usr: libc: Add math.h + musl math impl port

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/libc/src/musl-math/fdiml.c b/lib/libc/src/musl-math/fdiml.c
new file mode 100644
index 0000000..62e29b7
--- /dev/null
+++ b/lib/libc/src/musl-math/fdiml.c
@@ -0,0 +1,18 @@
+#include <math.h>
+#include <float.h>
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double fdiml(long double x, long double y)
+{
+	return fdim(x, y);
+}
+#else
+long double fdiml(long double x, long double y)
+{
+	if (isnan(x))
+		return x;
+	if (isnan(y))
+		return y;
+	return x > y ? x - y : 0;
+}
+#endif