fpu/fpu_misc.cc

   1 /////////////////////////////////////////////////////////////////////////
   2 // $Id: fpu_misc.cc,v 1.14 2008/05/10 13:34:01 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               st0_reg = floatx80_default_nan;
  56
  57           if (sti_tag == FPU_Tag_Empty)
  58               sti_reg = floatx80_default_nan;
  59       }
  60       else return;
  61   }
  62
  63   BX_WRITE_FPU_REG(st0_reg, i->rm());
  64   BX_WRITE_FPU_REG(sti_reg, 0);
  65 #else
  66   BX_INFO(("FXCH_STi: required FPU, configure --enable-fpu"));
  67 #endif
  68 }
  69
  70 /* D9 E0 */
  71 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FCHS(bxInstruction_c *i)
  72 {
  73 #if BX_SUPPORT_FPU
  74   BX_CPU_THIS_PTR prepareFPU(i);
  75
  76   if (IS_TAG_EMPTY(0)) {
  77       BX_CPU_THIS_PTR FPU_stack_underflow(0);
  78       return;
  79   }
  80
  81   clear_C1();
  82
  83   floatx80 st0_reg = BX_READ_FPU_REG(0);
  84   BX_WRITE_FPU_REG(floatx80_chs(st0_reg), 0);
  85 #else
  86   BX_INFO(("FCHS: required FPU, configure --enable-fpu"));
  87 #endif
  88 }
  89
  90 /* D9 E1 */
  91 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FABS(bxInstruction_c *i)
  92 {
  93 #if BX_SUPPORT_FPU
  94   BX_CPU_THIS_PTR prepareFPU(i);
  95
  96   if (IS_TAG_EMPTY(0)) {
  97       BX_CPU_THIS_PTR FPU_stack_underflow(0);
  98       return;
  99   }
 100
 101   clear_C1();
 102
 103   floatx80 st0_reg = BX_READ_FPU_REG(0);
 104   BX_WRITE_FPU_REG(floatx80_abs(st0_reg), 0);
 105 #else
 106   BX_INFO(("FABS: required FPU, configure --enable-fpu"));
 107 #endif
 108 }
 109
 110 /* D9 F6 */
 111 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FDECSTP(bxInstruction_c *i)
 112 {
 113 #if BX_SUPPORT_FPU
 114   BX_CPU_THIS_PTR prepareFPU(i);
 115
 116   clear_C1();
 117
 118   BX_CPU_THIS_PTR the_i387.tos = (BX_CPU_THIS_PTR the_i387.tos-1) & 7;
 119 #else
 120   BX_INFO(("FDECSTP: required FPU, configure --enable-fpu"));
 121 #endif
 122 }
 123
 124 /* D9 F7 */
 125 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FINCSTP(bxInstruction_c *i)
 126 {
 127 #if BX_SUPPORT_FPU
 128   BX_CPU_THIS_PTR prepareFPU(i);
 129
 130   clear_C1();
 131
 132   BX_CPU_THIS_PTR the_i387.tos = (BX_CPU_THIS_PTR the_i387.tos+1) & 7;
 133 #else
 134   BX_INFO(("FINCSTP: required FPU, configure --enable-fpu"));
 135 #endif
 136 }
 137
 138 /* DD C0 */
 139 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FFREE_STi(bxInstruction_c *i)
 140 {
 141 #if BX_SUPPORT_FPU
 142   BX_CPU_THIS_PTR prepareFPU(i);
 143   BX_CPU_THIS_PTR the_i387.FPU_settagi(FPU_Tag_Empty, i->rm());
 144 #else
 145   BX_INFO(("FFREE_STi: required FPU, configure --enable-fpu"));
 146 #endif
 147 }
 148
 149 /*
 150  * Free the st(0) register and pop it from the FPU stack.
 151  * "Undocumented" by Intel & AMD but mentioned in AMDs Athlon Docs.
 152  */
 153
 154 /* DF C0 */
 155 void BX_CPP_AttrRegparmN(1) BX_CPU_C::FFREEP_STi(bxInstruction_c *i)
 156 {
 157 #if BX_SUPPORT_FPU
 158   BX_CPU_THIS_PTR prepareFPU(i);
 159   BX_CPU_THIS_PTR the_i387.FPU_settagi(FPU_Tag_Empty, i->rm());
 160   BX_CPU_THIS_PTR the_i387.FPU_pop();
 161 #else
 162   BX_INFO(("FFREEP_STi: required FPU, configure --enable-fpu"));
 163 #endif
 164 }
 165
 166 #endif