xref: /illumos-gate/usr/src/lib/libm/common/complex/clogf.c (revision 3ba944265c4ae1fcf23ef758537c2e4f4feec16e)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
23  */
24 /*
25  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  */
28 
29 #pragma weak __clogf = clogf
30 
31 #include "libm.h"
32 #include "complex_wrapper.h"
33 
34 #if defined(__i386) && !defined(__amd64)
35 extern int __swapRP(int);
36 #endif
37 
38 fcomplex
39 clogf(fcomplex z) {
40 	fcomplex	ans;
41 	float		x, y, ax, ay;
42 	double		dx, dy;
43 	int		ix, iy, hx, hy;
44 
45 	x = F_RE(z);
46 	y = F_IM(z);
47 	hx = THE_WORD(x);
48 	hy = THE_WORD(y);
49 	ix = hx & 0x7fffffff;
50 	iy = hy & 0x7fffffff;
51 	ay = fabsf(y);
52 	ax = fabsf(x);
53 	F_IM(ans) = atan2f(y, x);
54 	if (ix >= 0x7f800000 || iy >= 0x7f800000) {
55 		/* x or y is Inf or NaN */
56 		if (iy == 0x7f800000)
57 			F_RE(ans) = ay;
58 		else if (ix == 0x7f800000)
59 			F_RE(ans) = ax;
60 		else
61 			F_RE(ans) = ax + ay;
62 	} else {
63 #if defined(__i386) && !defined(__amd64)
64 		int	rp = __swapRP(fp_extended);
65 #endif
66 		dx = (double)ax;
67 		dy = (double)ay;
68 		if (ix == 0x3f800000)
69 			F_RE(ans) = (float)(0.5 * log1p(dy * dy));
70 		else if (iy == 0x3f800000)
71 			F_RE(ans) = (float)(0.5 * log1p(dx * dx));
72 		else if ((ix | iy) == 0)
73 			F_RE(ans) = -1.0f / ax;
74 		else
75 			F_RE(ans) = (float)(0.5 * log(dx * dx + dy * dy));
76 #if defined(__i386) && !defined(__amd64)
77 		if (rp != fp_extended)
78 			(void) __swapRP(rp);
79 #endif
80 	}
81 	return (ans);
82 }
83