1 files changed, 48 insertions, 0 deletions
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index a9589d882e6..188be08d716 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -71957,6 +71957,54 @@ _ACEOF
   fi
 
 
+
+
+  ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether static objects can be aligned to the cacheline size" >&5
+$as_echo_n "checking whether static objects can be aligned to the cacheline size... " >&6; }
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+struct alignas(__GCC_DESTRUCTIVE_SIZE) Aligned { };
+		    alignas(Aligned) static char buf[sizeof(Aligned) * 16];
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  ac_alignas_cacheline=yes
+else
+  ac_alignas_cacheline=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  if test "$ac_alignas_cacheline" = yes; then
+
+cat >>confdefs.h <<_ACEOF
+#define _GLIBCXX_CAN_ALIGNAS_DESTRUCTIVE_SIZE 1
+_ACEOF
+
+  fi
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_alignas_cacheline" >&5
+$as_echo "$ac_alignas_cacheline" >&6; }
+
+  ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+
 # Define documentation rules conditionally.
 
 # See if makeinfo has been installed and is modern enough