1 files changed, 37 insertions, 0 deletions
diff --git a/lib/libm/modff.c b/lib/libm/modff.c
new file mode 100644
index 00000000..d40752ba
--- /dev/null
+++ b/lib/libm/modff.c
@@ -0,0 +1,37 @@
+#include "libm.h"
+
+float modff(float x, float *iptr)
+{
+	union {
+		float f;
+		uint32_t i;
+	} u = { x };
+	uint32_t mask;
+	int e = (int)(u.i >> 23 & 0xff) - 0x7f;
+
+	/* no fractional part */
+	if (e >= 23) {
+		*iptr = x;
+		if (e == 0x80 && u.i << 9 != 0) { /* nan */
+			return x;
+		}
+		u.i &= 0x80000000;
+		return u.f;
+	}
+	/* no integral part */
+	if (e < 0) {
+		u.i &= 0x80000000;
+		*iptr = u.f;
+		return x;
+	}
+
+	mask = 0x007fffff >> e;
+	if ((u.i & mask) == 0) {
+		*iptr = x;
+		u.i &= 0x80000000;
+		return u.f;
+	}
+	u.i &= ~mask;
+	*iptr = u.f;
+	return x - u.f;
+}