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 logb = __logb
  31 #pragma weak _logb = __logb
  32 
  33 #include "libm.h"
  34 #include "xpg6.h"       /* __xpg6 */
  35 #define _C99SUSv3_logb  _C99SUSv3_logb_subnormal_is_like_ilogb
  36 
  37 #if defined(__x86)
  38 static const double two52 = 4503599627370496.0;
  39 #else
  40 /*
  41  * v: high part of a non-zero subnormal |x|; w: low part of |x|
  42  */
  43 static int
  44 ilogb_subnormal(unsigned v, unsigned w) {
  45         int r = -1022 - 52;
  46 
  47         if (v)
  48                 r += 32;
  49         else
  50                 v = w;
  51         if (v & 0xffff0000)

  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 __logb = logb
  31 #pragma weak _logb = logb
  32 
  33 #include "libm.h"
  34 #include "xpg6.h"       /* __xpg6 */
  35 #define _C99SUSv3_logb  _C99SUSv3_logb_subnormal_is_like_ilogb
  36 
  37 #if defined(__x86)
  38 static const double two52 = 4503599627370496.0;
  39 #else
  40 /*
  41  * v: high part of a non-zero subnormal |x|; w: low part of |x|
  42  */
  43 static int
  44 ilogb_subnormal(unsigned v, unsigned w) {
  45         int r = -1022 - 52;
  46 
  47         if (v)
  48                 r += 32;
  49         else
  50                 v = w;
  51         if (v & 0xffff0000)