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Fi CMPXCHG

This commit is contained in:
Luke Usher 2018-09-25 22:24:36 +01:00
parent bf9b7a26f6
commit 427cf4e513
1 changed files with 15 additions and 8 deletions
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23
src/CxbxKrnl/EmuX86.cpp
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@ -816,16 +816,24 @@ bool EmuX86_Opcode_CMPXCHG(LPEXCEPTION_POINTERS e, _DInst& info)
if (!EmuX86_Operand_Read(e, info, 0, &dest))
return false;
if (src == dest) {
// Setup read/write to EAX
// Write the destination operand into EAX
OperandAddress eaxOpAddr;
eaxOpAddr.addr = (uint32_t)EmuX86_GetRegisterPointer(e, R_EAX);
eaxOpAddr.is_internal_addr = true;
eaxOpAddr.is_register = true;
eaxOpAddr.size = info.ops[1].size;
uint32_t eaxVal = EmuX86_Addr_Read(eaxOpAddr);
if (eaxVal == dest) {
// Write the source value to the destination operand
if (!EmuX86_Operand_Write(e, info, 0, src)) {
return false;
}
} else {
// Write the dest value to the source operand
if (!EmuX86_Operand_Write(e, info, 1, dest)) {
return false;
}
// Write the desintation operand to eax
EmuX86_Addr_Write(eaxOpAddr, dest);
}
// Perform arithmatic operation for flag calculation
@ -833,8 +841,8 @@ bool EmuX86_Opcode_CMPXCHG(LPEXCEPTION_POINTERS e, _DInst& info)
__asm {
push eflags // push context eflags on the stack
popfd // pop context eflags into host eflags
mov eax, dest
cmp eax, src // perform the operation, this updates eflags for us!
mov eax, eaxVal
cmp eax, dest // perform the operation, this updates eflags for us!
pushfd // push the updated host flags onto the stack
pop eflags // pop the updated host flags back into our eflags register
}
@ -1451,7 +1459,6 @@ bool EmuX86_Opcode_TEST(LPEXCEPTION_POINTERS e, _DInst& info)
popfd // pop context eflags into host eflags
mov eax, dest
test eax, src // perform the operation, this updates eflags for us!
mov result, eax
pushfd // push the updated host flags onto the stack
pop eflags // pop the updated host flags back into our eflags register
}