[NFC] CallGraph related cleanup

Summary: Tidy up some CallGraph-related code in preparation for D82572.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82686

llvm/include/llvm/Analysis/CallGraph.h

@@ -412,7 +412,7 @@ public:
 // graphs by the generic graph algorithms.
 //
 
-// Provide graph traits for tranversing call graphs using standard graph
+// Provide graph traits for traversing call graphs using standard graph
 // traversals.
 template <> struct GraphTraits<CallGraphNode *> {
   using NodeRef = CallGraphNode *;

llvm/lib/Analysis/CallGraphSCCPass.cpp

@@ -230,17 +230,16 @@ bool CGPassManager::RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG,
       // If this call site is null, then the function pass deleted the call
       // entirely and the WeakTrackingVH nulled it out.
       auto *Call = dyn_cast_or_null<CallBase>(I->first);
-      if (!I->first ||
+      if (!Call ||
           // If we've already seen this call site, then the FunctionPass RAUW'd
           // one call with another, which resulted in two "uses" in the edge
           // list of the same call.
-          Calls.count(I->first) ||
+          Calls.count(Call) ||
 
           // If the call edge is not from a call or invoke, or it is a
           // instrinsic call, then the function pass RAUW'd a call with
           // another value. This can happen when constant folding happens
           // of well known functions etc.
-          !Call ||
           (Call->getCalledFunction() &&
            Call->getCalledFunction()->isIntrinsic() &&
            Intrinsic::isLeaf(Call->getCalledFunction()->getIntrinsicID()))) {
@@ -267,14 +266,13 @@ bool CGPassManager::RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG,
         continue;
       }
 
-      assert(!Calls.count(I->first) &&
-             "Call site occurs in node multiple times");
+      assert(!Calls.count(Call) && "Call site occurs in node multiple times");
 
       if (Call) {
         Function *Callee = Call->getCalledFunction();
         // Ignore intrinsics because they're not really function calls.
         if (!Callee || !(Callee->isIntrinsic()))
-          Calls.insert(std::make_pair(I->first, I->second));
+          Calls.insert(std::make_pair(Call, I->second));
       }
       ++I;
     }

llvm/lib/Transforms/IPO/SyntheticCountsPropagation.cpp

@@ -109,8 +109,7 @@ PreservedAnalyses SyntheticCountsPropagation::run(Module &M,
     Optional<Scaled64> Res = None;
     if (!Edge.first)
       return Res;
-    assert(isa<Instruction>(Edge.first));
-    CallBase &CB = cast<CallBase>(*Edge.first);
+    CallBase &CB = *cast<CallBase>(Edge.first);
     Function *Caller = CB.getCaller();
     auto &BFI = FAM.getResult<BlockFrequencyAnalysis>(*Caller);