LLVM  3.7.0
Macros | Functions
StatepointLowering.cpp File Reference
#include "StatepointLowering.h"
#include "SelectionDAGBuilder.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/GCMetadata.h"
#include "llvm/CodeGen/GCStrategy.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Statepoint.h"
#include "llvm/Target/TargetLowering.h"
#include <algorithm>
Include dependency graph for StatepointLowering.cpp:

Go to the source code of this file.

Macros

#define DEBUG_TYPE   "statepoint-lowering"
 

Functions

 STATISTIC (NumSlotsAllocatedForStatepoints,"Number of stack slots allocated for statepoints")
 
 STATISTIC (NumOfStatepoints,"Number of statepoint nodes encountered")
 
 STATISTIC (StatepointMaxSlotsRequired,"Maximum number of stack slots required for a singe statepoint")
 
static void pushStackMapConstant (SmallVectorImpl< SDValue > &Ops, SelectionDAGBuilder &Builder, uint64_t Value)
 
static Optional< intfindPreviousSpillSlot (const Value *Val, SelectionDAGBuilder &Builder, int LookUpDepth)
 Utility function for reservePreviousStackSlotForValue. More...
 
static void reservePreviousStackSlotForValue (const Value *IncomingValue, SelectionDAGBuilder &Builder)
 Try to find existing copies of the incoming values in stack slots used for statepoint spilling. More...
 
static void removeDuplicatesGCPtrs (SmallVectorImpl< const Value * > &Bases, SmallVectorImpl< const Value * > &Ptrs, SmallVectorImpl< const Value * > &Relocs, SelectionDAGBuilder &Builder)
 Remove any duplicate (as SDValues) from the derived pointer pairs. More...
 
static SDNodelowerCallFromStatepoint (ImmutableStatepoint ISP, MachineBasicBlock *LandingPad, SelectionDAGBuilder &Builder, SmallVectorImpl< SDValue > &PendingExports)
 Extract call from statepoint, lower it and return pointer to the call node. More...
 
static void getIncomingStatepointGCValues (SmallVectorImpl< const Value * > &Bases, SmallVectorImpl< const Value * > &Ptrs, SmallVectorImpl< const Value * > &Relocs, ImmutableStatepoint StatepointSite, SelectionDAGBuilder &Builder)
 Callect all gc pointers coming into statepoint intrinsic, clean them up, and return two arrays: Bases - base pointers incoming to this statepoint Ptrs - derived pointers incoming to this statepoint 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. More...
 
static std::pair< SDValue,
SDValue
spillIncomingStatepointValue (SDValue Incoming, SDValue Chain, SelectionDAGBuilder &Builder)
 Spill a value incoming to the statepoint. More...
 
static void lowerIncomingStatepointValue (SDValue Incoming, SmallVectorImpl< SDValue > &Ops, SelectionDAGBuilder &Builder)
 Lower a single value incoming to a statepoint node. More...
 
static void lowerStatepointMetaArgs (SmallVectorImpl< SDValue > &Ops, ImmutableStatepoint StatepointSite, SelectionDAGBuilder &Builder)
 Lower deopt state and gc pointer arguments of the statepoint. More...
 

Macro Definition Documentation

#define DEBUG_TYPE   "statepoint-lowering"

Definition at line 33 of file StatepointLowering.cpp.

Function Documentation

static Optional<int> findPreviousSpillSlot ( const Value Val,
SelectionDAGBuilder Builder,
int  LookUpDepth 
)
static

Utility function for reservePreviousStackSlotForValue.

Tries to find stack slot index to which we have spilled value for previous statepoints. LookUpDepth specifies maximum DFS depth this function is allowed to look.

Definition at line 119 of file StatepointLowering.cpp.

References llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), llvm::SelectionDAGBuilder::FuncInfo, llvm::GCRelocateOperands::getDerivedPtr(), llvm::GCRelocateOperands::getStatepoint(), llvm::Optional< T >::hasValue(), llvm::isGCRelocate(), llvm::None, and llvm::FunctionLoweringInfo::StatepointRelocatedValues.

Referenced by reservePreviousStackSlotForValue().

static void getIncomingStatepointGCValues ( SmallVectorImpl< const Value * > &  Bases,
SmallVectorImpl< const Value * > &  Ptrs,
SmallVectorImpl< const Value * > &  Relocs,
ImmutableStatepoint  StatepointSite,
SelectionDAGBuilder Builder 
)
static

Callect all gc pointers coming into statepoint intrinsic, clean them up, and return two arrays: Bases - base pointers incoming to this statepoint Ptrs - derived pointers incoming to this statepoint 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.

Definition at line 371 of file StatepointLowering.cpp.

References llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::getRelocates(), llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), removeDuplicatesGCPtrs(), and llvm::SmallVectorTemplateCommon< T >::size().

Referenced by lowerStatepointMetaArgs().

static SDNode* lowerCallFromStatepoint ( ImmutableStatepoint  ISP,
MachineBasicBlock LandingPad,
SelectionDAGBuilder Builder,
SmallVectorImpl< SDValue > &  PendingExports 
)
static

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

Definition at line 286 of file StatepointLowering.cpp.

References llvm::CallingConv::AnyReg, llvm::StatepointBase< const Function, const Instruction, const Value, ImmutableCallSite >::CallArgsBeginPos, llvm::ISD::CALLSEQ_END, llvm::ISD::CopyFromReg, llvm::FunctionLoweringInfo::CreateRegs(), llvm::CS, llvm::SelectionDAGBuilder::DAG, llvm::SelectionDAGBuilder::FuncInfo, llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::getActualReturnType(), llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::getCalledValue(), llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::getCallSite(), llvm::SelectionDAG::getContext(), llvm::SelectionDAGBuilder::getCurSDLoc(), llvm::SelectionDAG::getDataLayout(), llvm::SelectionDAG::getEntryNode(), llvm::SelectionDAG::getIntPtrConstant(), llvm::SDValue::getNode(), llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::getNumCallArgs(), llvm::SDNode::getOpcode(), llvm::SDNode::getOperand(), llvm::SelectionDAG::getTargetLoweringInfo(), llvm::SelectionDAGBuilder::getValue(), llvm::Type::isVoidTy(), llvm::ISD::LOAD, llvm::SelectionDAGBuilder::lowerCallOperands(), llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), llvm::SelectionDAGBuilder::setValue(), and llvm::FunctionLoweringInfo::ValueMap.

Referenced by llvm::SelectionDAGBuilder::LowerStatepoint().

static void lowerIncomingStatepointValue ( SDValue  Incoming,
SmallVectorImpl< SDValue > &  Ops,
SelectionDAGBuilder Builder 
)
static

Lower a single value incoming to a statepoint node.

This value can be either a deopt value or a gc value, the handling is the same. We special case constants and allocas, then fall back to spilling if required.

Definition at line 427 of file StatepointLowering.cpp.

References llvm::SelectionDAGBuilder::DAG, llvm::SelectionDAGBuilder::getRoot(), llvm::SelectionDAG::getTargetFrameIndex(), llvm::SDValue::getValueType(), llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), pushStackMapConstant(), llvm::SelectionDAG::setRoot(), and spillIncomingStatepointValue().

Referenced by lowerStatepointMetaArgs().

static void lowerStatepointMetaArgs ( SmallVectorImpl< SDValue > &  Ops,
ImmutableStatepoint  StatepointSite,
SelectionDAGBuilder Builder 
)
static

Lower deopt state and gc pointer arguments of the statepoint.

The actual lowering is described in lowerIncomingStatepointValue. This function is responsible for lowering everything in the right position and playing some tricks to avoid redundant stack manipulation where possible. On completion, 'Ops' will contain ready to use operands for machine code statepoint. The chain nodes will have already been created and the DAG root will be set to the last value spilled (if any were).

Definition at line 467 of file StatepointLowering.cpp.

References llvm::SelectionDAGBuilder::DAG, llvm::SelectionDAGBuilder::ExportFromCurrentBlock(), llvm::SelectionDAGBuilder::FuncInfo, llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::gc_args(), llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::getCallSite(), getIncomingStatepointGCValues(), llvm::CallSiteBase< FunTy, BBTy, ValTy, UserTy, InstrTy, CallTy, InvokeTy, IterTy >::getInstruction(), llvm::StatepointLoweringState::getLocation(), llvm::SDValue::getNode(), llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::getNumTotalVMSArgs(), llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::getRelocates(), llvm::GCFunctionInfo::getStrategy(), llvm::SelectionDAG::getTargetFrameIndex(), llvm::SelectionDAGBuilder::getValue(), llvm::SDValue::getValueType(), llvm::SelectionDAGBuilder::GFI, llvm::GCStrategy::isGCManagedPointer(), llvm::CallSiteBase< FunTy, BBTy, ValTy, UserTy, InstrTy, CallTy, InvokeTy, IterTy >::isInvoke(), lowerIncomingStatepointValue(), llvm::None, llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), pushStackMapConstant(), reservePreviousStackSlotForValue(), llvm::SelectionDAGBuilder::StatepointLowering, llvm::FunctionLoweringInfo::StatepointRelocatedValues, llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::vm_state_args(), llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::vm_state_begin(), and llvm::StatepointBase< FunTy, InstructionTy, ValueTy, CallSiteTy >::vm_state_end().

Referenced by llvm::SelectionDAGBuilder::LowerStatepoint().

static void pushStackMapConstant ( SmallVectorImpl< SDValue > &  Ops,
SelectionDAGBuilder Builder,
uint64_t  Value 
)
static
static void removeDuplicatesGCPtrs ( SmallVectorImpl< const Value * > &  Bases,
SmallVectorImpl< const Value * > &  Ptrs,
SmallVectorImpl< const Value * > &  Relocs,
SelectionDAGBuilder Builder 
)
static

Remove any duplicate (as SDValues) from the derived pointer pairs.

This is not required for correctness. It's purpose is to reduce the size of StackMap section. It has no effect on the number of spill slots required or the actual lowering.

Definition at line 253 of file StatepointLowering.cpp.

References llvm::SmallSet< T, N, C >::count(), llvm::SelectionDAGBuilder::getValue(), llvm::SmallSet< T, N, C >::insert(), llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), and llvm::SmallVectorTemplateCommon< T >::size().

Referenced by getIncomingStatepointGCValues().

static void reservePreviousStackSlotForValue ( const Value IncomingValue,
SelectionDAGBuilder Builder 
)
static
static std::pair<SDValue, SDValue> spillIncomingStatepointValue ( SDValue  Incoming,
SDValue  Chain,
SelectionDAGBuilder Builder 
)
static

Spill a value incoming to the statepoint.

It might be either part of vmstate or gcstate. In both cases unconditionally spill it on the stack unless it is a null constant. Return pair with first element being frame index containing saved value and second element with outgoing chain from the emitted store

Definition at line 397 of file StatepointLowering.cpp.

References llvm::StatepointLoweringState::allocateStackSlot(), llvm::SelectionDAGBuilder::DAG, llvm::SelectionDAGBuilder::getCurSDLoc(), llvm::MachinePointerInfo::getFixedStack(), llvm::StatepointLoweringState::getLocation(), llvm::SDValue::getNode(), llvm::SelectionDAG::getStore(), llvm::SelectionDAG::getTargetFrameIndex(), llvm::SDValue::getValueType(), llvm::StatepointLoweringState::setLocation(), and llvm::SelectionDAGBuilder::StatepointLowering.

Referenced by lowerIncomingStatepointValue().

STATISTIC ( NumSlotsAllocatedForStatepoints  ,
"Number of stack slots allocated for statepoints  
)
STATISTIC ( NumOfStatepoints  ,
"Number of statepoint nodes encountered"   
)
STATISTIC ( StatepointMaxSlotsRequired  ,
"Maximum number of stack slots required for a singe statepoint"   
)