ShuriZma
/
Cxbx-Reloaded
mirror of https://github.com/Cxbx-Reloaded/Cxbx-Reloaded.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

X86 : Implemented NEG opcode

This commit is contained in:
PatrickvL 2018-09-24 12:52:31 +02:00
parent 17fdc8e01d
commit 9487ec09a7
1 changed files with 31 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
src/CxbxKrnl/EmuX86.cpp
View File

@ -1016,6 +1016,34 @@ bool EmuX86_Opcode_MOVZX(LPEXCEPTION_POINTERS e, _DInst& info)
return true;
}
bool EmuX86_Opcode_NEG(LPEXCEPTION_POINTERS e, _DInst& info)
{
// NEG reads and writes the same operand :
OperandAddress opAddr;
if (!EmuX86_Operand_Addr_ForReadWrite(e, info, 0, OUT opAddr))
return false;
uint32_t dest = EmuX86_Addr_Read(opAddr);
uint32_t src = dest;
// NEG Destination
uint32_t result = 0-dest;
// Write back the result
EmuX86_Addr_Write(opAddr, result);
// The OF, SF, ZF, AF, CF, and PF flags are set according to the result.
EmuX86_SetFlags_OSZAPC(e,
/*EMUX86_EFLAG_OF*/OF_Sub(result, src, dest),
/*EMUX86_EFLAG_SF*/SFCalc(result),
/*EMUX86_EFLAG_ZF*/ZFCalc(result),
/*EMUX86_EFLAG_AF*/AFCalc(result, src, dest),
/*EMUX86_EFLAG_PF*/PFCalc(result),
/*EMUX86_EFLAG_CF*/(dest != 0));
return true;
}
bool EmuX86_Opcode_NOT(LPEXCEPTION_POINTERS e, _DInst& info)
{
// NOT reads and writes the same operand :
@ -2783,6 +2811,9 @@ bool EmuX86_DecodeException(LPEXCEPTION_POINTERS e)
case I_MOVZX:
if (EmuX86_Opcode_MOVZX(e, info)) break;
goto opcode_error;
case I_NEG:
if (EmuX86_Opcode_NEG(e, info)) break;
goto opcode_error;
case I_NOT:
if (EmuX86_Opcode_NOT(e, info)) break;
goto opcode_error;