usr/src/lib/libm/common/complex/cproj.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 __cproj = cproj
  31
  32 /* INDENT OFF */
  33 /*
  34  * dcomplex cproj(dcomplex z);
  35  *
  36  * If one of the component of z = (x,y) is an inf, then
  37  *      cproj(z) = (+inf, copysign(0,y));
  38  * otherwise,
  39  *      cproj(z) = z
  40  */
  41 /* INDENT ON */
  42
  43 #include "libm.h"                       /* fabs */
  44 #include "complex_wrapper.h"
  45
  46 static const double zero = 0.0;
  47
  48 dcomplex
  49 cproj(dcomplex z) {
  50         double x, y;
  51         int ix, iy, hx, hy, lx, ly;
  52
  53         x = D_RE(z);
  54         y = D_IM(z);
  55         hx = HI_WORD(x);
  56         lx = LO_WORD(x);
  57         hy = HI_WORD(y);
  58         ly = LO_WORD(y);
  59         ix = hx & 0x7fffffff;
  60         iy = hy & 0x7fffffff;
  61         if (ISINF(iy, ly)) {
  62                 D_RE(z) = fabs(y);
  63                 D_IM(z) = hy >= 0 ? zero : -zero;
  64         } else if (ISINF(ix, lx)) {
  65                 D_RE(z) = fabs(x);
  66                 D_IM(z) = hy >= 0 ? zero : -zero;
  67         }
  68         return (z);
  69 }