Imported Upstream version 1.57.0upstream/1.57.0

1 files changed, 229 insertions, 0 deletions

diff --git a/boost/multiprecision/detail/bitscan.hpp b/boost/multiprecision/detail/bitscan.hpp
new file mode 100644
index 0000000000..40602a939b
--- /dev/null
+++ b/boost/multiprecision/detail/bitscan.hpp
@@ -0,0 +1,229 @@
+///////////////////////////////////////////////////////////////
+//  Copyright 2013 John Maddock. 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_
+//
+// Comparison operators for cpp_int_backend:
+//
+#ifndef BOOST_MP_DETAIL_BITSCAN_HPP
+#define BOOST_MP_DETAIL_BITSCAN_HPP
+
+#if defined(BOOST_MSVC) && (defined(_M_IX86) || defined(_M_X64))
+#include <Intrin.h>
+#endif
+
+namespace boost{ namespace multiprecision{ namespace detail{
+
+template <class Unsigned>
+inline unsigned find_lsb(Unsigned mask, const mpl::int_<0>&)
+{
+   unsigned result = 0;
+   while(!(mask & 1u))
+   {
+      mask >>= 1;
+      ++result;
+   }
+   return result;
+}
+
+template <class Unsigned>
+inline unsigned find_msb(Unsigned mask, const mpl::int_<0>&)
+{
+   unsigned index = 0;
+   while(mask)
+   {
+      ++index;
+      mask >>= 1;
+   }
+   return --index;
+}
+
+#if defined(BOOST_MSVC) && (defined(_M_IX86) || defined(_M_X64))
+
+#pragma intrinsic(_BitScanForward,_BitScanReverse)
+
+BOOST_FORCEINLINE unsigned find_lsb(unsigned long mask, const mpl::int_<1>&)
+{
+   unsigned long result;
+   _BitScanForward(&result, mask);
+   return result;
+}
+
+BOOST_FORCEINLINE unsigned find_msb(unsigned long mask, const mpl::int_<1>&)
+{
+   unsigned long result;
+   _BitScanReverse(&result, mask);
+   return result;
+}
+#ifdef _M_X64
+
+#pragma intrinsic(_BitScanForward64,_BitScanReverse64)
+
+BOOST_FORCEINLINE unsigned find_lsb(unsigned __int64 mask, const mpl::int_<2>&)
+{
+   unsigned long result;
+   _BitScanForward64(&result, mask);
+   return result;
+}
+template <class Unsigned>
+BOOST_FORCEINLINE unsigned find_msb(Unsigned mask, const mpl::int_<2>&)
+{
+   unsigned long result;
+   _BitScanReverse64(&result, mask);
+   return result;
+}
+#endif
+
+template <class Unsigned>
+BOOST_FORCEINLINE unsigned find_lsb(Unsigned mask)
+{
+   typedef typename make_unsigned<Unsigned>::type ui_type;
+   typedef typename mpl::if_c<
+      sizeof(Unsigned) <= sizeof(unsigned long),
+      mpl::int_<1>,
+#ifdef _M_X64
+      typename mpl::if_c<
+         sizeof(Unsigned) <= sizeof(__int64),
+         mpl::int_<2>,
+         mpl::int_<0>
+      >::type
+#else
+      mpl::int_<0>
+#endif
+   >::type tag_type;
+   return find_lsb(static_cast<ui_type>(mask), tag_type());
+}
+
+template <class Unsigned>
+BOOST_FORCEINLINE unsigned find_msb(Unsigned mask)
+{
+   typedef typename make_unsigned<Unsigned>::type ui_type;
+   typedef typename mpl::if_c<
+      sizeof(Unsigned) <= sizeof(unsigned long),
+      mpl::int_<1>,
+#ifdef _M_X64
+      typename mpl::if_c<
+         sizeof(Unsigned) <= sizeof(__int64),
+         mpl::int_<2>,
+         mpl::int_<0>
+      >::type
+#else
+      mpl::int_<0>
+#endif
+   >::type tag_type;
+   return find_msb(static_cast<ui_type>(mask), tag_type());
+}
+
+#elif defined(BOOST_GCC) || defined(__clang__) || (defined(BOOST_INTEL) && defined(__GNUC__))
+
+BOOST_FORCEINLINE unsigned find_lsb(unsigned mask, mpl::int_<1> const&)
+{
+   return __builtin_ctz(mask);
+}
+BOOST_FORCEINLINE unsigned find_lsb(unsigned long mask, mpl::int_<2> const&)
+{
+   return __builtin_ctzl(mask);
+}
+BOOST_FORCEINLINE unsigned find_lsb(unsigned long long mask, mpl::int_<3> const&)
+{
+   return __builtin_ctzll(mask);
+}
+BOOST_FORCEINLINE unsigned find_msb(unsigned mask, mpl::int_<1> const&)
+{
+   return sizeof(unsigned) * CHAR_BIT - 1 - __builtin_clz(mask);
+}
+BOOST_FORCEINLINE unsigned find_msb(unsigned long mask, mpl::int_<2> const&)
+{
+   return sizeof(unsigned long) * CHAR_BIT - 1 - __builtin_clzl(mask);
+}
+BOOST_FORCEINLINE unsigned find_msb(unsigned long long mask, mpl::int_<3> const&)
+{
+   return sizeof(unsigned long long) * CHAR_BIT - 1 - __builtin_clzll(mask);
+}
+
+template <class Unsigned>
+BOOST_FORCEINLINE unsigned find_lsb(Unsigned mask)
+{
+   typedef typename make_unsigned<Unsigned>::type ui_type;
+   typedef typename mpl::if_c<
+      sizeof(Unsigned) <= sizeof(unsigned),
+      mpl::int_<1>,
+      typename mpl::if_c<
+         sizeof(Unsigned) <= sizeof(unsigned long),
+         mpl::int_<2>,
+         typename mpl::if_c<
+            sizeof(Unsigned) <= sizeof(unsigned long long),
+            mpl::int_<3>,
+            mpl::int_<0>
+         >::type
+      >::type
+   >::type tag_type;
+   return find_lsb(static_cast<ui_type>(mask), tag_type());
+}
+template <class Unsigned>
+BOOST_FORCEINLINE unsigned find_msb(Unsigned mask)
+{
+   typedef typename make_unsigned<Unsigned>::type ui_type;
+   typedef typename mpl::if_c<
+      sizeof(Unsigned) <= sizeof(unsigned),
+      mpl::int_<1>,
+      typename mpl::if_c<
+         sizeof(Unsigned) <= sizeof(unsigned long),
+         mpl::int_<2>,
+         typename mpl::if_c<
+            sizeof(Unsigned) <= sizeof(unsigned long long),
+            mpl::int_<3>,
+            mpl::int_<0>
+         >::type
+      >::type
+   >::type tag_type;
+   return find_msb(static_cast<ui_type>(mask), tag_type());
+}
+#elif defined(BOOST_INTEL)
+BOOST_FORCEINLINE unsigned find_lsb(unsigned mask, mpl::int_<1> const&)
+{
+   return _bit_scan_forward(mask);
+}
+BOOST_FORCEINLINE unsigned find_msb(unsigned mask, mpl::int_<1> const&)
+{
+   return _bit_scan_reverse(mask);
+}
+template <class Unsigned>
+BOOST_FORCEINLINE unsigned find_lsb(Unsigned mask)
+{
+   typedef typename make_unsigned<Unsigned>::type ui_type;
+   typedef typename mpl::if_c<
+      sizeof(Unsigned) <= sizeof(unsigned),
+      mpl::int_<1>,
+      mpl::int_<0>
+   >::type tag_type;
+   return find_lsb(static_cast<ui_type>(mask), tag_type());
+}
+template <class Unsigned>
+BOOST_FORCEINLINE unsigned find_msb(Unsigned mask)
+{
+   typedef typename make_unsigned<Unsigned>::type ui_type;
+   typedef typename mpl::if_c<
+      sizeof(Unsigned) <= sizeof(unsigned),
+      mpl::int_<1>,
+      mpl::int_<0>
+   >::type tag_type;
+   return find_msb(static_cast<ui_type>(mask), tag_type());
+}
+#else
+template <class Unsigned>
+BOOST_FORCEINLINE unsigned find_lsb(Unsigned mask)
+{
+   return find_lsb(mask, mpl::int_<0>());
+}
+template <class Unsigned>
+BOOST_FORCEINLINE unsigned find_msb(Unsigned mask)
+{
+   return find_msb(mask, mpl::int_<0>());
+}
+#endif
+
+}}}
+
+#endif
+