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Implements 32-bit iret instruction

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This is necessary for wine and some wine-like emulation layers.

With this implemented then some Saint's Row games start running.

Fixes #1100
This commit is contained in:
Ryan Houdek 2021-06-21 00:20:44 -07:00
parent 424b93b5f8
commit d587485383
1 changed files with 16 additions and 10 deletions
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26
External/FEXCore/Source/Interface/Core/OpcodeDispatcher.cpp vendored
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@ -178,6 +178,7 @@ void OpDispatchBuilder::RETOp(OpcodeArgs) {
/*
stack contains:
Size of each member is 64-bit, 32-bit, or 16-bit depending on operating size
RIP
CS
EFLAGS
@ -185,8 +186,9 @@ RSP
SS
*/
void OpDispatchBuilder::IRETOp(OpcodeArgs) {
if (CTX->Config.Is64BitMode == false) {
LogMan::Msg::E("IRET only implemented for x64");
// Operand Size override unsupported!
if ((Op->Flags & X86Tables::DecodeFlags::FLAG_OPERAND_SIZE) != 0) {
LogMan::Msg::E("IRET only implemented for 64bit and 32bit sizes");
DecodeFailure = true;
return;
}
@ -197,7 +199,7 @@ void OpDispatchBuilder::IRETOp(OpcodeArgs) {
OrderedNode* SP = _LoadContext(GPRSize, offsetof(FEXCore::Core::CPUState, gregs[FEXCore::X86State::REG_RSP]), GPRClass);
// RIP (64 bits)
// RIP (64/32/16 bits)
auto NewRIP = _LoadMem(GPRClass, GPRSize, SP, GPRSize);
SP = _Add(SP, Constant);
//CS (lower 16 used)
@ -206,13 +208,17 @@ void OpDispatchBuilder::IRETOp(OpcodeArgs) {
//eflags (lower 16 used)
auto eflags = _LoadMem(GPRClass, GPRSize, SP, GPRSize);
SetPackedRFLAG(false, eflags);
SP = _Add(SP, Constant);
// RSP
_StoreContext(GPRClass, GPRSize, offsetof(FEXCore::Core::CPUState, gregs[FEXCore::X86State::REG_RSP]), _LoadMem(GPRClass, GPRSize, SP, GPRSize));
SP = _Add(SP, Constant);
//ss
_StoreContext(GPRClass, 2, offsetof(FEXCore::Core::CPUState, ss), _LoadMem(GPRClass, GPRSize, SP, GPRSize));
SP = _Add(SP, Constant);
if (CTX->Config.Is64BitMode) {
// RSP and SS only happen in 64-bit mode or if this is a CPL mode jump!
SP = _Add(SP, Constant);
// RSP
_StoreContext(GPRClass, GPRSize, offsetof(FEXCore::Core::CPUState, gregs[FEXCore::X86State::REG_RSP]), _LoadMem(GPRClass, GPRSize, SP, GPRSize));
SP = _Add(SP, Constant);
//ss
_StoreContext(GPRClass, 2, offsetof(FEXCore::Core::CPUState, ss), _LoadMem(GPRClass, GPRSize, SP, GPRSize));
SP = _Add(SP, Constant);
}
_ExitFunction(NewRIP);
BlockSetRIP = true;