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-rw-r--r--sysdeps/libm-ieee754/e_hypotf.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/e_hypotf.c b/sysdeps/libm-ieee754/e_hypotf.c
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+/* 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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: e_hypotf.c,v 1.5 1995/05/12 04:57:30 jtc Exp $";
+#endif
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+	float __ieee754_hypotf(float x, float y)
+#else
+	float __ieee754_hypot(x,y)
+	float x, y;
+#endif
+{
+	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**-60 */
+	   ha -= 0x5d800000; hb -= 0x5d800000;	k += 60;
+	   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(t1,0x3f000000);	/* t1=2^126 */
+		b *= t1;
+		a *= t1;
+		k -= 126;
+	    } else {		/* scale a and b by 2^60 */
+	        ha += 0x5d800000; 	/* a *= 2^60 */
+		hb += 0x5d800000;	/* b *= 2^60 */
+		k -= 60;
+		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  = __ieee754_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  = __ieee754_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;
+}