//
//===----------------------------------------------------------------------===//
+#include "llvm/CodeGen/GCMetadata.h"
#include "llvm/CodeGen/GCStrategy.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
namespace {
- /// LowerIntrinsics - This pass rewrites calls to the llvm.gcread or
- /// llvm.gcwrite intrinsics, replacing them with simple loads and stores as
- /// directed by the GCStrategy. It also performs automatic root initialization
- /// and custom intrinsic lowering.
- class LowerIntrinsics : public FunctionPass {
- static bool NeedsDefaultLoweringPass(const GCStrategy &C);
- static bool NeedsCustomLoweringPass(const GCStrategy &C);
- static bool CouldBecomeSafePoint(Instruction *I);
- bool PerformDefaultLowering(Function &F, GCStrategy &Coll);
- static bool InsertRootInitializers(Function &F,
- AllocaInst **Roots, unsigned Count);
-
- public:
- static char ID;
-
- LowerIntrinsics();
- const char *getPassName() const override;
- void getAnalysisUsage(AnalysisUsage &AU) const override;
-
- bool doInitialization(Module &M) override;
- bool runOnFunction(Function &F) override;
- };
-
-
- /// GCMachineCodeAnalysis - This is a target-independent pass over the machine
- /// function representation to identify safe points for the garbage collector
- /// in the machine code. It inserts labels at safe points and populates a
- /// GCMetadata record for each function.
- class GCMachineCodeAnalysis : public MachineFunctionPass {
- const TargetMachine *TM;
- GCFunctionInfo *FI;
- MachineModuleInfo *MMI;
- const TargetInstrInfo *TII;
-
- void FindSafePoints(MachineFunction &MF);
- void VisitCallPoint(MachineBasicBlock::iterator MI);
- MCSymbol *InsertLabel(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator MI,
- DebugLoc DL) const;
-
- void FindStackOffsets(MachineFunction &MF);
-
- public:
- static char ID;
-
- GCMachineCodeAnalysis();
- void getAnalysisUsage(AnalysisUsage &AU) const override;
-
- bool runOnMachineFunction(MachineFunction &MF) override;
- };
+/// LowerIntrinsics - This pass rewrites calls to the llvm.gcread or
+/// llvm.gcwrite intrinsics, replacing them with simple loads and stores as
+/// directed by the GCStrategy. It also performs automatic root initialization
+/// and custom intrinsic lowering.
+class LowerIntrinsics : public FunctionPass {
+ bool PerformDefaultLowering(Function &F, GCStrategy &Coll);
+public:
+ static char ID;
+
+ LowerIntrinsics();
+ const char *getPassName() const override;
+ void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+ bool doInitialization(Module &M) override;
+ bool runOnFunction(Function &F) override;
+};
+
+/// GCMachineCodeAnalysis - This is a target-independent pass over the machine
+/// function representation to identify safe points for the garbage collector
+/// in the machine code. It inserts labels at safe points and populates a
+/// GCMetadata record for each function.
+class GCMachineCodeAnalysis : public MachineFunctionPass {
+ GCFunctionInfo *FI;
+ MachineModuleInfo *MMI;
+ const TargetInstrInfo *TII;
+
+ void FindSafePoints(MachineFunction &MF);
+ void VisitCallPoint(MachineBasicBlock::iterator MI);
+ MCSymbol *InsertLabel(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
+ DebugLoc DL) const;
+
+ void FindStackOffsets(MachineFunction &MF);
+
+public:
+ static char ID;
+
+ GCMachineCodeAnalysis();
+ void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+ bool runOnMachineFunction(MachineFunction &MF) override;
+};
}
// -----------------------------------------------------------------------------
-INITIALIZE_PASS_BEGIN(LowerIntrinsics, "gc-lowering", "GC Lowering",
- false, false)
+INITIALIZE_PASS_BEGIN(LowerIntrinsics, "gc-lowering", "GC Lowering", false,
+ false)
INITIALIZE_PASS_DEPENDENCY(GCModuleInfo)
INITIALIZE_PASS_END(LowerIntrinsics, "gc-lowering", "GC Lowering", false, false)
-FunctionPass *llvm::createGCLoweringPass() {
- return new LowerIntrinsics();
-}
+FunctionPass *llvm::createGCLoweringPass() { return new LowerIntrinsics(); }
char LowerIntrinsics::ID = 0;
-LowerIntrinsics::LowerIntrinsics()
- : FunctionPass(ID) {
- initializeLowerIntrinsicsPass(*PassRegistry::getPassRegistry());
- }
+LowerIntrinsics::LowerIntrinsics() : FunctionPass(ID) {
+ initializeLowerIntrinsicsPass(*PassRegistry::getPassRegistry());
+}
const char *LowerIntrinsics::getPassName() const {
return "Lower Garbage Collection Instructions";
AU.addPreserved<DominatorTreeWrapperPass>();
}
+static bool NeedsDefaultLoweringPass(const GCStrategy &C) {
+ // Default lowering is necessary only if read or write barriers have a default
+ // action. The default for roots is no action.
+ return !C.customWriteBarrier() || !C.customReadBarrier() ||
+ C.initializeRoots();
+}
+
/// doInitialization - If this module uses the GC intrinsics, find them now.
bool LowerIntrinsics::doInitialization(Module &M) {
- // FIXME: This is rather antisocial in the context of a JIT since it performs
- // work against the entire module. But this cannot be done at
- // runFunction time (initializeCustomLowering likely needs to change
- // the module).
GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
assert(MI && "LowerIntrinsics didn't require GCModuleInfo!?");
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isDeclaration() && I->hasGC())
MI->getFunctionInfo(*I); // Instantiate the GC strategy.
- bool MadeChange = false;
- for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
- if (NeedsCustomLoweringPass(**I))
- if ((*I)->initializeCustomLowering(M))
- MadeChange = true;
-
- return MadeChange;
-}
-
-bool LowerIntrinsics::InsertRootInitializers(Function &F, AllocaInst **Roots,
- unsigned Count) {
- // Scroll past alloca instructions.
- BasicBlock::iterator IP = F.getEntryBlock().begin();
- while (isa<AllocaInst>(IP)) ++IP;
-
- // Search for initializers in the initial BB.
- SmallPtrSet<AllocaInst*,16> InitedRoots;
- for (; !CouldBecomeSafePoint(IP); ++IP)
- if (StoreInst *SI = dyn_cast<StoreInst>(IP))
- if (AllocaInst *AI =
- dyn_cast<AllocaInst>(SI->getOperand(1)->stripPointerCasts()))
- InitedRoots.insert(AI);
-
- // Add root initializers.
- bool MadeChange = false;
-
- for (AllocaInst **I = Roots, **E = Roots + Count; I != E; ++I)
- if (!InitedRoots.count(*I)) {
- StoreInst* SI = new StoreInst(ConstantPointerNull::get(cast<PointerType>(
- cast<PointerType>((*I)->getType())->getElementType())),
- *I);
- SI->insertAfter(*I);
- MadeChange = true;
- }
-
- return MadeChange;
-}
-
-bool LowerIntrinsics::NeedsDefaultLoweringPass(const GCStrategy &C) {
- // Default lowering is necessary only if read or write barriers have a default
- // action. The default for roots is no action.
- return !C.customWriteBarrier()
- || !C.customReadBarrier()
- || C.initializeRoots();
-}
-
-bool LowerIntrinsics::NeedsCustomLoweringPass(const GCStrategy &C) {
- // Custom lowering is only necessary if enabled for some action.
- return C.customWriteBarrier()
- || C.customReadBarrier()
- || C.customRoots();
+ return false;
}
/// CouldBecomeSafePoint - Predicate to conservatively determine whether the
/// instruction could introduce a safe point.
-bool LowerIntrinsics::CouldBecomeSafePoint(Instruction *I) {
+static bool CouldBecomeSafePoint(Instruction *I) {
// The natural definition of instructions which could introduce safe points
// are:
//
// libcalls upon lowering (e.g., div i64 on a 32-bit platform), so instead
// it is necessary to take a conservative approach.
- if (isa<AllocaInst>(I) || isa<GetElementPtrInst>(I) ||
- isa<StoreInst>(I) || isa<LoadInst>(I))
+ if (isa<AllocaInst>(I) || isa<GetElementPtrInst>(I) || isa<StoreInst>(I) ||
+ isa<LoadInst>(I))
return false;
// llvm.gcroot is safe because it doesn't do anything at runtime.
return true;
}
+static bool InsertRootInitializers(Function &F, AllocaInst **Roots,
+ unsigned Count) {
+ // Scroll past alloca instructions.
+ BasicBlock::iterator IP = F.getEntryBlock().begin();
+ while (isa<AllocaInst>(IP))
+ ++IP;
+
+ // Search for initializers in the initial BB.
+ SmallPtrSet<AllocaInst *, 16> InitedRoots;
+ for (; !CouldBecomeSafePoint(IP); ++IP)
+ if (StoreInst *SI = dyn_cast<StoreInst>(IP))
+ if (AllocaInst *AI =
+ dyn_cast<AllocaInst>(SI->getOperand(1)->stripPointerCasts()))
+ InitedRoots.insert(AI);
+
+ // Add root initializers.
+ bool MadeChange = false;
+
+ for (AllocaInst **I = Roots, **E = Roots + Count; I != E; ++I)
+ if (!InitedRoots.count(*I)) {
+ StoreInst *SI = new StoreInst(
+ ConstantPointerNull::get(cast<PointerType>(
+ cast<PointerType>((*I)->getType())->getElementType())),
+ *I);
+ SI->insertAfter(*I);
+ MadeChange = true;
+ }
+
+ return MadeChange;
+}
+
/// runOnFunction - Replace gcread/gcwrite intrinsics with loads and stores.
/// Leave gcroot intrinsics; the code generator needs to see those.
bool LowerIntrinsics::runOnFunction(Function &F) {
if (NeedsDefaultLoweringPass(S))
MadeChange |= PerformDefaultLowering(F, S);
- bool UseCustomLoweringPass = NeedsCustomLoweringPass(S);
- if (UseCustomLoweringPass)
- MadeChange |= S.performCustomLowering(F);
-
- // Custom lowering may modify the CFG, so dominators must be recomputed.
- if (UseCustomLoweringPass) {
- if (DominatorTreeWrapperPass *DTWP =
- getAnalysisIfAvailable<DominatorTreeWrapperPass>())
- DTWP->getDomTree().recalculate(F);
- }
-
return MadeChange;
}
bool LowerRd = !S.customReadBarrier();
bool InitRoots = S.initializeRoots();
- SmallVector<AllocaInst*, 32> Roots;
+ SmallVector<AllocaInst *, 32> Roots;
bool MadeChange = false;
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
case Intrinsic::gcwrite:
if (LowerWr) {
// Replace a write barrier with a simple store.
- Value *St = new StoreInst(CI->getArgOperand(0),
- CI->getArgOperand(2), CI);
+ Value *St =
+ new StoreInst(CI->getArgOperand(0), CI->getArgOperand(2), CI);
CI->replaceAllUsesWith(St);
CI->eraseFromParent();
}
if (InitRoots) {
// Initialize the GC root, but do not delete the intrinsic. The
// backend needs the intrinsic to flag the stack slot.
- Roots.push_back(cast<AllocaInst>(
- CI->getArgOperand(0)->stripPointerCasts()));
+ Roots.push_back(
+ cast<AllocaInst>(CI->getArgOperand(0)->stripPointerCasts()));
}
break;
default:
INITIALIZE_PASS(GCMachineCodeAnalysis, "gc-analysis",
"Analyze Machine Code For Garbage Collection", false, false)
-GCMachineCodeAnalysis::GCMachineCodeAnalysis()
- : MachineFunctionPass(ID) {}
+GCMachineCodeAnalysis::GCMachineCodeAnalysis() : MachineFunctionPass(ID) {}
void GCMachineCodeAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
MachineFunctionPass::getAnalysisUsage(AU);
MCSymbol *GCMachineCodeAnalysis::InsertLabel(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
DebugLoc DL) const {
- MCSymbol *Label = MBB.getParent()->getContext().CreateTempSymbol();
+ MCSymbol *Label = MBB.getParent()->getContext().createTempSymbol();
BuildMI(MBB, MI, DL, TII->get(TargetOpcode::GC_LABEL)).addSym(Label);
return Label;
}
++RAI;
if (FI->getStrategy().needsSafePoint(GC::PreCall)) {
- MCSymbol* Label = InsertLabel(*CI->getParent(), CI, CI->getDebugLoc());
+ MCSymbol *Label = InsertLabel(*CI->getParent(), CI, CI->getDebugLoc());
FI->addSafePoint(GC::PreCall, Label, CI->getDebugLoc());
}
if (FI->getStrategy().needsSafePoint(GC::PostCall)) {
- MCSymbol* Label = InsertLabel(*CI->getParent(), RAI, CI->getDebugLoc());
+ MCSymbol *Label = InsertLabel(*CI->getParent(), RAI, CI->getDebugLoc());
FI->addSafePoint(GC::PostCall, Label, CI->getDebugLoc());
}
}
void GCMachineCodeAnalysis::FindSafePoints(MachineFunction &MF) {
- for (MachineFunction::iterator BBI = MF.begin(),
- BBE = MF.end(); BBI != BBE; ++BBI)
- for (MachineBasicBlock::iterator MI = BBI->begin(),
- ME = BBI->end(); MI != ME; ++MI)
- if (MI->isCall())
+ for (MachineFunction::iterator BBI = MF.begin(), BBE = MF.end(); BBI != BBE;
+ ++BBI)
+ for (MachineBasicBlock::iterator MI = BBI->begin(), ME = BBI->end();
+ MI != ME; ++MI)
+ if (MI->isCall()) {
+ // Do not treat tail or sibling call sites as safe points. This is
+ // legal since any arguments passed to the callee which live in the
+ // remnants of the callers frame will be owned and updated by the
+ // callee if required.
+ if (MI->isTerminator())
+ continue;
VisitCallPoint(MI);
+ }
}
void GCMachineCodeAnalysis::FindStackOffsets(MachineFunction &MF) {
- const TargetFrameLowering *TFI = TM->getSubtargetImpl()->getFrameLowering();
+ const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
assert(TFI && "TargetRegisterInfo not available!");
for (GCFunctionInfo::roots_iterator RI = FI->roots_begin();
return false;
FI = &getAnalysis<GCModuleInfo>().getFunctionInfo(*MF.getFunction());
- if (!FI->getStrategy().needsSafePoints())
- return false;
-
- TM = &MF.getTarget();
MMI = &getAnalysis<MachineModuleInfo>();
- TII = TM->getSubtargetImpl()->getInstrInfo();
+ TII = MF.getSubtarget().getInstrInfo();
- // Find the size of the stack frame.
- FI->setFrameSize(MF.getFrameInfo()->getStackSize());
+ // Find the size of the stack frame. There may be no correct static frame
+ // size, we use UINT64_MAX to represent this.
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo();
+ const bool DynamicFrameSize = MFI->hasVarSizedObjects() ||
+ RegInfo->needsStackRealignment(MF);
+ FI->setFrameSize(DynamicFrameSize ? UINT64_MAX : MFI->getStackSize());
// Find all safe points.
- if (FI->getStrategy().customSafePoints()) {
- FI->getStrategy().findCustomSafePoints(*FI, MF);
- } else {
+ if (FI->getStrategy().needsSafePoints())
FindSafePoints(MF);
- }
- // Find the stack offsets for all roots.
+ // Find the concrete stack offsets for all roots (stack slots)
FindStackOffsets(MF);
return false;
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