run finalize functions in parallel

Summary:

(cherry picked from FBD16188733)

bolt/src/BinaryFunction.cpp

@@ -2560,7 +2560,7 @@ bool BinaryFunction::finalizeCFIState() {
   DEBUG(dbgs() << "Trying to fix CFI states for each BB after reordering.\n");
   DEBUG(dbgs() << "This is the list of CFI states for each BB of " << *this
                << ": ");
-
+               
   int32_t State = 0;
   bool SeenCold = false;
   auto Sep = "";

bolt/src/BinaryFunction.h

@@ -1088,6 +1088,7 @@ public:
   MCSymbol *getFunctionEndLabel() const {
     assert(BC.Ctx && "cannot be called with empty context");
     if (!FunctionEndLabel) {
+      std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
       FunctionEndLabel = BC.Ctx->createTempSymbol("func_end", true);
     }
     return FunctionEndLabel;
@@ -1096,6 +1097,7 @@ public:
   /// Return MC symbol associated with the end of the cold part of the function.
   MCSymbol *getFunctionColdEndLabel() const {
     if (!FunctionColdEndLabel) {
+      std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
       FunctionColdEndLabel = BC.Ctx->createTempSymbol("func_cold_end", true);
     }
     return FunctionColdEndLabel;

bolt/src/Exceptions.cpp

@@ -364,7 +364,7 @@ void BinaryFunction::parseLSDA(ArrayRef<uint8_t> LSDASectionData,
 void BinaryFunction::updateEHRanges() {
   if (getSize() == 0)
     return;
-
+    
   assert(CurrentState == State::CFG_Finalized && "unexpected state");
 
   // Build call sites table.
@@ -430,9 +430,14 @@ void BinaryFunction::updateEHRanges() {
         continue;
 
       // Same symbol is used for the beginning and the end of the range.
-      const MCSymbol *EHSymbol = BC.Ctx->createTempSymbol("EH", true);
+      const MCSymbol *EHSymbol;
       MCInst EHLabel;
-      BC.MIB->createEHLabel(EHLabel, EHSymbol, BC.Ctx.get());
+      {
+        std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
+        EHSymbol = BC.Ctx->createTempSymbol("EH", true);
+        BC.MIB->createEHLabel(EHLabel, EHSymbol, BC.Ctx.get());
+      }
+
       II = std::next(BB->insertPseudoInstr(II, EHLabel));
 
       // At this point we could be in one of the following states:

bolt/src/Passes/BinaryPasses.cpp

@@ -588,30 +588,30 @@ void FixupBranches::runOnFunctions(BinaryContext &BC) {
 }
 
 void FinalizeFunctions::runOnFunctions(BinaryContext &BC) {
-  for (auto &It : BC.getBinaryFunctions()) {
-    auto &Function = It.second;
-    const auto ShouldOptimize = shouldOptimize(Function);
-
-    // Always fix functions in relocation mode.
-    if (!BC.HasRelocations && !ShouldOptimize)
-      continue;
-
-    // Fix the CFI state.
-    if (ShouldOptimize && !Function.finalizeCFIState()) {
+  ParallelUtilities::WorkFuncTy WorkFun = [&](BinaryFunction &BF) {
+    if (shouldOptimize(BF) && !BF.finalizeCFIState()) {
       if (BC.HasRelocations) {
-        errs() << "BOLT-ERROR: unable to fix CFI state for function "
-               << Function << ". Exiting.\n";
+        errs() << "BOLT-ERROR: unable to fix CFI state for function " << BF
+               << ". Exiting.\n";
         exit(1);
       }
-      Function.setSimple(false);
-      continue;
+      BF.setSimple(false);
+      return;
     }
 
-    Function.setFinalized();
+    BF.setFinalized();
 
     // Update exception handling information.
-    Function.updateEHRanges();
-  }
+    BF.updateEHRanges();
+  };
+
+  ParallelUtilities::PredicateTy SkipPredicate = [&](const BinaryFunction &BF) {
+    return !BC.HasRelocations && !shouldOptimize(BF);
+  };
+
+  ParallelUtilities::runOnEachFunction(
+      BC, ParallelUtilities::SchedulingPolicy::SP_CONSTANT, WorkFun,
+      SkipPredicate, "FinalizeFunctions");
 }
 
 void LowerAnnotations::runOnFunctions(BinaryContext &BC) {