From 0b44a0315b47dd8eced9f3b7f31580cf14bbfc01 Mon Sep 17 00:00:00 2001
From: Rich Felker <dalias@aerifal.cx>
Date: Sat, 12 Feb 2011 00:22:29 -0500
Subject: initial check-in, version 0.5.0

---
 src/math/s_nextafterf.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 src/math/s_nextafterf.c

(limited to 'src/math/s_nextafterf.c')

diff --git a/src/math/s_nextafterf.c b/src/math/s_nextafterf.c
new file mode 100644
index 00000000..7ce08838
--- /dev/null
+++ b/src/math/s_nextafterf.c
@@ -0,0 +1,63 @@
+/* s_nextafterf.c -- float version of s_nextafter.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 <math.h>
+#include "math_private.h"
+
+float
+nextafterf(float x, float y)
+{
+        volatile float t;
+        int32_t hx,hy,ix,iy;
+
+        GET_FLOAT_WORD(hx,x);
+        GET_FLOAT_WORD(hy,y);
+        ix = hx&0x7fffffff;             /* |x| */
+        iy = hy&0x7fffffff;             /* |y| */
+
+        if((ix>0x7f800000) ||   /* x is nan */
+           (iy>0x7f800000))     /* y is nan */
+           return x+y;
+        if(x==y) return y;              /* x=y, return y */
+        if(ix==0) {                             /* x == 0 */
+            SET_FLOAT_WORD(x,(hy&0x80000000)|1);/* return +-minsubnormal */
+            t = x*x;
+            if(t==x) return t; else return x;   /* raise underflow flag */
+        }
+        if(hx>=0) {                             /* x > 0 */
+            if(hx>hy) {                         /* x > y, x -= ulp */
+                hx -= 1;
+            } else {                            /* x < y, x += ulp */
+                hx += 1;
+            }
+        } else {                                /* x < 0 */
+            if(hy>=0||hx>hy){                   /* x < y, x -= ulp */
+                hx -= 1;
+            } else {                            /* x > y, x += ulp */
+                hx += 1;
+            }
+        }
+        hy = hx&0x7f800000;
+        if(hy>=0x7f800000) return x+x;  /* overflow  */
+        if(hy<0x00800000) {             /* underflow */
+            t = x*x;
+            if(t!=x) {          /* raise underflow flag */
+                SET_FLOAT_WORD(y,hx);
+                return y;
+            }
+        }
+        SET_FLOAT_WORD(x,hx);
+        return x;
+}
-- 
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