From 8b6d88d2f87397d19af964a9d8e8be6ceaaeb1e6 Mon Sep 17 00:00:00 2001
From: Oscar Fuentes <ofv@wanadoo.es>
Date: Mon, 7 Dec 2009 05:29:59 +0000
Subject: [PATCH] Fixes the Atomic implementation if compiled by MSVC compiler.

sys::cas_flag should be long on this platform, InterlockedAdd() is
defined only for the Itanium architecture (according to MSDN).

Patch by Michael Beck!

llvm-svn: 90748
---
 llvm/include/llvm/System/Atomic.h | 4 ++++
 llvm/lib/System/Atomic.cpp        | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/llvm/include/llvm/System/Atomic.h b/llvm/include/llvm/System/Atomic.h
index 0c05d696e392..fc19369d11bd 100644
--- a/llvm/include/llvm/System/Atomic.h
+++ b/llvm/include/llvm/System/Atomic.h
@@ -20,7 +20,11 @@ namespace llvm {
   namespace sys {
     void MemoryFence();
 
+#ifdef _MSC_VER
+    typedef long cas_flag;
+#else
     typedef uint32_t cas_flag;
+#endif
     cas_flag CompareAndSwap(volatile cas_flag* ptr,
                             cas_flag new_value,
                             cas_flag old_value);
diff --git a/llvm/lib/System/Atomic.cpp b/llvm/lib/System/Atomic.cpp
index f9b55a186d18..7ba8b774d5e0 100644
--- a/llvm/lib/System/Atomic.cpp
+++ b/llvm/lib/System/Atomic.cpp
@@ -85,7 +85,7 @@ sys::cas_flag sys::AtomicAdd(volatile sys::cas_flag* ptr, sys::cas_flag val) {
 #elif defined(__GNUC__)
   return __sync_add_and_fetch(ptr, val);
 #elif defined(_MSC_VER)
-  return InterlockedAdd(ptr, val);
+  return InterlockedExchangeAdd(ptr, val) + val;
 #else
 #  error No atomic add implementation for your platform!
 #endif