1 files changed, 29 insertions, 11 deletions

diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 148bfa8..b8cfe3a 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -4895,9 +4895,8 @@ bool SimplifyCFGOpt::simplifyTerminatorOnSelect(Instruction *OldTerm,
       // We found both of the successors we were looking for.
       // Create a conditional branch sharing the condition of the select.
       BranchInst *NewBI = Builder.CreateCondBr(Cond, TrueBB, FalseBB);
-      if (TrueWeight != FalseWeight)
-        setBranchWeights(*NewBI, {TrueWeight, FalseWeight},
-                         /*IsExpected=*/false, /*ElideAllZero=*/true);
+      setBranchWeights(*NewBI, {TrueWeight, FalseWeight},
+                       /*IsExpected=*/false, /*ElideAllZero=*/true);
     }
   } else if (KeepEdge1 && (KeepEdge2 || TrueBB == FalseBB)) {
     // Neither of the selected blocks were successors, so this
@@ -4982,9 +4981,15 @@ bool SimplifyCFGOpt::simplifyIndirectBrOnSelect(IndirectBrInst *IBI,
   BasicBlock *TrueBB = TBA->getBasicBlock();
   BasicBlock *FalseBB = FBA->getBasicBlock();
 
+  // The select's profile becomes the profile of the conditional branch that
+  // replaces the indirect branch.
+  SmallVector<uint32_t> SelectBranchWeights(2);
+  if (!ProfcheckDisableMetadataFixes)
+    extractBranchWeights(*SI, SelectBranchWeights);
   // Perform the actual simplification.
-  return simplifyTerminatorOnSelect(IBI, SI->getCondition(), TrueBB, FalseBB, 0,
-                                    0);
+  return simplifyTerminatorOnSelect(IBI, SI->getCondition(), TrueBB, FalseBB,
+                                    SelectBranchWeights[0],
+                                    SelectBranchWeights[1]);
 }
 
 /// This is called when we find an icmp instruction
@@ -7952,19 +7957,27 @@ bool SimplifyCFGOpt::simplifySwitch(SwitchInst *SI, IRBuilder<> &Builder) {
 bool SimplifyCFGOpt::simplifyIndirectBr(IndirectBrInst *IBI) {
   BasicBlock *BB = IBI->getParent();
   bool Changed = false;
+  SmallVector<uint32_t> BranchWeights;
+  const bool HasBranchWeights = !ProfcheckDisableMetadataFixes &&
+                                extractBranchWeights(*IBI, BranchWeights);
+
+  DenseMap<const BasicBlock *, uint64_t> TargetWeight;
+  if (HasBranchWeights)
+    for (size_t I = 0, E = IBI->getNumDestinations(); I < E; ++I)
+      TargetWeight[IBI->getDestination(I)] += BranchWeights[I];
 
   // Eliminate redundant destinations.
   SmallPtrSet<Value *, 8> Succs;
   SmallSetVector<BasicBlock *, 8> RemovedSuccs;
-  for (unsigned i = 0, e = IBI->getNumDestinations(); i != e; ++i) {
-    BasicBlock *Dest = IBI->getDestination(i);
+  for (unsigned I = 0, E = IBI->getNumDestinations(); I != E; ++I) {
+    BasicBlock *Dest = IBI->getDestination(I);
     if (!Dest->hasAddressTaken() || !Succs.insert(Dest).second) {
       if (!Dest->hasAddressTaken())
         RemovedSuccs.insert(Dest);
       Dest->removePredecessor(BB);
-      IBI->removeDestination(i);
-      --i;
-      --e;
+      IBI->removeDestination(I);
+      --I;
+      --E;
       Changed = true;
     }
   }
@@ -7990,7 +8003,12 @@ bool SimplifyCFGOpt::simplifyIndirectBr(IndirectBrInst *IBI) {
     eraseTerminatorAndDCECond(IBI);
     return true;
   }
-
+  if (HasBranchWeights) {
+    SmallVector<uint64_t> NewBranchWeights(IBI->getNumDestinations());
+    for (size_t I = 0, E = IBI->getNumDestinations(); I < E; ++I)
+      NewBranchWeights[I] += TargetWeight.find(IBI->getDestination(I))->second;
+    setFittedBranchWeights(*IBI, NewBranchWeights, /*IsExpected=*/false);
+  }
   if (SelectInst *SI = dyn_cast<SelectInst>(IBI->getAddress())) {
     if (simplifyIndirectBrOnSelect(IBI, SI))
       return requestResimplify();