usr/src/lib/libm/common/complex/clogf.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 __clogf = clogf
  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 fcomplex
  39 clogf(fcomplex z) {
  40         fcomplex        ans;
  41         float           x, y, ax, ay;
  42         double          dx, dy;
  43         int             ix, iy, hx, hy;
  44
  45         x = F_RE(z);
  46         y = F_IM(z);
  47         hx = THE_WORD(x);
  48         hy = THE_WORD(y);
  49         ix = hx & 0x7fffffff;
  50         iy = hy & 0x7fffffff;
  51         ay = fabsf(y);
  52         ax = fabsf(x);
  53         F_IM(ans) = atan2f(y, x);
  54         if (ix >= 0x7f800000 || iy >= 0x7f800000) {
  55                 /* x or y is Inf or NaN */
  56                 if (iy == 0x7f800000)
  57                         F_RE(ans) = ay;
  58                 else if (ix == 0x7f800000)
  59                         F_RE(ans) = ax;
  60                 else
  61                         F_RE(ans) = ax + ay;
  62         } else {
  63 #if defined(__i386) && !defined(__amd64)
  64                 int     rp = __swapRP(fp_extended);
  65 #endif
  66                 dx = (double)ax;
  67                 dy = (double)ay;
  68                 if (ix == 0x3f800000)
  69                         F_RE(ans) = (float)(0.5 * log1p(dy * dy));
  70                 else if (iy == 0x3f800000)
  71                         F_RE(ans) = (float)(0.5 * log1p(dx * dx));
  72                 else if ((ix | iy) == 0)
  73                         F_RE(ans) = -1.0f / ax;
  74                 else
  75                         F_RE(ans) = (float)(0.5 * log(dx * dx + dy * dy));
  76 #if defined(__i386) && !defined(__amd64)
  77                 if (rp != fp_extended)
  78                         (void) __swapRP(rp);
  79 #endif
  80         }
  81         return (ans);
  82 }