1 files changed, 52 insertions, 0 deletions
diff --git a/src/math/truncf.c b/src/math/truncf.c
new file mode 100644
index 00000000..209586e1
--- /dev/null
+++ b/src/math/truncf.c
@@ -0,0 +1,52 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/s_truncf.c */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+/*
+ * truncf(x)
+ * Return x rounded toward 0 to integral value
+ * Method:
+ *      Bit twiddling.
+ * Exception:
+ *      Inexact flag raised if x not equal to truncf(x).
+ */
+
+#include "libm.h"
+
+static const float huge = 1.0e30F;
+
+float truncf(float x)
+{
+	int32_t i0,j0;
+	uint32_t i;
+
+	GET_FLOAT_WORD(i0, x);
+	j0 = ((i0>>23)&0xff) - 0x7f;
+	if (j0 < 23) {
+		if (j0 < 0) {  /* |x|<1, return 0*sign(x) */
+			/* raise inexact if x != 0 */
+			if (huge+x > 0.0F)
+				i0 &= 0x80000000;
+		} else {
+			i = 0x007fffff>>j0;
+			if ((i0&i) == 0)
+				return x; /* x is integral */
+			/* raise inexact */
+			if (huge+x > 0.0F)
+				i0 &= ~i;
+		}
+	} else {
+		if (j0 == 0x80)
+			return x + x;  /* inf or NaN */
+		return x;              /* x is integral */
+	}
+	SET_FLOAT_WORD(x, i0);
+	return x;
+}