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/*
23 * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
24 */
25/*
26 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27 * Use is subject to license terms.
28 */
29
30#pragma weak __csqrtf = csqrtf
31
32#include "libm.h"		/* sqrt/fabsf/sqrtf */
33#include "complex_wrapper.h"
34
35/* INDENT OFF */
36static const float zero = 0.0F;
37/* INDENT ON */
38
39fcomplex
40csqrtf(fcomplex z) {
41	fcomplex ans;
42	double dt, dx, dy;
43	float x, y, t, ax, ay, w;
44	int ix, iy, hx, hy;
45
46	x = F_RE(z);
47	y = F_IM(z);
48	hx = THE_WORD(x);
49	hy = THE_WORD(y);
50	ix = hx & 0x7fffffff;
51	iy = hy & 0x7fffffff;
52	ay = fabsf(y);
53	ax = fabsf(x);
54	if (ix >= 0x7f800000 || iy >= 0x7f800000) {
55		/* x or y is Inf or NaN */
56		if (iy == 0x7f800000)
57			F_IM(ans) = F_RE(ans) = ay;
58		else if (ix == 0x7f800000) {
59			if (hx > 0) {
60				F_RE(ans) = ax;
61				F_IM(ans) = ay * zero;
62			} else {
63				F_RE(ans) = ay * zero;
64				F_IM(ans) = ax;
65			}
66		} else
67			F_IM(ans) = F_RE(ans) = ax + ay;
68	} else if (iy == 0) {
69		if (hx >= 0) {
70			F_RE(ans) = sqrtf(ax);
71			F_IM(ans) = zero;
72		} else {
73			F_IM(ans) = sqrtf(ax);
74			F_RE(ans) = zero;
75		}
76	} else {
77		dx = (double) ax;
78		dy = (double) ay;
79		dt = sqrt(0.5 * (sqrt(dx * dx + dy * dy) + dx));
80		t = (float) dt;
81		w = (float) (dy / (dt + dt));
82		if (hx >= 0) {
83			F_RE(ans) = t;
84			F_IM(ans) = w;
85		} else {
86			F_IM(ans) = t;
87			F_RE(ans) = w;
88		}
89	}
90	if (hy < 0)
91		F_IM(ans) = -F_IM(ans);
92	return (ans);
93}
94