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 __llroundf = llroundf
  32 #if defined(__sparcv9) || defined(__amd64)
  33 #pragma weak lroundf = llroundf
  34 #pragma weak __lroundf = llroundf
  35 #endif
  36 
  37 #include "libm.h"
  38 
  39 long long
  40 llroundf(float x)
  41 {
  42         union {
  43                 unsigned i;
  44                 float f;
  45         } xx;
  46 
  47         unsigned hx, sx, i;
  48 
  49         xx.f = x;
  50         hx = xx.i & ~0x80000000;
  51         sx = xx.i & 0x80000000;
  52 
  53         if (hx < 0x4b000000) {               /* |x| < 2^23 */
  54                 /* handle |x| < 1 */
  55                 if (hx < 0x3f800000) {
  56                         if (hx >= 0x3f000000)
  57                                 return (sx ? -1LL : 1LL);
  58 
  59                         return (0LL);
  60                 }
  61 
  62                 /* round x at the integer bit */
  63                 i = 1 << (0x95 - (hx >> 23));
  64                 xx.i = (xx.i + i) & ~((i << 1) - 1);
  65 
  66                 /*
  67                  * on LP32 architectures, we can just convert x to a 32-bit
  68                  * integer and sign-extend it
  69                  */
  70                 return ((long)xx.f);
  71         }
  72 
  73         /* now x is nan, inf, or integral */
  74         return ((long long)x);
  75 }