[Mesa-dev] [PATCH 2/2] util/u_atomic: Add _InterlockedExchangeAdd8/16 for older MSVC.

[Jose Fonseca]

We need to build certain parts of Mesa (namely gallium, llvmpipe, and
therefore util) with Windows SDK 7.0.7600, which includes MSVC 2008.
---
 src/util/u_atomic.h | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/util/u_atomic.h b/src/util/u_atomic.h
index e123e17..f54def3 100644
--- a/src/util/u_atomic.h
+++ b/src/util/u_atomic.h
@@ -88,7 +88,7 @@
 
 #if _MSC_VER < 1600
 
-/* Implement _InterlockedCompareExchange8 in terms of InterlockedCompareExchange16 */
+/* Implement _InterlockedCompareExchange8 in terms of _InterlockedCompareExchange16 */
 static __inline
 char _InterlockedCompareExchange8(char volatile *Destination8, char Exchange8, char Comparand8)
 {
@@ -103,7 +103,7 @@ char _InterlockedCompareExchange8(char volatile *Destination8, char Exchange8, c
        * neighboring byte untouched */
       short Exchange16 = (Initial16 & ~Mask8) | ((short)Exchange8 << Shift8);
       short Comparand16 = Initial16;
-      short Initial16 = InterlockedCompareExchange16(Destination16, Exchange16, Comparand16);
+      short Initial16 = _InterlockedCompareExchange16(Destination16, Exchange16, Comparand16);
       if (Initial16 == Comparand16) {
          /* succeeded */
          return Comparand8;
@@ -114,6 +114,34 @@ char _InterlockedCompareExchange8(char volatile *Destination8, char Exchange8, c
    return Initial8;
 }
 
+/* Implement _InterlockedExchangeAdd16 in terms of _InterlockedCompareExchange16 */
+static __inline
+short _InterlockedExchangeAdd16(short volatile *Addend, short Value)
+{
+   short Initial = *Addend;
+   short Comparand;
+   do {
+      short Exchange = Initial + Value;
+      Comparand = Initial;
+      Initial = _InterlockedCompareExchange16(Addend, Exchange, Comparand);
+   } while(Initial != Comparand);
+   return Comparand;
+}
+
+/* Implement _InterlockedExchangeAdd8 in terms of _InterlockedCompareExchange8 */
+static __inline
+char _InterlockedExchangeAdd8(char volatile *Addend, char Value)
+{
+   char Initial = *Addend;
+   char Comparand;
+   do {
+      char Exchange = Initial + Value;
+      Comparand = Initial;
+      Initial = _InterlockedCompareExchange8(Addend, Exchange, Comparand);
+   } while(Initial != Comparand);
+   return Comparand;
+}
+
 #endif /* _MSC_VER < 1600 */
 
 /* MSVC supports decltype keyword, but it's only supported on C++ and doesn't
-- 
2.1.0