[src/trunk]: src/lib/libm/src one more

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/39284be1e4d5
branches:  trunk
changeset: 784790:39284be1e4d5
user:      christos <christos%NetBSD.org@localhost>
date:      Sat Feb 09 19:39:01 2013 +0000

description:
one more

diffstat:

 lib/libm/src/s_nexttowardf.c |  65 ++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 65 insertions(+), 0 deletions(-)

diffs (69 lines):

diff -r cb6e6d007edc -r 39284be1e4d5 lib/libm/src/s_nexttowardf.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libm/src/s_nexttowardf.c      Sat Feb 09 19:39:01 2013 +0000
@@ -0,0 +1,65 @@
+/*     $NetBSD: s_nexttowardf.c,v 1.1 2013/02/09 19:39:01 christos Exp $       */
+
+/*
+ * ====================================================
+ * 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>
+#if 0
+__FBSDID("$FreeBSD: src/lib/msun/src/s_nexttowardf.c,v 1.3 2011/02/10 07:38:38 das Exp $");
+#else
+__RCSID("$NetBSD: s_nexttowardf.c,v 1.1 2013/02/09 19:39:01 christos Exp $");
+#endif
+
+#include <float.h>
+
+#include "fpmath.h"
+#include "math.h"
+#include "math_private.h"
+
+#define        LDBL_INFNAN_EXP (LDBL_MAX_EXP * 2 - 1)
+
+float
+nexttowardf(float x, long double y)
+{
+       union IEEEl2bits uy;
+       volatile float t;
+       int32_t hx,ix;
+
+       GET_FLOAT_WORD(hx,x);
+       ix = hx&0x7fffffff;             /* |x| */
+       uy.e = y;
+
+       if((ix>0x7f800000) ||
+          (uy.bits.exp == LDBL_INFNAN_EXP &&
+           ((uy.bits.manh&~LDBL_NBIT)|uy.bits.manl) != 0))
+          return x+y;  /* x or y is nan */
+       if(x==y) return (float)y;               /* x=y, return y */
+       if(ix==0) {                             /* x == 0 */
+           SET_FLOAT_WORD(x,(uy.bits.sign<<31)|1);/* return +-minsubnormal */
+           t = x*x;
+           if(t==x) return t; else return x;   /* raise underflow flag */
+       }
+       if(hx>=0 ^ x < y)                       /* x -= ulp */
+           hx -= 1;
+       else                                    /* x += ulp */
+           hx += 1;
+       ix = hx&0x7f800000;
+       if(ix>=0x7f800000) return x+x;  /* overflow  */
+       if(ix<0x00800000) {             /* underflow */
+           t = x*x;
+           if(t!=x) {          /* raise underflow flag */
+               SET_FLOAT_WORD(x,hx);
+               return x;
+           }
+       }
+       SET_FLOAT_WORD(x,hx);
+       return x;
+}