Subject: [Boost-commit] svn:boost r54859 - trunk/boost/spirit/home/karma/numeric/detail
From: hartmut.kaiser_at_[hidden]
Date: 2009-07-10 10:57:19
Author: hkaiser
Date: 2009-07-10 10:57:18 EDT (Fri, 10 Jul 2009)
New Revision: 54859
URL: http://svn.boost.org/trac/boost/changeset/54859
Log:
Spirit: massive speedup fix for karma real generators (for built in floating point types)
Text files modified:
trunk/boost/spirit/home/karma/numeric/detail/numeric_utils.hpp | 54 +++++++++++++++++++++++++++++++++++++++
1 files changed, 53 insertions(+), 1 deletions(-)
Modified: trunk/boost/spirit/home/karma/numeric/detail/numeric_utils.hpp
==============================================================================
--- trunk/boost/spirit/home/karma/numeric/detail/numeric_utils.hpp (original)
+++ trunk/boost/spirit/home/karma/numeric/detail/numeric_utils.hpp 2009-07-10 10:57:18 EDT (Fri, 10 Jul 2009)
@@ -412,7 +412,6 @@
typedef detail::divide<Radix> divide_type;
typedef detail::remainder<Radix> remainder_type;
- // Common code for integer string representations
template <typename OutputIterator, typename T>
static bool
call(OutputIterator& sink, T n, T& num, int exp)
@@ -444,6 +443,59 @@
{
return call(sink, n, n, 0);
}
+
+ // helper function returning the biggest number representable either in
+ // a boost::long_long_type (if this does exist) or in a plain long
+ // otherwise
+#if defined(BOOST_HAS_LONG_LONG)
+ static std::size_t max_long()
+ {
+ return (std::numeric_limits<boost::long_long_type>::max)();
+ }
+#else
+ static std::size_t max_long()
+ {
+ return (std::numeric_limits<long>::max)();
+ }
+#endif
+
+ // Specialization for doubles and floats, falling back to long integers
+ // for representable values. These specializations speed up formatting
+ // of floating point numbers considerably as all the required
+ // arithmetics will be executed using integral data types.
+ template <typename OutputIterator>
+ static bool
+ call(OutputIterator& sink, long double n)
+ {
+ if (std::fabs(n) < max_long())
+ {
+ boost::long_long_type l(n);
+ return call(sink, l, l, 0);
+ }
+ return call(sink, n, n, 0);
+ }
+ template <typename OutputIterator>
+ static bool
+ call(OutputIterator& sink, double n)
+ {
+ if (std::fabs(n) < max_long())
+ {
+ boost::long_long_type l(n);
+ return call(sink, l, l, 0);
+ }
+ return call(sink, n, n, 0);
+ }
+ template <typename OutputIterator>
+ static bool
+ call(OutputIterator& sink, float n)
+ {
+ if (std::fabs(n) < max_long())
+ {
+ long l(n);
+ return call(sink, l, l, 0);
+ }
+ return call(sink, n, n, 0);
+ }
};
#undef BOOST_KARMA_NUMERICS_INNER_LOOP_PREFIX