[project @ 2005-11-18 15:13:46 by simonmar]

Add wcStore(), a write-combining store if supported

(I tried using it in the update code and only succeeded in making
things slower, but it might come in handy in the future)

ghc/includes/Stg.h

@@ -366,6 +366,24 @@ INLINE_HEADER StgInt64 PK_Int64(W_ p_src[])
 #define __STG_SPLIT_MARKER /* nothing */
 #endif
 
+/* -----------------------------------------------------------------------------
+   Write-combining store
+   -------------------------------------------------------------------------- */
+
+INLINE_HEADER void
+wcStore (StgPtr p, StgWord w)
+{
+#ifdef x86_64_HOST_ARCH    
+    __asm__(
+	"movnti\t%1, %0"
+	: "=m" (*p)
+	: "r" (w)
+	);
+#else
+      *p = w;
+#endif
+}
+
 /* -----------------------------------------------------------------------------
    Integer multiply with overflow
    -------------------------------------------------------------------------- */