vx32

Local 9vx git repository for patches.
git clone git://r-36.net/vx32
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e_hypotf.c (2242B)

      1 /* e_hypotf.c -- float version of e_hypot.c.
      2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
      3  */
      4 
      5 /*
      6  * ====================================================
      7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
      8  *
      9  * Developed at SunPro, a Sun Microsystems, Inc. business.
     10  * Permission to use, copy, modify, and distribute this
     11  * software is freely granted, provided that this notice
     12  * is preserved.
     13  * ====================================================
     14  */
     15 
     16 #ifndef lint
     17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/e_hypotf.c,v 1.9 2002/05/28 18:15:03 alfred Exp $";
     18 #endif
     19 
     20 #include "math.h"
     21 #include "math_private.h"
     22 
     23 float
     24 __ieee754_hypotf(float x, float y)
     25 {
     26 	float a=x,b=y,t1,t2,y1,y2,w;
     27 	int32_t j,k,ha,hb;
     28 
     29 	GET_FLOAT_WORD(ha,x);
     30 	ha &= 0x7fffffff;
     31 	GET_FLOAT_WORD(hb,y);
     32 	hb &= 0x7fffffff;
     33 	if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
     34 	SET_FLOAT_WORD(a,ha);	/* a <- |a| */
     35 	SET_FLOAT_WORD(b,hb);	/* b <- |b| */
     36 	if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */
     37 	k=0;
     38 	if(ha > 0x58800000) {	/* a>2**50 */
     39 	   if(ha >= 0x7f800000) {	/* Inf or NaN */
     40 	       w = a+b;			/* for sNaN */
     41 	       if(ha == 0x7f800000) w = a;
     42 	       if(hb == 0x7f800000) w = b;
     43 	       return w;
     44 	   }
     45 	   /* scale a and b by 2**-68 */
     46 	   ha -= 0x22000000; hb -= 0x22000000;	k += 68;
     47 	   SET_FLOAT_WORD(a,ha);
     48 	   SET_FLOAT_WORD(b,hb);
     49 	}
     50 	if(hb < 0x26800000) {	/* b < 2**-50 */
     51 	    if(hb <= 0x007fffff) {	/* subnormal b or 0 */
     52 	        if(hb==0) return a;
     53 		SET_FLOAT_WORD(t1,0x7e800000);	/* t1=2^126 */
     54 		b *= t1;
     55 		a *= t1;
     56 		k -= 126;
     57 	    } else {		/* scale a and b by 2^68 */
     58 	        ha += 0x22000000; 	/* a *= 2^68 */
     59 		hb += 0x22000000;	/* b *= 2^68 */
     60 		k -= 68;
     61 		SET_FLOAT_WORD(a,ha);
     62 		SET_FLOAT_WORD(b,hb);
     63 	    }
     64 	}
     65     /* medium size a and b */
     66 	w = a-b;
     67 	if (w>b) {
     68 	    SET_FLOAT_WORD(t1,ha&0xfffff000);
     69 	    t2 = a-t1;
     70 	    w  = __ieee754_sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));
     71 	} else {
     72 	    a  = a+a;
     73 	    SET_FLOAT_WORD(y1,hb&0xfffff000);
     74 	    y2 = b - y1;
     75 	    SET_FLOAT_WORD(t1,ha+0x00800000);
     76 	    t2 = a - t1;
     77 	    w  = __ieee754_sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));
     78 	}
     79 	if(k!=0) {
     80 	    SET_FLOAT_WORD(t1,0x3f800000+(k<<23));
     81 	    return t1*w;
     82 	} else return w;
     83 }