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 #if defined(ELFOBJ)
  31 #pragma weak fmin = __fmin
  32 #endif
  33 
  34 /*
  35  * fmin(x,y) returns the smaller of x and y.  If just one of the
  36  * arguments is NaN, fmin returns the other argument.  If both
  37  * arguments are NaN, fmin returns NaN.
  38  *
  39  * See fmaxf.c for a discussion of implementation trade-offs.
  40  */
  41 
  42 #include "libm.h"       /* for islessequal macro */
  43 
  44 #include <sys/isa_defs.h>
  45 
  46 double
  47 __fmin(double x, double y) {
  48         union {
  49                 unsigned i[2];
  50                 double d;
  51         } xx, yy;
  52         unsigned s;
  53 
  54         /* if y is nan, replace it by x */
  55         if (y != y)
  56                 y = x;
  57 
  58         /* if x is nan, replace it by y */
  59         if (x != x)
  60                 x = y;
  61 
  62         /* if x is greater than y or x and y are unordered, replace x by y */
  63 #if defined(COMPARISON_MACRO_BUG)
  64         if (x != x || x > y)
  65 #else
  66         if (!islessequal(x, y))
  67 #endif
  68                 x = y;
  69 
  70         /*
  71          * now x and y are either both NaN or both numeric; set the
  72          * sign of the result if either x or y has its sign set
  73          */
  74         xx.d = x;
  75         yy.d = y;
  76 #if defined(_BIG_ENDIAN)
  77         s = (xx.i[0] | yy.i[0]) & 0x80000000;
  78         xx.i[0] |= s;
  79 #else
  80         s = (xx.i[1] | yy.i[1]) & 0x80000000;
  81         xx.i[1] |= s;
  82 #endif
  83 
  84         return (xx.d);
  85 }