整理

include/boost/numeric/interval/detail/x86gcc_rounding_control.hpp

@@ -0,0 +1,51 @@
+/* Boost interval/detail/x86gcc_rounding_control.hpp file
+ *
+ * Copyright 2000 Jens Maurer
+ * Copyright 2002 Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion
+ *
+ * Distributed under the Boost Software License, Version 1.0.
+ * (See accompanying file LICENSE_1_0.txt or
+ * copy at http://www.boost.org/LICENSE_1_0.txt)
+ */
+
+#ifndef BOOST_NUMERIC_INTERVAL_DETAIL_X86GCC_ROUNDING_CONTROL_HPP
+#define BOOST_NUMERIC_INTERVAL_DETAIL_X86GCC_ROUNDING_CONTROL_HPP
+
+#if !defined(__GNUC__) && !(defined(__BORLANDC__) && defined(__clang__))
+#  error This header only works with GNU CC.
+#endif
+
+#if !defined(__i386__) && !defined(__x86_64__)
+#  error This header only works on x86 CPUs.
+#endif
+
+namespace boost {
+namespace numeric {
+namespace interval_lib {
+namespace detail {
+
+struct x86_rounding
+{
+  typedef unsigned short rounding_mode;
+
+  static void set_rounding_mode(const rounding_mode& mode)
+  { __asm__ __volatile__ ("fldcw %0" : : "m"(mode)); }
+
+  static void get_rounding_mode(rounding_mode& mode)
+  { __asm__ __volatile__ ("fnstcw %0" : "=m"(mode)); }
+
+  template<class T>
+  static T to_int(T r)
+  {
+    T r_;
+    __asm__ ("frndint" : "=&t"(r_) : "0"(r));
+    return r_;
+  }
+};
+
+} // namespace detail
+} // namespace interval_lib
+} // namespace numeric
+} // namespace boost
+
+#endif /* BOOST_NUMERIC_INTERVAL_DETAIL_X86GCC_ROUNDING_CONTROL_HPP */