1 files changed, 79 insertions, 0 deletions
diff --git a/src/boost/libs/context/performance/cycle_x86-64.hpp b/src/boost/libs/context/performance/cycle_x86-64.hpp
new file mode 100644
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--- /dev/null
+++ b/src/boost/libs/context/performance/cycle_x86-64.hpp
@@ -0,0 +1,79 @@
+
+//          Copyright Oliver Kowalke 2009.
+// 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 CYCLE_X86_64_H
+#define CYCLE_X86_64_H
+
+#include <algorithm>
+#include <numeric>
+#include <cstddef>
+#include <vector>
+
+#include <boost/assert.hpp>
+#include <boost/bind.hpp>
+#include <boost/cstdint.hpp>
+
+#define BOOST_CONTEXT_CYCLE
+
+typedef boost::uint64_t cycle_type;
+
+#if _MSC_VER >= 1400
+# include <intrin.h>
+# pragma intrinsic(__rdtsc)
+inline
+cycle_type cycles()
+{ return __rdtsc(); }
+#elif defined(__INTEL_COMPILER) || defined(__ICC) || defined(_ECC) || defined(__ICL)
+inline
+cycle_type cycles()
+{ return __rdtsc(); }
+#elif defined(__GNUC__) || defined(__SUNPRO_C)
+inline
+cycle_type cycles()
+{
+    boost::uint32_t lo, hi;
+
+    __asm__ __volatile__ (
+        "xorl %%eax, %%eax\n"
+        "cpuid\n"
+        ::: "%rax", "%rbx", "%rcx", "%rdx"
+    );
+    __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi) );
+    __asm__ __volatile__ (
+        "xorl %%eax, %%eax\n"
+        "cpuid\n"
+        ::: "%rax", "%rbx", "%rcx", "%rdx"
+    );
+
+    return ( cycle_type)hi << 32 | lo; 
+}
+#else
+# error "this compiler is not supported"
+#endif
+
+struct cycle_overhead
+{
+    cycle_type operator()()
+    {
+        cycle_type start( cycles() );
+        return cycles() - start;
+    }
+};
+
+inline
+cycle_type overhead_cycle()
+{
+    std::size_t iterations( 10);
+    std::vector< cycle_type >  overhead( iterations, 0);
+    for ( std::size_t i( 0); i < iterations; ++i)
+        std::generate(
+            overhead.begin(), overhead.end(),
+            cycle_overhead() );
+    BOOST_ASSERT( overhead.begin() != overhead.end() );
+    return std::accumulate( overhead.begin(), overhead.end(), 0) / iterations;
+}
+
+#endif // CYCLE_X86_64_H