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 /*
  27  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  28  * Use is subject to license terms.
  29  */
  30 
  31 #pragma weak fminf = __fminf
  32 
  33 #include "libm.h"                       /* for islessequal macro */
  34 
  35 float
  36 __fminf(float x, float y)
  37 {
  38         /*
  39          * On SPARC v8plus/v9, this could be implemented as follows
  40          * (assuming %f0 = x, %f1 = y, return value left in %f0):
  41          *
  42          * fcmps        %fcc0,%f1,%f1
  43          * fmovsu       %fcc0,%f0,%f1
  44          * fcmps        %fcc0,%f0,%f1
  45          * fmovsug      %fcc0,%f1,%f0
  46          * st           %f0,[x]
  47          * st           %f1,[y]
  48          * ld           [x],%l0
  49          * ld           [y],%l1
  50          * or           %l0,%l1,%l2
  51          * sethi        %hi(0x80000000),%l3
  52          * and          %l3,%l2,%l2
  53          * or           %l0,%l2,%l0
  54          * st           %l0,[x]
  55          * ld           [x],%f0
  56          *
  57          * If VIS instructions are available, use this code instead:
  58          *
  59          * fcmps        %fcc0,%f1,%f1
  60          * fmovsu       %fcc0,%f0,%f1
  61          * fcmps        %fcc0,%f0,%f1
  62          * fmovsug      %fcc0,%f1,%f0
  63          * fors         %f0,%f1,%f2
  64          * fzeros       %f3
  65          * fnegs        %f3,%f3
  66          * fands        %f3,%f2,%f2
  67          * fors         %f0,%f2,%f0
  68          *
  69          * If VIS 3.0 instructions are available, use this:
  70          *
  71          * flcmps       %fcc0,%f0,%f1
  72          * fmovsge      %fcc0,%f1,%f0   ! move if %fcc0 is 0 or 2
  73          */
  74 
  75         union {
  76                 unsigned i;
  77                 float f;
  78         } xx, yy;
  79 
  80         unsigned s;
  81 
  82         /* if y is nan, replace it by x */
  83         if (y != y)
  84                 y = x;
  85 
  86         /* if x is nan, replace it by y */
  87         if (x != x)
  88                 x = y;
  89 
  90         /* At this point, x and y are either both numeric, or both NaN */
  91         if (!isnan(x) && !islessequal(x, y))
  92                 x = y;
  93 
  94         /*
  95          * set the sign of the result if either x or y has its sign set
  96          */
  97         xx.f = x;
  98         yy.f = y;
  99         s = (xx.i | yy.i) & 0x80000000;
 100         xx.i |= s;
 101 
 102         return (xx.f);
 103 }