GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libm/src/e_atan2f.c Lines: 0 39 0.0 %
Date: 2017-11-13 Branches: 0 37 0.0 %

Line Branch Exec Source
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/* e_atan2f.c -- float version of e_atan2.c.
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 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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 */
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/*
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 * ====================================================
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 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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 *
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 * Developed at SunPro, a Sun Microsystems, Inc. business.
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 * Permission to use, copy, modify, and distribute this
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 * software is freely granted, provided that this notice
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 * is preserved.
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 * ====================================================
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 */
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#include "math.h"
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#include "math_private.h"
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static const float
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tiny  = 1.0e-30,
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zero  = 0.0,
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pi_o_4  = 7.8539818525e-01, /* 0x3f490fdb */
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pi_o_2  = 1.5707963705e+00, /* 0x3fc90fdb */
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pi      = 3.1415925026e+00, /* 0x40490fda */
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pi_lo   = 1.5099578832e-07; /* 0x34222168 */
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float
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atan2f(float y, float x)
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{
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	float z;
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	int32_t k,m,hx,hy,ix,iy;
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	GET_FLOAT_WORD(hx,x);
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	ix = hx&0x7fffffff;
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	GET_FLOAT_WORD(hy,y);
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	iy = hy&0x7fffffff;
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	if((ix>0x7f800000)||
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	   (iy>0x7f800000))	/* x or y is NaN */
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	   return x+y;
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	if(hx==0x3f800000) return atanf(y);   /* x=1.0 */
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	m = ((hy>>31)&1)|((hx>>30)&2);	/* 2*sign(x)+sign(y) */
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    /* when y = 0 */
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	if(iy==0) {
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	    switch(m) {
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		case 0:
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		case 1: return y; 	/* atan(+-0,+anything)=+-0 */
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		case 2: return  pi+tiny;/* atan(+0,-anything) = pi */
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		case 3: return -pi-tiny;/* atan(-0,-anything) =-pi */
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	    }
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	}
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    /* when x = 0 */
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	if(ix==0) return (hy<0)?  -pi_o_2-tiny: pi_o_2+tiny;
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    /* when x is INF */
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	if(ix==0x7f800000) {
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	    if(iy==0x7f800000) {
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		switch(m) {
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		    case 0: return  pi_o_4+tiny;/* atan(+INF,+INF) */
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		    case 1: return -pi_o_4-tiny;/* atan(-INF,+INF) */
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		    case 2: return  (float)3.0*pi_o_4+tiny;/*atan(+INF,-INF)*/
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		    case 3: return (float)-3.0*pi_o_4-tiny;/*atan(-INF,-INF)*/
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		}
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	    } else {
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		switch(m) {
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		    case 0: return  zero  ;	/* atan(+...,+INF) */
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		    case 1: return -zero  ;	/* atan(-...,+INF) */
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		    case 2: return  pi+tiny  ;	/* atan(+...,-INF) */
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		    case 3: return -pi-tiny  ;	/* atan(-...,-INF) */
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		}
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	    }
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	}
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    /* when y is INF */
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	if(iy==0x7f800000) return (hy<0)? -pi_o_2-tiny: pi_o_2+tiny;
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    /* compute y/x */
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	k = (iy-ix)>>23;
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	if(k > 60) z=pi_o_2+(float)0.5*pi_lo; 	/* |y/x| >  2**60 */
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	else if(hx<0&&k<-60) z=0.0; 	/* |y|/x < -2**60 */
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	else z=atanf(fabsf(y/x));	/* safe to do y/x */
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	switch (m) {
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	    case 0: return       z  ;	/* atan(+,+) */
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	    case 1: {
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	    	      u_int32_t zh;
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		      GET_FLOAT_WORD(zh,z);
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		      SET_FLOAT_WORD(z,zh ^ 0x80000000);
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		    }
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		    return       z  ;	/* atan(-,+) */
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	    case 2: return  pi-(z-pi_lo);/* atan(+,-) */
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	    default: /* case 3 */
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	    	    return  (z-pi_lo)-pi;/* atan(-,-) */
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	}
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}
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DEF_STD(atan2f);