//
//===----------------------------------------------------------------------===//
-#include "llvm/CodeGen/GCStrategy.h"
+#include "llvm/CodeGen/GCMetadata.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/Dominators.h"
+#include "llvm/IR/GCStrategy.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/Debug.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 {
+ 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;
+};
}
// -----------------------------------------------------------------------------
-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();
+}
+
+static bool NeedsCustomLoweringPass(const GCStrategy &C) {
+ // Custom lowering is only necessary if enabled for some action.
+ return C.customWriteBarrier() || C.customReadBarrier() || C.customRoots();
+}
+
/// 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
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();
-}
-
/// 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) {
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);
++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) {
FI->setFrameSize(MF.getFrameInfo()->getStackSize());
// Find all safe points.
- if (FI->getStrategy().customSafePoints()) {
- FI->getStrategy().findCustomSafePoints(*FI, MF);
- } else {
- FindSafePoints(MF);
- }
+ FindSafePoints(MF);
// Find the stack offsets for all roots.
FindStackOffsets(MF);