if((hx-0x3fff000000000000LL|lx)==0) return __atanl(y);
if(((hx-0x3fff000000000000LL)|lx)==0) return __atanl(y);
	long double __ieee754_atan2l(long double y, long double x)#else	long double __ieee754_atan2l(y,x)	long double  y,x;#endif{	long double z;	int64_t k,m,hx,hy,ix,iy;	u_int64_t lx,ly;	GET_LDOUBLE_WORDS64(hx,lx,x);	ix = hx&0x7fffffffffffffffLL;	GET_LDOUBLE_WORDS64(hy,ly,y);	iy = hy&0x7fffffffffffffffLL;	if(((ix|((lx|-lx)>>63))>0x7fff000000000000LL)||	   ((iy|((ly|-ly)>>63))>0x7fff000000000000LL))	/* x or y is NaN */	   return x+y;	if((hx-0x3fff000000000000LL|lx)==0) return __atanl(y);   /* x=1.0L */	m = ((hy>>63)&1)|((hx>>62)&2);	/* 2*sign(x)+sign(y) */    /* when y = 0 */	if((iy|ly)==0) {	    switch(m) {		case 0:		case 1: return y; 	/* atan(+-0,+anything)=+-0 */		case 2: return  pi+tiny;/* atan(+0,-anything) = pi */		case 3: return -pi-tiny;/* atan(-0,-anything) =-pi */	    }	}    /* when x = 0 */	if((ix|lx)==0) return (hy<0)?  -pi_o_2-tiny: pi_o_2+tiny;    /* when x is INF */	if(ix==0x7fff000000000000LL) {	    if(iy==0x7fff000000000000LL) {		switch(m) {		    case 0: return  pi_o_4+tiny;/* atan(+INF,+INF) */		    case 1: return -pi_o_4-tiny;/* atan(-INF,+INF) */		    case 2: return  3.0L*pi_o_4+tiny;/*atan(+INF,-INF)*/		    case 3: return -3.0L*pi_o_4-tiny;/*atan(-INF,-INF)*/		}	    } else {		switch(m) {		    case 0: return  zero  ;	/* atan(+...,+INF) */		    case 1: return -zero  ;	/* atan(-...,+INF) */		    case 2: return  pi+tiny  ;	/* atan(+...,-INF) */		    case 3: return -pi-tiny  ;	/* atan(-...,-INF) */		}	    }	}    /* when y is INF */	if(iy==0x7fff000000000000LL) return (hy<0)? -pi_o_2-tiny: pi_o_2+tiny;    /* compute y/x */	k = (iy-ix)>>48;	if(k > 120) z=pi_o_2+0.5L*pi_lo; 	/* |y/x| >  2**120 */	else if(hx<0&&k<-120) z=0.0L; 		/* |y|/x < -2**120 */	else z=__atanl(fabsl(y/x));		/* safe to do y/x */	switch (m) {	    case 0: return       z  ;	/* atan(+,+) */	    case 1: {	    	      u_int64_t zh;		      GET_LDOUBLE_MSW64(zh,z);		      SET_LDOUBLE_MSW64(z,zh ^ 0x8000000000000000ULL);		    }		    return       z  ;	/* atan(-,+) */	    case 2: return  pi-(z-pi_lo);/* atan(+,-) */	    default: /* case 3 */	    	    return  (z-pi_lo)-pi;/* atan(-,-) */	}}