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, 2 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/LiveRangeEdit.cpp b/llvm/lib/CodeGen/LiveRangeEdit.cpp
index 47da205df69..c4bfc0e876c 100644
--- a/llvm/lib/CodeGen/LiveRangeEdit.cpp
+++ b/llvm/lib/CodeGen/LiveRangeEdit.cpp
@@ -256,15 +256,8 @@ void LiveRangeEdit::eliminateDeadDef(MachineInstr *MI, ToShrinkSet &ToShrink) {
       // Check if MI reads any unreserved physregs.
       if (Reg && MOI->readsReg() && !MRI.isReserved(Reg))
         ReadsPhysRegs = true;
-      else if (MOI->isDef()) {
-        for (MCRegUnitIterator Units(Reg, MRI.getTargetRegisterInfo());
-             Units.isValid(); ++Units) {
-          if (LiveRange *LR = LIS.getCachedRegUnit(*Units)) {
-            if (VNInfo *VNI = LR->getVNInfoAt(Idx))
-              LR->removeValNo(VNI);
-          }
-        }
-      }
+      else if (MOI->isDef())
+        LIS.removePhysRegDefAt(Reg, Idx);
       continue;
     }
     LiveInterval &LI = LIS.getInterval(Reg);