LiveIntervalAnalysis: Remove LiveVariables requirement

This requirement was a huge hack to keep LiveVariables alive because it
was optionally used by TwoAddressInstructionPass and PHIElimination.
However we have AnalysisUsage::addUsedIfAvailable() which we can use in
those passes.

This re-applies r260806 with LiveVariables manually added to PowerPC to
hopefully not break the stage 2 bots this time.

llvm-svn: 267954

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/PHIElimination.cpp b/llvm/lib/CodeGen/PHIElimination.cpp
index 9cbb318f0c8..c65a5a7100d 100644
--- a/llvm/lib/CodeGen/PHIElimination.cpp
+++ b/llvm/lib/CodeGen/PHIElimination.cpp
@@ -120,6 +120,7 @@ INITIALIZE_PASS_END(PHIElimination, "phi-node-elimination",
                     "Eliminate PHI nodes for register allocation", false, false)
 
 void PHIElimination::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.addUsedIfAvailable<LiveVariables>();
   AU.addPreserved<LiveVariables>();
   AU.addPreserved<SlotIndexes>();
   AU.addPreserved<LiveIntervals>();