gallium: added util_is_inf_or_nan() function to u_math.h

diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h
index 9268a9bb7eea3eafda57130f44181742ebe6d99d..e5003af01d89fa35191ba8f157a607f6e87bd548 100644 (file)
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -319,6 +319,18 @@ util_iround(float f)
 
 
 
+/**
+ * Test if x is NaN or +/- infinity.
+ */
+static INLINE boolean
+util_is_inf_or_nan(float x)
+{
+   union fi tmp;
+   tmp.f = x;
+   return !(int)((unsigned int)((tmp.i & 0x7fffffff)-0x7f800000) >> 31);
+}
+
+
 /**
  * Find first bit set in word.  Least significant bit is 1.
  * Return 0 if no bits set.