Tell the register allocator about new unused virtual registers.
This allows the allocator to free any resources used by the virtual register,
including physical register assignments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127560 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveRangeEdit.h b/lib/CodeGen/LiveRangeEdit.h
index 363f4d7..a784826 100644
--- a/lib/CodeGen/LiveRangeEdit.h
+++ b/lib/CodeGen/LiveRangeEdit.h
@@ -34,6 +34,11 @@
struct Delegate {
/// Called immediately before erasing a dead machine instruction.
virtual void LRE_WillEraseInstruction(MachineInstr *MI) {}
+
+ /// Called when a virtual register is no longer used. Return false to defer
+ /// its deletion from LiveIntervals.
+ virtual bool LRE_CanEraseVirtReg(unsigned) { return true; }
+
virtual ~Delegate() {}
};
@@ -150,6 +155,10 @@
return rematted_.count(ParentVNI);
}
+ /// eraseVirtReg - Notify the delegate that Reg is no longer in use, and try
+ /// to erase it from LIS.
+ void eraseVirtReg(unsigned Reg, LiveIntervals &LIS);
+
/// eliminateDeadDefs - Try to delete machine instructions that are now dead
/// (allDefsAreDead returns true). This may cause live intervals to be trimmed
/// and further dead efs to be eliminated.