[Hexagon] Cache reached blocks in bit tracker instead of scanning list

llvm-svn: 300701

llvm/lib/Target/Hexagon/BitTracker.cpp

@@ -1011,12 +1011,7 @@ void BT::subst(RegisterRef OldRR, RegisterRef NewRR) {
 bool BT::reached(const MachineBasicBlock *B) const {
   int BN = B->getNumber();
   assert(BN >= 0);
-  for (EdgeSetType::iterator I = EdgeExec.begin(), E = EdgeExec.end();
-       I != E; ++I) {
-    if (I->second == BN)
-      return true;
-  }
-  return false;
+  return ReachedBB.count(BN);
 }
 
 // Visit an individual instruction. This could be a newly added instruction,
@@ -1036,6 +1031,8 @@ void BT::reset() {
   EdgeExec.clear();
   InstrExec.clear();
   Map.clear();
+  ReachedBB.clear();
+  ReachedBB.reserve(MF.size());
 }
 
 void BT::run() {
@@ -1068,6 +1065,7 @@ void BT::run() {
     if (EdgeExec.count(Edge))
       continue;
     EdgeExec.insert(Edge);
+    ReachedBB.insert(Edge.second);
 
     const MachineBasicBlock &B = *MF.getBlockNumbered(Edge.second);
     MachineBasicBlock::const_iterator It = B.begin(), End = B.end();

llvm/lib/Target/Hexagon/BitTracker.h

@@ -10,6 +10,7 @@
 #ifndef LLVM_LIB_TARGET_HEXAGON_BITTRACKER_H
 #define LLVM_LIB_TARGET_HEXAGON_BITTRACKER_H
 
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/CodeGen/MachineFunction.h"
@@ -68,10 +69,11 @@ private:
   typedef std::set<const MachineInstr *> InstrSetType;
   typedef std::queue<CFGEdge> EdgeQueueType;
 
-  EdgeSetType EdgeExec;       // Executable flow graph edges.
-  InstrSetType InstrExec;     // Executable instructions.
-  EdgeQueueType FlowQ;        // Work queue of CFG edges.
-  bool Trace;                 // Enable tracing for debugging.
+  EdgeSetType EdgeExec;         // Executable flow graph edges.
+  InstrSetType InstrExec;       // Executable instructions.
+  EdgeQueueType FlowQ;          // Work queue of CFG edges.
+  DenseSet<unsigned> ReachedBB; // Cache of reached blocks.
+  bool Trace;                   // Enable tracing for debugging.
 
   const MachineEvaluator &ME;
   MachineFunction &MF;