For your follow-up patch, do you already have a copyright assignment

>>for contributions to GCC? We'll probably need that before it can be

>>accepted. We don't need one for this patch, because what remains of

>>your original patch is just the testsuite changes, which are

>>mechanical and not copyrightable.

>

>We also need to adjust the linker script to avoid adding new exports

>to old symbol versions, revised patch attached. I think it would be

>better to make configure define a macro like

>HAVE_EXCEPTION_PTR_SINCE_GCC6 and use that in the linker script

>instead of testing __GCC_ATOMIC_INT_LOCK_FREE directly. I'll work on

>that.


Here's what I plan to commit to trunk tomorrow.

Comments

Jonathan Wakely Jan. 4, 2017, 11:02 a.m. UTC | #1 
On 03/01/17 15:32 +0000, Jonathan Wakely wrote:
>Here's what I plan to commit to trunk tomorrow.


Committed to trunk.
Christophe Lyon Jan. 4, 2017, 3 p.m. UTC | #2 
Hi Jonathan,

On 4 January 2017 at 12:02, Jonathan Wakely <jwakely@redhat.com> wrote:
> On 03/01/17 15:32 +0000, Jonathan Wakely wrote:

>>

>> Here's what I plan to commit to trunk tomorrow.

>

>

> Committed to trunk.

>

>

After this commit (r244051), I do see improvements, but also a few new failures.
The big picture is at
http://people.linaro.org/~christophe.lyon/cross-validation/gcc/trunk/244051/report-build-info.html

Where the expected improvements for arm-none-eabi, with default cpu&fpu are:
http://people.linaro.org/~christophe.lyon/cross-validation/gcc/trunk/244051/arm-none-eabi/diff-libstdc++-rh60-arm-none-eabi-default-default-default.txt

New failures appear when forcing -march=armv5t in runtestflags (the 3
red items in the 1st report):

  - FAIL appears              [     => FAIL]:

  18_support/exception_ptr/60612-terminate.cc execution test
  18_support/exception_ptr/60612-unexpected.cc execution test
  30_threads/packaged_task/members/at_thread_exit.cc execution test
  30_threads/promise/members/at_thread_exit.cc execution test

Note that in these cases we are compiling the test cases with
-march=armv5t, but link
with libraries built --with-cpu=cortex-a9, so there might be a mismatch?

Christophe
Jonathan Wakely Jan. 4, 2017, 3:10 p.m. UTC | #3 
On 04/01/17 16:00 +0100, Christophe Lyon wrote:
>Hi Jonathan,

>

>On 4 January 2017 at 12:02, Jonathan Wakely <jwakely@redhat.com> wrote:

>> On 03/01/17 15:32 +0000, Jonathan Wakely wrote:

>>>

>>> Here's what I plan to commit to trunk tomorrow.

>>

>>

>> Committed to trunk.

>>

>>

>After this commit (r244051), I do see improvements, but also a few new failures.

>The big picture is at

>http://people.linaro.org/~christophe.lyon/cross-validation/gcc/trunk/244051/report-build-info.html

>

>Where the expected improvements for arm-none-eabi, with default cpu&fpu are:

>http://people.linaro.org/~christophe.lyon/cross-validation/gcc/trunk/244051/arm-none-eabi/diff-libstdc++-rh60-arm-none-eabi-default-default-default.txt

>

>New failures appear when forcing -march=armv5t in runtestflags (the 3

>red items in the 1st report):

>

>  - FAIL appears              [     => FAIL]:

>

>  18_support/exception_ptr/60612-terminate.cc execution test

>  18_support/exception_ptr/60612-unexpected.cc execution test

>  30_threads/packaged_task/members/at_thread_exit.cc execution test

>  30_threads/promise/members/at_thread_exit.cc execution test

>

>Note that in these cases we are compiling the test cases with

>-march=armv5t, but link

>with libraries built --with-cpu=cortex-a9, so there might be a mismatch?


Yes, this is probably the same issue as PR63829

Richard's comment on the bug report says that arm should always use
atomics, via kernel helpers if necessary, so that there is no ABI
change when using -march for older CPUs.

I don't know how to do that, but I hope we can make some progress on
it for gcc 8.
Christophe Lyon Jan. 4, 2017, 3:22 p.m. UTC | #4 
On 4 January 2017 at 16:10, Jonathan Wakely <jwakely@redhat.com> wrote:
> On 04/01/17 16:00 +0100, Christophe Lyon wrote:

>>

>> Hi Jonathan,

>>

>> On 4 January 2017 at 12:02, Jonathan Wakely <jwakely@redhat.com> wrote:

>>>

>>> On 03/01/17 15:32 +0000, Jonathan Wakely wrote:

>>>>

>>>>

>>>> Here's what I plan to commit to trunk tomorrow.

>>>

>>>

>>>

>>> Committed to trunk.

>>>

>>>

>> After this commit (r244051), I do see improvements, but also a few new

>> failures.

>> The big picture is at

>>

>> http://people.linaro.org/~christophe.lyon/cross-validation/gcc/trunk/244051/report-build-info.html

>>

>> Where the expected improvements for arm-none-eabi, with default cpu&fpu

>> are:

>>

>> http://people.linaro.org/~christophe.lyon/cross-validation/gcc/trunk/244051/arm-none-eabi/diff-libstdc++-rh60-arm-none-eabi-default-default-default.txt

>>

>> New failures appear when forcing -march=armv5t in runtestflags (the 3

>> red items in the 1st report):

>>

>>  - FAIL appears              [     => FAIL]:

>>

>>  18_support/exception_ptr/60612-terminate.cc execution test

>>  18_support/exception_ptr/60612-unexpected.cc execution test

>>  30_threads/packaged_task/members/at_thread_exit.cc execution test

>>  30_threads/promise/members/at_thread_exit.cc execution test

>>

>> Note that in these cases we are compiling the test cases with

>> -march=armv5t, but link

>> with libraries built --with-cpu=cortex-a9, so there might be a mismatch?

>

>

> Yes, this is probably the same issue as PR63829


Indeed.

>

> Richard's comment on the bug report says that arm should always use

> atomics, via kernel helpers if necessary, so that there is no ABI

> change when using -march for older CPUs.

>

> I don't know how to do that, but I hope we can make some progress on

> it for gcc 8.

>

That would be good, maybe Richard can post an example in
bugzilla?

Thanks,

Christophe
diff mbox

Patch

commit fa070e976709218d9927e2ed880bd29f7f98106f
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Dec 16 15:22:21 2016 +0000

    Support exception propagation without lock-free atomic int
    
    2017-01-03  Pauli Nieminen  <suokkos@gmail.com>
    	    Jonathan Wakely  <jwakely@redhat.com>
    
    	PR libstdc++/64735
    	* acinclude.m4 (GLIBCXX_CHECK_EXCEPTION_PTR_SYMVER): Define.
    	* config.h.in: Regenerate.
    	* config/abi/pre/gnu.ver [HAVE_EXCEPTION_PTR_SINCE_GCC46]
    	(GLIBCXX_3.4.15, GLIBCXX_3.4.21, CXXABI_1.3.3, CXXABI_1.3.5): Make
    	exports for exception_ptr, nested_exception, and future conditional.
    	[HAVE_EXCEPTION_PTR_SINCE_GCC46] (GLIBCXX_3.4.23, CXXABI_1.3.11): Add
    	exports for exception_ptr, nested_exception, and future conditional.
    	* configure: Regenerate.
    	* configure.ac: Use GLIBCXX_CHECK_EXCEPTION_PTR_SYMVER.
    	* include/std/future: Remove check for ATOMIC_INT_LOCK_FREE
    	* libsupc++/eh_atomics.h: New file for internal use only.
    	(__eh_atomic_inc, __eh_atomic_dec): New.
    	* libsupc++/eh_ptr.cc (exception_ptr::_M_addref)
    	(exception_ptr::_M_release) (__gxx_dependent_exception_cleanup)
    	(rethrow_exception): Use eh_atomics.h reference counting helpers.
    	* libsupc++/eh_throw.cc (__gxx_exception_cleanup): Likewise.
    	* libsupc++/eh_tm.cc (free_any_cxa_exception): Likewise.
    	* libsupc++/exception: Remove check for ATOMIC_INT_LOCK_FREE.
    	* libsupc++/exception_ptr.h: Likewise.
    	* libsupc++/guard.cc: Include header for ATOMIC_INT_LOCK_FREE macro.
    	* libsupc++/nested_exception.cc: Remove check for
    	ATOMIC_INT_LOCK_FREE.
    	* libsupc++/nested_exception.h: Likewise.
    	* src/c++11/future.cc: Likewise.
    	* testsuite/18_support/exception_ptr/*: Remove atomic builtins checks.
    	* testsuite/18_support/nested_exception/*: Likewise.
    	* testsuite/30_threads/async/*: Likewise.
    	* testsuite/30_threads/future/*: Likewise.
    	* testsuite/30_threads/headers/future/types_std_c++0x.cc: Likewise.
    	* testsuite/30_threads/packaged_task/*: Likewise.
    	* testsuite/30_threads/promise/*: Likewise.
    	* testsuite/30_threads/shared_future/*: Likewise.

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index c88e473..a7e1c26 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -4480,6 +4480,43 @@  AC_DEFUN([GLIBCXX_CHECK_SIZE_T_MANGLING], [
     [Define to the letter to which size_t is mangled.])
 ])
 
+dnl
+dnl Determine whether std::exception_ptr symbols should be exported with
+dnl the symbol versions from GCC 4.6.0 or GCC 7.0.0, depending on which
+dnl release first added support for std::exception_ptr. Originally it was
+dnl only supported for targets with always-lock-free atomics for int, but
+dnl since GCC 7.0 it is supported for all targets.
+dnl
+AC_DEFUN([GLIBCXX_CHECK_EXCEPTION_PTR_SYMVER], [
+  if test $enable_symvers != no; then
+    AC_MSG_CHECKING([for first version to support std::exception_ptr])
+    case ${target} in
+      aarch64-*-* | alpha-*-* | hppa*-*-* | i?86-*-* | x86_64-*-* | \
+      m68k-*-* | powerpc*-*-* | s390*-*-* | *-*-solaris* )
+        ac_exception_ptr_since_gcc46=yes
+        ;;
+      *)
+        # If the value of this macro changes then we will need to hardcode
+        # yes/no here for additional targets based on the original value.
+        AC_TRY_COMPILE([], [
+          #if __GCC_ATOMIC_INT_LOCK_FREE <= 1
+          # error atomic int not always lock free
+          #endif
+          ],
+          [ac_exception_ptr_since_gcc46=yes],
+          [ac_exception_ptr_since_gcc46=no])
+        ;;
+    esac
+    if test x"$ac_exception_ptr_since_gcc46" = x"yes" ; then
+      AC_DEFINE(HAVE_EXCEPTION_PTR_SINCE_GCC46, 1,
+        [Define to 1 if GCC 4.6 supported std::exception_ptr for the target])
+      AC_MSG_RESULT([4.6.0])
+    else
+      AC_MSG_RESULT([7.1.0])
+    fi
+  fi
+])
+
 # Macros from the top-level gcc directory.
 m4_include([../config/gc++filt.m4])
 m4_include([../config/tls.m4])
diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index 09ddfeb..41ad510 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -123,6 +123,9 @@ 
 /* Define if EWOULDBLOCK exists. */
 #undef HAVE_EWOULDBLOCK
 
+/* Define to 1 if GCC 4.6 supported std::exception_ptr for the target */
+#undef HAVE_EXCEPTION_PTR_SINCE_GCC46
+
 /* Define to 1 if you have the <execinfo.h> header file. */
 #undef HAVE_EXECINFO_H
 
diff --git a/libstdc++-v3/config/abi/pre/gnu.ver b/libstdc++-v3/config/abi/pre/gnu.ver
index 10bba01..3e6e70b 100644
--- a/libstdc++-v3/config/abi/pre/gnu.ver
+++ b/libstdc++-v3/config/abi/pre/gnu.ver
@@ -1503,6 +1503,9 @@  GLIBCXX_3.4.15 {
     _ZNSt14error_categoryC*;
     _ZNSt14error_categoryD*;
 
+#ifdef HAVE_EXCEPTION_PTR_SINCE_GCC46
+    # std::future symbols are only present in this version when
+    # atomic operations on int are always lock-free.
     _ZNSt13__future_base12_Result_baseC*;
     _ZNSt13__future_base12_Result_baseD*;
     _ZTINSt13__future_base12_Result_baseE;
@@ -1511,6 +1514,7 @@  GLIBCXX_3.4.15 {
     _ZNSt13__future_base11_State_baseD*;
     _ZTINSt13__future_base11_State_baseE;
     _ZTVNSt13__future_base11_State_baseE;
+#endif
 
 } GLIBCXX_3.4.14;
 
@@ -1687,8 +1691,10 @@  GLIBCXX_3.4.21 {
 
     # std::notify_all_at_thread_exit
     _ZSt25notify_all_at_thread_exitRSt18condition_variableSt11unique_lockISt5mutexE;
+#ifdef HAVE_EXCEPTION_PTR_SINCE_GCC46
     # std::__future_base::_State_baseV2::_Make_ready::_M_set()
     _ZNSt13__future_base13_State_baseV211_Make_ready6_M_setEv;
+#endif
 
     # ABI-tagged std::basic_string
     _ZNSt7__cxx1112basic_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE1[01]**;
@@ -1947,6 +1953,16 @@  GLIBCXX_3.4.23 {
     _ZNSsC[12]ERKSs[jmy]RKSaIcE;
     _ZNSbIwSt11char_traitsIwESaIwEEC[12]ERKS2_mRKS1_;
 
+#ifndef HAVE_EXCEPTION_PTR_SINCE_GCC46
+    # std::future symbols are exported in the first version to support
+    # std::exception_ptr
+    _ZNSt13__future_base12_Result_baseC*;
+    _ZNSt13__future_base12_Result_baseD*;
+    _ZTINSt13__future_base12_Result_baseE;
+    _ZTVNSt13__future_base12_Result_baseE;
+    _ZNSt13__future_base13_State_baseV211_Make_ready6_M_setEv;
+#endif
+
 } GLIBCXX_3.4.22;
 
 # Symbols in the support library (libsupc++) have their own tag.
@@ -2080,6 +2096,7 @@  CXXABI_1.3.3 {
     _ZTIPDi;
     _ZTIPKDi;
 
+#ifdef HAVE_EXCEPTION_PTR_SINCE_GCC46
     # exception_ptr
     _ZNSt15__exception_ptr13exception_ptrC1Ev;
     _ZNSt15__exception_ptr13exception_ptrC2Ev;
@@ -2099,6 +2116,7 @@  CXXABI_1.3.3 {
 
     _ZSt17current_exceptionv;
     _ZSt17rethrow_exceptionNSt15__exception_ptr13exception_ptrE;
+#endif
 
 } CXXABI_1.3.2;
 
@@ -2129,10 +2147,12 @@  CXXABI_1.3.5 {
     # FNV hash.
     _ZSt15_Fnv_hash_bytesPKv*;
 
+#ifdef HAVE_EXCEPTION_PTR_SINCE_GCC46
     # std::nested_exception
     _ZNSt16nested_exceptionD*;
     _ZTISt16nested_exception;
     _ZTVSt16nested_exception;
+#endif
 
 } CXXABI_1.3.4;
 
@@ -2209,6 +2229,33 @@  CXXABI_1.3.11 {
     _ZdaPvSt11align_val_tRKSt9nothrow_t;
     _ZdaPv[jmy]St11align_val_t;
 
+#ifndef HAVE_EXCEPTION_PTR_SINCE_GCC46
+    # exception_ptr
+    _ZNSt15__exception_ptr13exception_ptrC1Ev;
+    _ZNSt15__exception_ptr13exception_ptrC2Ev;
+    _ZNSt15__exception_ptr13exception_ptrC1ERKS0_;
+    _ZNSt15__exception_ptr13exception_ptrC2ERKS0_;
+    _ZNSt15__exception_ptr13exception_ptrC1EMS0_FvvE;
+    _ZNSt15__exception_ptr13exception_ptrC2EMS0_FvvE;
+    _ZNSt15__exception_ptr13exception_ptrD1Ev;
+    _ZNSt15__exception_ptr13exception_ptrD2Ev;
+    _ZNSt15__exception_ptr13exception_ptraSERKS0_;
+    _ZNKSt15__exception_ptr13exception_ptrcvMS0_FvvEEv;
+    _ZNKSt15__exception_ptr13exception_ptrntEv;
+    _ZNKSt15__exception_ptr13exception_ptr20__cxa_exception_typeEv;
+    _ZNSt15__exception_ptr13exception_ptr4swapERS0_;
+    _ZNSt15__exception_ptreqERKNS_13exception_ptrES2_;
+    _ZNSt15__exception_ptrneERKNS_13exception_ptrES2_;
+
+    _ZSt17current_exceptionv;
+    _ZSt17rethrow_exceptionNSt15__exception_ptr13exception_ptrE;
+
+    # std::nested_exception
+    _ZNSt16nested_exceptionD*;
+    _ZTISt16nested_exception;
+    _ZTVSt16nested_exception;
+#endif
+
 } CXXABI_1.3.10;
 
 # Symbols in the support library (libsupc++) supporting transactional memory.
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index cbd77f0..be6763a 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -80664,6 +80664,55 @@  _ACEOF
 
 
 
+# Check which release added std::exception_ptr for the target
+
+  if test $enable_symvers != no; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for first version to support std::exception_ptr" >&5
+$as_echo_n "checking for first version to support std::exception_ptr... " >&6; }
+    case ${target} in
+      aarch64-*-* | alpha-*-* | hppa*-*-* | i?86-*-* | x86_64-*-* | \
+      m68k-*-* | powerpc*-*-* | s390*-*-* | *-*-solaris* )
+        ac_exception_ptr_since_gcc46=yes
+        ;;
+      *)
+        # If the value of this macro changes then we will need to hardcode
+        # yes/no here for additional targets based on the original value.
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+          #if __GCC_ATOMIC_INT_LOCK_FREE <= 1
+          # error atomic int not always lock free
+          #endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_exception_ptr_since_gcc46=yes
+else
+  ac_exception_ptr_since_gcc46=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+        ;;
+    esac
+    if test x"$ac_exception_ptr_since_gcc46" = x"yes" ; then
+
+$as_echo "#define HAVE_EXCEPTION_PTR_SINCE_GCC46 1" >>confdefs.h
+
+      { $as_echo "$as_me:${as_lineno-$LINENO}: result: 4.6.0" >&5
+$as_echo "4.6.0" >&6; }
+    else
+      { $as_echo "$as_me:${as_lineno-$LINENO}: result: 7.1.0" >&5
+$as_echo "7.1.0" >&6; }
+    fi
+  fi
+
+
 # Define documentation rules conditionally.
 
 # See if makeinfo has been installed and is modern enough
diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index 7d0fafa..3d61771 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -419,6 +419,9 @@  GLIBCXX_CHECK_FILESYSTEM_DEPS
 # For Transactional Memory TS
 GLIBCXX_CHECK_SIZE_T_MANGLING
 
+# Check which release added std::exception_ptr for the target
+GLIBCXX_CHECK_EXCEPTION_PTR_SYMVER
+
 # Define documentation rules conditionally.
 
 # See if makeinfo has been installed and is modern enough
diff --git a/libstdc++-v3/include/std/future b/libstdc++-v3/include/std/future
index 7897b6e..6351d7e 100644
--- a/libstdc++-v3/include/std/future
+++ b/libstdc++-v3/include/std/future
@@ -192,8 +192,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     future<__async_result_of<_Fn, _Args...>>
     async(_Fn&& __fn, _Args&&... __args);
 
-#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) \
-  && (ATOMIC_INT_LOCK_FREE > 1)
+#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
 
   /// Base class and enclosing scope.
   struct __future_base
@@ -1751,7 +1750,6 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 #endif // _GLIBCXX_ASYNC_ABI_COMPAT
 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
-       // && ATOMIC_INT_LOCK_FREE
 
   // @} group futures
 _GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/libsupc++/eh_atomics.h b/libstdc++-v3/libsupc++/eh_atomics.h
new file mode 100644
index 0000000..71b42a4
--- /dev/null
+++ b/libstdc++-v3/libsupc++/eh_atomics.h
@@ -0,0 +1,84 @@ 
+// Exception Handling support header for -*- C++ -*-
+
+// Copyright (C) 2016 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC 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 3, or (at your option)
+// any later version.
+//
+// GCC 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.
+//
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file eh_atomics.h
+ *  This is an internal header file, included by library source files.
+ *  Do not attempt to use it directly.
+ */
+
+#ifndef _EH_ATOMICS_H
+#define _EH_ATOMICS_H 1
+
+#include <bits/c++config.h>
+#include <bits/atomic_word.h>
+#include <bits/atomic_lockfree_defines.h>
+#if ATOMIC_INT_LOCK_FREE <= 1
+# include <ext/atomicity.h>
+#endif
+
+#pragma GCC visibility push(default)
+extern "C++" {
+namespace __gnu_cxx
+{
+  void
+  __eh_atomic_inc (_Atomic_word* __count) __attribute__((always_inline));
+
+  bool
+  __eh_atomic_dec (_Atomic_word* __count) __attribute__((always_inline));
+
+  // Increments the count.
+  inline void
+  __eh_atomic_inc (_Atomic_word* __count)
+  {
+#if ATOMIC_INT_LOCK_FREE > 1
+    __atomic_add_fetch (__count, 1, __ATOMIC_ACQ_REL);
+#else
+    _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE (__count);
+    __gnu_cxx::__atomic_add_dispatch (__count, 1);
+    _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER (__count);
+#endif
+  }
+
+  // Decrements the count and returns true if it reached zero.
+  inline bool
+  __eh_atomic_dec (_Atomic_word* __count)
+  {
+#if ATOMIC_INT_LOCK_FREE > 1
+    return __atomic_sub_fetch (__count, 1, __ATOMIC_ACQ_REL) == 0;
+#else
+    _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE (__count);
+    if (__gnu_cxx::__exchange_and_add_dispatch (__count, -1) == 1)
+      {
+	_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER (__count);
+	return true;
+      }
+    return false;
+#endif
+  }
+} // namespace __gnu_cxx
+}
+#pragma GCC visibility pop
+
+#endif // _EH_ATOMICS_H
diff --git a/libstdc++-v3/libsupc++/eh_ptr.cc b/libstdc++-v3/libsupc++/eh_ptr.cc
index 1308ff9..12d8d70 100644
--- a/libstdc++-v3/libsupc++/eh_ptr.cc
+++ b/libstdc++-v3/libsupc++/eh_ptr.cc
@@ -23,9 +23,7 @@ 
 // <http://www.gnu.org/licenses/>.
 
 #include <bits/c++config.h>
-#include <bits/atomic_lockfree_defines.h>
-
-#if ATOMIC_INT_LOCK_FREE > 1
+#include "eh_atomics.h"
 
 #define _GLIBCXX_EH_PTR_COMPAT
 
@@ -101,7 +99,7 @@  std::__exception_ptr::exception_ptr::_M_addref() noexcept
     {
       __cxa_refcounted_exception *eh =
 	__get_refcounted_exception_header_from_obj (_M_exception_object);
-      __atomic_add_fetch (&eh->referenceCount, 1, __ATOMIC_ACQ_REL);
+      __gnu_cxx::__eh_atomic_inc (&eh->referenceCount);
     }
 }
 
@@ -113,7 +111,7 @@  std::__exception_ptr::exception_ptr::_M_release() noexcept
     {
       __cxa_refcounted_exception *eh =
 	__get_refcounted_exception_header_from_obj (_M_exception_object);
-      if (__atomic_sub_fetch (&eh->referenceCount, 1, __ATOMIC_ACQ_REL) == 0)
+      if (__gnu_cxx::__eh_atomic_dec (&eh->referenceCount))
         {
 	  if (eh->exc.exceptionDestructor)
 	    eh->exc.exceptionDestructor (_M_exception_object);
@@ -211,7 +209,7 @@  __gxx_dependent_exception_cleanup(_Unwind_Reason_Code code,
 
   __cxa_free_dependent_exception (dep);
 
-  if (__atomic_sub_fetch (&header->referenceCount, 1, __ATOMIC_ACQ_REL) == 0)
+  if (__gnu_cxx::__eh_atomic_dec (&header->referenceCount))
     {
       if (header->exc.exceptionDestructor)
 	header->exc.exceptionDestructor (header + 1);
@@ -230,7 +228,7 @@  std::rethrow_exception(std::exception_ptr ep)
 
   __cxa_dependent_exception *dep = __cxa_allocate_dependent_exception ();
   dep->primaryException = obj;
-  __atomic_add_fetch (&eh->referenceCount, 1,  __ATOMIC_ACQ_REL);
+  __gnu_cxx::__eh_atomic_inc (&eh->referenceCount);
 
   dep->unexpectedHandler = get_unexpected ();
   dep->terminateHandler = get_terminate ();
@@ -252,5 +250,3 @@  std::rethrow_exception(std::exception_ptr ep)
 }
 
 #undef _GLIBCXX_EH_PTR_COMPAT
-
-#endif
diff --git a/libstdc++-v3/libsupc++/eh_throw.cc b/libstdc++-v3/libsupc++/eh_throw.cc
index 397decd..13428d9 100644
--- a/libstdc++-v3/libsupc++/eh_throw.cc
+++ b/libstdc++-v3/libsupc++/eh_throw.cc
@@ -24,6 +24,7 @@ 
 
 #include <bits/c++config.h>
 #include "unwind-cxx.h"
+#include "eh_atomics.h"
 
 using namespace __cxxabiv1;
 
@@ -42,17 +43,13 @@  __gxx_exception_cleanup (_Unwind_Reason_Code code, _Unwind_Exception *exc)
   if (code != _URC_FOREIGN_EXCEPTION_CAUGHT && code != _URC_NO_REASON)
     __terminate (header->exc.terminateHandler);
 
-#if ATOMIC_INT_LOCK_FREE > 1
-  if (__atomic_sub_fetch (&header->referenceCount, 1, __ATOMIC_ACQ_REL) == 0)
+  if (__gnu_cxx::__eh_atomic_dec (&header->referenceCount))
     {
-#endif
       if (header->exc.exceptionDestructor)
 	header->exc.exceptionDestructor (header + 1);
 
       __cxa_free_exception (header + 1);
-#if ATOMIC_INT_LOCK_FREE > 1
     }
-#endif
 }
 
 extern "C" __cxa_refcounted_exception*
diff --git a/libstdc++-v3/libsupc++/eh_tm.cc b/libstdc++-v3/libsupc++/eh_tm.cc
index d0ccd9e..ffb5ef6 100644
--- a/libstdc++-v3/libsupc++/eh_tm.cc
+++ b/libstdc++-v3/libsupc++/eh_tm.cc
@@ -24,6 +24,7 @@ 
 
 #include <cstdlib>
 #include "unwind-cxx.h"
+#include "eh_atomics.h"
 
 using namespace __cxxabiv1;
 
@@ -45,9 +46,7 @@  free_any_cxa_exception (_Unwind_Exception *eo)
       __cxa_free_dependent_exception (dep);
     }
 
-#if __GCC_ATOMIC_INT_LOCK_FREE > 1
-  if (__atomic_sub_fetch (&h->referenceCount, 1, __ATOMIC_ACQ_REL) == 0)
-#endif
+  if (__gnu_cxx::__eh_atomic_dec (&h->referenceCount))
     __cxa_free_exception (h + 1);
 }
 
diff --git a/libstdc++-v3/libsupc++/exception b/libstdc++-v3/libsupc++/exception
index 1ccf329..e51d31c 100644
--- a/libstdc++-v3/libsupc++/exception
+++ b/libstdc++-v3/libsupc++/exception
@@ -35,7 +35,6 @@ 
 #pragma GCC visibility push(default)
 
 #include <bits/c++config.h>
-#include <bits/atomic_lockfree_defines.h>
 #include <bits/exception.h>
 
 extern "C++" {
@@ -139,7 +138,7 @@  _GLIBCXX_END_NAMESPACE_VERSION
 
 #pragma GCC visibility pop
 
-#if (__cplusplus >= 201103L) && (ATOMIC_INT_LOCK_FREE > 1)
+#if (__cplusplus >= 201103L)
 #include <bits/exception_ptr.h>
 #include <bits/nested_exception.h>
 #endif
diff --git a/libstdc++-v3/libsupc++/exception_ptr.h b/libstdc++-v3/libsupc++/exception_ptr.h
index a2a9017..2447a5a 100644
--- a/libstdc++-v3/libsupc++/exception_ptr.h
+++ b/libstdc++-v3/libsupc++/exception_ptr.h
@@ -39,10 +39,6 @@ 
 #include <typeinfo>
 #include <new>
 
-#if ATOMIC_INT_LOCK_FREE < 2
-#  error This platform does not support exception propagation.
-#endif
-
 extern "C++" {
 
 namespace std 
diff --git a/libstdc++-v3/libsupc++/guard.cc b/libstdc++-v3/libsupc++/guard.cc
index ef0b8a8..19953bc 100644
--- a/libstdc++-v3/libsupc++/guard.cc
+++ b/libstdc++-v3/libsupc++/guard.cc
@@ -30,6 +30,7 @@ 
 #include <new>
 #include <ext/atomicity.h>
 #include <ext/concurrence.h>
+#include <bits/atomic_lockfree_defines.h>
 #if defined(__GTHREADS) && defined(__GTHREAD_HAS_COND) \
   && (ATOMIC_INT_LOCK_FREE > 1) && defined(_GLIBCXX_HAVE_LINUX_FUTEX)
 # include <climits>
diff --git a/libstdc++-v3/libsupc++/nested_exception.cc b/libstdc++-v3/libsupc++/nested_exception.cc
index 36951e2..7e1b545 100644
--- a/libstdc++-v3/libsupc++/nested_exception.cc
+++ b/libstdc++-v3/libsupc++/nested_exception.cc
@@ -25,7 +25,5 @@ 
 
 namespace std 
 {
-#if ATOMIC_INT_LOCK_FREE > 1
   nested_exception::~nested_exception() noexcept = default;
-#endif
 } // namespace std
diff --git a/libstdc++-v3/libsupc++/nested_exception.h b/libstdc++-v3/libsupc++/nested_exception.h
index 66e2ebf..35b025a 100644
--- a/libstdc++-v3/libsupc++/nested_exception.h
+++ b/libstdc++-v3/libsupc++/nested_exception.h
@@ -39,10 +39,6 @@ 
 #include <bits/c++config.h>
 #include <bits/move.h>
 
-#if ATOMIC_INT_LOCK_FREE < 2
-#  error This platform does not support exception propagation.
-#endif
-
 extern "C++" {
 
 namespace std
diff --git a/libstdc++-v3/src/c++11/future.cc b/libstdc++-v3/src/c++11/future.cc
index 3ed5bc9..e138567 100644
--- a/libstdc++-v3/src/c++11/future.cc
+++ b/libstdc++-v3/src/c++11/future.cc
@@ -78,8 +78,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
   const char*
   future_error::what() const noexcept { return logic_error::what(); }
 
-#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) \
-  && (ATOMIC_INT_LOCK_FREE > 1)
+#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
   __future_base::_Result_base::_Result_base() = default;
 
   __future_base::_Result_base::~_Result_base() = default;
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/40296.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/40296.cc
index 09d4f38..c7b8055 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/40296.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/40296.cc
@@ -1,5 +1,4 @@ 
 // { dg-do compile { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/60612-terminate.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/60612-terminate.cc
index 5d20f27..43aef95 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/60612-terminate.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/60612-terminate.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/60612-unexpected.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/60612-unexpected.cc
index c478627..3562892 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/60612-unexpected.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/60612-unexpected.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/62258.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/62258.cc
index 10eb754..a53b066 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/62258.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/62258.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2015-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/64241.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/64241.cc
index a94ae84..8e0e9c2 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/64241.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/64241.cc
@@ -17,7 +17,6 @@ 
 
 // { dg-options "-fno-exceptions -O0" }
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 #include <exception>
 #include <testsuite_hooks.h>
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/current_exception.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/current_exception.cc
index 5f83ddc..7ad78e2 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/current_exception.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/current_exception.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // 2008-05-25  Sebastian Redl  <sebastian.redl@getdesigned.at>
 
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/lifespan.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/lifespan.cc
index 51b3858..58b6a32 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/lifespan.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/lifespan.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // 2008-05-25  Sebastian Redl  <sebastian.redl@getdesigned.at>
 
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/make_exception_ptr.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/make_exception_ptr.cc
index 184b4de..f86b189 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/make_exception_ptr.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/make_exception_ptr.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/make_exception_ptr_2.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/make_exception_ptr_2.cc
index 3893f5f..bc225d6 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/make_exception_ptr_2.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/make_exception_ptr_2.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/move.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/move.cc
index bb18a46..4576844 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/move.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/move.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/requirements.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/requirements.cc
index fd47be8..7102be6 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/requirements.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/requirements.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/requirements_neg.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/requirements_neg.cc
index 7289cf3..60d01a9 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/requirements_neg.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/requirements_neg.cc
@@ -1,5 +1,4 @@ 
 // { dg-do compile { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/rethrow_exception.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/rethrow_exception.cc
index 288c7ef..c5461d8 100644
--- a/libstdc++-v3/testsuite/18_support/exception_ptr/rethrow_exception.cc
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/rethrow_exception.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // 2008-05-25  Sebastian Redl  <sebastian.redl@getdesigned.at>
 
diff --git a/libstdc++-v3/testsuite/18_support/nested_exception/51438.cc b/libstdc++-v3/testsuite/18_support/nested_exception/51438.cc
index 69fd02d..5b55fda 100644
--- a/libstdc++-v3/testsuite/18_support/nested_exception/51438.cc
+++ b/libstdc++-v3/testsuite/18_support/nested_exception/51438.cc
@@ -1,5 +1,4 @@ 
 // { dg-do compile { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/nested_exception/62154.cc b/libstdc++-v3/testsuite/18_support/nested_exception/62154.cc
index 29a8aeb..e6993c9 100644
--- a/libstdc++-v3/testsuite/18_support/nested_exception/62154.cc
+++ b/libstdc++-v3/testsuite/18_support/nested_exception/62154.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/nested_exception/68139.cc b/libstdc++-v3/testsuite/18_support/nested_exception/68139.cc
index e0e9fca..b2c4528 100644
--- a/libstdc++-v3/testsuite/18_support/nested_exception/68139.cc
+++ b/libstdc++-v3/testsuite/18_support/nested_exception/68139.cc
@@ -1,5 +1,4 @@ 
 // { dg-do compile { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2015-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/nested_exception/cons.cc b/libstdc++-v3/testsuite/18_support/nested_exception/cons.cc
index 859b505..da0842c 100644
--- a/libstdc++-v3/testsuite/18_support/nested_exception/cons.cc
+++ b/libstdc++-v3/testsuite/18_support/nested_exception/cons.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/nested_exception/nested_ptr.cc b/libstdc++-v3/testsuite/18_support/nested_exception/nested_ptr.cc
index 52d00ba..7d128f7 100644
--- a/libstdc++-v3/testsuite/18_support/nested_exception/nested_ptr.cc
+++ b/libstdc++-v3/testsuite/18_support/nested_exception/nested_ptr.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/nested_exception/rethrow_if_nested.cc b/libstdc++-v3/testsuite/18_support/nested_exception/rethrow_if_nested.cc
index cd44b1c..1af61d6 100644
--- a/libstdc++-v3/testsuite/18_support/nested_exception/rethrow_if_nested.cc
+++ b/libstdc++-v3/testsuite/18_support/nested_exception/rethrow_if_nested.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/nested_exception/rethrow_nested.cc b/libstdc++-v3/testsuite/18_support/nested_exception/rethrow_nested.cc
index 2f307c8..b477b25 100644
--- a/libstdc++-v3/testsuite/18_support/nested_exception/rethrow_nested.cc
+++ b/libstdc++-v3/testsuite/18_support/nested_exception/rethrow_nested.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/18_support/nested_exception/throw_with_nested.cc b/libstdc++-v3/testsuite/18_support/nested_exception/throw_with_nested.cc
index 143521f..55e0e9d 100644
--- a/libstdc++-v3/testsuite/18_support/nested_exception/throw_with_nested.cc
+++ b/libstdc++-v3/testsuite/18_support/nested_exception/throw_with_nested.cc
@@ -1,5 +1,4 @@ 
 // { dg-do run { target c++11 } }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/async/42819.cc b/libstdc++-v3/testsuite/30_threads/async/42819.cc
index 9a605fb..87555d3 100644
--- a/libstdc++-v3/testsuite/30_threads/async/42819.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/42819.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/async/49668.cc b/libstdc++-v3/testsuite/30_threads/async/49668.cc
index 1da2e45..e2f8d8e 100644
--- a/libstdc++-v3/testsuite/30_threads/async/49668.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/49668.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/async/54297.cc b/libstdc++-v3/testsuite/30_threads/async/54297.cc
index 68b1be0..318f6cb 100644
--- a/libstdc++-v3/testsuite/30_threads/async/54297.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/54297.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 // { dg-require-sleep "" }
 
 // Copyright (C) 2012-2017 Free Software Foundation, Inc.
diff --git a/libstdc++-v3/testsuite/30_threads/async/any.cc b/libstdc++-v3/testsuite/30_threads/async/any.cc
index 27fe8c7..03a152f 100644
--- a/libstdc++-v3/testsuite/30_threads/async/any.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/any.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/async/async.cc b/libstdc++-v3/testsuite/30_threads/async/async.cc
index 3c90bca..34f8ec4 100644
--- a/libstdc++-v3/testsuite/30_threads/async/async.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/async.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/async/except.cc b/libstdc++-v3/testsuite/30_threads/async/except.cc
index 6047d0c..d2ac3ed 100644
--- a/libstdc++-v3/testsuite/30_threads/async/except.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/except.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/async/forced_unwind.cc b/libstdc++-v3/testsuite/30_threads/async/forced_unwind.cc
index 85ece1d..2597d2a 100644
--- a/libstdc++-v3/testsuite/30_threads/async/forced_unwind.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/forced_unwind.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/async/launch.cc b/libstdc++-v3/testsuite/30_threads/async/launch.cc
index 65420ff..2015f7b 100644
--- a/libstdc++-v3/testsuite/30_threads/async/launch.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/launch.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/async/lwg2021.cc b/libstdc++-v3/testsuite/30_threads/async/lwg2021.cc
index ffcb623..8b38b78 100644
--- a/libstdc++-v3/testsuite/30_threads/async/lwg2021.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/lwg2021.cc
@@ -20,7 +20,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // LWG 2021. Further incorrect usages of result_of
 // Arguments to result_of should use decay.
diff --git a/libstdc++-v3/testsuite/30_threads/async/sync.cc b/libstdc++-v3/testsuite/30_threads/async/sync.cc
index 07cbff9..b41f65d 100644
--- a/libstdc++-v3/testsuite/30_threads/async/sync.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/sync.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/cons/assign_neg.cc b/libstdc++-v3/testsuite/30_threads/future/cons/assign_neg.cc
index 53dd4fa..a32070a 100644
--- a/libstdc++-v3/testsuite/30_threads/future/cons/assign_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/cons/assign_neg.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/cons/constexpr.cc b/libstdc++-v3/testsuite/30_threads/future/cons/constexpr.cc
index 25de49f..cd50611 100644
--- a/libstdc++-v3/testsuite/30_threads/future/cons/constexpr.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/cons/constexpr.cc
@@ -2,7 +2,6 @@ 
 // { dg-options "-fno-inline -g0" }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 // { dg-final { scan-assembler-not "_ZNSt6futureIvEC2Ev" } }
 // { dg-final { scan-assembler-not "_ZNSt6futureIiEC2Ev" } }
 
diff --git a/libstdc++-v3/testsuite/30_threads/future/cons/copy_neg.cc b/libstdc++-v3/testsuite/30_threads/future/cons/copy_neg.cc
index be3a539..58a7f73 100644
--- a/libstdc++-v3/testsuite/30_threads/future/cons/copy_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/cons/copy_neg.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/cons/default.cc b/libstdc++-v3/testsuite/30_threads/future/cons/default.cc
index b2e148e..783b38e 100644
--- a/libstdc++-v3/testsuite/30_threads/future/cons/default.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/cons/default.cc
@@ -1,7 +1,6 @@ 
 // { dg-do run { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/cons/move.cc b/libstdc++-v3/testsuite/30_threads/future/cons/move.cc
index 5a3c0ef..763066b 100644
--- a/libstdc++-v3/testsuite/30_threads/future/cons/move.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/cons/move.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/cons/move_assign.cc b/libstdc++-v3/testsuite/30_threads/future/cons/move_assign.cc
index 52cb2dd..9157348 100644
--- a/libstdc++-v3/testsuite/30_threads/future/cons/move_assign.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/cons/move_assign.cc
@@ -1,7 +1,6 @@ 
 // { dg-do run { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/members/45133.cc b/libstdc++-v3/testsuite/30_threads/future/members/45133.cc
index e16fd08..0a4e901 100644
--- a/libstdc++-v3/testsuite/30_threads/future/members/45133.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/members/45133.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/members/get.cc b/libstdc++-v3/testsuite/30_threads/future/members/get.cc
index 44509e3..531706a 100644
--- a/libstdc++-v3/testsuite/30_threads/future/members/get.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/members/get.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/members/get2.cc b/libstdc++-v3/testsuite/30_threads/future/members/get2.cc
index da8c048..451d97b 100644
--- a/libstdc++-v3/testsuite/30_threads/future/members/get2.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/members/get2.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/members/share.cc b/libstdc++-v3/testsuite/30_threads/future/members/share.cc
index d08b8d0..9619ff1 100644
--- a/libstdc++-v3/testsuite/30_threads/future/members/share.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/members/share.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/members/valid.cc b/libstdc++-v3/testsuite/30_threads/future/members/valid.cc
index 66a5db7..b43f1687 100644
--- a/libstdc++-v3/testsuite/30_threads/future/members/valid.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/members/valid.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/members/wait.cc b/libstdc++-v3/testsuite/30_threads/future/members/wait.cc
index 157a28c..cc73758 100644
--- a/libstdc++-v3/testsuite/30_threads/future/members/wait.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/members/wait.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/members/wait_for.cc b/libstdc++-v3/testsuite/30_threads/future/members/wait_for.cc
index 408066f..e77606b 100644
--- a/libstdc++-v3/testsuite/30_threads/future/members/wait_for.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/members/wait_for.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/members/wait_until.cc b/libstdc++-v3/testsuite/30_threads/future/members/wait_until.cc
index 998eda6..f9fef11 100644
--- a/libstdc++-v3/testsuite/30_threads/future/members/wait_until.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/members/wait_until.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/future/requirements/explicit_instantiation.cc b/libstdc++-v3/testsuite/30_threads/future/requirements/explicit_instantiation.cc
index aa2ae0a..1a6e262 100644
--- a/libstdc++-v3/testsuite/30_threads/future/requirements/explicit_instantiation.cc
+++ b/libstdc++-v3/testsuite/30_threads/future/requirements/explicit_instantiation.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/headers/future/types_std_c++0x.cc b/libstdc++-v3/testsuite/30_threads/headers/future/types_std_c++0x.cc
index 0c30622..4c15fbf 100644
--- a/libstdc++-v3/testsuite/30_threads/headers/future/types_std_c++0x.cc
+++ b/libstdc++-v3/testsuite/30_threads/headers/future/types_std_c++0x.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" } 
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/49668.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/49668.cc
index a8fb01b..4107004 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/49668.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/49668.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/60564.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/60564.cc
index a80f4b6..a1d4e35 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/60564.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/60564.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/1.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/1.cc
index c922038..dd7f214 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/1.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/1.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/2.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/2.cc
index 8264d19..c729434 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/2.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/2.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/3.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/3.cc
index e74d3e7..30ae5da 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/3.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/3.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/56492.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/56492.cc
index 37f7043..7073360 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/56492.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/56492.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2013-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc.cc
index e6ba631..c45c9ea 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc2.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc2.cc
index e2ebceb..f664391 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc2.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc2.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc_min.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc_min.cc
index 23f7133..e1f99e0 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc_min.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/alloc_min.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/assign_neg.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/assign_neg.cc
index 7c4edb9..f8f501e 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/assign_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/assign_neg.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/copy_neg.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/copy_neg.cc
index f95fbfd..8d007f8 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/copy_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/copy_neg.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/move.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/move.cc
index 5bc750b..bd5cbd5 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/move.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/move.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/move_assign.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/move_assign.cc
index 6d89b08..165b977 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/cons/move_assign.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/cons/move_assign.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/forced_unwind.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/forced_unwind.cc
index 2d63602..cff9279 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/forced_unwind.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/forced_unwind.cc
@@ -1,7 +1,6 @@ 
 // { dg-do run { target *-*-linux* *-*-gnu* } }
 // { dg-options "-pthread" { target *-*-linux* *-*-gnu* *-*-solaris* } }
 // { dg-require-effective-target c++11 }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/at_thread_exit.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/at_thread_exit.cc
index 3cc2a9c..60700e2 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/at_thread_exit.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/at_thread_exit.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/get_future.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/get_future.cc
index 039384c..e11ef8c 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/get_future.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/get_future.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/get_future2.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/get_future2.cc
index 57c2f45..d0664b0 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/get_future2.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/get_future2.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke.cc
index 1755998..0099f37 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke2.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke2.cc
index 5dd85c2..9a08879 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke2.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke2.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke3.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke3.cc
index 1cce180..20e14fc 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke3.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke3.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke4.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke4.cc
index f3439de..7ff3f08 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke4.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke4.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke5.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke5.cc
index a4231ea..2be1e8d 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke5.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/invoke5.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/reset.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/reset.cc
index bde58d3..2643120 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/reset.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/reset.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/reset2.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/reset2.cc
index 2eb2d09..79a33cd 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/reset2.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/reset2.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/swap.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/swap.cc
index aec95d7..b2453d0 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/swap.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/swap.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/members/valid.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/members/valid.cc
index f131827..422b951 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/members/valid.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/members/valid.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/requirements/explicit_instantiation.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/requirements/explicit_instantiation.cc
index a508b31..ea3d0b4 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/requirements/explicit_instantiation.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/requirements/explicit_instantiation.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/uses_allocator.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/uses_allocator.cc
index 76fd7d8..5cda284 100644
--- a/libstdc++-v3/testsuite/30_threads/packaged_task/uses_allocator.cc
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/uses_allocator.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/60966.cc b/libstdc++-v3/testsuite/30_threads/promise/60966.cc
index dff1540..38c45fd 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/60966.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/60966.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/69106.cc b/libstdc++-v3/testsuite/30_threads/promise/69106.cc
index e59d6a7..a209279 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/69106.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/69106.cc
@@ -18,7 +18,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 #include <future>
 
diff --git a/libstdc++-v3/testsuite/30_threads/promise/cons/1.cc b/libstdc++-v3/testsuite/30_threads/promise/cons/1.cc
index 035f605..0c5d209 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/cons/1.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/cons/1.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/cons/alloc.cc b/libstdc++-v3/testsuite/30_threads/promise/cons/alloc.cc
index f233be2..a51dd2a 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/cons/alloc.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/cons/alloc.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/cons/alloc2.cc b/libstdc++-v3/testsuite/30_threads/promise/cons/alloc2.cc
index 0febeb3..ad7f35b 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/cons/alloc2.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/cons/alloc2.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/cons/alloc_min.cc b/libstdc++-v3/testsuite/30_threads/promise/cons/alloc_min.cc
index 002ea04..388da2d 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/cons/alloc_min.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/cons/alloc_min.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/cons/assign_neg.cc b/libstdc++-v3/testsuite/30_threads/promise/cons/assign_neg.cc
index 32e3a6a..837ffae 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/cons/assign_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/cons/assign_neg.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/cons/copy_neg.cc b/libstdc++-v3/testsuite/30_threads/promise/cons/copy_neg.cc
index 921f18b..0d9db76 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/cons/copy_neg.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/cons/copy_neg.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/cons/move.cc b/libstdc++-v3/testsuite/30_threads/promise/cons/move.cc
index 9d7e1e8..a62b465 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/cons/move.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/cons/move.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/cons/move_assign.cc b/libstdc++-v3/testsuite/30_threads/promise/cons/move_assign.cc
index efd44b7..65f9546 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/cons/move_assign.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/cons/move_assign.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/members/at_thread_exit.cc b/libstdc++-v3/testsuite/30_threads/promise/members/at_thread_exit.cc
index 867ff7f..08331bf 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/members/at_thread_exit.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/members/at_thread_exit.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2014-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/members/get_future.cc b/libstdc++-v3/testsuite/30_threads/promise/members/get_future.cc
index f20316a..72ae208 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/members/get_future.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/members/get_future.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/members/get_future2.cc b/libstdc++-v3/testsuite/30_threads/promise/members/get_future2.cc
index 229577a..117de2c 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/members/get_future2.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/members/get_future2.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/members/set_exception.cc b/libstdc++-v3/testsuite/30_threads/promise/members/set_exception.cc
index f285e72..6ff4a34 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/members/set_exception.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/members/set_exception.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/members/set_exception2.cc b/libstdc++-v3/testsuite/30_threads/promise/members/set_exception2.cc
index 6fd8495..1b1a066 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/members/set_exception2.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/members/set_exception2.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/members/set_value.cc b/libstdc++-v3/testsuite/30_threads/promise/members/set_value.cc
index fcfa187..7c08278 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/members/set_value.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/members/set_value.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/members/set_value2.cc b/libstdc++-v3/testsuite/30_threads/promise/members/set_value2.cc
index 9f3839a..0c4e87a 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/members/set_value2.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/members/set_value2.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/members/set_value3.cc b/libstdc++-v3/testsuite/30_threads/promise/members/set_value3.cc
index 595f0e9..110b79a 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/members/set_value3.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/members/set_value3.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/members/swap.cc b/libstdc++-v3/testsuite/30_threads/promise/members/swap.cc
index d0d4b73..15b1a17 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/members/swap.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/members/swap.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/requirements/explicit_instantiation.cc b/libstdc++-v3/testsuite/30_threads/promise/requirements/explicit_instantiation.cc
index 3b125e9..5d6bcf3 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/requirements/explicit_instantiation.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/requirements/explicit_instantiation.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/promise/uses_allocator.cc b/libstdc++-v3/testsuite/30_threads/promise/uses_allocator.cc
index 71a6c64..d083153 100644
--- a/libstdc++-v3/testsuite/30_threads/promise/uses_allocator.cc
+++ b/libstdc++-v3/testsuite/30_threads/promise/uses_allocator.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2011-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/cons/assign.cc b/libstdc++-v3/testsuite/30_threads/shared_future/cons/assign.cc
index a1d70ff..6716416 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/cons/assign.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/cons/assign.cc
@@ -1,7 +1,6 @@ 
 // { dg-do run { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/cons/constexpr.cc b/libstdc++-v3/testsuite/30_threads/shared_future/cons/constexpr.cc
index e8e5594..afacf44 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/cons/constexpr.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/cons/constexpr.cc
@@ -2,7 +2,6 @@ 
 // { dg-options "-fno-inline -g0" }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 // { dg-final { scan-assembler-not "_ZNSt13shared_futureIvEC2Ev" } }
 // { dg-final { scan-assembler-not "_ZNSt13shared_futureIiEC2Ev" } }
 
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/cons/copy.cc b/libstdc++-v3/testsuite/30_threads/shared_future/cons/copy.cc
index fe1308e..9f037bf 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/cons/copy.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/cons/copy.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/cons/default.cc b/libstdc++-v3/testsuite/30_threads/shared_future/cons/default.cc
index 9d8040c..a4d5c8a 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/cons/default.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/cons/default.cc
@@ -1,7 +1,6 @@ 
 // { dg-do run { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/cons/move.cc b/libstdc++-v3/testsuite/30_threads/shared_future/cons/move.cc
index 24777e6..6e9d8f8 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/cons/move.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/cons/move.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/cons/move_assign.cc b/libstdc++-v3/testsuite/30_threads/shared_future/cons/move_assign.cc
index f9f71d8..68910c1 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/cons/move_assign.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/cons/move_assign.cc
@@ -1,7 +1,6 @@ 
 // { dg-do run { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/members/45133.cc b/libstdc++-v3/testsuite/30_threads/shared_future/members/45133.cc
index 0e205ae..6933bed 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/members/45133.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/members/45133.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/members/get.cc b/libstdc++-v3/testsuite/30_threads/shared_future/members/get.cc
index 270edab..0e84d8b 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/members/get.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/members/get.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/members/get2.cc b/libstdc++-v3/testsuite/30_threads/shared_future/members/get2.cc
index 6c50ce4..4bfa177 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/members/get2.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/members/get2.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/members/valid.cc b/libstdc++-v3/testsuite/30_threads/shared_future/members/valid.cc
index 1c436c0..dda7a57 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/members/valid.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/members/valid.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2010-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/members/wait.cc b/libstdc++-v3/testsuite/30_threads/shared_future/members/wait.cc
index 6f98a86..725180f 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/members/wait.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/members/wait.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/members/wait_for.cc b/libstdc++-v3/testsuite/30_threads/shared_future/members/wait_for.cc
index 7220af1..7d62ffd 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/members/wait_for.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/members/wait_for.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/members/wait_until.cc b/libstdc++-v3/testsuite/30_threads/shared_future/members/wait_until.cc
index ce0133b..5eac3d1 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/members/wait_until.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/members/wait_until.cc
@@ -3,7 +3,6 @@ 
 // { dg-require-effective-target c++11 }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_future/requirements/explicit_instantiation.cc b/libstdc++-v3/testsuite/30_threads/shared_future/requirements/explicit_instantiation.cc
index 69747d6..a48d45c 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_future/requirements/explicit_instantiation.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_future/requirements/explicit_instantiation.cc
@@ -1,7 +1,6 @@ 
 // { dg-do compile { target c++11 } }
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
-// { dg-require-atomic-builtins "" }
 
 // Copyright (C) 2009-2017 Free Software Foundation, Inc.
 //