usr/src/lib/libm/common/complex/ccoshl.c

   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 __ccoshl = ccoshl
  31
  32 #include "libm.h"       /* coshl/expl/fabsl/scalbnl/sincosl/sinhl/__k_cexpl */
  33 #include "complex_wrapper.h"
  34
  35 /* INDENT OFF */
  36 static const long double zero = 0.0L, half = 0.5L;
  37 /* INDENT ON */
  38
  39 ldcomplex
  40 ccoshl(ldcomplex z) {
  41         long double t, x, y, S, C;
  42         int hx, ix, hy, iy, n;
  43         ldcomplex ans;
  44
  45         x = LD_RE(z);
  46         y = LD_IM(z);
  47         hx = HI_XWORD(x);
  48         ix = hx & 0x7fffffff;
  49         hy = HI_XWORD(y);
  50         iy = hy & 0x7fffffff;
  51         x = fabsl(x);
  52         y = fabsl(y);
  53
  54         (void) sincosl(y, &S, &C);
  55         if (ix >= 0x4004e000) { /* |x| > 60 = prec/2 (14,28,34,60) */
  56                 if (ix >= 0x400C62E4) { /* |x| > 11356.52... ~ log(2**16384) */
  57                         if (ix >= 0x7fff0000) { /* |x| is inf or NaN */
  58                                 if (y == zero) {
  59                                         LD_RE(ans) = x;
  60                                         LD_IM(ans) = y;
  61                                 } else if (iy >= 0x7fff0000) {
  62                                         LD_RE(ans) = x;
  63                                         LD_IM(ans) = x - y;
  64                                 } else {
  65                                         LD_RE(ans) = C * x;
  66                                         LD_IM(ans) = S * x;
  67                                 }
  68                         } else {
  69                                 t = __k_cexpl(x, &n);
  70                                                 /* return exp(x)=t*2**n */
  71                                 LD_RE(ans) = scalbnl(C * t, n - 1);
  72                                 LD_IM(ans) = scalbnl(S * t, n - 1);
  73                         }
  74                 } else {
  75                         t = expl(x) * half;
  76                         LD_RE(ans) = C * t;
  77                         LD_IM(ans) = S * t;
  78                 }
  79         } else {
  80                 if (x == zero) {        /* x = 0, return (C,0) */
  81                         LD_RE(ans) = C;
  82                         LD_IM(ans) = zero;
  83                 } else {
  84                         LD_RE(ans) = C * coshl(x);
  85                         LD_IM(ans) = S * sinhl(x);
  86                 }
  87         }
  88         if ((hx ^ hy) < 0)
  89                 LD_IM(ans) = -LD_IM(ans);
  90         return (ans);
  91 }