1 files changed, 13 insertions, 0 deletions
diff --git a/src/math/fmax.c b/src/math/fmax.c
new file mode 100644
index 00000000..0b6bf6f3
--- /dev/null
+++ b/src/math/fmax.c
@@ -0,0 +1,13 @@
+#include "libm.h"
+
+double fmax(double x, double y)
+{
+	if (isnan(x))
+		return y;
+	if (isnan(y))
+		return x;
+	/* handle signed zeros, see C99 Annex F.9.9.2 */
+	if (signbit(x) != signbit(y))
+		return signbit(x) ? y : x;
+	return x < y ? y : x;
+}