clogl.c revision ddc0e0b53c661f6e439e3b7072b3ef353eadb4af
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma weak __clogl = clogl
#include "libm.h" /* atan2l/fabsl/isinfl/log1pl/logl/__k_clog_rl */
#include "complex_wrapper.h"
#include "longdouble.h"
#if defined(__sparc)
#define SIGP7 120
#define HSIGP7 60
#elif defined(__x86)
#define SIGP7 70
#define HSIGP7 35
#endif
/* INDENT OFF */
static const long double zero = 0.0L, half = 0.5L, one = 1.0L;
/* INDENT ON */
ldcomplex
clogl(ldcomplex z) {
ldcomplex ans;
long double x, y, t, ax, ay;
int n, ix, iy, hx, hy;
x = LD_RE(z);
y = LD_IM(z);
hx = HI_XWORD(x);
hy = HI_XWORD(y);
ix = hx & 0x7fffffff;
iy = hy & 0x7fffffff;
ay = fabsl(y);
ax = fabsl(x);
LD_IM(ans) = atan2l(y, x);
if (ix < iy || (ix == iy && ix < 0x7fff0000 && ax < ay)) {
/* swap x and y to force ax>=ay */
t = ax;
ax = ay;
ay = t;
n = ix, ix = iy;
iy = n;
}
n = (ix - iy) >> 16;
if (ix >= 0x7fff0000) { /* x or y is Inf or NaN */
if (isinfl(ax))
LD_RE(ans) = ax;
else if (isinfl(ay))
LD_RE(ans) = ay;
else
LD_RE(ans) = ax + ay;
} else if (ay == zero)
LD_RE(ans) = logl(ax);
else if (((0x3fffffff - ix) ^ (ix - 0x3ffe0000)) >= 0) {
/* 0.5 <= x < 2 */
if (ix >= 0x3fff0000) {
if (ax == one)
LD_RE(ans) = half * log1pl(ay * ay);
else if (n >= SIGP7)
LD_RE(ans) = logl(ax);
else
LD_RE(ans) = half * (log1pl(ay * ay + (ax -
one) * (ax + one)));
} else if (n >= SIGP7)
LD_RE(ans) = logl(ax);
else
LD_RE(ans) = __k_clog_rl(x, y, &t);
} else if (n >= HSIGP7)
LD_RE(ans) = logl(ax);
else if (ix < 0x5f3f0000 && iy >= 0x20bf0000)
/* 2**-8000 < y < x < 2**8000 */
LD_RE(ans) = half * logl(ax * ax + ay * ay);
else {
t = ay / ax;
LD_RE(ans) = logl(ax) + half * log1pl(t * t);
}
return (ans);
}