1 files changed, 64 insertions, 0 deletions
diff --git a/src/math/floorf.c b/src/math/floorf.c
new file mode 100644
index 00000000..958abf5b
--- /dev/null
+++ b/src/math/floorf.c
@@ -0,0 +1,64 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/s_floorf.c */
+/*
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+/*
+ * floorf(x)
+ * Return x rounded toward -inf to integral value
+ * Method:
+ *      Bit twiddling.
+ * Exception:
+ *      Inexact flag raised if x not equal to floorf(x).
+ */
+
+#include "libm.h"
+
+static const float huge = 1.0e30;
+
+float floorf(float x)
+{
+	int32_t i0,j0;
+	uint32_t i;
+
+	GET_FLOAT_WORD(i0, x);
+	// FIXME: signed shift
+	j0 = ((i0>>23)&0xff) - 0x7f;
+	if (j0 < 23) {
+		if (j0 < 0) {  /* |x| < 1 */
+			/* raise inexact if x != 0 */
+			if (huge+x > (float)0.0) {
+				if (i0 >= 0)  /* x >= 0 */
+					i0 = 0;
+				else if ((i0&0x7fffffff) != 0)
+					i0 = 0xbf800000;
+			}
+		} else {
+			i = 0x007fffff>>j0;
+			if ((i0&i) == 0)
+				return x; /* x is integral */
+			/* raise inexact flag */
+			if (huge+x > (float)0.0) {
+				if (i0 < 0)
+					i0 += 0x00800000>>j0;
+				i0 &= ~i;
+			}
+		}
+	} else {
+		if (j0 == 0x80)  /* inf or NaN */
+			return x+x;
+		else
+			return x;  /* x is integral */
+	}
+	SET_FLOAT_WORD(x, i0);
+	return x;
+}