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 <sys/cdefs.h> 17 #include "math.h" 18 #include "math_private.h" 19 20 float 21 hypotf(float x, float y) 22 { 23 float a,b,t1,t2,y1,y2,w; 24 int32_t j,k,ha,hb; 25 26 GET_FLOAT_WORD(ha,x); 27 ha &= 0x7fffffff; 28 GET_FLOAT_WORD(hb,y); 29 hb &= 0x7fffffff; 30 if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;} 31 a = fabsf(a); 32 b = fabsf(b); 33 if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */ 34 k=0; 35 if(ha > 0x58800000) { /* a>2**50 */ 36 if(ha >= 0x7f800000) { /* Inf or NaN */ 37 /* Use original arg order iff result is NaN; quieten sNaNs. */ 38 w = fabsl(x+0.0L)-fabsf(y+0); 39 if(ha == 0x7f800000) w = a; 40 if(hb == 0x7f800000) w = b; 41 return w; 42 } 43 /* scale a and b by 2**-68 */ 44 ha -= 0x22000000; hb -= 0x22000000; k += 68; 45 SET_FLOAT_WORD(a,ha); 46 SET_FLOAT_WORD(b,hb); 47 } 48 if(hb < 0x26800000) { /* b < 2**-50 */ 49 if(hb <= 0x007fffff) { /* subnormal b or 0 */ 50 if(hb==0) return a; 51 SET_FLOAT_WORD(t1,0x7e800000); /* t1=2^126 */ 52 b *= t1; 53 a *= t1; 54 k -= 126; 55 } else { /* scale a and b by 2^68 */ 56 ha += 0x22000000; /* a *= 2^68 */ 57 hb += 0x22000000; /* b *= 2^68 */ 58 k -= 68; 59 SET_FLOAT_WORD(a,ha); 60 SET_FLOAT_WORD(b,hb); 61 } 62 } 63 /* medium size a and b */ 64 w = a-b; 65 if (w>b) { 66 SET_FLOAT_WORD(t1,ha&0xfffff000); 67 t2 = a-t1; 68 w = sqrtf(t1*t1-(b*(-b)-t2*(a+t1))); 69 } else { 70 a = a+a; 71 SET_FLOAT_WORD(y1,hb&0xfffff000); 72 y2 = b - y1; 73 SET_FLOAT_WORD(t1,(ha+0x00800000)&0xfffff000); 74 t2 = a - t1; 75 w = sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b))); 76 } 77 if(k!=0) { 78 SET_FLOAT_WORD(t1,(127+k)<<23); 79 return t1*w; 80 } else return w; 81 } 82