rem: ic(PI,     3.1415926535897931160E0   ,   1,  1.921FB54442D18)
context: vc(athfhi, 4.6364760900080611433E-1  ,6338,3fed,da7b,2b0d,  -1, .ED63382B0DDA7B)vc(athflo, 1.9338828231967579916E-19 ,5005,2164,92c0,9cfe, -62, .E450059CFE92C0)vc(PIo4,   7.8539816339744830676E-1  ,0fda,4049,68c2,a221,   0, .C90FDAA22168C2)vc(at1fhi, 9.8279372324732906796E-1  ,985e,407b,b4d9,940f,   0, .FB985E940FB4D9)vc(at1flo,-3.5540295636764633916E-18 ,1edc,a383,eaea,34d6, -57,-.831EDC34D6EAEA)vc(PIo2,   1.5707963267948966135E0   ,0fda,40c9,68c2,a221,   1, .C90FDAA22168C2)vc(PI,     3.1415926535897932270E0   ,0fda,4149,68c2,a221,   2, .C90FDAA22168C2)vc(a1,     3.3333333333333473730E-1  ,aaaa,3faa,ab75,aaaa,  -1, .AAAAAAAAAAAB75)vc(a2,    -2.0000000000017730678E-1  ,cccc,bf4c,946e,cccd,  -2,-.CCCCCCCCCD946E)vc(a3,     1.4285714286694640301E-1  ,4924,3f12,4262,9274,  -2, .92492492744262)vc(a4,    -1.1111111135032672795E-1  ,8e38,bee3,6292,ebc6,  -3,-.E38E38EBC66292)vc(a5,     9.0909091380563043783E-2  ,2e8b,3eba,d70c,b31b,  -3, .BA2E8BB31BD70C)vc(a6,    -7.6922954286089459397E-2  ,89c8,be9d,7f18,27c3,  -3,-.9D89C827C37F18)vc(a7,     6.6663180891693915586E-2  ,86b4,3e88,9e58,ae37,  -3, .8886B4AE379E58)vc(a8,    -5.8772703698290408927E-2  ,bba5,be70,a942,8481,  -4,-.F0BBA58481A942)vc(a9,     5.2170707402812969804E-2  ,b0f3,3e55,13ab,a1ab,  -4, .D5B0F3A1AB13AB)vc(a10,   -4.4895863157820361210E-2  ,e4b9,be37,048f,7fd1,  -4,-.B7E4B97FD1048F)vc(a11,    3.3006147437343875094E-2  ,3174,3e07,2d87,3cf7,  -4, .8731743CF72D87)vc(a12,   -1.4614844866464185439E-2  ,731a,bd6f,76d9,2f34,  -6,-.EF731A2F3476D9)ic(athfhi, 4.6364760900080609352E-1  ,  -2,  1.DAC670561BB4F)ic(athflo, 4.6249969567426939759E-18 , -58,  1.5543B8F253271)ic(PIo4,   7.8539816339744827900E-1  ,  -1,  1.921FB54442D18)ic(at1fhi, 9.8279372324732905408E-1  ,  -1,  1.F730BD281F69B)ic(at1flo,-2.4407677060164810007E-17 , -56, -1.C23DFEFEAE6B5)ic(PIo2,   1.5707963267948965580E0   ,   0,  1.921FB54442D18)ic(PI,     3.1415926535897931160E0   ,   1,  1.921FB54442D18)ic(a1,     3.3333333333333942106E-1  ,  -2,  1.55555555555C3)ic(a2,    -1.9999999999979536924E-1  ,  -3, -1.9999999997CCD)ic(a3,     1.4285714278004377209E-1  ,  -3,  1.24924921EC1D7)ic(a4,    -1.1111110579344973814E-1  ,  -4, -1.C71C7059AF280)ic(a5,     9.0908906105474668324E-2  ,  -4,  1.745CE5AA35DB2)ic(a6,    -7.6919217767468239799E-2  ,  -4, -1.3B0FA54BEC400)ic(a7,     6.6614695906082474486E-2  ,  -4,  1.10DA924597FFF)ic(a8,    -5.8358371008508623523E-2  ,  -5, -1.DE125FDDBD793)ic(a9,     4.9850617156082015213E-2  ,  -5,  1.9860524BDD807)ic(a10,   -3.6700606902093604877E-2  ,  -5, -1.2CA6C04C6937A)ic(a11,    1.6438029044759730479E-2  ,  -6,  1.0D52174A1BB54)#ifdef vccast#define	athfhi	vccast(athfhi)#define	athflo	vccast(athflo)#define	PIo4	vccast(PIo4)#define	at1fhi	vccast(at1fhi)#define	at1flo	vccast(at1flo)#define	PIo2	vccast(PIo2)#define	PI	vccast(PI)#define	a1	vccast(a1)#define	a2	vccast(a2)#define	a3	vccast(a3)#define	a4	vccast(a4)#define	a5	vccast(a5)#define	a6	vccast(a6)#define	a7	vccast(a7)#define	a8	vccast(a8)#define	a9	vccast(a9)#define	a10	vccast(a10)#define	a11	vccast(a11)#define	a12	vccast(a12)#endifdoubleatan2(double y, double x){	static const double zero=0, one=1, small=1.0E-9, big=1.0E18;	double t,z,signy,signx,hi,lo;	int k,m;#if !defined(vax)&&!defined(tahoe)    /* if x or y is NAN */	if(x!=x) return(x); if(y!=y) return(y);#endif	/* !defined(vax)&&!defined(tahoe) */    /* copy down the sign of y and x */	signy = copysign(one,y) ;	signx = copysign(one,x) ;    /* if x is 1.0, goto begin */	if(x==1) { y=copysign(y,one); t=y; if(finite(t)) goto begin;}    /* when y = 0 */	if(y==zero) return((signx==one)?y:copysign(PI,signy));    /* when x = 0 */	if(x==zero) return(copysign(PIo2,signy));    /* when x is INF */	if(!finite(x)) {	    if(!finite(y))		return(copysign((signx==one)?PIo4:3*PIo4,signy));	    else		return(copysign((signx==one)?zero:PI,signy));	}    /* when y is INF */	if(!finite(y)) return(copysign(PIo2,signy));    /* compute y/x */	x=copysign(x,one);	y=copysign(y,one);	if((m=(k=logb(y))-logb(x)) > 60) t=big+big;	    else if(m < -80 ) t=y/x;	    else { t = y/x ; y = scalb(y,-k); x=scalb(x,-k); }    /* begin argument reduction */begin:	if (t < 2.4375) {	/* truncate 4(t+1/16) to integer for branching */	    k = 4 * (t+0.0625);	    switch (k) {	    /* t is in [0,7/16] */	    case 0:	    case 1:		if (t < small) {		    (void volatile)(big + small) ;  /* raise inexact flag */		    return (copysign((signx>zero)?t:PI-t,signy));		}		hi = zero;  lo = zero;  break;	    /* t is in [7/16,11/16] */	    case 2:		hi = athfhi; lo = athflo;		z = x+x;		t = ( (y+y) - x ) / ( z +  y ); break;	    /* t is in [11/16,19/16] */	    case 3:	    case 4:		hi = PIo4; lo = zero;		t = ( y - x ) / ( x + y ); break;	    /* t is in [19/16,39/16] */	    default:		hi = at1fhi; lo = at1flo;		z = y-x; y=y+y+y; t = x+x;		t = ( (z+z)-x ) / ( t + y ); break;	    }	}	/* end of if (t < 2.4375) */	else	{	    hi = PIo2; lo = zero;	    /* t is in [2.4375, big] */	    if (t <= big) {		t = - x / y; 	    } else {	    	/* t is in [big, INF] */		(void volatile)(big+small);	/* raise inexact flag */		t = zero;	    }	}    /* end of argument reduction */    /* compute atan(t) for t in [-.4375, .4375] */	z = t*t;#if defined(vax)||defined(tahoe)	z = t*(z*(a1+z*(a2+z*(a3+z*(a4+z*(a5+z*(a6+z*(a7+z*(a8+			z*(a9+z*(a10+z*(a11+z*a12))))))))))));#else	/* defined(vax)||defined(tahoe) */	z = t*(z*(a1+z*(a2+z*(a3+z*(a4+z*(a5+z*(a6+z*(a7+z*(a8+			z*(a9+z*(a10+z*a11)))))))))));#endif	/* defined(vax)||defined(tahoe) */	z = lo - z; z += t; z += hi;	return(copysign((signx>zero)?z:PI-z,signy));}