mesa: add signbit() macro

Reviewed-by: Matt Turner <mattst88@gmail.com>

diff --git a/src/mesa/main/imports.h b/src/mesa/main/imports.h
index 81da51047174d0a6a8c1081591399fec41c32890..a78d67966f890de867348fabc985d48c437b0b07 100644 (file)
--- a/src/mesa/main/imports.h
+++ b/src/mesa/main/imports.h
@@ -145,6 +145,13 @@ static inline int isblank(int ch) { return ch == ' ' || ch == '\t'; }
 /*@}*/
 
 
+/*
+ * signbit() is a macro on Linux.  Not available on Windows.
+ */
+#ifndef signbit
+#define signbit(x) ((x) < 0.0f)
+#endif
+
 
 /** single-precision inverse square root */
 static inline float