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      1 
      2 /*---------------------------------------------------------------*/
      3 /*--- begin                               guest_generic_x87.h ---*/
      4 /*---------------------------------------------------------------*/
      5 
      6 /*
      7    This file is part of Valgrind, a dynamic binary instrumentation
      8    framework.
      9 
     10    Copyright (C) 2004-2010 OpenWorks LLP
     11       info (at) open-works.net
     12 
     13    This program is free software; you can redistribute it and/or
     14    modify it under the terms of the GNU General Public License as
     15    published by the Free Software Foundation; either version 2 of the
     16    License, or (at your option) any later version.
     17 
     18    This program is distributed in the hope that it will be useful, but
     19    WITHOUT ANY WARRANTY; without even the implied warranty of
     20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     21    General Public License for more details.
     22 
     23    You should have received a copy of the GNU General Public License
     24    along with this program; if not, write to the Free Software
     25    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
     26    02110-1301, USA.
     27 
     28    The GNU General Public License is contained in the file COPYING.
     29 
     30    Neither the names of the U.S. Department of Energy nor the
     31    University of California nor the names of its contributors may be
     32    used to endorse or promote products derived from this software
     33    without prior written permission.
     34 */
     35 
     36 /* This file contains functions for doing some x87-specific
     37    operations.  Both the amd64 and x86 front ends (guests) indirectly
     38    call these functions via guest helper calls.  By putting them here,
     39    code duplication is avoided.  Some of these functions are tricky
     40    and hard to verify, so there is much to be said for only having one
     41    copy thereof.
     42 */
     43 
     44 #ifndef __VEX_GUEST_GENERIC_X87_H
     45 #define __VEX_GUEST_GENERIC_X87_H
     46 
     47 #include "libvex_basictypes.h"
     48 
     49 
     50 /* Convert an IEEE754 double (64-bit) into an x87 extended double
     51    (80-bit), mimicing the hardware fairly closely.  Both numbers are
     52    stored little-endian.  Limitations, all of which could be fixed,
     53    given some level of hassle:
     54 
     55    * Identity of NaNs is not preserved.
     56 
     57    See comments in the code for more details.
     58 */
     59 extern
     60 void convert_f64le_to_f80le ( /*IN*/UChar* f64, /*OUT*/UChar* f80 );
     61 
     62 
     63 /* Convert an x87 extended double (80-bit) into an IEEE 754 double
     64    (64-bit), mimicking the hardware fairly closely.  Both numbers are
     65    stored little-endian.  Limitations, both of which could be fixed,
     66    given some level of hassle:
     67 
     68    * Rounding following truncation could be a bit better.
     69 
     70    * Identity of NaNs is not preserved.
     71 
     72    See comments in the code for more details.
     73 */
     74 extern
     75 void convert_f80le_to_f64le ( /*IN*/UChar* f80, /*OUT*/UChar* f64 );
     76 
     77 
     78 /* Layout of the real x87 state. */
     79 typedef
     80    struct {
     81       UShort env[14];
     82       UChar  reg[80];
     83    }
     84    Fpu_State;
     85 
     86 /* Offsets, in 16-bit ints, into the FPU environment (env) area. */
     87 #define FP_ENV_CTRL   0
     88 #define FP_ENV_STAT   2
     89 #define FP_ENV_TAG    4
     90 #define FP_ENV_IP     6 /* and 7 */
     91 #define FP_ENV_CS     8
     92 #define FP_ENV_OPOFF  10 /* and 11 */
     93 #define FP_ENV_OPSEL  12
     94 #define FP_REG(ii)    (10*(7-(ii)))
     95 
     96 
     97 /* Do the computations for x86/amd64 FXTRACT.  Called directly from
     98    generated code.  CLEAN HELPER. */
     99 extern ULong x86amd64g_calculate_FXTRACT ( ULong arg, HWord getExp );
    100 
    101 /* Compute result and new OSZACP flags for all PCMP{E,I}STR{I,M}
    102    variants.  See bigger comment on implementation of this function
    103    for details on call/return conventions. */
    104 extern Bool compute_PCMPxSTRx ( /*OUT*/V128* resV,
    105                                 /*OUT*/UInt* resOSZACP,
    106                                 V128* argLV,  V128* argRV,
    107                                 UInt zmaskL, UInt zmaskR,
    108                                 UInt imm8,   Bool isxSTRM );
    109 
    110 #endif /* ndef __VEX_GUEST_GENERIC_X87_H */
    111 
    112 /*---------------------------------------------------------------*/
    113 /*--- end                                 guest_generic_x87.h ---*/
    114 /*---------------------------------------------------------------*/
    115