fpu/fpu_misc.cc

   1 /////////////////////////////////////////////////////////////////////////
   2 // $Id: fpu_misc.cc,v 1.13 2008/04/04 21:05:37 sshwarts Exp $
   3 /////////////////////////////////////////////////////////////////////////
   4 //
   5 //   Copyright (c) 2003 Stanislav Shwartsman
   6 //          Written by Stanislav Shwartsman [sshwarts at sourceforge net]
   7 //
   8 //  This library is free software; you can redistribute it and/or
   9 //  modify it under the terms of the GNU Lesser General Public
  10 //  License as published by the Free Software Foundation; either
  11 //  version 2 of the License, or (at your option) any later version.
  12 //
  13 //  This library is distributed in the hope that it will be useful,
  14 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 //  Lesser General Public License for more details.
  17 //
  18 //  You should have received a copy of the GNU Lesser General Public
  19 //  License along with this library; if not, write to the Free Software
  20 //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  21 //
  22 /////////////////////////////////////////////////////////////////////////
  23
  24 #define NEED_CPU_REG_SHORTCUTS 1
  25 #include "bochs.h"
  26 #include "cpu/cpu.h"
  27 #define LOG_THIS BX_CPU_THIS_PTR
  28
  29 #if BX_SUPPORT_FPU
  30
  31 #include "softfloatx80.h"
  32
  33 /* D9 C8 */
  34 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FXCH_STi(bxInstruction_c *i)
  35 {
  36 #if BX_SUPPORT_FPU
  37   BX_CPU_THIS_PTR prepareFPU(i);
  38
  39   int st0_tag = BX_CPU_THIS_PTR the_i387.FPU_gettagi(0);
  40   int sti_tag = BX_CPU_THIS_PTR the_i387.FPU_gettagi(i->rm());
  41
  42   floatx80 st0_reg = BX_READ_FPU_REG(0);
  43   floatx80 sti_reg = BX_READ_FPU_REG(i->rm());
  44
  45   clear_C1();
  46
  47   if (st0_tag == FPU_Tag_Empty || sti_tag == FPU_Tag_Empty)
  48   {
  49       BX_CPU_THIS_PTR FPU_exception(FPU_EX_Stack_Underflow);
  50
  51       if(BX_CPU_THIS_PTR the_i387.is_IA_masked())
  52       {
  53           /* Masked response */
  54           if (st0_tag == FPU_Tag_Empty)
  55           {
  56               st0_reg = floatx80_default_nan;
  57               st0_tag = FPU_Tag_Special;
  58           }
  59           if (sti_tag == FPU_Tag_Empty)
  60           {
  61               sti_reg = floatx80_default_nan;
  62               sti_tag = FPU_Tag_Special;
  63           }
  64       }
  65       else return;
  66   }
  67
  68   BX_WRITE_FPU_REGISTER_AND_TAG(st0_reg, st0_tag, i->rm());
  69   BX_WRITE_FPU_REGISTER_AND_TAG(sti_reg, sti_tag, 0);
  70 #else
  71   BX_INFO(("FXCH_STi: required FPU, configure --enable-fpu"));
  72 #endif
  73 }
  74
  75 /* D9 E0 */
  76 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FCHS(bxInstruction_c *i)
  77 {
  78 #if BX_SUPPORT_FPU
  79   BX_CPU_THIS_PTR prepareFPU(i);
  80
  81   int st0_tag = BX_CPU_THIS_PTR the_i387.FPU_gettagi(0);
  82   if (st0_tag == FPU_Tag_Empty)
  83   {
  84       BX_CPU_THIS_PTR FPU_stack_underflow(0);
  85       return;
  86   }
  87
  88   clear_C1();
  89
  90   floatx80 st0_reg = BX_READ_FPU_REG(0);
  91   BX_WRITE_FPU_REGISTER_AND_TAG(floatx80_chs(st0_reg), st0_tag, 0);
  92 #else
  93   BX_INFO(("FCHS: required FPU, configure --enable-fpu"));
  94 #endif
  95 }
  96
  97 /* D9 E1 */
  98 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FABS(bxInstruction_c *i)
  99 {
 100 #if BX_SUPPORT_FPU
 101   BX_CPU_THIS_PTR prepareFPU(i);
 102
 103   int st0_tag = BX_CPU_THIS_PTR the_i387.FPU_gettagi(0);
 104   if (st0_tag == FPU_Tag_Empty)
 105   {
 106       BX_CPU_THIS_PTR FPU_stack_underflow(0);
 107       return;
 108   }
 109
 110   clear_C1();
 111
 112   floatx80 st0_reg = BX_READ_FPU_REG(0);
 113   BX_WRITE_FPU_REGISTER_AND_TAG(floatx80_abs(st0_reg), st0_tag, 0);
 114 #else
 115   BX_INFO(("FABS: required FPU, configure --enable-fpu"));
 116 #endif
 117 }
 118
 119 /* D9 F6 */
 120 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FDECSTP(bxInstruction_c *i)
 121 {
 122 #if BX_SUPPORT_FPU
 123   BX_CPU_THIS_PTR prepareFPU(i);
 124
 125   clear_C1();
 126
 127   BX_CPU_THIS_PTR the_i387.tos = (BX_CPU_THIS_PTR the_i387.tos-1) & 7;
 128 #else
 129   BX_INFO(("FDECSTP: required FPU, configure --enable-fpu"));
 130 #endif
 131 }
 132
 133 /* D9 F7 */
 134 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FINCSTP(bxInstruction_c *i)
 135 {
 136 #if BX_SUPPORT_FPU
 137   BX_CPU_THIS_PTR prepareFPU(i);
 138
 139   clear_C1();
 140
 141   BX_CPU_THIS_PTR the_i387.tos = (BX_CPU_THIS_PTR the_i387.tos+1) & 7;
 142 #else
 143   BX_INFO(("FINCSTP: required FPU, configure --enable-fpu"));
 144 #endif
 145 }
 146
 147 /* DD C0 */
 148 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FFREE_STi(bxInstruction_c *i)
 149 {
 150 #if BX_SUPPORT_FPU
 151   BX_CPU_THIS_PTR prepareFPU(i);
 152   BX_CPU_THIS_PTR the_i387.FPU_settagi(FPU_Tag_Empty, i->rm());
 153 #else
 154   BX_INFO(("FFREE_STi: required FPU, configure --enable-fpu"));
 155 #endif
 156 }
 157
 158 /*
 159  * Free the st(0) register and pop it from the FPU stack.
 160  * "Undocumented" by Intel & AMD but mentioned in AMDs Athlon Docs.
 161  */
 162
 163 /* DF C0 */
 164 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FFREEP_STi(bxInstruction_c *i)
 165 {
 166 #if BX_SUPPORT_FPU
 167   BX_CPU_THIS_PTR prepareFPU(i);
 168   BX_CPU_THIS_PTR the_i387.FPU_settagi(FPU_Tag_Empty, i->rm());
 169   BX_CPU_THIS_PTR the_i387.FPU_pop();
 170 #else
 171   BX_INFO(("FFREEP_STi: required FPU, configure --enable-fpu"));
 172 #endif
 173 }
 174
 175 #endif