diff --git a/cryptest.sh b/cryptest.sh
index e4508728..5e26aebf 100755
--- a/cryptest.sh
+++ b/cryptest.sh
@@ -172,14 +172,6 @@ if [[ (-z "$HAVE_CXX17") ]]; then
 	fi
 fi
 
-if [[ (-z "$HAVE_GNU17") ]]; then
-	HAVE_GNU17=0
-	"$CXX" -DCRYPTOPP_ADHOC_MAIN -std=gnu++17 adhoc.cpp -o "$TMP/adhoc.exe" > /dev/null 2>&1
-	if [[ "$?" -eq "0" ]]; then
-		HAVE_GNU17=1
-	fi
-fi
-
 # Hit or miss, mostly miss.
 if [[ (-z "$HAVE_CXX14") ]]; then
 	HAVE_CXX14=0
@@ -189,14 +181,6 @@ if [[ (-z "$HAVE_CXX14") ]]; then
 	fi
 fi
 
-if [[ (-z "$HAVE_GNU14") ]]; then
-	HAVE_GNU14=0
-	"$CXX" -DCRYPTOPP_ADHOC_MAIN -std=gnu++14 adhoc.cpp -o "$TMP/adhoc.exe" > /dev/null 2>&1
-	if [[ "$?" -eq "0" ]]; then
-		HAVE_GNU14=1
-	fi
-fi
-
 # Hit or miss, mostly hit.
 if [[ (-z "$HAVE_CXX11") ]]; then
 	HAVE_CXX11=0
@@ -206,14 +190,6 @@ if [[ (-z "$HAVE_CXX11") ]]; then
 	fi
 fi
 
-if [[ (-z "$HAVE_GNU11") ]]; then
-	HAVE_GNU11=0
-	"$CXX" -DCRYPTOPP_ADHOC_MAIN -std=gnu++11 adhoc.cpp -o "$TMP/adhoc.exe" > /dev/null 2>&1
-	if [[ "$?" -eq "0" ]]; then
-		HAVE_GNU11=1
-	fi
-fi
-
 # OpenBSD 5.7 and OS X 10.5 cannot consume -std=c++03
 if [[ (-z "$HAVE_CXX03") ]]; then
 	HAVE_CXX03=0
@@ -452,9 +428,6 @@ elif [[ "$IS_DARWIN" -ne "0" ]]; then
 	echo "IS_DARWIN: $IS_DARWIN" | tee -a "$TEST_RESULTS"
 fi
 
-if [[ "$IS_PPC" -ne "0" ]]; then
-	echo "IS_PPC: $IS_PPC" | tee -a "$TEST_RESULTS"
-fi
 if [[ "$IS_ARM64" -ne "0" ]]; then
 	echo "IS_ARM64: $IS_ARM64" | tee -a "$TEST_RESULTS"
 elif [[ "$IS_ARM32" -ne "0" ]]; then
@@ -491,12 +464,9 @@ fi
 echo | tee -a "$TEST_RESULTS"
 echo "HAVE_CXX03: $HAVE_CXX03" | tee -a "$TEST_RESULTS"
 echo "HAVE_CXX11: $HAVE_CXX11" | tee -a "$TEST_RESULTS"
-echo "HAVE_GNU11: $HAVE_GNU11" | tee -a "$TEST_RESULTS"
-if [[ ("$HAVE_CXX14" -ne "0" || "$HAVE_CXX17" -ne "0" || "$HAVE_GNU14" -ne "0" || "$HAVE_GNU17" -ne "0") ]]; then
+if [[ ("$HAVE_CXX14" -ne "0" || "$HAVE_CXX17" -ne "0") ]]; then
 	echo "HAVE_CXX14: $HAVE_CXX14" | tee -a "$TEST_RESULTS"
-	echo "HAVE_GNU14: $HAVE_GNU14" | tee -a "$TEST_RESULTS"
 	echo "HAVE_CXX17: $HAVE_CXX17" | tee -a "$TEST_RESULTS"
-	echo "HAVE_GNU17: $HAVE_GNU17" | tee -a "$TEST_RESULTS"
 fi
 if [[ "$HAVE_LDGOLD" -ne "0" ]]; then
 	echo "HAVE_LDGOLD: $HAVE_LDGOLD" | tee -a "$TEST_RESULTS"
@@ -1008,65 +978,6 @@ if [[ "$HAVE_CXX11" -ne "0" ]]; then
 	fi
 fi
 
-############################################
-# gnu++11 debug and release build
-if [[ "$HAVE_GNU11" -ne "0" ]]; then
-
-	############################################
-	# Debug build
-	echo
-	echo "************************************" | tee -a "$TEST_RESULTS"
-	echo "Testing: debug, gnu++11" | tee -a "$TEST_RESULTS"
-	echo
-
-	unset CXXFLAGS
-	"$MAKE" clean > /dev/null 2>&1
-	rm -f adhoc.cpp > /dev/null 2>&1
-
-	export CXXFLAGS="$DEBUG_CXXFLAGS -std=gnu++11 ${RETAINED_CXXFLAGS[@]}"
-	"$MAKE" "${MAKEARGS[@]}" CXX="$CXX" static dynamic cryptest.exe 2>&1 | tee -a "$TEST_RESULTS"
-
-	if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-		echo "ERROR: failed to make cryptest.exe" | tee -a "$TEST_RESULTS"
-	else
-		./cryptest.exe v 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute validation suite" | tee -a "$TEST_RESULTS"
-		fi
-		./cryptest.exe tv all 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute test vectors" | tee -a "$TEST_RESULTS"
-		fi
-	fi
-
-	############################################
-	# Release build
-	echo
-	echo "************************************" | tee -a "$TEST_RESULTS"
-	echo "Testing: release, gnu++11" | tee -a "$TEST_RESULTS"
-	echo
-
-	unset CXXFLAGS
-	"$MAKE" clean > /dev/null 2>&1
-	rm -f adhoc.cpp > /dev/null 2>&1
-
-	export CXXFLAGS="$RELEASE_CXXFLAGS -std=gnu++11 ${RETAINED_CXXFLAGS[@]}"
-	"$MAKE" "${MAKEARGS[@]}" CXX="$CXX" static dynamic cryptest.exe 2>&1 | tee -a "$TEST_RESULTS"
-
-	if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-		echo "ERROR: failed to make cryptest.exe" | tee -a "$TEST_RESULTS"
-	else
-		./cryptest.exe v 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute validation suite" | tee -a "$TEST_RESULTS"
-		fi
-		./cryptest.exe tv all 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute test vectors" | tee -a "$TEST_RESULTS"
-		fi
-	fi
-fi
-
 ############################################
 # c++14 debug and release build
 if [[ "$HAVE_CXX14" -ne "0" ]]; then
@@ -1126,65 +1037,6 @@ if [[ "$HAVE_CXX14" -ne "0" ]]; then
 	fi
 fi
 
-############################################
-# gnu++14 debug and release build
-if [[ "$HAVE_GNU14" -ne "0" ]]; then
-
-	############################################
-	# Debug build
-	echo
-	echo "************************************" | tee -a "$TEST_RESULTS"
-	echo "Testing: debug, gnu++14" | tee -a "$TEST_RESULTS"
-	echo
-
-	unset CXXFLAGS
-	"$MAKE" clean > /dev/null 2>&1
-	rm -f adhoc.cpp > /dev/null 2>&1
-
-	export CXXFLAGS="$DEBUG_CXXFLAGS -std=gnu++14 ${RETAINED_CXXFLAGS[@]}"
-	"$MAKE" "${MAKEARGS[@]}" CXX="$CXX" static dynamic cryptest.exe 2>&1 | tee -a "$TEST_RESULTS"
-
-	if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-		echo "ERROR: failed to make cryptest.exe" | tee -a "$TEST_RESULTS"
-	else
-		./cryptest.exe v 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute validation suite" | tee -a "$TEST_RESULTS"
-		fi
-		./cryptest.exe tv all 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute test vectors" | tee -a "$TEST_RESULTS"
-		fi
-	fi
-
-	############################################
-	# Release build
-	echo
-	echo "************************************" | tee -a "$TEST_RESULTS"
-	echo "Testing: release, gnu++14" | tee -a "$TEST_RESULTS"
-	echo
-
-	unset CXXFLAGS
-	"$MAKE" clean > /dev/null 2>&1
-	rm -f adhoc.cpp > /dev/null 2>&1
-
-	export CXXFLAGS="$RELEASE_CXXFLAGS -std=gnu++14 ${RETAINED_CXXFLAGS[@]}"
-	"$MAKE" "${MAKEARGS[@]}" CXX="$CXX" static dynamic cryptest.exe 2>&1 | tee -a "$TEST_RESULTS"
-
-	if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-		echo "ERROR: failed to make cryptest.exe" | tee -a "$TEST_RESULTS"
-	else
-		./cryptest.exe v 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute validation suite" | tee -a "$TEST_RESULTS"
-		fi
-		./cryptest.exe tv all 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute test vectors" | tee -a "$TEST_RESULTS"
-		fi
-	fi
-fi
-
 ############################################
 # c++17 debug and release build
 if [[ "$HAVE_CXX17" -ne "0" ]]; then
@@ -1244,65 +1096,6 @@ if [[ "$HAVE_CXX17" -ne "0" ]]; then
 	fi
 fi
 
-############################################
-# gnu++17 debug and release build
-if [[ "$HAVE_GNU17" -ne "0" ]]; then
-
-	############################################
-	# Debug build
-	echo
-	echo "************************************" | tee -a "$TEST_RESULTS"
-	echo "Testing: debug, gnu++17" | tee -a "$TEST_RESULTS"
-	echo
-
-	unset CXXFLAGS
-	"$MAKE" clean > /dev/null 2>&1
-	rm -f adhoc.cpp > /dev/null 2>&1
-
-	export CXXFLAGS="$DEBUG_CXXFLAGS -std=gnu++17 ${RETAINED_CXXFLAGS[@]}"
-	"$MAKE" "${MAKEARGS[@]}" CXX="$CXX" static dynamic cryptest.exe 2>&1 | tee -a "$TEST_RESULTS"
-
-	if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-		echo "ERROR: failed to make cryptest.exe" | tee -a "$TEST_RESULTS"
-	else
-		./cryptest.exe v 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute validation suite" | tee -a "$TEST_RESULTS"
-		fi
-		./cryptest.exe tv all 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute test vectors" | tee -a "$TEST_RESULTS"
-		fi
-	fi
-
-	############################################
-	# Release build
-	echo
-	echo "************************************" | tee -a "$TEST_RESULTS"
-	echo "Testing: release, gnu++17" | tee -a "$TEST_RESULTS"
-	echo
-
-	unset CXXFLAGS
-	"$MAKE" clean > /dev/null 2>&1
-	rm -f adhoc.cpp > /dev/null 2>&1
-
-	export CXXFLAGS="$RELEASE_CXXFLAGS -std=gnu++17 ${RETAINED_CXXFLAGS[@]}"
-	"$MAKE" "${MAKEARGS[@]}" CXX="$CXX" static dynamic cryptest.exe 2>&1 | tee -a "$TEST_RESULTS"
-
-	if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-		echo "ERROR: failed to make cryptest.exe" | tee -a "$TEST_RESULTS"
-	else
-		./cryptest.exe v 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute validation suite" | tee -a "$TEST_RESULTS"
-		fi
-		./cryptest.exe tv all 2>&1 | tee -a "$TEST_RESULTS"
-		if [[ ("${PIPESTATUS[0]}" -ne "0") ]]; then
-			echo "ERROR: failed to execute test vectors" | tee -a "$TEST_RESULTS"
-		fi
-	fi
-fi
-
 ############################################
 # X32 debug and release build
 if [[ "$HAVE_X32" -ne "0" ]]; then
diff --git a/misc.h b/misc.h
index 655100f6..63ed4e29 100644
--- a/misc.h
+++ b/misc.h
@@ -221,11 +221,10 @@ struct NewObject
 //! \brief A memory barrier
 //! \details MEMORY_BARRIER attempts to ensure reads and writes are completed
 //!   in the absence of a language synchronization point. It is used by the
-//!   Singleton class if the compiler supports it. The barrier is provided at the
-//!   customary places in a double-checked initialization.
-//! \details Internally, MEMORY_BARRIER uses <tt>std::atomic_thread_fence</tt> if
-//!   C++11 atomics are available. Otherwise, <tt>intrinsic(_ReadWriteBarrier)</tt>,
-//!   <tt>_ReadWriteBarrier()</tt> or <tt>__asm__("" ::: "memory")</tt> is used.
+//!   Singleton class if the compiler supports it. The use is provided at the
+//!   customary check points in a double-checked initialization.
+//! \details Internally, MEMORY_BARRIER uses <tt>intrinsic(_ReadWriteBarrier)</tt>,
+//!   <tt>_ReadWriteBarrier()</tt> or <tt>__asm__("" ::: "memory")</tt>.
 #define MEMORY_BARRIER ...
 #else
 #if defined(CRYPTOPP_CXX11_ATOMICS)
@@ -249,8 +248,8 @@ struct NewObject
 //! \details This class safely initializes a static object in a multithreaded environment. For C++03
 //!   and below it will do so without using locks for portability. If two threads call Ref() at the same
 //!   time, they may get back different references, and one object may end up being memory leaked. This
-//!   is by design. For C++11 and above, a standard double-checked locking pattern with thread fences
-//!   are used. The locks and fences are standard and do not hinder portability.
+//!   is by design. For C++11 and above, a standard double-checked locking pattern with memory fences
+//!   is used. The locks and fences are standard and do not hinder portability.
 //! \sa <A HREF="http://preshing.com/20130930/double-checked-locking-is-fixed-in-cpp11/">Double-Checked Locking is Fixed In C++11</A>
 template <class T, class F = NewObject<T>, int instance=0>
 class Singleton
diff --git a/socketft.cpp b/socketft.cpp
index ff6e0d40..42a00182 100644
--- a/socketft.cpp
+++ b/socketft.cpp
@@ -109,12 +109,10 @@ void Socket::CloseSocket()
 		BOOL result = CancelIoEx((HANDLE) m_s, NULL);
 		assert(result || (!result && GetLastError() == ERROR_NOT_FOUND));
 		CheckAndHandleError_int("closesocket", closesocket(m_s));
-		CRYPTOPP_UNUSED(result);	// Used by assert in debug builds
 # else
 		BOOL result = CancelIo((HANDLE) m_s);
 		assert(result || (!result && GetLastError() == ERROR_NOT_FOUND));
 		CheckAndHandleError_int("closesocket", closesocket(m_s));
-		CRYPTOPP_UNUSED(result);
 # endif
 #else
 		CheckAndHandleError_int("close", close(m_s));
@@ -370,11 +368,9 @@ SocketReceiver::~SocketReceiver()
 # if defined(USE_WINDOWS8_API)
 	BOOL result = CancelIoEx((HANDLE) m_s.GetSocket(), NULL);
 	assert(result || (!result && GetLastError() == ERROR_NOT_FOUND));
-	CRYPTOPP_UNUSED(result);	// Used by assert in debug builds
 # else
 	BOOL result = CancelIo((HANDLE) m_s.GetSocket());
 	assert(result || (!result && GetLastError() == ERROR_NOT_FOUND));
-	CRYPTOPP_UNUSED(result);
 # endif
 #endif
 }
@@ -460,11 +456,9 @@ SocketSender::~SocketSender()
 # if defined(USE_WINDOWS8_API)
 	BOOL result = CancelIoEx((HANDLE) m_s.GetSocket(), NULL);
 	assert(result || (!result && GetLastError() == ERROR_NOT_FOUND));
-	CRYPTOPP_UNUSED(result);	// Used by assert in debug builds
 # else
 	BOOL result = CancelIo((HANDLE) m_s.GetSocket());
 	assert(result || (!result && GetLastError() == ERROR_NOT_FOUND));
-	CRYPTOPP_UNUSED(result);
 # endif
 #endif
 }