STATISTIC(StatepointMaxSlotsRequired,
"Maximum number of stack slots required for a singe statepoint");
-void
-StatepointLoweringState::startNewStatepoint(SelectionDAGBuilder &Builder) {
+void StatepointLoweringState::startNewStatepoint(SelectionDAGBuilder &Builder) {
// Consistency check
assert(PendingGCRelocateCalls.empty() &&
"Trying to visit statepoint before finished processing previous one");
/// Extract call from statepoint, lower it and return pointer to the
/// call node. Also update NodeMap so that getValue(statepoint) will
/// reference lowered call result
-static SDNode *lowerCallFromStatepoint(const CallInst &CI,
- SelectionDAGBuilder &Builder) {
-
- assert(Intrinsic::experimental_gc_statepoint ==
- dyn_cast<IntrinsicInst>(&CI)->getIntrinsicID() &&
- "function called must be the statepoint function");
+static SDNode *
+lowerCallFromStatepoint(ImmutableStatepoint ISP, MachineBasicBlock *LandingPad,
+ SelectionDAGBuilder &Builder,
+ SmallVectorImpl<SDValue> &PendingExports) {
+
+ ImmutableCallSite CS(ISP.getCallSite());
+
+ SDValue ActualCallee = Builder.getValue(ISP.getActualCallee());
+
+ // Handle immediate and symbolic callees.
+ if (auto *ConstCallee = dyn_cast<ConstantSDNode>(ActualCallee.getNode()))
+ ActualCallee = Builder.DAG.getIntPtrConstant(ConstCallee->getZExtValue(),
+ Builder.getCurSDLoc(),
+ /*isTarget=*/true);
+ else if (auto *SymbolicCallee =
+ dyn_cast<GlobalAddressSDNode>(ActualCallee.getNode()))
+ ActualCallee = Builder.DAG.getTargetGlobalAddress(
+ SymbolicCallee->getGlobal(), SDLoc(SymbolicCallee),
+ SymbolicCallee->getValueType(0));
+
+ assert(CS.getCallingConv() != CallingConv::AnyReg &&
+ "anyregcc is not supported on statepoints!");
+
+ Type *DefTy = ISP.getActualReturnType();
+ bool HasDef = !DefTy->isVoidTy();
+
+ SDValue ReturnValue, CallEndVal;
+ std::tie(ReturnValue, CallEndVal) = Builder.lowerCallOperands(
+ ISP.getCallSite(), ImmutableStatepoint::CallArgsBeginPos,
+ ISP.getNumCallArgs(), ActualCallee, DefTy, LandingPad,
+ false /* IsPatchPoint */);
+
+ SDNode *CallEnd = CallEndVal.getNode();
+
+ // Get a call instruction from the call sequence chain. Tail calls are not
+ // allowed. The following code is essentially reverse engineering X86's
+ // LowerCallTo.
+ //
+ // We are expecting DAG to have the following form:
+ //
+ // ch = eh_label (only in case of invoke statepoint)
+ // ch, glue = callseq_start ch
+ // ch, glue = X86::Call ch, glue
+ // ch, glue = callseq_end ch, glue
+ // get_return_value ch, glue
+ //
+ // get_return_value can either be a CopyFromReg to grab the return value from
+ // %RAX, or it can be a LOAD to load a value returned by reference via a stack
+ // slot.
+
+ if (HasDef && (CallEnd->getOpcode() == ISD::CopyFromReg ||
+ CallEnd->getOpcode() == ISD::LOAD))
+ CallEnd = CallEnd->getOperand(0).getNode();
+
+ assert(CallEnd->getOpcode() == ISD::CALLSEQ_END && "expected!");
- ImmutableStatepoint StatepointOperands(&CI);
-
- // Lower the actual call itself - This is a bit of a hack, but we want to
- // avoid modifying the actual lowering code. This is similiar in intent to
- // the LowerCallOperands mechanism used by PATCHPOINT, but is structured
- // differently. Hopefully, this is slightly more robust w.r.t. calling
- // convention, return values, and other function attributes.
- Value *ActualCallee = const_cast<Value *>(StatepointOperands.actualCallee());
-
- std::vector<Value *> Args;
- CallInst::const_op_iterator arg_begin = StatepointOperands.call_args_begin();
- CallInst::const_op_iterator arg_end = StatepointOperands.call_args_end();
- Args.insert(Args.end(), arg_begin, arg_end);
- // TODO: remove the creation of a new instruction! We should not be
- // modifying the IR (even temporarily) at this point.
- CallInst *Tmp = CallInst::Create(ActualCallee, Args);
- Tmp->setTailCall(CI.isTailCall());
- Tmp->setCallingConv(CI.getCallingConv());
- Tmp->setAttributes(CI.getAttributes());
- Builder.LowerCallTo(Tmp, Builder.getValue(ActualCallee), false);
-
- // Handle the return value of the call iff any.
- const bool HasDef = !Tmp->getType()->isVoidTy();
if (HasDef) {
- // The value of the statepoint itself will be the value of call itself.
- // We'll replace the actually call node shortly. gc_result will grab
- // this value.
- Builder.setValue(&CI, Builder.getValue(Tmp));
+ if (CS.isInvoke()) {
+ // Result value will be used in different basic block for invokes
+ // so we need to export it now. But statepoint call has a different type
+ // than the actuall call. It means that standart exporting mechanism will
+ // create register of the wrong type. So instead we need to create
+ // register with correct type and save value into it manually.
+ // TODO: To eliminate this problem we can remove gc.result intrinsics
+ // completelly and make statepoint call to return a tuple.
+ unsigned Reg = Builder.FuncInfo.CreateRegs(ISP.getActualReturnType());
+ RegsForValue RFV(*Builder.DAG.getContext(),
+ Builder.DAG.getTargetLoweringInfo(), Reg,
+ ISP.getActualReturnType());
+ SDValue Chain = Builder.DAG.getEntryNode();
+
+ RFV.getCopyToRegs(ReturnValue, Builder.DAG, Builder.getCurSDLoc(), Chain,
+ nullptr);
+ PendingExports.push_back(Chain);
+ Builder.FuncInfo.ValueMap[CS.getInstruction()] = Reg;
+ } else {
+ // The value of the statepoint itself will be the value of call itself.
+ // We'll replace the actually call node shortly. gc_result will grab
+ // this value.
+ Builder.setValue(CS.getInstruction(), ReturnValue);
+ }
} else {
// The token value is never used from here on, just generate a poison value
- Builder.setValue(&CI, Builder.DAG.getIntPtrConstant(-1));
+ Builder.setValue(CS.getInstruction(),
+ Builder.DAG.getIntPtrConstant(-1, Builder.getCurSDLoc()));
}
- // Remove the fake entry we created so we don't have a hanging reference
- // after we delete this node.
- Builder.removeValue(Tmp);
- delete Tmp;
- Tmp = nullptr;
-
- // Search for the call node
- // The following code is essentially reverse engineering X86's
- // LowerCallTo.
- SDNode *CallNode = nullptr;
-
- // We just emitted a call, so it should be last thing generated
- SDValue Chain = Builder.DAG.getRoot();
-
- // Find closest CALLSEQ_END walking back through lowered nodes if needed
- SDNode *CallEnd = Chain.getNode();
- int Sanity = 0;
- while (CallEnd->getOpcode() != ISD::CALLSEQ_END) {
- CallEnd = CallEnd->getGluedNode();
- assert(CallEnd && "Can not find call node");
- assert(Sanity < 20 && "should have found call end already");
- Sanity++;
- }
- assert(CallEnd->getOpcode() == ISD::CALLSEQ_END &&
- "Expected a callseq node.");
- assert(CallEnd->getGluedNode());
- // Step back inside the CALLSEQ
- CallNode = CallEnd->getGluedNode();
- return CallNode;
+ return CallEnd->getOperand(0).getNode();
}
/// Callect all gc pointers coming into statepoint intrinsic, clean them up,
/// Relocs - the gc_relocate corresponding to each base/ptr pair
/// Elements of this arrays should be in one-to-one correspondence with each
/// other i.e Bases[i], Ptrs[i] are from the same gcrelocate call
-static void
-getIncomingStatepointGCValues(SmallVectorImpl<const Value *> &Bases,
- SmallVectorImpl<const Value *> &Ptrs,
- SmallVectorImpl<const Value *> &Relocs,
- ImmutableCallSite Statepoint,
- SelectionDAGBuilder &Builder) {
- // Search for relocated pointers. Note that working backwards from the
- // gc_relocates ensures that we only get pairs which are actually relocated
- // and used after the statepoint.
- // TODO: This logic should probably become a utility function in Statepoint.h
- for (const User *U : cast<CallInst>(Statepoint.getInstruction())->users()) {
- if (!isGCRelocate(U)) {
- continue;
- }
- GCRelocateOperands relocateOpers(U);
- Relocs.push_back(cast<Value>(U));
- Bases.push_back(relocateOpers.basePtr());
- Ptrs.push_back(relocateOpers.derivedPtr());
+static void getIncomingStatepointGCValues(
+ SmallVectorImpl<const Value *> &Bases, SmallVectorImpl<const Value *> &Ptrs,
+ SmallVectorImpl<const Value *> &Relocs, ImmutableStatepoint StatepointSite,
+ SelectionDAGBuilder &Builder) {
+ for (GCRelocateOperands relocateOpers :
+ StatepointSite.getRelocates(StatepointSite)) {
+ Relocs.push_back(relocateOpers.getUnderlyingCallSite().getInstruction());
+ Bases.push_back(relocateOpers.getBasePtr());
+ Ptrs.push_back(relocateOpers.getDerivedPtr());
}
// Remove any redundant llvm::Values which map to the same SDValue as another
// such in the stackmap. This is required so that the consumer can
// parse any internal format to the deopt state. It also handles null
// pointers and other constant pointers in GC states
- Ops.push_back(
- Builder.DAG.getTargetConstant(StackMaps::ConstantOp, MVT::i64));
- Ops.push_back(Builder.DAG.getTargetConstant(C->getSExtValue(), MVT::i64));
+ Ops.push_back(Builder.DAG.getTargetConstant(StackMaps::ConstantOp,
+ Builder.getCurSDLoc(),
+ MVT::i64));
+ Ops.push_back(Builder.DAG.getTargetConstant(C->getSExtValue(),
+ Builder.getCurSDLoc(),
+ MVT::i64));
} else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Incoming)) {
- // This handles allocas as arguments to the statepoint
- const TargetLowering &TLI = Builder.DAG.getTargetLoweringInfo();
- Ops.push_back(
- Builder.DAG.getTargetFrameIndex(FI->getIndex(), TLI.getPointerTy()));
+ // This handles allocas as arguments to the statepoint (this is only
+ // really meaningful for a deopt value. For GC, we'd be trying to
+ // relocate the address of the alloca itself?)
+ Ops.push_back(Builder.DAG.getTargetFrameIndex(FI->getIndex(),
+ Incoming.getValueType()));
} else {
// Otherwise, locate a spill slot and explicitly spill it so it
// can be found by the runtime later. We currently do not support
/// statepoint. The chain nodes will have already been created and the DAG root
/// will be set to the last value spilled (if any were).
static void lowerStatepointMetaArgs(SmallVectorImpl<SDValue> &Ops,
- ImmutableStatepoint Statepoint,
+ ImmutableStatepoint StatepointSite,
SelectionDAGBuilder &Builder) {
// Lower the deopt and gc arguments for this statepoint. Layout will
// be: deopt argument length, deopt arguments.., gc arguments...
SmallVector<const Value *, 64> Bases, Ptrs, Relocations;
- getIncomingStatepointGCValues(Bases, Ptrs, Relocations,
- Statepoint.getCallSite(), Builder);
+ getIncomingStatepointGCValues(Bases, Ptrs, Relocations, StatepointSite,
+ Builder);
#ifndef NDEBUG
// Check that each of the gc pointer and bases we've gotten out of the
// heap. This is basically just here to help catch errors during statepoint
// insertion. TODO: This should actually be in the Verifier, but we can't get
// to the GCStrategy from there (yet).
- if (Builder.GFI) {
- GCStrategy &S = Builder.GFI->getStrategy();
- for (const Value *V : Bases) {
- auto Opt = S.isGCManagedPointer(V);
- if (Opt.hasValue()) {
- assert(Opt.getValue() &&
- "non gc managed base pointer found in statepoint");
- }
+ GCStrategy &S = Builder.GFI->getStrategy();
+ for (const Value *V : Bases) {
+ auto Opt = S.isGCManagedPointer(V);
+ if (Opt.hasValue()) {
+ assert(Opt.getValue() &&
+ "non gc managed base pointer found in statepoint");
}
- for (const Value *V : Ptrs) {
- auto Opt = S.isGCManagedPointer(V);
- if (Opt.hasValue()) {
- assert(Opt.getValue() &&
- "non gc managed derived pointer found in statepoint");
- }
+ }
+ for (const Value *V : Ptrs) {
+ auto Opt = S.isGCManagedPointer(V);
+ if (Opt.hasValue()) {
+ assert(Opt.getValue() &&
+ "non gc managed derived pointer found in statepoint");
}
- for (const Value *V : Relocations) {
- auto Opt = S.isGCManagedPointer(V);
- if (Opt.hasValue()) {
- assert(Opt.getValue() && "non gc managed pointer relocated");
- }
+ }
+ for (const Value *V : Relocations) {
+ auto Opt = S.isGCManagedPointer(V);
+ if (Opt.hasValue()) {
+ assert(Opt.getValue() && "non gc managed pointer relocated");
}
}
#endif
-
-
// Before we actually start lowering (and allocating spill slots for values),
// reserve any stack slots which we judge to be profitable to reuse for a
// particular value. This is purely an optimization over the code below and
// doesn't change semantics at all. It is important for performance that we
// reserve slots for both deopt and gc values before lowering either.
- for (auto I = Statepoint.vm_state_begin() + 1, E = Statepoint.vm_state_end();
+ for (auto I = StatepointSite.vm_state_begin() + 1,
+ E = StatepointSite.vm_state_end();
I != E; ++I) {
Value *V = *I;
SDValue Incoming = Builder.getValue(V);
// First, prefix the list with the number of unique values to be
// lowered. Note that this is the number of *Values* not the
// number of SDValues required to lower them.
- const int NumVMSArgs = Statepoint.numTotalVMSArgs();
- Ops.push_back(
- Builder.DAG.getTargetConstant(StackMaps::ConstantOp, MVT::i64));
- Ops.push_back(Builder.DAG.getTargetConstant(NumVMSArgs, MVT::i64));
+ const int NumVMSArgs = StatepointSite.getNumTotalVMSArgs();
+ Ops.push_back( Builder.DAG.getTargetConstant(StackMaps::ConstantOp,
+ Builder.getCurSDLoc(),
+ MVT::i64));
+ Ops.push_back(Builder.DAG.getTargetConstant(NumVMSArgs, Builder.getCurSDLoc(),
+ MVT::i64));
- assert(NumVMSArgs + 1 == std::distance(Statepoint.vm_state_begin(),
- Statepoint.vm_state_end()));
+ assert(NumVMSArgs + 1 == std::distance(StatepointSite.vm_state_begin(),
+ StatepointSite.vm_state_end()));
// The vm state arguments are lowered in an opaque manner. We do
// not know what type of values are contained within. We skip the
// explicitly just above. We could have left it in the loop and
// not done it explicitly, but it's far easier to understand this
// way.
- for (auto I = Statepoint.vm_state_begin() + 1, E = Statepoint.vm_state_end();
+ for (auto I = StatepointSite.vm_state_begin() + 1,
+ E = StatepointSite.vm_state_end();
I != E; ++I) {
const Value *V = *I;
SDValue Incoming = Builder.getValue(V);
SDValue Incoming = Builder.getValue(V);
lowerIncomingStatepointValue(Incoming, Ops, Builder);
}
+
+ // If there are any explicit spill slots passed to the statepoint, record
+ // them, but otherwise do not do anything special. These are user provided
+ // allocas and give control over placement to the consumer. In this case,
+ // it is the contents of the slot which may get updated, not the pointer to
+ // the alloca
+ for (Value *V : StatepointSite.gc_args()) {
+ SDValue Incoming = Builder.getValue(V);
+ if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Incoming)) {
+ // This handles allocas as arguments to the statepoint
+ Ops.push_back(Builder.DAG.getTargetFrameIndex(FI->getIndex(),
+ Incoming.getValueType()));
+ }
+ }
}
+
void SelectionDAGBuilder::visitStatepoint(const CallInst &CI) {
+ // Check some preconditions for sanity
+ assert(isStatepoint(&CI) &&
+ "function called must be the statepoint function");
+
+ LowerStatepoint(ImmutableStatepoint(&CI));
+}
+
+void SelectionDAGBuilder::LowerStatepoint(
+ ImmutableStatepoint ISP, MachineBasicBlock *LandingPad /*=nullptr*/) {
// The basic scheme here is that information about both the original call and
// the safepoint is encoded in the CallInst. We create a temporary call and
// lower it, then reverse engineer the calling sequence.
- // Check some preconditions for sanity
- assert(isStatepoint(&CI) &&
- "function called must be the statepoint function");
NumOfStatepoints++;
// Clear state
StatepointLowering.startNewStatepoint(*this);
+ ImmutableCallSite CS(ISP.getCallSite());
+
#ifndef NDEBUG
// Consistency check
- for (const User *U : CI.users()) {
+ for (const User *U : CS->users()) {
const CallInst *Call = cast<CallInst>(U);
if (isGCRelocate(Call))
StatepointLowering.scheduleRelocCall(*Call);
}
#endif
- ImmutableStatepoint ISP(&CI);
#ifndef NDEBUG
// If this is a malformed statepoint, report it early to simplify debugging.
// This should catch any IR level mistake that's made when constructing or
// TODO: This if should become an assert. For now, we allow the GCStrategy
// to be optional for backwards compatibility. This will only last a short
// period (i.e. a couple of weeks).
- if (GFI) {
- assert(GFI->getStrategy().useStatepoints() &&
- "GCStrategy does not expect to encounter statepoints");
- }
+ assert(GFI->getStrategy().useStatepoints() &&
+ "GCStrategy does not expect to encounter statepoints");
#endif
-
// Lower statepoint vmstate and gcstate arguments
- SmallVector<SDValue, 10> LoweredArgs;
- lowerStatepointMetaArgs(LoweredArgs, ISP, *this);
+ SmallVector<SDValue, 10> LoweredMetaArgs;
+ lowerStatepointMetaArgs(LoweredMetaArgs, ISP, *this);
// Get call node, we will replace it later with statepoint
- SDNode *CallNode = lowerCallFromStatepoint(CI, *this);
+ SDNode *CallNode =
+ lowerCallFromStatepoint(ISP, LandingPad, *this, PendingExports);
// Construct the actual STATEPOINT node with all the appropriate arguments
// and return values.
// Get number of arguments incoming directly into call node
unsigned NumCallRegArgs =
CallNode->getNumOperands() - (Glue.getNode() ? 4 : 3);
- Ops.push_back(DAG.getTargetConstant(NumCallRegArgs, MVT::i32));
+ Ops.push_back(DAG.getTargetConstant(NumCallRegArgs, getCurSDLoc(), MVT::i32));
// Add call target
SDValue CallTarget = SDValue(CallNode->getOperand(1).getNode(), 0);
// Add a leading constant argument with the Flags and the calling convention
// masked together
- CallingConv::ID CallConv = CI.getCallingConv();
- int Flags = dyn_cast<ConstantInt>(CI.getArgOperand(2))->getZExtValue();
+ CallingConv::ID CallConv = CS.getCallingConv();
+ int Flags = cast<ConstantInt>(CS.getArgument(2))->getZExtValue();
assert(Flags == 0 && "not expected to be used");
- Ops.push_back(DAG.getTargetConstant(StackMaps::ConstantOp, MVT::i64));
- Ops.push_back(
- DAG.getTargetConstant(Flags | ((unsigned)CallConv << 1), MVT::i64));
+ Ops.push_back(DAG.getTargetConstant(StackMaps::ConstantOp, getCurSDLoc(),
+ MVT::i64));
+ Ops.push_back(DAG.getTargetConstant(Flags | ((unsigned)CallConv << 1),
+ getCurSDLoc(), MVT::i64));
// Insert all vmstate and gcstate arguments
- Ops.insert(Ops.end(), LoweredArgs.begin(), LoweredArgs.end());
+ Ops.insert(Ops.end(), LoweredMetaArgs.begin(), LoweredMetaArgs.end());
// Add register mask from call node
Ops.push_back(*RegMaskIt);
// input. This allows someone else to chain off us as needed.
SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
- SDNode *StatepointMCNode = DAG.getMachineNode(TargetOpcode::STATEPOINT,
- getCurSDLoc(), NodeTys, Ops);
+ SDNode *StatepointMCNode =
+ DAG.getMachineNode(TargetOpcode::STATEPOINT, getCurSDLoc(), NodeTys, Ops);
// Replace original call
DAG.ReplaceAllUsesWith(CallNode, StatepointMCNode); // This may update Root
// The result value of the gc_result is simply the result of the actual
// call. We've already emitted this, so just grab the value.
Instruction *I = cast<Instruction>(CI.getArgOperand(0));
- assert(isStatepoint(I) &&
- "first argument must be a statepoint token");
-
- setValue(&CI, getValue(I));
+ assert(isStatepoint(I) && "first argument must be a statepoint token");
+
+ if (isa<InvokeInst>(I)) {
+ // For invokes we should have stored call result in a virtual register.
+ // We can not use default getValue() functionality to copy value from this
+ // register because statepoint and actuall call return types can be
+ // different, and getValue() will use CopyFromReg of the wrong type,
+ // which is always i32 in our case.
+ PointerType *CalleeType =
+ cast<PointerType>(ImmutableStatepoint(I).getActualCallee()->getType());
+ Type *RetTy =
+ cast<FunctionType>(CalleeType->getElementType())->getReturnType();
+ SDValue CopyFromReg = getCopyFromRegs(I, RetTy);
+
+ assert(CopyFromReg.getNode());
+ setValue(&CI, CopyFromReg);
+ } else {
+ setValue(&CI, getValue(I));
+ }
}
void SelectionDAGBuilder::visitGCRelocate(const CallInst &CI) {
#endif
GCRelocateOperands relocateOpers(&CI);
- SDValue SD = getValue(relocateOpers.derivedPtr());
+ SDValue SD = getValue(relocateOpers.getDerivedPtr());
if (isa<ConstantSDNode>(SD) || isa<FrameIndexSDNode>(SD)) {
// We didn't need to spill these special cases (constants and allocas).
// it may allow more scheduling opprtunities
SDValue Chain = getRoot();
- Loc = DAG.getLoad(SpillSlot.getValueType(), getCurSDLoc(), Chain,
- SpillSlot, MachinePointerInfo::getFixedStack(FI), false,
- false, false, 0);
+ Loc = DAG.getLoad(SpillSlot.getValueType(), getCurSDLoc(), Chain, SpillSlot,
+ MachinePointerInfo::getFixedStack(FI), false, false,
+ false, 0);
StatepointLowering.setRelocLocation(SD, Loc);
projects / oota-llvm.git / blobdiff