Keep UsedBlocks info accurate.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35140 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp
index 6a9f428..734a06f 100644
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -160,6 +160,8 @@
     // Realize that the destination register is defined by the PHI copy now, not
     // the PHI itself.
     LV->getVarInfo(DestReg).DefInst = PHICopy;
+
+    LV->getVarInfo(IncomingReg).UsedBlocks[MBB.getNumber()] = true;
   }
 
   // Adjust the VRegPHIUseCount map to account for the removal of this PHI
@@ -210,6 +212,7 @@
     // instruction kills the incoming value.
     //
     LiveVariables::VarInfo &InRegVI = LV->getVarInfo(SrcReg);
+    InRegVI.UsedBlocks[opBlock.getNumber()] = true;
 
     // Loop over all of the successors of the basic block, checking to see
     // if the value is either live in the block, or if it is killed in the