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 #if defined(ELFOBJ)
  31 #pragma weak coshl = __coshl
  32 #endif
  33 
  34 #include "libm.h"

  35 
  36 /*
  37  * COSH(X)
  38  * RETURN THE HYPERBOLIC COSINE OF X
  39  *
  40  * Method :
  41  *      1. Replace x by |x| (COSH(x) = COSH(-x)).
  42  *      2.
  43  *                                                      [ EXP(x) - 1 ]^2
  44  *          0        <= x <= 0.3465  :  COSH(x) := 1 + -------------------
  45  *                                                         2*EXP(x)
  46  *
  47  *                                                 EXP(x) +  1/EXP(x)
  48  *          0.3465   <= x <= thresh  :  COSH(x) := -------------------
  49  *                                                         2
  50  *          thresh   <= x <= lnovft  :  COSH(x) := EXP(x)/2
  51  *          lnovft   <= x <  INF     :  COSH(x) := SCALBN(EXP(x-MEP1*ln2),ME)
  52  *
  53  *
  54  * here

  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 #if defined(ELFOBJ)
  31 #pragma weak coshl = __coshl
  32 #endif
  33 
  34 #include "libm.h"
  35 #include "longdouble.h"
  36 
  37 /*
  38  * COSH(X)
  39  * RETURN THE HYPERBOLIC COSINE OF X
  40  *
  41  * Method :
  42  *      1. Replace x by |x| (COSH(x) = COSH(-x)).
  43  *      2.
  44  *                                                      [ EXP(x) - 1 ]^2
  45  *          0        <= x <= 0.3465  :  COSH(x) := 1 + -------------------
  46  *                                                         2*EXP(x)
  47  *
  48  *                                                 EXP(x) +  1/EXP(x)
  49  *          0.3465   <= x <= thresh  :  COSH(x) := -------------------
  50  *                                                         2
  51  *          thresh   <= x <= lnovft  :  COSH(x) := EXP(x)/2
  52  *          lnovft   <= x <  INF     :  COSH(x) := SCALBN(EXP(x-MEP1*ln2),ME)
  53  *
  54  *
  55  * here