usr/src/lib/libm/common/complex/ccoshf.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  * 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 __ccoshf = ccoshf
  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 static const float zero = 0.0F, half = 0.5F;
  39
  40 fcomplex
  41 ccoshf(fcomplex z) {
  42         float           t, x, y, S, C;
  43         double          w;
  44         int             hx, ix, hy, iy, n;
  45         fcomplex        ans;
  46
  47         x = F_RE(z);
  48         y = F_IM(z);
  49         hx = THE_WORD(x);
  50         ix = hx & 0x7fffffff;
  51         hy = THE_WORD(y);
  52         iy = hy & 0x7fffffff;
  53         x = fabsf(x);
  54         y = fabsf(y);
  55
  56         sincosf(y, &S, &C);
  57         if (ix >= 0x41600000) { /* |x| > 14 = prec/2 (14,28,34,60) */
  58                 if (ix >= 0x42B171AA) { /* |x| > 88.722... ~ log(2**128) */
  59                         if (ix >= 0x7f800000) { /* |x| is inf or NaN */
  60                                 if (iy == 0) {
  61                                         F_RE(ans) = x;
  62                                         F_IM(ans) = y;
  63                                 } else if (iy >= 0x7f800000) {
  64                                         F_RE(ans) = x;
  65                                         F_IM(ans) = x - y;
  66                                 } else {
  67                                         F_RE(ans) = C * x;
  68                                         F_IM(ans) = S * x;
  69                                 }
  70                         } else {
  71 #if defined(__i386) && !defined(__amd64)
  72                                 int     rp = __swapRP(fp_extended);
  73 #endif
  74                                 /* return (C, S) * exp(x) / 2 */
  75                                 w = __k_cexp((double)x, &n);
  76                                 F_RE(ans) = (float)scalbn(C * w, n - 1);
  77                                 F_IM(ans) = (float)scalbn(S * w, n - 1);
  78 #if defined(__i386) && !defined(__amd64)
  79                                 if (rp != fp_extended)
  80                                         (void) __swapRP(rp);
  81 #endif
  82                         }
  83                 } else {
  84                         t = expf(x) * half;
  85                         F_RE(ans) = C * t;
  86                         F_IM(ans) = S * t;
  87                 }
  88         } else {
  89                 if (ix == 0) {  /* x = 0, return (C,0) */
  90                         F_RE(ans) = C;
  91                         F_IM(ans) = zero;
  92                 } else {
  93                         F_RE(ans) = C * coshf(x);
  94                         F_IM(ans) = S * sinhf(x);
  95                 }
  96         }
  97         if ((hx ^ hy) < 0)
  98                 F_IM(ans) = -F_IM(ans);
  99         return (ans);
 100 }