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/e_hypotf.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 src/math/e_hypotf.c

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

diff --git a/src/math/e_hypotf.c b/src/math/e_hypotf.c
new file mode 100644
index 00000000..13773554
--- /dev/null
+++ b/src/math/e_hypotf.c
@@ -0,0 +1,79 @@
+/* e_hypotf.c -- float version of e_hypot.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
+hypotf(float x, float y)
+{
+        float a=x,b=y,t1,t2,y1,y2,w;
+        int32_t j,k,ha,hb;
+
+        GET_FLOAT_WORD(ha,x);
+        ha &= 0x7fffffff;
+        GET_FLOAT_WORD(hb,y);
+        hb &= 0x7fffffff;
+        if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
+        SET_FLOAT_WORD(a,ha);   /* a <- |a| */
+        SET_FLOAT_WORD(b,hb);   /* b <- |b| */
+        if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */
+        k=0;
+        if(ha > 0x58800000) {   /* a>2**50 */
+           if(ha >= 0x7f800000) {       /* Inf or NaN */
+               w = a+b;                 /* for sNaN */
+               if(ha == 0x7f800000) w = a;
+               if(hb == 0x7f800000) w = b;
+               return w;
+           }
+           /* scale a and b by 2**-68 */
+           ha -= 0x22000000; hb -= 0x22000000;  k += 68;
+           SET_FLOAT_WORD(a,ha);
+           SET_FLOAT_WORD(b,hb);
+        }
+        if(hb < 0x26800000) {   /* b < 2**-50 */
+            if(hb <= 0x007fffff) {      /* subnormal b or 0 */
+                if(hb==0) return a;
+                SET_FLOAT_WORD(t1,0x7e800000);  /* t1=2^126 */
+                b *= t1;
+                a *= t1;
+                k -= 126;
+            } else {            /* scale a and b by 2^68 */
+                ha += 0x22000000;       /* a *= 2^68 */
+                hb += 0x22000000;       /* b *= 2^68 */
+                k -= 68;
+                SET_FLOAT_WORD(a,ha);
+                SET_FLOAT_WORD(b,hb);
+            }
+        }
+    /* medium size a and b */
+        w = a-b;
+        if (w>b) {
+            SET_FLOAT_WORD(t1,ha&0xfffff000);
+            t2 = a-t1;
+            w  = sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));
+        } else {
+            a  = a+a;
+            SET_FLOAT_WORD(y1,hb&0xfffff000);
+            y2 = b - y1;
+            SET_FLOAT_WORD(t1,ha+0x00800000);
+            t2 = a - t1;
+            w  = sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));
+        }
+        if(k!=0) {
+            SET_FLOAT_WORD(t1,0x3f800000+(k<<23));
+            return t1*w;
+        } else return w;
+}
-- 
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