[NFC][RDA] Break-up initialization code

Separate out the initialization code from the loop traversal so
that the analysis can be reset and re-run by a user.

1 files changed, 25 insertions, 19 deletions

diff --git a/llvm/lib/CodeGen/ReachingDefAnalysis.cpp b/llvm/lib/CodeGen/ReachingDefAnalysis.cpp
index 03122ae..c14fa8c 100644
--- a/llvm/lib/CodeGen/ReachingDefAnalysis.cpp
+++ b/llvm/lib/CodeGen/ReachingDefAnalysis.cpp
@@ -136,38 +136,44 @@ void ReachingDefAnalysis::processBasicBlock(
 bool ReachingDefAnalysis::runOnMachineFunction(MachineFunction &mf) {
   MF = &mf;
   TRI = MF->getSubtarget().getRegisterInfo();
+  LLVM_DEBUG(dbgs() << "********** REACHING DEFINITION ANALYSIS **********\n");
+  init();
+  traverse();
+  return false;
+}
 
+void ReachingDefAnalysis::releaseMemory() {
+  // Clear the internal vectors.
+  MBBOutRegsInfos.clear();
+  MBBReachingDefs.clear();
+  InstIds.clear();
   LiveRegs.clear();
-  NumRegUnits = TRI->getNumRegUnits();
-
-  MBBReachingDefs.resize(mf.getNumBlockIDs());
+}
 
-  LLVM_DEBUG(dbgs() << "********** REACHING DEFINITION ANALYSIS **********\n");
+void ReachingDefAnalysis::reset() {
+  releaseMemory();
+  init();
+  traverse();
+}
 
+void ReachingDefAnalysis::init() {
+  NumRegUnits = TRI->getNumRegUnits();
+  MBBReachingDefs.resize(MF->getNumBlockIDs());
   // Initialize the MBBOutRegsInfos
-  MBBOutRegsInfos.resize(mf.getNumBlockIDs());
+  MBBOutRegsInfos.resize(MF->getNumBlockIDs());
+  LoopTraversal Traversal;
+  TraversedMBBOrder = Traversal.traverse(*MF);
+}
 
+void ReachingDefAnalysis::traverse() {
   // Traverse the basic blocks.
-  LoopTraversal Traversal;
-  LoopTraversal::TraversalOrder TraversedMBBOrder = Traversal.traverse(mf);
-  for (LoopTraversal::TraversedMBBInfo TraversedMBB : TraversedMBBOrder) {
+  for (LoopTraversal::TraversedMBBInfo TraversedMBB : TraversedMBBOrder)
     processBasicBlock(TraversedMBB);
-  }
-
   // Sorting all reaching defs found for a ceartin reg unit in a given BB.
   for (MBBDefsInfo &MBBDefs : MBBReachingDefs) {
     for (MBBRegUnitDefs &RegUnitDefs : MBBDefs)
       llvm::sort(RegUnitDefs);
   }
-
-  return false;
-}
-
-void ReachingDefAnalysis::releaseMemory() {
-  // Clear the internal vectors.
-  MBBOutRegsInfos.clear();
-  MBBReachingDefs.clear();
-  InstIds.clear();
 }
 
 int ReachingDefAnalysis::getReachingDef(MachineInstr *MI, int PhysReg) const {