From 2a8a9d1def49b2673814e2307520fd02f9d536dd Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sat, 9 Jul 2011 07:56:04 +0000
Subject: [PATCH] * atomic.h (ATOMIC_OR): _InterlockedOr is unavailable in VC6.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32472 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog |  4 +++-
 atomic.h  | 15 ++++++++++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 2775002d5a..330a564881 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,6 @@
-Sat Jul  9 16:54:35 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Sat Jul  9 16:56:01 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* atomic.h (ATOMIC_OR): _InterlockedOr is unavailable in VC6.
 
 	* numeric.c (ULLONG_MAX): fallback definition.
 
diff --git a/atomic.h b/atomic.h
index ad9b339994..5b3fb99024 100644
--- a/atomic.h
+++ b/atomic.h
@@ -2,7 +2,7 @@
 #define RUBY_ATOMIC_H
 
 #ifdef _WIN32
-#ifdef _MSC_VER
+#if defined _MSC_VER && _MSC_VER > 1200
 #pragma intrinsic(_InterlockedOr)
 #endif
 typedef LONG rb_atomic_t;
@@ -12,6 +12,19 @@ typedef LONG rb_atomic_t;
 # define ATOMIC_DEC(var) InterlockedDecrement(&(var))
 #if defined __GNUC__
 # define ATOMIC_OR(var, val) __asm__("lock\n\t" "orl\t%1, %0" : "=m"(var) : "Ir"(val))
+#elif defined _MSC_VER && _MSC_VER <= 1200
+# define ATOMIC_OR(var, val) rb_w32_atomic_or(&(var), (val))
+static inline void
+rb_w32_atomic_or(volatile rb_atomic_t *var, rb_atomic_t val)
+{
+#ifdef _M_IX86
+    __asm mov eax, var;
+    __asm mov ecx, val;
+    __asm lock or [eax], ecx;
+#else
+#error unsupported architecture
+#endif
+}
 #else
 # define ATOMIC_OR(var, val) _InterlockedOr(&(var), (val))
 #endif