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[] = "$FreeBSD$"; 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 } 84