Files
FEX-Emu--FEX/Source/Interface/IR/Passes/RedundantFlagCalculationElimination.cpp
T
Ryan Houdek 199cfd76d8 Refactor IR and other changes that are hard to split
I had to change how blocks are represented to make it easier to parse
This required a fairly substantial refactor that makes it so blocks are
represented differently and we can walk them sequentially.

This will make future analysis easier to deal with.
Had to rewrite the passes and core's parsing of the IR afterwards.

Moved RA in to a optimization pass to be shared between the JIT backends
This works because x86-64 and AArch64 RA can be identical.

Still doesn't support PHI nodes or spilling correctly, this is the first
step in the process of getting there.
2020-03-06 07:55:13 +02:00

86 lines
2.6 KiB
C++

#include "Interface/IR/PassManager.h"
#include "Interface/Core/OpcodeDispatcher.h"
namespace FEXCore::IR {
class RedundantFlagCalculationEliminination final : public FEXCore::IR::Pass {
public:
bool Run(OpDispatchBuilder *Disp) override;
};
bool RedundantFlagCalculationEliminination::Run(OpDispatchBuilder *Disp) {
std::array<OrderedNode*, 32> LastValidFlagStores{};
bool Changed = false;
auto CurrentIR = Disp->ViewIR();
uintptr_t ListBegin = CurrentIR.GetListData();
uintptr_t DataBegin = CurrentIR.GetData();
auto Begin = CurrentIR.begin();
auto Op = Begin();
OrderedNode *RealNode = Op->GetNode(ListBegin);
auto HeaderOp = RealNode->Op(DataBegin)->CW<FEXCore::IR::IROp_IRHeader>();
LogMan::Throw::A(HeaderOp->Header.Op == OP_IRHEADER, "First op wasn't IRHeader");
OrderedNode *BlockNode = HeaderOp->Blocks.GetNode(ListBegin);
while (1) {
auto BlockIROp = BlockNode->Op(DataBegin)->CW<FEXCore::IR::IROp_CodeBlock>();
LogMan::Throw::A(BlockIROp->Header.Op == OP_CODEBLOCK, "IR type failed to be a code block");
// We grab these nodes this way so we can iterate easily
auto CodeBegin = CurrentIR.at(BlockIROp->Begin);
auto CodeLast = CurrentIR.at(BlockIROp->Last);
while (1) {
auto CodeOp = CodeBegin();
OrderedNode *CodeNode = CodeOp->GetNode(ListBegin);
auto IROp = CodeNode->Op(DataBegin);
if (IROp->Op == OP_STOREFLAG) {
auto Op = IROp->CW<IR::IROp_StoreFlag>();
// If we have had a valid flag store previously and it hasn't been touched until this new store
// Then just delete the old one and let DCE to take care of the rest
if (LastValidFlagStores[Op->Flag] != nullptr) {
Disp->Unlink(LastValidFlagStores[Op->Flag]);
Changed = true;
}
// Set this node as the last one valid for this flag
LastValidFlagStores[Op->Flag] = RealNode;
}
else if (IROp->Op == OP_LOADFLAG) {
auto Op = IROp->CW<IR::IROp_LoadFlag>();
// If we loaded a flag then we can't track past this
LastValidFlagStores[Op->Flag] = nullptr;
}
// CodeLast is inclusive. So we still need to dump the CodeLast op as well
if (CodeBegin == CodeLast) {
break;
}
++CodeBegin;
}
if (BlockIROp->Next.ID() == 0) {
break;
} else {
BlockNode = BlockIROp->Next.GetNode(ListBegin);
}
// We don't track across block boundaries
LastValidFlagStores.fill(nullptr);
}
return Changed;
}
FEXCore::IR::Pass* CreateRedundantFlagCalculationEliminination() {
return new RedundantFlagCalculationEliminination{};
}
}