///////////////////////////////////////////////////////////////////////// // $Id: ferr.cc,v 1.7 2006-03-06 22:03:04 sshwarts Exp $ ///////////////////////////////////////////////////////////////////////// // // Copyright (c) 2003 Stanislav Shwartsman // Written by Stanislav Shwartsman // // This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 2 of the License, or (at your option) any later version. // // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA // ///////////////////////////////////////////////////////////////////////// #define NEED_CPU_REG_SHORTCUTS 1 #include "bochs.h" #include "cpu/cpu.h" #define LOG_THIS BX_CPU_THIS_PTR #if BX_SUPPORT_FPU #include "softfloat-specialize.h" void BX_CPU_C::FPU_stack_overflow(void) { /* The masked response */ if (BX_CPU_THIS_PTR the_i387.is_IA_masked()) { BX_CPU_THIS_PTR the_i387.FPU_push(); BX_WRITE_FPU_REGISTER_AND_TAG(floatx80_default_nan, FPU_Tag_Special, 0); } FPU_exception(FPU_EX_Stack_Overflow); } void BX_CPU_C::FPU_stack_underflow(int stnr, int pop_stack) { /* The masked response */ if (BX_CPU_THIS_PTR the_i387.is_IA_masked()) { BX_WRITE_FPU_REGISTER_AND_TAG(floatx80_default_nan, FPU_Tag_Special, stnr); if (pop_stack) BX_CPU_THIS_PTR the_i387.FPU_pop(); } FPU_exception(FPU_EX_Stack_Underflow); } /* Returns 1 if unmasked exception occured */ int BX_CPU_C::FPU_exception(int exception) { int unmasked = 0; /* Extract only the bits which we use to set the status word */ exception &= (FPU_SW_Exceptions_Mask); /* Set the corresponding exception bits */ FPU_PARTIAL_STATUS |= exception; /* Set summary bits iff exception isn't masked */ if (FPU_PARTIAL_STATUS & ~FPU_CONTROL_WORD & FPU_CW_Exceptions_Mask) { FPU_PARTIAL_STATUS |= (FPU_SW_Summary | FPU_SW_Backward); unmasked = 1; } if (exception & (FPU_SW_Stack_Fault | FPU_EX_Precision)) { if (! (exception & FPU_SW_C1)) /* This bit distinguishes over- from underflow for a stack fault, and roundup from round-down for precision loss. */ FPU_PARTIAL_STATUS &= ~FPU_SW_C1; } return unmasked; } #endif