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/*
* 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 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "@(#)cpowf.c 1.6 06/01/23 SMI"
#pragma weak cpowf = __cpowf
#include "libm.h"
#include "complex_wrapper.h"
#if defined(__i386) && !defined(__amd64)
extern int __swapRP(int);
#endif
static const double
dpi = 3.1415926535897931160E0, /* Hex 2^ 1 * 1.921FB54442D18 */
dhalf = 0.5,
dsqrt2 = 1.41421356237309514547, /* 3FF6A09E 667F3BCD */
dinvpi = 0.3183098861837906715377675;
static const float one = 1.0F, zero = 0.0F;
#define hiinf 0x7f800000
fcomplex
cpowf(fcomplex z, fcomplex w) {
fcomplex ans;
float x, y, u, v, t, c, s;
double dx, dy, du, dv, dt, dc, ds, dp, dq, dr;
int ix, iy, hx, hy, hv, hu, iu, iv, j;
x = F_RE(z);
y = F_IM(z);
u = F_RE(w);
v = F_IM(w);
hx = THE_WORD(x);
hy = THE_WORD(y);
hu = THE_WORD(u);
hv = THE_WORD(v);
ix = hx & 0x7fffffff;
iy = hy & 0x7fffffff;
iu = hu & 0x7fffffff;
iv = hv & 0x7fffffff;
j = 0;
if (iv == 0) { /* z**(real) */
if (hu == 0x3f800000) { /* (anything) ** 1 is itself */
F_RE(ans) = x;
F_IM(ans) = y;
} else if (iu == 0) { /* (anything) ** 0 is 1 */
F_RE(ans) = one;
F_IM(ans) = zero;
} else if (iy == 0) { /* (real)**(real) */
F_IM(ans) = zero;
if (hx < 0 && ix < hiinf && iu < hiinf) {
/* -x ** u is exp(i*pi*u)*pow(x,u) */
t = powf(-x, u);
sincospif(u, &s, &c);
F_RE(ans) = (c == zero)? c: c * t;
F_IM(ans) = (s == zero)? s: s * t;
} else {
F_RE(ans) = powf(x, u);
}
} else if (ix == 0 || ix >= hiinf || iy >= hiinf) {
if (ix > hiinf || iy > hiinf || iu > hiinf) {
F_RE(ans) = F_IM(ans) = x + y + u;
} else {
v = fabsf(y);
if (ix != 0)
v += fabsf(x);
t = atan2pif(y, x);
sincospif(t * u, &s, &c);
F_RE(ans) = (c == zero)? c: c * v;
F_IM(ans) = (s == zero)? s: s * v;
}
} else if (ix == iy) { /* if |x| == |y| */
#if defined(__i386) && !defined(__amd64)
int rp = __swapRP(fp_extended);
#endif
dx = (double)x;
du = (double)u;
dt = (hx >= 0)? 0.25 : 0.75;
if (hy < 0)
dt = -dt;
dr = pow(dsqrt2 * dx, du);
sincospi(dt * du, &ds, &dc);
F_RE(ans) = (float)(dr * dc);
F_IM(ans) = (float)(dr * ds);
#if defined(__i386) && !defined(__amd64)
if (rp != fp_extended)
(void) __swapRP(rp);
#endif
} else {
j = 1;
}
if (j == 0)
return (ans);
}
if (iu >= hiinf || iv >= hiinf || ix >= hiinf || iy >= hiinf) {
/*
* non-zero imaginery part(s) with inf component(s) yields NaN
*/
t = fabsf(x) + fabsf(y) + fabsf(u) + fabsf(v);
F_RE(ans) = F_IM(ans) = t - t;
} else {
#if defined(__i386) && !defined(__amd64)
int rp = __swapRP(fp_extended);
#endif
/* INDENT OFF */
/*
* r = u*log(hypot(x,y))-v*atan2(y,x),
* q = u*atan2(y,x)+v*log(hypot(x,y))
* or
* r = u*log(hypot(x,y))-v*pi*atan2pi(y,x),
* q/pi = u*atan2pi(y,x)+v*log(hypot(x,y))/pi
* ans = exp(r)*(cospi(q/pi) + i sinpi(q/pi))
*/
/* INDENT ON */
dx = (double)x;
dy = (double)y;
du = (double)u;
dv = (double)v;
if (ix > 0x3f000000 && ix < 0x40000000) /* .5 < |x| < 2 */
dt = dhalf * log1p((dx - 1.0) * (dx + 1.0) + dy * dy);
else if (iy > 0x3f000000 && iy < 0x40000000) /* .5 < |y| < 2 */
dt = dhalf * log1p((dy - 1.0) * (dy + 1.0) + dx * dx);
else
dt = dhalf * log(dx * dx + dy * dy);
dp = atan2pi(dy, dx);
if (iv == 0) { /* dv = 0 */
dr = exp(du * dt);
dq = du * dp;
} else {
dr = exp(du * dt - dv * dp * dpi);
dq = du * dp + dv * dt * dinvpi;
}
sincospi(dq, &ds, &dc);
F_RE(ans) = (float)(dr * dc);
F_IM(ans) = (float)(dr * ds);
#if defined(__i386) && !defined(__amd64)
if (rp != fp_extended)
(void) __swapRP(rp);
#endif
}
return (ans);
}
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