1 files changed, 33 insertions, 0 deletions
diff --git a/lib/libm/rintf.c b/lib/libm/rintf.c
new file mode 100644
index 00000000..5db9e0fe
--- /dev/null
+++ b/lib/libm/rintf.c
@@ -0,0 +1,33 @@
+#include <float.h>
+#include <math.h>
+#include <stdint.h>
+
+#if FLT_EVAL_METHOD == 0
+#define EPS FLT_EPSILON
+#elif FLT_EVAL_METHOD == 1
+#define EPS DBL_EPSILON
+#elif FLT_EVAL_METHOD == 2
+#define EPS LDBL_EPSILON
+#endif
+static const float_t toint = 1 / EPS;
+
+float rintf(float x)
+{
+	union {
+		float f;
+		uint32_t i;
+	} u = { x };
+	int e = u.i >> 23 & 0xff;
+	int s = u.i >> 31;
+	float_t y;
+
+	if (e >= 0x7f + 23)
+		return x;
+	if (s)
+		y = x - toint + toint;
+	else
+		y = x + toint - toint;
+	if (y == 0)
+		return s ? -0.0f : 0.0f;
+	return y;
+}