PR 571: Implements an accurate argument reduction algorithm for huge inputs of sin/cos and call it instead of falling back to std::sin/std::cos.

This makes both the small and huge argument cases faster because:
- for small inputs this removes the last pselect
- for large inputs only the reduction part follows a scalar path,
the rest use the same SIMD path as the small-argument case.

Eigen/src/Core/util/Meta.h

@@ -636,8 +636,41 @@ template<> EIGEN_STRONG_INLINE EIGEN_DEVICE_FUNC
 bool not_equal_strict(const double& x,const double& y) { return std::not_equal_to<double>()(x,y); }
 #endif
 
+/** \internal extract the bits of the float \a x */
+inline unsigned int as_uint(float x)
+{
+  unsigned int ret;
+  std::memcpy(&ret, &x, sizeof(float));
+  return ret;
+}
+
 } // end namespace numext
 
 } // end namespace Eigen
 
+// Define portable (u)int{32,64} types
+#if EIGEN_HAS_CXX11
+#include <cstdint>
+namespace Eigen {
+namespace numext {
+typedef std::uint32_t uint32_t;
+typedef std::int32_t  int32_t;
+typedef std::uint64_t uint64_t;
+typedef std::int64_t  int64_t;
+}
+}
+#else
+// Without c++11, all compilers able to compile Eigen also
+// provides the C99 stdint.h header file.
+#include <stdint.h>
+namespace Eigen {
+namespace numext {
+typedef ::uint32_t uint32_t;
+typedef ::int32_t  int32_t;
+typedef ::uint64_t uint64_t;
+typedef ::int64_t  int64_t;
+}
+}
+#endif
+
 #endif // EIGEN_META_H