usr/src/lib/libm/common/R/hypotf.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 __hypotf = hypotf
  31
  32 #include "libm.h"
  33
  34 float
  35 hypotf(float x, float y) {
  36         double dx, dy;
  37         float w;
  38         int ix, iy;
  39
  40         ix = (*(int *) &x) & 0x7fffffff;
  41         iy = (*(int *) &y) & 0x7fffffff;
  42         if (ix >= 0x7f800000) {
  43                 if (ix == 0x7f800000)
  44                         *(int *) &w = x == y ? iy : ix; /* w = |x| = inf */
  45                 else if (iy == 0x7f800000)
  46                         *(int *) &w = x == y ? ix : iy; /* w = |y| = inf */
  47                 else
  48                         w = fabsf(x) * fabsf(y);        /* + -> * for Cheetah */
  49         } else if (iy >= 0x7f800000) {
  50                 if (iy == 0x7f800000)
  51                         *(int *) &w = x == y ? ix : iy; /* w = |y| = inf */
  52                 else
  53                         w = fabsf(x) * fabsf(y);        /* + -> * for Cheetah */
  54         } else if (ix == 0)
  55                 *(int *) &w = iy;       /* w = |y|  */
  56         else if (iy == 0)
  57                 *(int *) &w = ix;       /* w = |x|  */
  58         else {
  59                 dx = (double) x;
  60                 dy = (double) y;
  61                 w = (float) sqrt(dx * dx + dy * dy);
  62         }
  63         return (w);
  64 }