Skip to content

Commit

Permalink
targets/x86_64: Set equivalencePtr. for branches/phis
Browse files Browse the repository at this point in the history
  • Loading branch information
@avdgrinten
avdgrinten committed Mar 16, 2019
1 parent 648ce8f commit 293b7f5
Showing 1 changed file with 51 additions and 37 deletions.
88 changes: 51 additions & 37 deletions lib/target-x86_64/alloc-regs.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -207,7 +207,7 @@ struct MoveChain {
bool isTarget = false;

// Index of the corresponding PseudoMoveMultiple operand.
int operandIndex = -1;
std::vector<int> indicesOfTarget;

MoveChain *uniqueSource = nullptr;

Expand Down Expand Up @@ -711,6 +711,7 @@ void AllocateRegistersImpl::_collectBlockIntervals(BasicBlock *bb) {
auto nodeCompound = _phiCompounds.at(edges[i]->sink()->phiNode());
auto sourceInterval = new LiveInterval;
nodeCompound->intervals.push_back(sourceInterval);
sourceInterval->equivalencePointer = intervalMap.at(originalAlias)->equivalencePointer;
sourceInterval->associatedValue = pseudoMoveResult;
sourceInterval->compound = nodeCompound;
assert(sourceInterval->associatedValue);
Expand Down Expand Up @@ -739,6 +740,7 @@ void AllocateRegistersImpl::_collectBlockIntervals(BasicBlock *bb) {

auto copyInterval = new LiveInterval;
copyCompound->intervals.push_back(copyInterval);
copyInterval->equivalencePointer = intervalMap.at(originalOperand)->equivalencePointer;
copyInterval->associatedValue = pseudoMoveResult;
copyInterval->compound = copyCompound;
copyInterval->originPc = ProgramCounter{bb, inBlock, pseudoMove, afterInstruction};
Expand All @@ -759,6 +761,7 @@ void AllocateRegistersImpl::_collectBlockIntervals(BasicBlock *bb) {

auto copyInterval = new LiveInterval;
copyCompound->intervals.push_back(copyInterval);
copyInterval->equivalencePointer = intervalMap.at(originalOperand)->equivalencePointer;
copyInterval->associatedValue = pseudoMoveResult;
copyInterval->compound = copyCompound;
copyInterval->originPc = ProgramCounter{bb, inBlock, pseudoMove, afterInstruction};
Expand Down Expand Up @@ -967,10 +970,16 @@ void AllocateRegistersImpl::_establishAllocation(BasicBlock *bb) {
auto operandChain = &chains[operandRegister];
auto resultChain = &chains[resultRegister];

assert(!resultChain->uniqueSource);
resultChain->isTarget = true;
resultChain->operandIndex = i;
resultChain->uniqueSource = operandChain;
resultChain->indicesOfTarget.push_back(i);
if (!resultChain->uniqueSource) {
resultChain->uniqueSource = operandChain;
} else {
// If there are multiple moves to the same target,
// the source registers must be identical.
// TODO: Lift this restriction.
assert(resultChain->uniqueSource == operandChain);
}

operandChain->isSource = true;
operandChain->pendingMovesFromThisSource++;
Expand All @@ -981,39 +990,44 @@ void AllocateRegistersImpl::_establishAllocation(BasicBlock *bb) {

// Helper function to emit a single move of a move chain.
auto emitMoveToChain = [&] (MoveChain *targetChain) {
auto index = targetChain->operandIndex;
auto srcChain = targetChain->uniqueSource;
assert(!targetChain->didMoveToThisTarget);
assert(srcChain->pendingMovesFromThisSource > 0);

auto operandInterval = liveMap.at(pseudoMoveMultiple->operand(index).get());
auto resultInterval = resultMap.at(pseudoMoveMultiple->result(index).get());
assert(operandInterval->compound->allocatedRegister == chainRegister(srcChain));
assert(resultInterval->compound->allocatedRegister == chainRegister(targetChain));

// Emit the new move instruction.
auto move = std::make_unique<MovMRInstruction>(
pseudoMoveMultiple->operand(index).get());
auto moveResult = pseudoMoveMultiple->result(index).reset();
pseudoMoveMultiple->operand(index) = nullptr;
move->result.set(std::move(moveResult));

fixMoveIntervals(operandInterval, resultInterval, move.get());
bb->insertInstruction(it, std::move(move));
_numRegisterMoves++;

// Update the MoveChain structs.
targetChain->didMoveToThisTarget = true;

srcChain->pendingMovesFromThisSource--;
if (srcChain->isTail())
activeTails.push_back(srcChain);

auto cycleChain = srcChain->cyclePointer;
if(cycleChain && cycleChain != targetChain->cyclePointer) {
cycleChain->pendingMovesFromThisCycle--;
if (!cycleChain->pendingMovesFromThisCycle)
activeCycles.push_back(cycleChain);
// TODO: This generates duplicate moves.
// Introduce a VirtualAlias instruction to alias all sources/results.
std::cout << " There are " << targetChain->indicesOfTarget.size()
<< " moves to target register " << chainRegister(targetChain) << std::endl;
for (int index : targetChain->indicesOfTarget) {
auto srcChain = targetChain->uniqueSource;
assert(!targetChain->didMoveToThisTarget);
assert(srcChain->pendingMovesFromThisSource > 0);

auto operandInterval = liveMap.at(pseudoMoveMultiple->operand(index).get());
auto resultInterval = resultMap.at(pseudoMoveMultiple->result(index).get());
assert(operandInterval->compound->allocatedRegister == chainRegister(srcChain));
assert(resultInterval->compound->allocatedRegister == chainRegister(targetChain));

// Emit the new move instruction.
auto move = std::make_unique<MovMRInstruction>(
pseudoMoveMultiple->operand(index).get());
auto moveResult = pseudoMoveMultiple->result(index).reset();
pseudoMoveMultiple->operand(index) = nullptr;
move->result.set(std::move(moveResult));

fixMoveIntervals(operandInterval, resultInterval, move.get());
bb->insertInstruction(it, std::move(move));
_numRegisterMoves++;

// Update the MoveChain structs.
targetChain->didMoveToThisTarget = true;

srcChain->pendingMovesFromThisSource--;
if (srcChain->isTail())
activeTails.push_back(srcChain);

auto cycleChain = srcChain->cyclePointer;
if(cycleChain && cycleChain != targetChain->cyclePointer) {
cycleChain->pendingMovesFromThisCycle--;
if (!cycleChain->pendingMovesFromThisCycle)
activeCycles.push_back(cycleChain);
}
}
};

Expand Down

0 comments on commit 293b7f5

Please sign in to comment.