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 #include "cdefs-compat.h" 17 //__FBSDID("$FreeBSD: src/lib/msun/src/e_hypotf.c,v 1.14 2011/10/15 07:00:28 das Exp $"); 18 19 #include <openlibm_math.h> 20 21 #include "math_private.h" 22 23 OLM_DLLEXPORT float 24 __ieee754_hypotf(float x, float y) 25 { 26 float a,b,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 a = fabsf(a); 35 b = fabsf(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 /* Use original arg order iff result is NaN; quieten sNaNs. */ 41 w = fabsf(x+0.0F)-fabsf(y+0.0F); 42 if(ha == 0x7f800000) w = a; 43 if(hb == 0x7f800000) w = b; 44 return w; 45 } 46 /* scale a and b by 2**-68 */ 47 ha -= 0x22000000; hb -= 0x22000000; k += 68; 48 SET_FLOAT_WORD(a,ha); 49 SET_FLOAT_WORD(b,hb); 50 } 51 if(hb < 0x26800000) { /* b < 2**-50 */ 52 if(hb <= 0x007fffff) { /* subnormal b or 0 */ 53 if(hb==0) return a; 54 SET_FLOAT_WORD(t1,0x7e800000); /* t1=2^126 */ 55 b *= t1; 56 a *= t1; 57 k -= 126; 58 } else { /* scale a and b by 2^68 */ 59 ha += 0x22000000; /* a *= 2^68 */ 60 hb += 0x22000000; /* b *= 2^68 */ 61 k -= 68; 62 SET_FLOAT_WORD(a,ha); 63 SET_FLOAT_WORD(b,hb); 64 } 65 } 66 /* medium size a and b */ 67 w = a-b; 68 if (w>b) { 69 SET_FLOAT_WORD(t1,ha&0xfffff000); 70 t2 = a-t1; 71 w = __ieee754_sqrtf(t1*t1-(b*(-b)-t2*(a+t1))); 72 } else { 73 a = a+a; 74 SET_FLOAT_WORD(y1,hb&0xfffff000); 75 y2 = b - y1; 76 SET_FLOAT_WORD(t1,(ha+0x00800000)&0xfffff000); 77 t2 = a - t1; 78 w = __ieee754_sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b))); 79 } 80 if(k!=0) { 81 SET_FLOAT_WORD(t1,0x3f800000+(k<<23)); 82 return t1*w; 83 } else return w; 84 } 85