util: Define ffs for MinGW.

diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h
index aa4fa17..ab6f39a 100644 (file)
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -341,6 +341,10 @@ unsigned ffs( unsigned u )
 }
 #endif
 
+#ifdef __MINGW32__
+#define ffs __builtin_ffs
+#endif
+
 
 /**
  * Return float bits.