LiveIntervalAnalysis: Factor out code to update liveness on physreg def removal

This cleans up code and is more in line with the general philosophy of
modifying LiveIntervals through LiveIntervalAnalysis instead of changing
them directly.

llvm-svn: 226687

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
index 36aeaa176a2..48daf2ccd06 100644
--- a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -1367,3 +1367,11 @@ LiveIntervals::repairIntervalsInRange(MachineBasicBlock *MBB,
     repairOldRegInRange(Begin, End, endIdx, LI, Reg);
   }
 }
+
+void LiveIntervals::removePhysRegDefAt(unsigned Reg, SlotIndex Pos) {
+  for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
+    if (LiveRange *LR = getCachedRegUnit(*Units))
+      if (VNInfo *VNI = LR->getVNInfoAt(Pos))
+        LR->removeValNo(VNI);
+  }
+}