1 files changed, 68 insertions, 0 deletions
diff --git a/src/math/truncl.c b/src/math/truncl.c
new file mode 100644
index 00000000..d817e9ad
--- /dev/null
+++ b/src/math/truncl.c
@@ -0,0 +1,68 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/s_truncl.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.
+ * ====================================================
+ */
+/*
+ * truncl(x)
+ * Return x rounded toward 0 to integral value
+ * Method:
+ *      Bit twiddling.
+ * Exception:
+ *      Inexact flag raised if x not equal to truncl(x).
+ */
+
+#include "libm.h"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double truncl(long double x)
+{
+	return trunc(x);
+}
+#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
+#ifdef LDBL_IMPLICIT_NBIT
+#define MANH_SIZE       (LDBL_MANH_SIZE + 1)
+#else
+#define MANH_SIZE       LDBL_MANH_SIZE
+#endif
+
+static const long double huge = 1.0e300;
+static const float zero[] = { 0.0, -0.0 };
+
+long double truncl(long double x)
+{
+	union IEEEl2bits u = { .e = x };
+	int e = u.bits.exp - LDBL_MAX_EXP + 1;
+
+	if (e < MANH_SIZE - 1) {
+		if (e < 0) {
+			/* raise inexact if x != 0 */
+			if (huge + x > 0.0)
+				u.e = zero[u.bits.sign];
+		} else {
+			uint64_t m = ((1llu << MANH_SIZE) - 1) >> (e + 1);
+			if (((u.bits.manh & m) | u.bits.manl) == 0)
+				return x;     /* x is integral */
+			/* raise inexact */
+			if (huge + x > 0.0) {
+				u.bits.manh &= ~m;
+				u.bits.manl = 0;
+			}
+		}
+	} else if (e < LDBL_MANT_DIG - 1) {
+		uint64_t m = (uint64_t)-1 >> (64 - LDBL_MANT_DIG + e + 1);
+		if ((u.bits.manl & m) == 0)
+			return x;     /* x is integral */
+		/* raise inexact */
+		if (huge + x > 0.0)
+			u.bits.manl &= ~m;
+	}
+	return u.e;
+}
+#endif