From 9606e3f321c59d10f827a9768fbb78498cfb8e8a Mon Sep 17 00:00:00 2001
From: Tim Blechmann <tim@klingt.org>
Date: Thu, 3 Oct 2013 09:17:42 +0000
Subject: [PATCH] atomic: 64bit cas support for 32bit windows

fixes #9193

[SVN r86144]
---
 include/boost/atomic/detail/interlocked.hpp |  4 +++
 include/boost/atomic/detail/windows.hpp     | 27 +++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/include/boost/atomic/detail/interlocked.hpp b/include/boost/atomic/detail/interlocked.hpp
index ae8518d..2de5171 100644
--- a/include/boost/atomic/detail/interlocked.hpp
+++ b/include/boost/atomic/detail/interlocked.hpp
@@ -107,10 +107,14 @@
 
 #else // defined(_M_AMD64) || defined(_M_IA64)
 
+#pragma intrinsic(_InterlockedCompareExchange64)
+
 #define BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE_POINTER(dest, exchange, compare) ((void*)_InterlockedCompareExchange((long*)(dest), (long)(exchange), (long)(compare)))
 #define BOOST_ATOMIC_INTERLOCKED_EXCHANGE_POINTER(dest, newval) ((void*)_InterlockedExchange((long*)(dest), (long)(newval)))
 #define BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD_POINTER(dest, byte_offset) ((void*)BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD((long*)(dest), byte_offset))
 
+#define BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE64(dest, exchange, compare) _InterlockedCompareExchange64((__int64*)(dest), (__int64)(exchange), (__int64)(compare))
+
 #endif // defined(_M_AMD64) || defined(_M_IA64)
 
 #else // defined(_MSC_VER) && _MSC_VER >= 1400
diff --git a/include/boost/atomic/detail/windows.hpp b/include/boost/atomic/detail/windows.hpp
index fcd0178..5b2a377 100644
--- a/include/boost/atomic/detail/windows.hpp
+++ b/include/boost/atomic/detail/windows.hpp
@@ -1310,10 +1310,19 @@ public:
     value_type
     fetch_add(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
     {
+#if defined(BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD64)
         platform_fence_before(order);
         v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD64(&v_, v));
         platform_fence_after(order);
         return v;
+#else
+        value_type tmp = load(memory_order_relaxed);
+        for (; !compare_exchange_weak(tmp, tmp + v, order, memory_order_relaxed);)
+        {
+            BOOST_ATOMIC_X86_PAUSE();
+        }
+        return tmp;
+#endif
     }
 
     value_type
@@ -1326,10 +1335,19 @@ public:
     value_type
     exchange(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
     {
+#if defined(BOOST_ATOMIC_INTERLOCKED_EXCHANGE64)
         platform_fence_before(order);
         v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE64(&v_, v));
         platform_fence_after(order);
         return v;
+#else
+        value_type tmp = load(memory_order_relaxed);
+        for (; !compare_exchange_weak(tmp, v, order, memory_order_relaxed);)
+        {
+            BOOST_ATOMIC_X86_PAUSE();
+        }
+        return tmp;
+#endif
     }
 
     bool
@@ -1474,6 +1492,7 @@ public:
     value_type
     exchange(value_type const& v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
     {
+#if defined(BOOST_ATOMIC_INTERLOCKED_EXCHANGE64)
         storage_type tmp = 0;
         memcpy(&tmp, &v, sizeof(value_type));
         platform_fence_before(order);
@@ -1482,6 +1501,14 @@ public:
         value_type res;
         memcpy(&res, &tmp, sizeof(value_type));
         return res;
+#else
+        value_type cur = load(memory_order_relaxed);
+        for (; !compare_exchange_weak(cur, v, order, memory_order_relaxed);)
+        {
+            BOOST_ATOMIC_X86_PAUSE();
+        }
+        return cur;
+#endif
     }
 
     bool