1 files changed, 59 insertions, 17 deletions

diff --git a/contrib/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/contrib/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
index f2723bd..8754c71 100644
--- a/contrib/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/contrib/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -130,7 +130,8 @@ static bool mergeEmptyReturnBlocks(Function &F) {
 /// iterating until no more changes are made.
 static bool iterativelySimplifyCFG(Function &F, const TargetTransformInfo &TTI,
                                    AssumptionCache *AC,
-                                   unsigned BonusInstThreshold) {
+                                   unsigned BonusInstThreshold,
+                                   bool LateSimplifyCFG) {
   bool Changed = false;
   bool LocalChange = true;
 
@@ -145,7 +146,7 @@ static bool iterativelySimplifyCFG(Function &F, const TargetTransformInfo &TTI,
 
     // Loop over all of the basic blocks and remove them if they are unneeded.
     for (Function::iterator BBIt = F.begin(); BBIt != F.end(); ) {
-      if (SimplifyCFG(&*BBIt++, TTI, BonusInstThreshold, AC, &LoopHeaders)) {
+      if (SimplifyCFG(&*BBIt++, TTI, BonusInstThreshold, AC, &LoopHeaders, LateSimplifyCFG)) {
         LocalChange = true;
         ++NumSimpl;
       }
@@ -156,10 +157,12 @@ static bool iterativelySimplifyCFG(Function &F, const TargetTransformInfo &TTI,
 }
 
 static bool simplifyFunctionCFG(Function &F, const TargetTransformInfo &TTI,
-                                AssumptionCache *AC, int BonusInstThreshold) {
+                                AssumptionCache *AC, int BonusInstThreshold,
+                                bool LateSimplifyCFG) {
   bool EverChanged = removeUnreachableBlocks(F);
   EverChanged |= mergeEmptyReturnBlocks(F);
-  EverChanged |= iterativelySimplifyCFG(F, TTI, AC, BonusInstThreshold);
+  EverChanged |= iterativelySimplifyCFG(F, TTI, AC, BonusInstThreshold,
+                                        LateSimplifyCFG);
 
   // If neither pass changed anything, we're done.
   if (!EverChanged) return false;
@@ -173,7 +176,8 @@ static bool simplifyFunctionCFG(Function &F, const TargetTransformInfo &TTI,
     return true;
 
   do {
-    EverChanged = iterativelySimplifyCFG(F, TTI, AC, BonusInstThreshold);
+    EverChanged = iterativelySimplifyCFG(F, TTI, AC, BonusInstThreshold,
+                                         LateSimplifyCFG);
     EverChanged |= removeUnreachableBlocks(F);
   } while (EverChanged);
 
@@ -181,17 +185,19 @@ static bool simplifyFunctionCFG(Function &F, const TargetTransformInfo &TTI,
 }
 
 SimplifyCFGPass::SimplifyCFGPass()
-    : BonusInstThreshold(UserBonusInstThreshold) {}
+    : BonusInstThreshold(UserBonusInstThreshold),
+      LateSimplifyCFG(true) {}
 
-SimplifyCFGPass::SimplifyCFGPass(int BonusInstThreshold)
-    : BonusInstThreshold(BonusInstThreshold) {}
+SimplifyCFGPass::SimplifyCFGPass(int BonusInstThreshold, bool LateSimplifyCFG)
+    : BonusInstThreshold(BonusInstThreshold),
+      LateSimplifyCFG(LateSimplifyCFG) {}
 
 PreservedAnalyses SimplifyCFGPass::run(Function &F,
                                        FunctionAnalysisManager &AM) {
   auto &TTI = AM.getResult<TargetIRAnalysis>(F);
   auto &AC = AM.getResult<AssumptionAnalysis>(F);
 
-  if (!simplifyFunctionCFG(F, TTI, &AC, BonusInstThreshold))
+  if (!simplifyFunctionCFG(F, TTI, &AC, BonusInstThreshold, LateSimplifyCFG))
     return PreservedAnalyses::all();
   PreservedAnalyses PA;
   PA.preserve<GlobalsAA>();
@@ -199,16 +205,17 @@ PreservedAnalyses SimplifyCFGPass::run(Function &F,
 }
 
 namespace {
-struct CFGSimplifyPass : public FunctionPass {
-  static char ID; // Pass identification, replacement for typeid
+struct BaseCFGSimplifyPass : public FunctionPass {
   unsigned BonusInstThreshold;
   std::function<bool(const Function &)> PredicateFtor;
+  bool LateSimplifyCFG;
 
-  CFGSimplifyPass(int T = -1,
-                  std::function<bool(const Function &)> Ftor = nullptr)
-      : FunctionPass(ID), PredicateFtor(std::move(Ftor)) {
+  BaseCFGSimplifyPass(int T, bool LateSimplifyCFG,
+                      std::function<bool(const Function &)> Ftor,
+                      char &ID)
+      : FunctionPass(ID), PredicateFtor(std::move(Ftor)),
+        LateSimplifyCFG(LateSimplifyCFG) {
     BonusInstThreshold = (T == -1) ? UserBonusInstThreshold : unsigned(T);
-    initializeCFGSimplifyPassPass(*PassRegistry::getPassRegistry());
   }
   bool runOnFunction(Function &F) override {
     if (skipFunction(F) || (PredicateFtor && !PredicateFtor(F)))
@@ -218,7 +225,7 @@ struct CFGSimplifyPass : public FunctionPass {
         &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
     const TargetTransformInfo &TTI =
         getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
-    return simplifyFunctionCFG(F, TTI, AC, BonusInstThreshold);
+    return simplifyFunctionCFG(F, TTI, AC, BonusInstThreshold, LateSimplifyCFG);
   }
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
@@ -227,6 +234,26 @@ struct CFGSimplifyPass : public FunctionPass {
     AU.addPreserved<GlobalsAAWrapperPass>();
   }
 };
+
+struct CFGSimplifyPass : public BaseCFGSimplifyPass {
+  static char ID; // Pass identification, replacement for typeid
+
+  CFGSimplifyPass(int T = -1,
+                  std::function<bool(const Function &)> Ftor = nullptr)
+                  : BaseCFGSimplifyPass(T, false, Ftor, ID) {
+    initializeCFGSimplifyPassPass(*PassRegistry::getPassRegistry());
+  }
+};
+
+struct LateCFGSimplifyPass : public BaseCFGSimplifyPass {
+  static char ID; // Pass identification, replacement for typeid
+
+  LateCFGSimplifyPass(int T = -1,
+                      std::function<bool(const Function &)> Ftor = nullptr)
+                      : BaseCFGSimplifyPass(T, true, Ftor, ID) {
+    initializeLateCFGSimplifyPassPass(*PassRegistry::getPassRegistry());
+  }
+};
 }
 
 char CFGSimplifyPass::ID = 0;
@@ -237,9 +264,24 @@ INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
 INITIALIZE_PASS_END(CFGSimplifyPass, "simplifycfg", "Simplify the CFG", false,
                     false)
 
+char LateCFGSimplifyPass::ID = 0;
+INITIALIZE_PASS_BEGIN(LateCFGSimplifyPass, "latesimplifycfg",
+                      "Simplify the CFG more aggressively", false, false)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_END(LateCFGSimplifyPass, "latesimplifycfg",
+                    "Simplify the CFG more aggressively", false, false)
+
 // Public interface to the CFGSimplification pass
 FunctionPass *
 llvm::createCFGSimplificationPass(int Threshold,
-                                  std::function<bool(const Function &)> Ftor) {
+    std::function<bool(const Function &)> Ftor) {
   return new CFGSimplifyPass(Threshold, std::move(Ftor));
 }
+
+// Public interface to the LateCFGSimplification pass
+FunctionPass *
+llvm::createLateCFGSimplificationPass(int Threshold, 
+                                  std::function<bool(const Function &)> Ftor) {
+  return new LateCFGSimplifyPass(Threshold, std::move(Ftor));
+}