GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libm/src/e_atan2l.c Lines: 0 51 0.0 %
Date: 2017-11-13 Branches: 0 53 0.0 %

Line Branch Exec Source
1
/*	$OpenBSD: e_atan2l.c,v 1.2 2016/09/12 19:47:02 guenther Exp $	*/
2
/* @(#)e_atan2.c 1.3 95/01/18 */
3
/* FreeBSD: head/lib/msun/src/e_atan2.c 176451 2008-02-22 02:30:36Z das */
4
/*
5
 * ====================================================
6
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
7
 *
8
 * Developed at SunSoft, a Sun Microsystems, Inc. business.
9
 * Permission to use, copy, modify, and distribute this
10
 * software is freely granted, provided that this notice
11
 * is preserved.
12
 * ====================================================
13
 *
14
 */
15
16
/*
17
 * See comments in e_atan2.c.
18
 * Converted to long double by David Schultz <das@FreeBSD.ORG>.
19
 * Adapted for OpenBSD by Martynas Venckus <martynas@openbsd.org>.
20
 */
21
22
#include <float.h>
23
#include <math.h>
24
25
#include "invtrig.h"
26
#include "math.h"
27
#include "math_private.h"
28
29
#ifdef EXT_IMPLICIT_NBIT
30
#define	LDBL_NBIT	0
31
#else /* EXT_IMPLICIT_NBIT */
32
#define	LDBL_NBIT	0x80000000
33
#endif /* EXT_IMPLICIT_NBIT */
34
35
static volatile long double
36
tiny  = 1.0e-300;
37
static const long double
38
zero  = 0.0;
39
40
#if defined(__amd64__) || defined(__i386__)
41
/* XXX Work around the fact that gcc truncates long double constants on i386 */
42
static volatile double
43
pi1 =  3.14159265358979311600e+00,	/*  0x1.921fb54442d18p+1  */
44
pi2 =  1.22514845490862001043e-16;	/*  0x1.1a80000000000p-53 */
45
#define	pi	((long double)pi1 + pi2)
46
#else
47
static const long double
48
pi =  3.14159265358979323846264338327950280e+00L;
49
#endif
50
51
long double
52
atan2l(long double y, long double x)
53
{
54
	union {
55
		long double e;
56
		struct ieee_ext bits;
57
	} ux, uy;
58
	long double z;
59
	int32_t k,m;
60
	int16_t exptx, expsignx, expty, expsigny;
61
62
	uy.e = y;
63
	expsigny = (uy.bits.ext_sign << 15) | uy.bits.ext_exp;
64
	expty = expsigny & 0x7fff;
65
	ux.e = x;
66
	expsignx = (ux.bits.ext_sign << 15) | ux.bits.ext_exp;
67
	exptx = expsignx & 0x7fff;
68
69
	if ((exptx==BIAS+LDBL_MAX_EXP &&
70
	     ((ux.bits.ext_frach&~LDBL_NBIT)
71
#ifdef EXT_FRACHMBITS
72
		| ux.bits.ext_frachm
73
#endif /* EXT_FRACHMBITS */
74
#ifdef EXT_FRACLMBITS
75
		| ux.bits.ext_fraclm
76
#endif /* EXT_FRACLMBITS */
77
		| ux.bits.ext_fracl)!=0) ||	/* x is NaN */
78
	    (expty==BIAS+LDBL_MAX_EXP &&
79
	     ((uy.bits.ext_frach&~LDBL_NBIT)
80
#ifdef EXT_FRACHMBITS
81
		| uy.bits.ext_frachm
82
#endif /* EXT_FRACHMBITS */
83
#ifdef EXT_FRACLMBITS
84
		| uy.bits.ext_fraclm
85
#endif /* EXT_FRACLMBITS */
86
		| uy.bits.ext_fracl)!=0))	/* y is NaN */
87
	    return x+y;
88
	if (expsignx==BIAS && ((ux.bits.ext_frach&~LDBL_NBIT)
89
#ifdef EXT_FRACHMBITS
90
		| ux.bits.ext_frachm
91
#endif /* EXT_FRACHMBITS */
92
#ifdef EXT_FRACLMBITS
93
		| ux.bits.ext_fraclm
94
#endif /* EXT_FRACLMBITS */
95
		| ux.bits.ext_fracl)==0)
96
	    return atanl(y);					/* x=1.0 */
97
	m = ((expsigny>>15)&1)|((expsignx>>14)&2);	/* 2*sign(x)+sign(y) */
98
99
    /* when y = 0 */
100
	if(expty==0 && ((uy.bits.ext_frach&~LDBL_NBIT)
101
#ifdef EXT_FRACHMBITS
102
		| uy.bits.ext_frachm
103
#endif /* EXT_FRACHMBITS */
104
#ifdef EXT_FRACLMBITS
105
		| uy.bits.ext_fraclm
106
#endif /* EXT_FRACLMBITS */
107
		| uy.bits.ext_fracl)==0) {
108
	    switch(m) {
109
		case 0:
110
		case 1: return y; 	/* atan(+-0,+anything)=+-0 */
111
		case 2: return  pi+tiny;/* atan(+0,-anything) = pi */
112
		case 3: return -pi-tiny;/* atan(-0,-anything) =-pi */
113
	    }
114
	}
115
    /* when x = 0 */
116
	if(exptx==0 && ((ux.bits.ext_frach&~LDBL_NBIT)
117
#ifdef EXT_FRACHMBITS
118
		| ux.bits.ext_frachm
119
#endif /* EXT_FRACHMBITS */
120
#ifdef EXT_FRACLMBITS
121
		| ux.bits.ext_fraclm
122
#endif /* EXT_FRACLMBITS */
123
		| ux.bits.ext_fracl)==0)
124
	    return (expsigny<0)?  -pio2_hi-tiny: pio2_hi+tiny;
125
126
    /* when x is INF */
127
	if(exptx==BIAS+LDBL_MAX_EXP) {
128
	    if(expty==BIAS+LDBL_MAX_EXP) {
129
		switch(m) {
130
		    case 0: return  pio2_hi*0.5+tiny;/* atan(+INF,+INF) */
131
		    case 1: return -pio2_hi*0.5-tiny;/* atan(-INF,+INF) */
132
		    case 2: return  1.5*pio2_hi+tiny;/*atan(+INF,-INF)*/
133
		    case 3: return -1.5*pio2_hi-tiny;/*atan(-INF,-INF)*/
134
		}
135
	    } else {
136
		switch(m) {
137
		    case 0: return  zero  ;	/* atan(+...,+INF) */
138
		    case 1: return -zero  ;	/* atan(-...,+INF) */
139
		    case 2: return  pi+tiny  ;	/* atan(+...,-INF) */
140
		    case 3: return -pi-tiny  ;	/* atan(-...,-INF) */
141
		}
142
	    }
143
	}
144
    /* when y is INF */
145
	if(expty==BIAS+LDBL_MAX_EXP)
146
	    return (expsigny<0)? -pio2_hi-tiny: pio2_hi+tiny;
147
148
    /* compute y/x */
149
	k = expty-exptx;
150
	if(k > LDBL_MANT_DIG+2) {			/* |y/x| huge */
151
	    z=pio2_hi+pio2_lo;
152
	    m&=1;
153
	}
154
	else if(expsignx<0&&k<-LDBL_MANT_DIG-2) z=0.0; 	/* |y/x| tiny, x<0 */
155
	else z=atanl(fabsl(y/x));		/* safe to do y/x */
156
	switch (m) {
157
	    case 0: return       z  ;	/* atan(+,+) */
158
	    case 1: return      -z  ;	/* atan(-,+) */
159
	    case 2: return  pi-(z-pi_lo);/* atan(+,-) */
160
	    default: /* case 3 */
161
	    	    return  (z-pi_lo)-pi;/* atan(-,-) */
162
	}
163
}
164
DEF_STD(atan2l);