[CallPrinter] Adding heat coloring to CallPrinter

This patch introduces the heat coloring of the Call Printer which is based
on the relative "hotness" of each function. The patch is a part of sequence of
three patches, related to graphs Heat Coloring.
Another feature added is the flag similar to "-cfg-dot-filename-prefix",
which allows to write the graph into a named .pdf

Reviewers: rcorcs, apilipenko, davidxl, sfertile, fedor.sergeev, eraman, bollu

Differential Revision: https://reviews.llvm.org/D77172

include/llvm/Analysis/HeatUtils.h

@@ -22,6 +22,10 @@ namespace llvm {
 class BlockFrequencyInfo;
 class Function;
 
+// Returns number of calls of calledFunction by callerFunction.
+uint64_t
+getNumOfCalls(Function &callerFunction, Function &calledFunction);
+
 // Returns the maximum frequency of a BB in a function.
 uint64_t getMaxFreq(const Function &F, const BlockFrequencyInfo *BFI);
 

lib/Analysis/CallPrinter.cpp

@@ -14,63 +14,279 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/CallPrinter.h"
+#include "llvm/Analysis/BlockFrequencyInfo.h"
+#include "llvm/Analysis/BranchProbabilityInfo.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/DOTGraphTraitsPass.h"
+#include "llvm/Analysis/HeatUtils.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/InitializePasses.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallSet.h"
 
 using namespace llvm;
 
+// This option shows static (relative) call counts.
+// FIXME:
+// Need to show real counts when profile data is available
+static cl::opt<bool> ShowHeatColors("callgraph-heat-colors", cl::init(false),
+                                    cl::Hidden,
+                                    cl::desc("Show heat colors in call-graph"));
+
+static cl::opt<bool>
+    ShowEdgeWeight("callgraph-show-weights", cl::init(false), cl::Hidden,
+                       cl::desc("Show edges labeled with weights"));
+
+static cl::opt<bool>
+    CallMultiGraph("callgraph-multigraph", cl::init(false), cl::Hidden,
+            cl::desc("Show call-multigraph (do not remove parallel edges)"));
+
+static cl::opt<std::string> CallGraphDotFilenamePrefix(
+    "callgraph-dot-filename-prefix", cl::Hidden,
+    cl::desc("The prefix used for the CallGraph dot file names."));
+
 namespace llvm {
 
-template <> struct DOTGraphTraits<CallGraph *> : public DefaultDOTGraphTraits {
-  DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
+class CallGraphDOTInfo {
+private:
+  Module *M;
+  CallGraph *CG;
+  DenseMap<const Function *, uint64_t> Freq;
+  uint64_t MaxFreq;
 
-  static std::string getGraphName(CallGraph *Graph) { return "Call graph"; }
+public:
+  std::function<BlockFrequencyInfo *(Function &)> LookupBFI;
 
-  std::string getNodeLabel(CallGraphNode *Node, CallGraph *Graph) {
-    if (Function *Func = Node->getFunction())
-      return std::string(Func->getName());
+  CallGraphDOTInfo(Module *M, CallGraph *CG,
+                   function_ref<BlockFrequencyInfo *(Function &)> LookupBFI)
+      : M(M), CG(CG), LookupBFI(LookupBFI) {
+    MaxFreq = 0;
 
-    return "external node";
+    for (auto F = M->getFunctionList().begin(); F != M->getFunctionList().end(); ++F) {
+      uint64_t localSumFreq = 0;
+      SmallSet<Function *, 16> Callers;
+      for (User *U : (*F).users())
+        if (isa<CallInst>(U))
+          Callers.insert(cast<Instruction>(U)->getFunction());
+      for (auto iter = Callers.begin() ; iter != Callers.end() ; ++iter)
+        localSumFreq += getNumOfCalls((**iter), *F);
+      if (localSumFreq >= MaxFreq)
+        MaxFreq = localSumFreq;
+      Freq[&*F] = localSumFreq;
+    }
+    if (!CallMultiGraph)
+      removeParallelEdges();
+  }
+
+  Module *getModule() const { return M; }
+
+  CallGraph *getCallGraph() const { return CG; }
+
+  uint64_t getFreq(const Function *F) { return Freq[F]; }
+
+  uint64_t getMaxFreq() { return MaxFreq; }
+
+private:
+  void removeParallelEdges() {
+    for (auto &I : (*CG)) {
+      CallGraphNode *Node = I.second.get();
+
+      bool FoundParallelEdge = true;
+      while (FoundParallelEdge) {
+        SmallSet<Function *, 16> Visited;
+        FoundParallelEdge = false;
+        for (auto CI = Node->begin(), CE = Node->end(); CI != CE; CI++) {
+          if (!(Visited.insert(CI->second->getFunction())).second) {
+            FoundParallelEdge = true;
+            Node->removeCallEdge(CI);
+            break;
+          }
+        }
+      }
+    }
   }
 };
 
-struct AnalysisCallGraphWrapperPassTraits {
-  static CallGraph *getGraph(CallGraphWrapperPass *P) {
-    return &P->getCallGraph();
+template <>
+struct GraphTraits<CallGraphDOTInfo *>
+    : public GraphTraits<const CallGraphNode *> {
+  static NodeRef getEntryNode(CallGraphDOTInfo *CGInfo) {
+    // Start at the external node!
+    return CGInfo->getCallGraph()->getExternalCallingNode();
+  }
+
+  typedef std::pair<const Function *const, std::unique_ptr<CallGraphNode>>
+      PairTy;
+  static const CallGraphNode *CGGetValuePtr(const PairTy &P) {
+    return P.second.get();
+  }
+
+  // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
+  typedef mapped_iterator<CallGraph::const_iterator, decltype(&CGGetValuePtr)>
+      nodes_iterator;
+
+  static nodes_iterator nodes_begin(CallGraphDOTInfo *CGInfo) {
+    return nodes_iterator(CGInfo->getCallGraph()->begin(), &CGGetValuePtr);
+  }
+  static nodes_iterator nodes_end(CallGraphDOTInfo *CGInfo) {
+    return nodes_iterator(CGInfo->getCallGraph()->end(), &CGGetValuePtr);
+  }
+};
+
+template <>
+struct DOTGraphTraits<CallGraphDOTInfo *> : public DefaultDOTGraphTraits {
+
+  DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
+
+  static std::string getGraphName(CallGraphDOTInfo *CGInfo) {
+    return "Call graph: " +
+           std::string(CGInfo->getModule()->getModuleIdentifier());
+  }
+
+  static bool isNodeHidden(const CallGraphNode *Node) {
+    if (CallMultiGraph || Node->getFunction())
+      return false;
+    return true;
+  }
+
+  std::string getNodeLabel(const CallGraphNode *Node,
+                           CallGraphDOTInfo *CGInfo) {
+    if (Node == CGInfo->getCallGraph()->getExternalCallingNode())
+      return "external caller";
+    if (Node == CGInfo->getCallGraph()->getCallsExternalNode())
+      return "external callee";
+
+    if (Function *Func = Node->getFunction())
+      return std::string(Func->getName());
+    return "external node";
+  }
+  static const CallGraphNode *CGGetValuePtr(CallGraphNode::CallRecord P) {
+    return P.second;
+  }
+
+  // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
+  typedef mapped_iterator<CallGraphNode::const_iterator,
+                          decltype(&CGGetValuePtr)>
+      nodes_iterator;
+
+  std::string getEdgeAttributes(const CallGraphNode *Node, nodes_iterator I,
+                                CallGraphDOTInfo *CGInfo) {
+    if (!ShowEdgeWeight)
+      return "";
+
+    Function *Caller = Node->getFunction();
+    if (Caller == nullptr || Caller->isDeclaration())
+      return "";
+
+    Function *Callee = (*I)->getFunction();
+    if (Callee == nullptr)
+      return "";
+
+    uint64_t Counter = getNumOfCalls(*Caller, *Callee);
+    double Width =
+        1 + 2 * (double(Counter) / CGInfo->getMaxFreq());
+    std::string Attrs = "label=\"" + std::to_string(Counter) +
+                        "\" penwidth=" + std::to_string(Width);
+    return Attrs;
+  }
+
+  std::string getNodeAttributes(const CallGraphNode *Node,
+                                CallGraphDOTInfo *CGInfo) {
+    Function *F = Node->getFunction();
+    if (F == nullptr)
+      return "";
+    std::string attrs = "";
+    if (ShowHeatColors) {
+      uint64_t freq = CGInfo->getFreq(F);
+      std::string color = getHeatColor(freq, CGInfo->getMaxFreq());
+      std::string edgeColor = (freq <= (CGInfo->getMaxFreq() / 2))
+                                  ? getHeatColor(0)
+                                  : getHeatColor(1);
+      attrs = "color=\"" + edgeColor + "ff\", style=filled, fillcolor=\"" +
+              color + "80\"";
+    }
+    return attrs;
   }
 };
 
 } // end llvm namespace
 
 namespace {
-
-struct CallGraphViewer
-    : public DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
-                                        AnalysisCallGraphWrapperPassTraits> {
+// Viewer
+class CallGraphViewer : public ModulePass {
+public:
   static char ID;
+  CallGraphViewer() : ModulePass(ID) {}
 
-  CallGraphViewer()
-      : DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
-                                   AnalysisCallGraphWrapperPassTraits>(
-            "callgraph", ID) {
-    initializeCallGraphViewerPass(*PassRegistry::getPassRegistry());
-  }
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+  bool runOnModule(Module &M) override;
 };
 
-struct CallGraphDOTPrinter : public DOTGraphTraitsModulePrinter<
-                              CallGraphWrapperPass, true, CallGraph *,
-                              AnalysisCallGraphWrapperPassTraits> {
-  static char ID;
+void CallGraphViewer::getAnalysisUsage(AnalysisUsage &AU) const {
+  ModulePass::getAnalysisUsage(AU);
+  AU.addRequired<BlockFrequencyInfoWrapperPass>();
+  AU.setPreservesAll();
+}
 
-  CallGraphDOTPrinter()
-      : DOTGraphTraitsModulePrinter<CallGraphWrapperPass, true, CallGraph *,
-                                    AnalysisCallGraphWrapperPassTraits>(
-            "callgraph", ID) {
-    initializeCallGraphDOTPrinterPass(*PassRegistry::getPassRegistry());
-  }
+bool CallGraphViewer::runOnModule(Module &M) {
+  auto LookupBFI = [this](Function &F) {
+    return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();
+  };
+
+  CallGraph CG(M);
+  CallGraphDOTInfo CFGInfo(&M, &CG, LookupBFI);
+
+  std::string Title =
+      DOTGraphTraits<CallGraphDOTInfo *>::getGraphName(&CFGInfo);
+  ViewGraph(&CFGInfo, "callgraph", true, Title);
+
+  return false;
+}
+
+// DOT Printer
+
+class CallGraphDOTPrinter : public ModulePass {
+public:
+  static char ID;
+  CallGraphDOTPrinter() : ModulePass(ID) {}
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+  bool runOnModule(Module &M) override;
 };
 
+void CallGraphDOTPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
+  ModulePass::getAnalysisUsage(AU);
+  AU.addRequired<BlockFrequencyInfoWrapperPass>();
+  AU.setPreservesAll();
+}
+
+bool CallGraphDOTPrinter::runOnModule(Module &M) {
+  auto LookupBFI = [this](Function &F) {
+    return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();
+  };
+
+  std::string Filename;
+  if (!CallGraphDotFilenamePrefix.empty())
+    Filename = (CallGraphDotFilenamePrefix + ".callgraph.dot");
+  else
+    Filename = (std::string(M.getModuleIdentifier()) + ".callgraph.dot");
+  errs() << "Writing '" << Filename << "'...";
+
+  std::error_code EC;
+  raw_fd_ostream File(Filename, EC, sys::fs::F_Text);
+
+  CallGraph CG(M);
+  CallGraphDOTInfo CFGInfo(&M, &CG, LookupBFI);
+
+  if (!EC)
+    WriteGraph(File, &CFGInfo);
+  else
+    errs() << "  error opening file for writing!";
+  errs() << "\n";
+
+  return false;
+}
+
 } // end anonymous namespace
 
 char CallGraphViewer::ID = 0;

lib/Analysis/HeatUtils.cpp

@@ -36,6 +36,19 @@ static const std::string heatPalette[heatSize] = {
     "#d24b40", "#d0473d", "#cc403a", "#ca3b37", "#c53334", "#c32e31", "#be242e",
     "#bb1b2c", "#b70d28"};
 
+uint64_t
+getNumOfCalls(Function &callerFunction, Function &calledFunction) {
+  uint64_t counter = 0;
+  for (User *U : calledFunction.users()) {
+    if (auto CI = dyn_cast<CallInst>(U)) {
+      if (CI->getCaller() == (&callerFunction)) {
+          counter += 1;
+      }
+    }
+  }
+  return counter;
+}
+
 uint64_t getMaxFreq(const Function &F, const BlockFrequencyInfo *BFI) {
   uint64_t maxFreq = 0;
   for (const BasicBlock &BB : F) {

test/Other/heat-colors-graphs.ll

@@ -1,9 +1,11 @@
 ; RUN: opt < %s -analyze -dot-cfg -cfg-heat-colors -cfg-dot-filename-prefix=%t 2>/dev/null
-; RUN: FileCheck %s -input-file=%t.f.dot
+; RUN: FileCheck %s -input-file=%t.f.dot --check-prefixes=CHECK-CFG,CHECK-BOTH
+; RUN: opt %s -dot-callgraph -callgraph-heat-colors -callgraph-dot-filename-prefix=%t 2>/dev/null
+; RUN: FileCheck %s -input-file=%t.callgraph.dot --check-prefix=CHECK-BOTH
 
-; CHECK: color="#{{[(a-z)(0-9)]+}}", style={{[a-z]+}}, fillcolor="#{{[(a-z)(0-9)]+}}"
-; CHECK: color="#{{[(a-z)(0-9)]+}}", style={{[a-z]+}}, fillcolor="#{{[(a-z)(0-9)]+}}"
-; CHECK: color="#{{[(a-z)(0-9)]+}}", style={{[a-z]+}}, fillcolor="#{{[(a-z)(0-9)]+}}"
+; CHECK-BOTH: color="#{{[(a-z)(0-9)]+}}", style={{[a-z]+}}, fillcolor="#{{[(a-z)(0-9)]+}}"
+; CHECK-CFG: color="#{{[(a-z)(0-9)]+}}", style={{[a-z]+}}, fillcolor="#{{[(a-z)(0-9)]+}}"
+; CHECK-CFG: color="#{{[(a-z)(0-9)]+}}", style={{[a-z]+}}, fillcolor="#{{[(a-z)(0-9)]+}}"
 
 define void @f(i32) {
 entry:

test/Other/heat-colors-multigraph.ll

@@ -0,0 +1,16 @@
+; RUN: opt %s -dot-callgraph -callgraph-multigraph -callgraph-dot-filename-prefix=%t 2>/dev/null
+; RUN: FileCheck %s -input-file=%t.callgraph.dot --check-prefix=CHECK-MULTIGRAPH
+; RUN: opt %s -dot-callgraph -callgraph-dot-filename-prefix=%t 2>/dev/null
+; RUN: FileCheck %s -input-file=%t.callgraph.dot --check-prefix=CHECK
+
+; CHECK-MULTIGRAPH: {external caller}
+; CHECK-NOT: {external caller}
+
+define void @bar() {
+  ret void
+}
+
+define void @foo() {
+  call void @bar()
+  ret void
+}