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/*--- This file (guest_generic_x87.h) is                      ---*/
/*--- Copyright (C) OpenWorks LLP.  All rights reserved.      ---*/
/*---                                                         ---*/
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/*
   This file is part of LibVEX, a library for dynamic binary
   instrumentation and translation.

   Copyright (C) 2004-2009 OpenWorks LLP.  All rights reserved.

   This library is made available under a dual licensing scheme.

   If you link LibVEX against other code all of which is itself
   licensed under the GNU General Public License, version 2 dated June
   1991 ("GPL v2"), then you may use LibVEX under the terms of the GPL
   v2, as appearing in the file LICENSE.GPL.  If the file LICENSE.GPL
   is missing, you can obtain a copy of the GPL v2 from the Free
   Software Foundation Inc., 51 Franklin St, Fifth Floor, Boston, MA
   02110-1301, USA.

   For any other uses of LibVEX, you must first obtain a commercial
   license from OpenWorks LLP.  Please contact info@open-works.co.uk
   for information about commercial licensing.

   This software is provided by OpenWorks LLP "as is" and any express
   or implied warranties, including, but not limited to, the implied
   warranties of merchantability and fitness for a particular purpose
   are disclaimed.  In no event shall OpenWorks LLP be liable for any
   direct, indirect, incidental, special, exemplary, or consequential
   damages (including, but not limited to, procurement of substitute
   goods or services; loss of use, data, or profits; or business
   interruption) however caused and on any theory of liability,
   whether in contract, strict liability, or tort (including
   negligence or otherwise) arising in any way out of the use of this
   software, even if advised of the possibility of such damage.

   Neither the names of the U.S. Department of Energy nor the
   University of California nor the names of its contributors may be
   used to endorse or promote products derived from this software
   without prior written permission.
*/

/* This file contains functions for doing some x87-specific
   operations.  Both the amd64 and x86 front ends (guests) indirectly
   call these functions via guest helper calls.  By putting them here,
   code duplication is avoided.  Some of these functions are tricky
   and hard to verify, so there is much to be said for only having one
   copy thereof.
*/

#ifndef __VEX_GUEST_GENERIC_X87_H
#define __VEX_GUEST_GENERIC_X87_H

#include "libvex_basictypes.h"


/* Convert an IEEE754 double (64-bit) into an x87 extended double
   (80-bit), mimicing the hardware fairly closely.  Both numbers are
   stored little-endian.  Limitations, all of which could be fixed,
   given some level of hassle:

   * Identity of NaNs is not preserved.

   See comments in the code for more details.
*/
extern
void convert_f64le_to_f80le ( /*IN*/UChar* f64, /*OUT*/UChar* f80 );


/* Convert an x87 extended double (80-bit) into an IEEE 754 double
   (64-bit), mimicking the hardware fairly closely.  Both numbers are
   stored little-endian.  Limitations, both of which could be fixed,
   given some level of hassle:

   * Rounding following truncation could be a bit better.

   * Identity of NaNs is not preserved.

   See comments in the code for more details.
*/
extern
void convert_f80le_to_f64le ( /*IN*/UChar* f80, /*OUT*/UChar* f64 );


/* Layout of the real x87 state. */
typedef
   struct {
      UShort env[14];
      UChar  reg[80];
   }
   Fpu_State;

/* Offsets, in 16-bit ints, into the FPU environment (env) area. */
#define FP_ENV_CTRL   0
#define FP_ENV_STAT   2
#define FP_ENV_TAG    4
#define FP_ENV_IP     6 /* and 7 */
#define FP_ENV_CS     8
#define FP_ENV_OPOFF  10 /* and 11 */
#define FP_ENV_OPSEL  12
#define FP_REG(ii)    (10*(7-(ii)))


/* Do the computations for x86/amd64 FXTRACT */
extern ULong x86amd64g_calculate_FXTRACT ( ULong arg, HWord getExp );



#endif /* ndef __VEX_GUEST_GENERIC_X87_H */

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/*--- end                                 guest_generic_x87.h ---*/
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