ifndef not ifdef....like I said, it works for me on my mingw either way
Modified: trunk/reactos/lib/crt/include/float.h

Modified: trunk/reactos/lib/crt/include/float.h
--- trunk/reactos/lib/crt/include/float.h	2005-11-25 04:14:59 UTC (rev 19541)
+++ trunk/reactos/lib/crt/include/float.h	2005-11-25 04:39:08 UTC (rev 19542)
@@ -91,7 +91,7 @@
 #define _FPE_STACKUNDERFLOW	0x8b
 #define _FPE_EXPLICITGEN	0x8c    /* raise( SIGFPE ); */
 
-#ifdef __GNUC__
+#ifndef __GNUC__
 #define DBL_MAX_10_EXP  308  
 #define S_IFIFO			-1
 #define UINT64_MAX	0xffffffffffffffff