//
//===----------------------------------------------------------------------===//
+#include "llvm/CodeGen/GCMetadata.h"
#include "llvm/CodeGen/GCStrategy.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
/// 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;
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
- // 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;
+ return false;
}
-
/// CouldBecomeSafePoint - Predicate to conservatively determine whether the
/// instruction could introduce a safe point.
static bool CouldBecomeSafePoint(Instruction *I) {
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;
}
++BBI)
for (MachineBasicBlock::iterator MI = BBI->begin(), ME = BBI->end();
MI != ME; ++MI)
- if (MI->isCall())
+ 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;