Remove GC roots that reference dead objects.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166763 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nicolas Geoffray 2012-10-26 09:15:55 +00:00
parent 8b1b4136a0
commit 0bd10f2af3
2 changed files with 15 additions and 3 deletions

View File

@ -122,6 +122,11 @@ namespace llvm {
Roots.push_back(GCRoot(Num, Metadata));
}
/// removeStackRoot - Removes a root.
roots_iterator removeStackRoot(roots_iterator position) {
return Roots.erase(position);
}
/// addSafePoint - Notes the existence of a safe point. Num is the ID of the
/// label just prior to the safe point (if the code generator is using
/// MachineModuleInfo).

View File

@ -388,9 +388,16 @@ void GCMachineCodeAnalysis::FindStackOffsets(MachineFunction &MF) {
const TargetFrameLowering *TFI = TM->getFrameLowering();
assert(TFI && "TargetRegisterInfo not available!");
for (GCFunctionInfo::roots_iterator RI = FI->roots_begin(),
RE = FI->roots_end(); RI != RE; ++RI)
RI->StackOffset = TFI->getFrameIndexOffset(MF, RI->Num);
for (GCFunctionInfo::roots_iterator RI = FI->roots_begin();
RI != FI->roots_end();) {
// If the root references a dead object, no need to keep it.
if (MF.getFrameInfo()->isDeadObjectIndex(RI->Num)) {
RI = FI->removeStackRoot(RI);
} else {
RI->StackOffset = TFI->getFrameIndexOffset(MF, RI->Num);
++RI;
}
}
}
bool GCMachineCodeAnalysis::runOnMachineFunction(MachineFunction &MF) {