usr/src/lib/libm/common/complex/cexpl.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 __cexpl = cexpl
  31
  32 #include "libm.h"               /* expl/isinfl/iszerol/scalbnl/sincosl */
  33 #include "complex_wrapper.h"
  34
  35 extern int isinfl(long double);
  36 extern int iszerol(long double);
  37
  38 /* INDENT OFF */
  39 static const long double zero = 0.0L;
  40 /* INDENT ON */
  41
  42 ldcomplex
  43 cexpl(ldcomplex z) {
  44         ldcomplex ans;
  45         long double x, y, t, c, s;
  46         int n, ix, iy, hx, hy;
  47
  48         x = LD_RE(z);
  49         y = LD_IM(z);
  50         hx = HI_XWORD(x);
  51         hy = HI_XWORD(y);
  52         ix = hx & 0x7fffffff;
  53         iy = hy & 0x7fffffff;
  54         if (iszerol(y)) {       /* y = 0 */
  55                 LD_RE(ans) = expl(x);
  56                 LD_IM(ans) = y;
  57         } else if (isinfl(x)) { /* x is +-inf */
  58                 if (hx < 0) {
  59                         if (iy >= 0x7fff0000) {
  60                                 LD_RE(ans) = zero;
  61                                 LD_IM(ans) = zero;
  62                         } else {
  63                                 sincosl(y, &s, &c);
  64                                 LD_RE(ans) = zero * c;
  65                                 LD_IM(ans) = zero * s;
  66                         }
  67                 } else {
  68                         if (iy >= 0x7fff0000) {
  69                                 LD_RE(ans) = x;
  70                                 LD_IM(ans) = y - y;
  71                         } else {
  72                                 (void) sincosl(y, &s, &c);
  73                                 LD_RE(ans) = x * c;
  74                                 LD_IM(ans) = x * s;
  75                         }
  76                 }
  77         } else {
  78                 (void) sincosl(y, &s, &c);
  79                 if (ix >= 0x400C62E4) { /* |x| > 11356.52... ~ log(2**16384) */
  80                         t = __k_cexpl(x, &n);
  81                         LD_RE(ans) = scalbnl(t * c, n);
  82                         LD_IM(ans) = scalbnl(t * s, n);
  83                 } else {
  84                         t = expl(x);
  85                         LD_RE(ans) = t * c;
  86                         LD_IM(ans) = t * s;
  87                 }
  88         }
  89         return (ans);
  90 }