usr/src/lib/libm/common/R/floorf.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 __ceilf = ceilf
  31 #pragma weak __floorf = floorf
  32
  33 /* INDENT OFF */
  34 /*
  35  * ceilf(x)     return the biggest integral value (in float) below x
  36  * floorf(x)    return the least integral value (in float) above x
  37  *
  38  * NOTE: ceilf(x) and floorf(x) return result
  39  * with the same sign as x's,  including 0.0F.
  40  */
  41
  42 #include "libm.h"
  43
  44 static const float xf[] = {
  45 /* ZEROF */     0.0f,
  46 /* ONEF */      1.0f,
  47 /* MONEF */     -1.0f,
  48 /* HUGEF */     1.0e30f,
  49 };
  50
  51 #define ZEROF   xf[0]
  52 #define ONEF    xf[1]
  53 #define MONEF   xf[2]
  54 #define HUGEF   xf[3]
  55 /* INDENT ON */
  56
  57 float
  58 ceilf(float x) {
  59         volatile float dummy;
  60         int hx, k, j, ix;
  61
  62         hx = *(int *) &x;
  63         ix = hx & ~0x80000000;
  64         k = ix >> 23;
  65         if (((k - 127) ^ (k - 150)) < 0) {
  66                 k = (1 << (150 - k)) - 1;
  67                 if ((k & hx) != 0)
  68                         dummy = HUGEF + x;      /* raise inexact */
  69                 j = k & (~(hx >> 31));
  70                 *(int *) &x = (hx + j) & ~k;
  71                 return (x);
  72         } else if (k <= 126) {
  73                 dummy = HUGEF + x;
  74                 if (hx > 0)
  75                         return (ONEF);
  76                 else if (ix == 0)
  77                         return (x);
  78                 else
  79                         return (-ZEROF);
  80         } else
  81                 /* signal invalid if x is a SNaN */
  82                 return (x * ONEF);              /* +0 -> *1 for Cheetah */
  83 }
  84
  85 float
  86 floorf(float x) {
  87         volatile float dummy;
  88         int hx, k, j, ix;
  89
  90         hx = *(int *) &x;
  91         ix = hx & ~0x80000000;
  92         k = ix >> 23;
  93         if (((k - 127) ^ (k - 150)) < 0) {
  94                 k = (1 << (150 - k)) - 1;
  95                 if ((k & hx) != 0)
  96                         dummy = HUGEF + x;      /* raise inexact */
  97                 j = k & (hx >> 31);
  98                 *(int *) &x = (hx + j) & ~k;
  99                 return (x);
 100         } else if (k <= 126) {
 101                 dummy = HUGEF + x;
 102                 if (hx > 0)
 103                         return (ZEROF);
 104                 else if (ix == 0)
 105                         return (x);
 106                 else
 107                         return (MONEF);
 108         } else
 109                 /* signal invalid if x is a SNaN */
 110                 return (x * ONEF);              /* +0 -> *1 for Cheetah */
 111 }