[lib][libm] Add floorf and ceilf

external/lib/libm/s_floorf.c

Index: external/lib/libm/s_floorf.c
diff --git a/external/lib/libm/s_floorf.c b/external/lib/libm/s_floorf.c
new file mode 100644
index 0000000000000000000000000000000000000000..6b510dee3a80ae5f03568c592e86a47c0e242a1d
--- /dev/null
+++ b/external/lib/libm/s_floorf.c
@@ -0,0 +1,61 @@
+/* s_floorf.c -- float version of s_floor.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.
+ * ====================================================
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * 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 "math.h"
+#include "math_private.h"
+
+static const float huge = 1.0e30;
+
+float
+floorf(float x)
+{
+	int32_t i0,j0;
+	u_int32_t i;
+	GET_FLOAT_WORD(i0,x);
+	j0 = ((i0>>23)&0xff)-0x7f;
+	if(j0<23) {
+	    if(j0<0) { 	/* raise inexact if x != 0 */
+		if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
+		    if(i0>=0) {i0=0;}
+		    else if((i0&0x7fffffff)!=0)
+			{ i0=0xbf800000;}
+		}
+	    } else {
+		i = (0x007fffff)>>j0;
+		if((i0&i)==0) return x; /* x is integral */
+		if(huge+x>(float)0.0) {	/* raise inexact flag */
+		    if(i0<0) i0 += (0x00800000)>>j0;
+		    i0 &= (~i);
+		}
+	    }
+	} else {
+	    if(j0==0x80) return x+x;	/* inf or NaN */
+	    else return x;		/* x is integral */
+	}
+	SET_FLOAT_WORD(x,i0);
+	return x;
+}