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 "math.h" 17 #include "math_private.h" 18 19 float 20 hypotf(float x, float y) 21 { 22 float a,b,t1,t2,y1,y2,w; 23 int32_t j,k,ha,hb; 24 25 GET_FLOAT_WORD(ha,x); 26 ha &= 0x7fffffff; 27 GET_FLOAT_WORD(hb,y); 28 hb &= 0x7fffffff; 29 if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;} 30 a = fabsf(a); 31 b = fabsf(b); 32 if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */ 33 k=0; 34 if(ha > 0x58800000) { /* a>2**50 */ 35 if(ha >= 0x7f800000) { /* Inf or NaN */ 36 /* Use original arg order iff result is NaN; quieten sNaNs. */ 37 w = fabsl(x+0.0L)-fabsf(y+0); 38 if(ha == 0x7f800000) w = a; 39 if(hb == 0x7f800000) w = b; 40 return w; 41 } 42 /* scale a and b by 2**-68 */ 43 ha -= 0x22000000; hb -= 0x22000000; k += 68; 44 SET_FLOAT_WORD(a,ha); 45 SET_FLOAT_WORD(b,hb); 46 } 47 if(hb < 0x26800000) { /* b < 2**-50 */ 48 if(hb <= 0x007fffff) { /* subnormal b or 0 */ 49 if(hb==0) return a; 50 SET_FLOAT_WORD(t1,0x7e800000); /* t1=2^126 */ 51 b *= t1; 52 a *= t1; 53 k -= 126; 54 } else { /* scale a and b by 2^68 */ 55 ha += 0x22000000; /* a *= 2^68 */ 56 hb += 0x22000000; /* b *= 2^68 */ 57 k -= 68; 58 SET_FLOAT_WORD(a,ha); 59 SET_FLOAT_WORD(b,hb); 60 } 61 } 62 /* medium size a and b */ 63 w = a-b; 64 if (w>b) { 65 SET_FLOAT_WORD(t1,ha&0xfffff000); 66 t2 = a-t1; 67 w = sqrtf(t1*t1-(b*(-b)-t2*(a+t1))); 68 } else { 69 a = a+a; 70 SET_FLOAT_WORD(y1,hb&0xfffff000); 71 y2 = b - y1; 72 SET_FLOAT_WORD(t1,(ha+0x00800000)&0xfffff000); 73 t2 = a - t1; 74 w = sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b))); 75 } 76 if(k!=0) { 77 SET_FLOAT_WORD(t1,(127+k)<<23); 78 return t1*w; 79 } else return w; 80 } 81