Remove GC roots that reference dead objects.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166763 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/GCStrategy.cpp b/lib/CodeGen/GCStrategy.cpp
index 8de541d..f4755bb 100644
--- a/lib/CodeGen/GCStrategy.cpp
+++ b/lib/CodeGen/GCStrategy.cpp
@@ -388,9 +388,16 @@
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) {