Heat Coloring for CFGPrinter and CallPrinter

[knaumov]

Summary

Extends the CFGPrinter and CallPrinter with heat colors based on heuristics or profiling information.

This patch was firstly published by Rodrigo Caetano Rocha (@rcorcs) on 11/24/17. After several rounds of reviews, it was deployed, but, mainly due to the conflict with Polly, it was reverted. After that, the conflict with Polly alongside some other small issues was fixed, but never deployed. The diff then was closed due to the commit that probably happened during migration. I would like to bring this change upstream. I have taken it up to me to make some changes regarding flags initialization and refactoring some older tests to match the new output of CFGPrinter specifically. All the further info on the patch you can find in the previous reviews.

Initial diff: reviews.llvm.org/D40425
First commit: reviews.llvm.org/rL335996
Revert commit: reviews.llvm.org/rL336000
Polly fix: reviews.llvm.org/D49154

[knaumov]

ping

[davidxl]

llvm/lib/Analysis/HeatUtils.cpp

39

You can use ProfileSummaryInfo::hasProfileSummary interface.

66

parameter not used

67

clang-format

73

The function entry count should have the information

99

for the program's max count, max function count, get it from ProfileSummaryInfo.

[sfertile]

I'm embarrassed to say I though the old patches landed after the Polly fix, so I really appreciate you taking the time to update the patches.

I've added a few comments to start/ One thing I would suggest is running clang-format over all the changes.

llvm/include/llvm/Analysis/CFGPrinter.h

237

Minor nit: Fix the extra white space.

241

Remove extra blank line.

250

const unsigned MaxEdgeWidth = 2
so shouldn't this just be double Width = 1.0 + WeightPercent;

252

Can we convert the else block into an early return instead -->

if (!CFGInfo->useRawEdgeWeights())
  return formatv("label=\"{0:P}\" penwidth={1}", WeightPercent, Width).str();

[knaumov]

Addressed @davidxl and @sfertile comments.

Answering @davidxl 's comment on "The function entry count should have the information", line 73, HeatUtils.cpp:
This function counts the number of calls of one specific function by another specific function while Function.entryCount() returns number entries for this function.

Answering @davidxl 's comment on "for the program's max count, max function count, get it from ProfileSummaryInfo.", line 99, HeatUtils.cpp:
ProfileSummaryInfo doesn't contain info on the maximum frequency in the module, it needs to be calculated.

Updates:

• Ran clang-format through all the files
• Deleted some function which had no use (see hasProfiling function)
• Deleted const unsigned variables

[knaumov]

ping

[davidxl]

In D73142#1855835, @knaumov wrote:

Addressed @davidxl and @sfertile comments.

Answering @davidxl 's comment on "The function entry count should have the information", line 73, HeatUtils.cpp:
This function counts the number of calls of one specific function by another specific function while Function.entryCount() returns number entries for this function.

Answering @davidxl 's comment on "for the program's max count, max function count, get it from ProfileSummaryInfo.", line 99, HeatUtils.cpp:
ProfileSummaryInfo doesn't contain info on the maximum frequency in the module, it needs to be calculated.

Updates:

• Ran clang-format through all the files
• Deleted some function which had no use (see hasProfiling function)
• Deleted const unsigned variables

The max count info from a module can be misleading. The module itself in most of the cases are cold, so profile summary should be used for cases when profile data is available.

Another major issue is that when real profile is not available (when heurstic is used), the blockfrequency value is relative to the a function, so you can not really compare block frequency values across function boundaries. For that, a round of synthetic profile count propagation is needed.

llvm/lib/Analysis/CallPrinter.cpp

37

By looking at the code, it seems that the difference of 'full' vs 'nonfull' is a whether it is a multi-graph or not.

71

How can this be? The caller of the callsite can not be a declaration.

[knaumov]

Changes:

• Renamed a flag ("callgraph-full" -> "call-multigraph") to reflect its purpose more clearly
• Removed unnecessary if-check
• General refactoring and restructuring
• Removed useHeuristic from the code - from the structure of the code it is vivid that useHeuristic variable used in getMaxFreq functions is always set to "true" and never becomes "false".

Addressing @davidxl 's comments:
ProfileSummaryInfo class will not be useful in this problem as it only gives the result on
whether the BB or the Function is hot or cold, without information on how hot or cold
it is when compared to the other BBs or Functions.
On the other hand, I agree with the fact that comparing local maximum BB frequencies
in function throughout the module is useless and can be misleading. However, I don't
see any "nice" way out of that, as the solution that you suggested (SyntheticCountsPropagation pass)
involves altering the module which should be avoided in a diagnostical pass. Also, as CallGraphs
are printed per function, there is no worry that the colors are going to be somewhat misleading.

[davidxl]

Since it is meaningless to compare blockfrequency across function boundaries (and computing module max): the following can be done

1. when profile is available, try to compute max block count (actual profile count) per module
2. when profile is not available, try to do function scope heat coloring only.

[knaumov]

• Removed flag that was targeting coloring BB based on their relative hotness across the module.

I have decided to do that for the following reasons:

1. The patch is self-contained without this feature. This feature can be added in a follow-up patch.
2. The feature itself is not as important and valuable as was first thought of.

My suggestions for implementing this feature:
Although we only have a relative frequency of BB with respect to the function, using the relative frequency of a function with respect to the module we can translate it to be relative to the module. We can do that using ProfileSummary to get the number of entries per a function.

[knaumov]

Fixes:

• Restoring the effect of clang-format

The effect of clang-format was restored for better readability of the patch

• Deleted Heuristic fully

As I said in the previous diffs, Heuristic bool was always true and never changing.

• Transferred CFGPrinter back to Function Pass

The patch was made module in order to implement the comparison between BB across functions. As this patch is not targeting this behavior, the pass was decided to remain Function Pass

• Small stylistics changes

[davidxl]

is there call graph related test case?

Also some sample output file of the CFG and CallGraph with heat color will be helpful.

llvm/include/llvm/Analysis/HeatUtils.h

29

Add documentation.

33

add documentation. Similarly for other interfaces.

llvm/lib/Analysis/CallPrinter.cpp

83

this quadratic behavior.

[knaumov]

Fixes:

• Added documentation to the new functions
• Added two test cases - one for multigraph, the second one for heat CallGraph/CFG specifically
• Reduced the quadratic behavior that was mentioned by @davidxl . There is no way to reduce the behavior to smaller than O(n^2), but I've made it to (n^2)/2. There is no need to go beyond this as this is just a debugging feature that is not to be used outside of debugging.

Also, I am attaching two samples of heat coloring - CFG and CallGraph.

good_cfg.pdf19 KBDownload

good_callgraph.pdf14 KBDownload

[knaumov]

Ping

[davidxl]

The cfg example (and pdf) looks great. However the callgraph example looks not quite right. Can you provide the test_for_loop.ll file as well? thanks.

[davidxl]

If you split the CFG part of the changes into a separate patch, I think it is almost in good shape to land first.

[knaumov]

All of the related patches were successfully reviewed and landed!
Thanks to everyone who has participated in this long journey!

llvm/include/llvm/Analysis/CFGPrinter.h

 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_ANALYSIS_CFGPRINTER_H
 #define LLVM_ANALYSIS_CFGPRINTER_H
 
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/Module.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/PassManager.h"
+#include "llvm/Analysis/BlockFrequencyInfo.h"
+#include "llvm/Analysis/BranchProbabilityInfo.h"
+#include "llvm/Analysis/HeatUtils.h"
+#include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/GraphWriter.h"
 
 namespace llvm {
 class CFGViewerPass
     : public PassInfoMixin<CFGViewerPass> {
 public:
-  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
 };
 
 class CFGOnlyViewerPass
     : public PassInfoMixin<CFGOnlyViewerPass> {
 public:
-  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
 };
 
 class CFGPrinterPass
     : public PassInfoMixin<CFGPrinterPass> {
 public:
-  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
 };
 
 class CFGOnlyPrinterPass
     : public PassInfoMixin<CFGOnlyPrinterPass> {
 public:
-  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
+};
+
+class CFGDOTInfo {
+private:
+  const Function *F;
+  const BlockFrequencyInfo *BFI;
+  const BranchProbabilityInfo *BPI;
+  uint64_t MaxFreq;
+  bool ShowHeat;
+  bool Heuristic;
+  bool EdgeWeights;
+  bool RawWeights;
+
+public:
+  CFGDOTInfo(const Function *F) : CFGDOTInfo(F, nullptr, nullptr, 0) { }
+
+  CFGDOTInfo(const Function *F, const BlockFrequencyInfo *BFI,
+             BranchProbabilityInfo *BPI, uint64_t MaxFreq)
+      : F(F), BFI(BFI), BPI(BPI), MaxFreq(MaxFreq) {
+    ShowHeat = false;
+    Heuristic = true;
+    EdgeWeights = true;
+    RawWeights = true;
+  }
+
+  const BlockFrequencyInfo *getBFI() { return BFI; }
+
+  const BranchProbabilityInfo *getBPI() { return BPI; }
+
+  const Function *getFunction() { return this->F; }
+
+  uint64_t getMaxFreq() { return MaxFreq; }
+
+  uint64_t getFreq(const BasicBlock *BB) {
+    return getBlockFreq(BB, BFI, Heuristic);
+  }
+
+  void setHeatColors(bool ShowHeat) { this->ShowHeat = ShowHeat; }
+
+  bool showHeatColors() { return ShowHeat; }
+
+  void setHeuristic(bool Heuristic) { this->Heuristic = Heuristic; }
+
+  bool useHeuristic() { return Heuristic; }
+
+  void setRawEdgeWeights(bool RawWeights) { this->RawWeights = RawWeights; }
+
+  bool useRawEdgeWeights() { return RawWeights; }
+
+  void setEdgeWeights(bool EdgeWeights) { this->EdgeWeights = EdgeWeights; }
+
+  bool showEdgeWeights() { return EdgeWeights; }
 };
 
-template<>
-struct DOTGraphTraits<const Function*> : public DefaultDOTGraphTraits {
+template <>
+struct GraphTraits<CFGDOTInfo *> : public GraphTraits<const BasicBlock *> {
+  static NodeRef getEntryNode(CFGDOTInfo *CFGInfo) {
+    return &(CFGInfo->getFunction()->getEntryBlock());
+  }
+
+  // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
+  using nodes_iterator = pointer_iterator<Function::const_iterator>;
+
+  static nodes_iterator nodes_begin(CFGDOTInfo *CFGInfo) {
+    return nodes_iterator(CFGInfo->getFunction()->begin());
+  }
+
+  static nodes_iterator nodes_end(CFGDOTInfo *CFGInfo) {
+    return nodes_iterator(CFGInfo->getFunction()->end());
+  }
+
+  static size_t size(CFGDOTInfo *CFGInfo) { return CFGInfo->getFunction()->size(); }
+};
+
+template <> struct DOTGraphTraits<CFGDOTInfo *> : public DefaultDOTGraphTraits {
 
-  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
+  DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
 
-  static std::string getGraphName(const Function *F) {
-    return "CFG for '" + F->getName().str() + "' function";
+  static std::string getGraphName(CFGDOTInfo *CFGInfo) {
+    return "CFG for '" + CFGInfo->getFunction()->getName().str() + "' function";
   }
 
-  static std::string getSimpleNodeLabel(const BasicBlock *Node,
-                                        const Function *) {
+  static std::string getSimpleNodeLabel(const BasicBlock *Node, CFGDOTInfo *) {
     if (!Node->getName().empty())
       return Node->getName().str();
 
     std::string Str;
     raw_string_ostream OS(Str);
 
     Node->printAsOperand(OS, false);
     return OS.str();
   }
 
   static std::string getCompleteNodeLabel(const BasicBlock *Node,
-                                          const Function *) {
+                                          CFGDOTInfo *) {
     enum { MaxColumns = 80 };
     std::string Str;
     raw_string_ostream OS(Str);
 
     if (Node->getName().empty()) {
       Node->printAsOperand(OS, false);
       OS << ":";
     }
for (unsigned i = 0; i != OutStr.length(); ++i) {
       else
         ++ColNum;
       if (OutStr[i] == ' ')
         LastSpace = i;
     }
     return OutStr;
   }
 
-  std::string getNodeLabel(const BasicBlock *Node,
-                           const Function *Graph) {
+  std::string getNodeLabel(const BasicBlock *Node, CFGDOTInfo *CFGInfo) {
+
     if (isSimple())
-      return getSimpleNodeLabel(Node, Graph);
+      return getSimpleNodeLabel(Node, CFGInfo);
     else
-      return getCompleteNodeLabel(Node, Graph);
+      return getCompleteNodeLabel(Node, CFGInfo);
   }
 
   static std::string getEdgeSourceLabel(const BasicBlock *Node,
                                         succ_const_iterator I) {
     // Label source of conditional branches with "T" or "F"
     if (const BranchInst *BI = dyn_cast<BranchInst>(Node->getTerminator()))
       if (BI->isConditional())
         return (I == succ_begin(Node)) ? "T" : "F";
if (const SwitchInst *SI = dyn_cast<SwitchInst>(Node->getTerminator())) {
       OS << Case.getCaseValue()->getValue();
       return OS.str();
     }
     return "";
   }
 
   /// Display the raw branch weights from PGO.
   std::string getEdgeAttributes(const BasicBlock *Node, succ_const_iterator I,
-                                const Function *F) {
+                                CFGDOTInfo *CFGInfo) {
+    if (!CFGInfo->showEdgeWeights())
+      return "";
+
+    const unsigned MaxEdgeWidth = 2;
+
     const Instruction *TI = Node->getTerminator();
     if (TI->getNumSuccessors() == 1)
+      return "penwidth="+std::to_string(MaxEdgeWidth);
+
+    unsigned OpNo = I.getSuccessorIndex();
+
+
+
+    if (OpNo >= TI->getNumSuccessors())
+
       return "";
 
+    std::string Attrs = "";
+
+    BasicBlock *SuccBB = TI->getSuccessor(OpNo);
+    auto BranchProb = CFGInfo->getBPI()->getEdgeProbability(Node,SuccBB);
+    double WeightPercent = ((double)BranchProb.getNumerator()) /
+                           ((double)BranchProb.getDenominator());
+    double Width = 1+(MaxEdgeWidth-1)*WeightPercent;
+
+    if (CFGInfo->useRawEdgeWeights()) {
+      // Prepend a 'W' to indicate that this is a weight rather than the actual
+      // profile count (due to scaling).
+
+      uint64_t Freq = CFGInfo->getFreq(Node);
+      Attrs = formatv("label=\"W:{0}\" penwidth={1}", (uint64_t)(Freq*WeightPercent), Width);
+      if (Attrs.size())
+        return Attrs;
+
       MDNode *WeightsNode = TI->getMetadata(LLVMContext::MD_prof);
       if (!WeightsNode)
-      return "";
+        return Attrs;
 
       MDString *MDName = cast<MDString>(WeightsNode->getOperand(0));
       if (MDName->getString() != "branch_weights")
-      return "";
+        return Attrs;
 
       unsigned OpNo = I.getSuccessorIndex() + 1;
       if (OpNo >= WeightsNode->getNumOperands())
-      return "";
+        return Attrs;
       ConstantInt *Weight =
           mdconst::dyn_extract<ConstantInt>(WeightsNode->getOperand(OpNo));
       if (!Weight)
+        return Attrs;
+
+      Attrs = "label=\"W:" + std::to_string(Weight->getZExtValue()) + "\" penwidth=" + std::to_string(Width);
+    } else {
+      //formatting value to percentage
+      Attrs = formatv("label=\"{0:P}\" penwidth={1}", WeightPercent, Width);
+    }
+    return Attrs;
+  }
+
+  std::string getNodeAttributes(const BasicBlock *Node, CFGDOTInfo *CFGInfo) {
+
+    if (!CFGInfo->showHeatColors())
       return "";
 
-    // Prepend a 'W' to indicate that this is a weight rather than the actual
-    // profile count (due to scaling).
-    return ("label=\"W:" + Twine(Weight->getZExtValue()) + "\"").str();
+    uint64_t Freq = CFGInfo->getFreq(Node);
+    std::string Color = getHeatColor(Freq, CFGInfo->getMaxFreq());
+    std::string EdgeColor = (Freq <= (CFGInfo->getMaxFreq() / 2))
+                             ? (getHeatColor(0))
+                             : (getHeatColor(1));
+
+    std::string Attrs = "color=\"" + EdgeColor + "ff\", style=filled,"+
+                        "fillcolor=\"" + Color + "70\"";
+    return Attrs;
+  }
+  bool isNodeHidden(const BasicBlock *Node) {
+    return false;
   }
 };
-} // End llvm namespace
+} // namespace llvm
 
 namespace llvm {
-  class FunctionPass;
-  FunctionPass *createCFGPrinterLegacyPassPass ();
-  FunctionPass *createCFGOnlyPrinterLegacyPassPass ();
-} // End llvm namespace
+class ModulePass;
+ModulePass *createCFGPrinterLegacyPassPass();
+ModulePass *createCFGOnlyPrinterLegacyPassPass();
+} // namespace llvm
 
 #endif

llvm/include/llvm/Analysis/HeatUtils.h

+//===-- HeatUtils.h - Utility for printing heat colors ----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Utility for printing heat colors based on heuristics or profiling
+// information.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_HEATUTILS_H
+#define LLVM_ANALYSIS_HEATUTILS_H
+
+#include "llvm/Analysis/BlockFrequencyInfo.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/CallSite.h"
+
+#include <string>
+
+namespace llvm {
+
+bool hasProfiling(const Module &M);
+
+uint64_t getBlockFreq(const BasicBlock *BB, const BlockFrequencyInfo *BFI,
+                      bool useHeuristic = true);
+
+uint64_t getNumOfCalls(Function &callerFunction, Function &calledFunction,
+                       function_ref<BlockFrequencyInfo *(Function &)> LookupBFI,
+                       bool useHeuristic = true);
+
+uint64_t getNumOfCalls(CallSite &callsite,
+                       function_ref<BlockFrequencyInfo *(Function &)> LookupBFI,
+                       bool useHeuristic = true);
+
+uint64_t getMaxFreq(const Function &F, const BlockFrequencyInfo *BFI,
+                    bool useHeuristic = true);
+
+uint64_t getMaxFreq(Module &M,
+                    function_ref<BlockFrequencyInfo *(Function &)> LookupBFI,
+                    bool useHeuristic = true);
+
+std::string getHeatColor(uint64_t freq, uint64_t maxFreq);
+
+std::string getHeatColor(double percent);
+
+} // namespace llvm
+
+#endif
 No newline at end of file

llvm/lib/Analysis/CFGPrinter.cpp

static cl::opt<std::string> CFGFuncName(
     "cfg-func-name", cl::Hidden,
     cl::desc("The name of a function (or its substring)"
              " whose CFG is viewed/printed."));
 
 static cl::opt<std::string> CFGDotFilenamePrefix(
     "cfg-dot-filename-prefix", cl::Hidden,
     cl::desc("The prefix used for the CFG dot file names."));
 
+static cl::opt<bool> CFGHeatPerFunction("cfg-heat-per-function",
+                                        cl::init(false), cl::Hidden,
+                                        cl::desc("Heat CFG per function"));
+
+static cl::opt<bool> ShowHeatColors("cfg-heat-colors", cl::init(false),
+                                    cl::Hidden,
+                                    cl::desc("Show heat colors in CFG"));
+
+static cl::opt<bool> UseRawEdgeWeight("cfg-raw-weights", cl::init(false),
+                                      cl::Hidden,
+                                      cl::desc("Use raw weights for labels. "
+                                               "Use percentages as default."));
+
+static cl::opt<bool> ShowEdgeWeight("cfg-weights", cl::init(false), cl::Hidden,
+                                    cl::desc("Show edges labeled with weights"));
+
+static void writeHeatCFGToDotFile(Function &F, BlockFrequencyInfo *BFI,
+                                 BranchProbabilityInfo *BPI, uint64_t MaxFreq,
+                                 bool UseHeuristic, bool isSimple) {
+  std::string Filename =
+      (CFGDotFilenamePrefix + "." + F.getName() + ".dot").str();
+  errs() << "Writing '" << Filename << "'...";
+
+  std::error_code EC;
+  raw_fd_ostream File(Filename, EC, sys::fs::F_Text);
+
+  CFGDOTInfo CFGInfo(&F, BFI, BPI, MaxFreq);
+  CFGInfo.setHeuristic(UseHeuristic);
+  CFGInfo.setHeatColors(ShowHeatColors);
+  CFGInfo.setEdgeWeights(ShowEdgeWeight);
+  CFGInfo.setRawEdgeWeights(UseRawEdgeWeight);
+
+  if (!EC)
+    WriteGraph(File, &CFGInfo, isSimple);
+  else
+    errs() << "  error opening file for writing!";
+  errs() << "\n";
+}
+
+static void writeAllCFGsToDotFile(Module &M,
+                       function_ref<BlockFrequencyInfo *(Function &)> LookupBFI,
+                       function_ref<BranchProbabilityInfo *(Function &)> LookupBPI,
+                       bool isSimple) {
+  bool UseHeuristic = true;
+  uint64_t MaxFreq = 0;
+  if (!CFGHeatPerFunction)
+    MaxFreq = getMaxFreq(M, LookupBFI, UseHeuristic);
+
+  for (auto &F : M) {
+    if (F.isDeclaration()) continue;
+    auto *BFI = LookupBFI(F);
+    auto *BPI = LookupBPI(F);
+    if (CFGHeatPerFunction)
+      MaxFreq = getMaxFreq(F, BFI, UseHeuristic);
+    writeHeatCFGToDotFile(F, BFI, BPI, MaxFreq, UseHeuristic, isSimple);
+  }
+
+}
+
+static void viewHeatCFG(Function &F, BlockFrequencyInfo *BFI,
+                                 BranchProbabilityInfo *BPI, uint64_t MaxFreq,
+                                 bool UseHeuristic, bool isSimple) {
+  CFGDOTInfo CFGInfo(&F, BFI, BPI, MaxFreq);
+  CFGInfo.setHeuristic(UseHeuristic);
+  CFGInfo.setHeatColors(ShowHeatColors);
+  CFGInfo.setEdgeWeights(ShowEdgeWeight);
+  CFGInfo.setRawEdgeWeights(UseRawEdgeWeight);
+
+  ViewGraph(&CFGInfo, "cfg." + F.getName(), isSimple);
+}
+
+static void viewAllCFGs(Module &M,
+                       function_ref<BlockFrequencyInfo *(Function &)> LookupBFI,
+                       function_ref<BranchProbabilityInfo *(Function &)> LookupBPI,
+                       bool isSimple) {
+  bool UseHeuristic = true;
+  uint64_t MaxFreq = 0;
+  if (!CFGHeatPerFunction)
+    MaxFreq = getMaxFreq(M, LookupBFI, UseHeuristic);
+
+  for (auto &F : M) {
+    if (F.isDeclaration()) continue;
+    auto *BFI = LookupBFI(F);
+    auto *BPI = LookupBPI(F);
+    if (CFGHeatPerFunction)
+      MaxFreq = getMaxFreq(F, BFI, UseHeuristic);
+    viewHeatCFG(F, BFI, BPI, MaxFreq, UseHeuristic, isSimple);
+  }
+}
+
 namespace {
-  struct CFGViewerLegacyPass : public FunctionPass {
+  struct CFGViewerLegacyPass : public ModulePass {
     static char ID; // Pass identifcation, replacement for typeid
-    CFGViewerLegacyPass() : FunctionPass(ID) {
+    CFGViewerLegacyPass() : ModulePass(ID) {
       initializeCFGViewerLegacyPassPass(*PassRegistry::getPassRegistry());
     }
 
-    bool runOnFunction(Function &F) override {
-      F.viewCFG();
+    bool runOnModule(Module &M) override {
+      auto LookupBFI = [this](Function &F) {
+        return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();
+      };
+      auto LookupBPI = [this](Function &F) {
+        return &this->getAnalysis<BranchProbabilityInfoWrapperPass>(F).getBPI();
+      };
+      viewAllCFGs(M, LookupBFI, LookupBPI, /*isSimple=*/false);
       return false;
     }
 
-    void print(raw_ostream &OS, const Module* = nullptr) const override {}
+    void print(raw_ostream &OS, const Module * = nullptr) const override {}
 
     void getAnalysisUsage(AnalysisUsage &AU) const override {
+      ModulePass::getAnalysisUsage(AU);
+      AU.addRequired<BlockFrequencyInfoWrapperPass>();
+      AU.addRequired<BranchProbabilityInfoWrapperPass>();
       AU.setPreservesAll();
     }
-  };
 }
 
 char CFGViewerLegacyPass::ID = 0;
 INITIALIZE_PASS(CFGViewerLegacyPass, "view-cfg", "View CFG of function", false, true)
 
-PreservedAnalyses CFGViewerPass::run(Function &F,
-                                     FunctionAnalysisManager &AM) {
-  F.viewCFG();
+PreservedAnalyses CFGViewerPass::run(Module &M,
+                                     ModuleAnalysisManager &AM) {
+  auto &FAM = AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
+  auto LookupBFI = [&FAM](Function &F) {
+    return &FAM.getResult<BlockFrequencyAnalysis>(F);
+  };
+  auto LookupBPI = [&FAM](Function &F) {
+    return &FAM.getResult<BranchProbabilityAnalysis>(F);
+  };
+  viewAllCFGs(M, LookupBFI, LookupBPI, /*isSimple=*/false);
   return PreservedAnalyses::all();
 }
 
 
 namespace {
-  struct CFGOnlyViewerLegacyPass : public FunctionPass {
+  struct CFGOnlyViewerLegacyPass : public ModulePass {
     static char ID; // Pass identifcation, replacement for typeid
-    CFGOnlyViewerLegacyPass() : FunctionPass(ID) {
+    CFGOnlyViewerLegacyPass() : ModulePass(ID) {
       initializeCFGOnlyViewerLegacyPassPass(*PassRegistry::getPassRegistry());
     }
 
-    bool runOnFunction(Function &F) override {
-      F.viewCFGOnly();
+    bool runOnModule(Module &M) override {
+      auto LookupBFI = [this](Function &F) {
+        return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();
+      };
+      auto LookupBPI = [this](Function &F) {
+        return &this->getAnalysis<BranchProbabilityInfoWrapperPass>(F).getBPI();
+      };
+      viewAllCFGs(M, LookupBFI, LookupBPI, /*isSimple=*/true);
       return false;
     }
 
-    void print(raw_ostream &OS, const Module* = nullptr) const override {}
+    void print(raw_ostream &OS, const Module * = nullptr) const override {}
 
     void getAnalysisUsage(AnalysisUsage &AU) const override {
+      ModulePass::getAnalysisUsage(AU);
+      AU.addRequired<BlockFrequencyInfoWrapperPass>();
+      AU.addRequired<BranchProbabilityInfoWrapperPass>();
       AU.setPreservesAll();
     }
   };
 }
 
 char CFGOnlyViewerLegacyPass::ID = 0;
 INITIALIZE_PASS(CFGOnlyViewerLegacyPass, "view-cfg-only",
                 "View CFG of function (with no function bodies)", false, true)
 
-PreservedAnalyses CFGOnlyViewerPass::run(Function &F,
-                                         FunctionAnalysisManager &AM) {
-  F.viewCFGOnly();
+PreservedAnalyses CFGOnlyViewerPass::run(Module &M,
+                                         ModuleAnalysisManager &AM) {
+  auto &FAM = AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
+  auto LookupBFI = [&FAM](Function &F) {
+    return &FAM.getResult<BlockFrequencyAnalysis>(F);
+  };
+  auto LookupBPI = [&FAM](Function &F) {
+    return &FAM.getResult<BranchProbabilityAnalysis>(F);
+  };
+  viewAllCFGs(M, LookupBFI, LookupBPI, /*isSimple=*/true);
   return PreservedAnalyses::all();
 }
 
-static void writeCFGToDotFile(Function &F, bool CFGOnly = false) {
-  if (!CFGFuncName.empty() && !F.getName().contains(CFGFuncName))
-     return;
-  std::string Filename =
-      (CFGDotFilenamePrefix + "." + F.getName() + ".dot").str();
-  errs() << "Writing '" << Filename << "'...";
-
-  std::error_code EC;
-  raw_fd_ostream File(Filename, EC, sys::fs::OF_Text);
-
-  if (!EC)
-    WriteGraph(File, (const Function*)&F, CFGOnly);
-  else
-    errs() << "  error opening file for writing!";
-  errs() << "\n";
-}
-
 namespace {
-  struct CFGPrinterLegacyPass : public FunctionPass {
+  struct CFGPrinterLegacyPass : public ModulePass {
     static char ID; // Pass identification, replacement for typeid
-    CFGPrinterLegacyPass() : FunctionPass(ID) {
+    CFGPrinterLegacyPass() : ModulePass(ID) {
       initializeCFGPrinterLegacyPassPass(*PassRegistry::getPassRegistry());
     }
 
-    bool runOnFunction(Function &F) override {
-      writeCFGToDotFile(F);
+    bool runOnModule(Module &M) override {
+      auto LookupBFI = [this](Function &F) {
+        return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();
+      };
+      auto LookupBPI = [this](Function &F) {
+        return &this->getAnalysis<BranchProbabilityInfoWrapperPass>(F).getBPI();
+      };
+      writeAllCFGsToDotFile(M, LookupBFI, LookupBPI, /*isSimple=*/false);
       return false;
     }
 
-    void print(raw_ostream &OS, const Module* = nullptr) const override {}
+    void print(raw_ostream &OS, const Module * = nullptr) const override {}
 
     void getAnalysisUsage(AnalysisUsage &AU) const override {
+      ModulePass::getAnalysisUsage(AU);
+      AU.addRequired<BlockFrequencyInfoWrapperPass>();
+      AU.addRequired<BranchProbabilityInfoWrapperPass>();
       AU.setPreservesAll();
     }
   };
 }
 
 char CFGPrinterLegacyPass::ID = 0;
 INITIALIZE_PASS(CFGPrinterLegacyPass, "dot-cfg", "Print CFG of function to 'dot' file",
                 false, true)
 
-PreservedAnalyses CFGPrinterPass::run(Function &F,
-                                      FunctionAnalysisManager &AM) {
-  writeCFGToDotFile(F);
+PreservedAnalyses CFGPrinterPass::run(Module &M,
+                                      ModuleAnalysisManager &AM) {
+  auto &FAM = AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
+  auto LookupBFI = [&FAM](Function &F) {
+    return &FAM.getResult<BlockFrequencyAnalysis>(F);
+  };
+  auto LookupBPI = [&FAM](Function &F) {
+    return &FAM.getResult<BranchProbabilityAnalysis>(F);
+  };
+  writeAllCFGsToDotFile(M, LookupBFI, LookupBPI, /*isSimple=*/false);
   return PreservedAnalyses::all();
 }
 
 namespace {
-  struct CFGOnlyPrinterLegacyPass : public FunctionPass {
+  struct CFGOnlyPrinterLegacyPass : public ModulePass {
     static char ID; // Pass identification, replacement for typeid
-    CFGOnlyPrinterLegacyPass() : FunctionPass(ID) {
+    CFGOnlyPrinterLegacyPass() : ModulePass(ID) {
       initializeCFGOnlyPrinterLegacyPassPass(*PassRegistry::getPassRegistry());
     }
 
-    bool runOnFunction(Function &F) override {
-      writeCFGToDotFile(F, /*CFGOnly=*/true);
+    bool runOnModule(Module &M) override {
+      auto LookupBFI = [this](Function &F) {
+        return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();
+      };
+      auto LookupBPI = [this](Function &F) {
+        return &this->getAnalysis<BranchProbabilityInfoWrapperPass>(F).getBPI();
+      };
+      writeAllCFGsToDotFile(M, LookupBFI, LookupBPI, /*isSimple=*/true);
       return false;
     }
-    void print(raw_ostream &OS, const Module* = nullptr) const override {}
+    void print(raw_ostream &OS, const Module * = nullptr) const override {}
 
     void getAnalysisUsage(AnalysisUsage &AU) const override {
+      ModulePass::getAnalysisUsage(AU);
+      AU.addRequired<BlockFrequencyInfoWrapperPass>();
+      AU.addRequired<BranchProbabilityInfoWrapperPass>();
       AU.setPreservesAll();
     }
   };
 }
 
 char CFGOnlyPrinterLegacyPass::ID = 0;
 INITIALIZE_PASS(CFGOnlyPrinterLegacyPass, "dot-cfg-only",
    "Print CFG of function to 'dot' file (with no function bodies)",
    false, true)
 
-PreservedAnalyses CFGOnlyPrinterPass::run(Function &F,
-                                          FunctionAnalysisManager &AM) {
-  writeCFGToDotFile(F, /*CFGOnly=*/true);
+PreservedAnalyses CFGOnlyPrinterPass::run(Module &M,
+                                          ModuleAnalysisManager &AM) {
+  auto &FAM = AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
+  auto LookupBFI = [&FAM](Function &F) {
+    return &FAM.getResult<BlockFrequencyAnalysis>(F);
+  };
+  auto LookupBPI = [&FAM](Function &F) {
+    return &FAM.getResult<BranchProbabilityAnalysis>(F);
+  };
+  writeAllCFGsToDotFile(M, LookupBFI, LookupBPI, /*isSimple=*/true);
   return PreservedAnalyses::all();
 }
 
 /// viewCFG - This function is meant for use from the debugger.  You can just
 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
 /// program, displaying the CFG of the current function.  This depends on there
 /// being a 'dot' and 'gv' program in your path.
 ///
 void Function::viewCFG() const {
   if (!CFGFuncName.empty() && !getName().contains(CFGFuncName))
      return;
-  ViewGraph(this, "cfg" + getName());
+  CFGDOTInfo CFGInfo(this);
+  ViewGraph(&CFGInfo, "cfg" + getName());
 }
 
 /// viewCFGOnly - This function is meant for use from the debugger.  It works
 /// just like viewCFG, but it does not include the contents of basic blocks
 /// into the nodes, just the label.  If you are only interested in the CFG
 /// this can make the graph smaller.
 ///
 void Function::viewCFGOnly() const {
   if (!CFGFuncName.empty() && !getName().contains(CFGFuncName))
      return;
-  ViewGraph(this, "cfg" + getName(), true);
+  CFGDOTInfo CFGInfo(this);
+  ViewGraph(&CFGInfo, "cfg" + getName(), true);
 }
 
-FunctionPass *llvm::createCFGPrinterLegacyPassPass () {
+ModulePass *llvm::createCFGPrinterLegacyPassPass() {
   return new CFGPrinterLegacyPass();
 }
 
-FunctionPass *llvm::createCFGOnlyPrinterLegacyPassPass () {
+ModulePass *llvm::createCFGOnlyPrinterLegacyPassPass() {
   return new CFGOnlyPrinterLegacyPass();
-}
-
+}

llvm/lib/Analysis/CMakeLists.txt

add_llvm_component_library(LLVMAnalysis
   DependenceGraphBuilder.cpp
   DivergenceAnalysis.cpp
   DomPrinter.cpp
   DomTreeUpdater.cpp
   DominanceFrontier.cpp
   EHPersonalities.cpp
   GlobalsModRef.cpp
   GuardUtils.cpp
+  HeatUtils.cpp
   IVDescriptors.cpp
   IVUsers.cpp
   IndirectCallPromotionAnalysis.cpp
   InlineCost.cpp
   InstCount.cpp
   InstructionPrecedenceTracking.cpp
   InstructionSimplify.cpp
   Interval.cpp

llvm/lib/Analysis/CallPrinter.cpp

 //===- CallPrinter.cpp - DOT printer for call graph -----------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines '-dot-callgraph', which emit a callgraph.<fnname>.dot
 // containing the call graph of a module.
 //
 // There is also a pass available to directly call dotty ('-view-callgraph').
 //
 //===----------------------------------------------------------------------===//
 
 #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;
 
+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>
+    EstimateEdgeWeight("callgraph-weights", cl::init(false), cl::Hidden,
+                       cl::desc("Show edges labeled with weights"));
+
+static cl::opt<bool>
+    FullCallGraph("callgraph-full", cl::init(false), cl::Hidden,
+                  cl::desc("Show full call-graph (including external nodes)"));
+
+static cl::opt<bool> UseCallCounter(
+    "callgraph-call-count", cl::init(false), cl::Hidden,
+    cl::desc("Use function's call counter as a heat metric. "
+             "The default is the function's maximum block frequency."));
+
 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;
+  uint64_t MaxEdgeCount;
+
+public:
+  std::function<BlockFrequencyInfo *(Function &)> LookupBFI;
+
+  CallGraphDOTInfo(Module *M, CallGraph *CG,
+                   function_ref<BlockFrequencyInfo *(Function &)> LookupBFI)
+      : M(M), CG(CG), LookupBFI(LookupBFI) {
+    MaxFreq = 0;
+    MaxEdgeCount = 0;
+
+    for (Function &F : *M) {
+      Freq[&F] = 0;
+
+      if (FullCallGraph) {
+        for (User *U : F.users()) {
+          auto CS = CallSite(U);
+          if (!CS.getCaller()->isDeclaration()) {
+            uint64_t Counter = getNumOfCalls(CS, LookupBFI);
+            if (Counter > MaxEdgeCount) {
+              MaxEdgeCount = Counter;
+            }
+          }
+        }
+      }
+
+      if (F.isDeclaration())
+        continue;
+      uint64_t localMaxFreq = 0;
+      if (UseCallCounter) {
+        Function::ProfileCount EntryCount = F.getEntryCount();
+        if (EntryCount.hasValue())
+          localMaxFreq = EntryCount.getCount();
+      } else {
+        localMaxFreq = llvm::getMaxFreq(F, LookupBFI(F));
+      }
+      if (localMaxFreq >= MaxFreq)
+        MaxFreq = localMaxFreq;
+      Freq[&F] = localMaxFreq;
+
+      if (!FullCallGraph) {
+        for (Function &Callee : *M) {
+          uint64_t Counter = getNumOfCalls(F, Callee, LookupBFI);
+          if (Counter > MaxEdgeCount) {
+            MaxEdgeCount = Counter;
+          }
+        }
+      }
+    }
+    if (!FullCallGraph)
+      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; }
+
+  uint64_t getMaxEdgeCount() { return MaxEdgeCount; }
+
+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.count(CI->second->getFunction()))
+            Visited.insert(CI->second->getFunction());
+          else {
+            FoundParallelEdge = true;
+            Node->removeCallEdge(CI);
+            break;
+          }
+        }
+      }
+    }
+  }
+};
+
+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 {
+
+  SmallSet<User *, 16> VisitedCallSites;  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 (FullCallGraph)
+      return false;
+
+    if (Node->getFunction())
+      return false;
 
-  static std::string getGraphName(CallGraph *Graph) { return "Call graph"; }
+    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";
 
-  std::string getNodeLabel(CallGraphNode *Node, CallGraph *Graph) {
     if (Function *Func = Node->getFunction())
       return Func->getName();
 
     return "external node";
   }
-};
+  static const CallGraphNode *CGGetValuePtr(CallGraphNode::CallRecord P) {
+    return P.second;
+  }
 
-struct AnalysisCallGraphWrapperPassTraits {
-  static CallGraph *getGraph(CallGraphWrapperPass *P) {
-    return &P->getCallGraph();
+  // 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 (!EstimateEdgeWeight)
+      return "";
+
+    Function *Caller = Node->getFunction();
+    if (Caller == nullptr || Caller->isDeclaration())
+      return "";
+
+    Function *Callee = (*I)->getFunction();
+    if (Callee == nullptr)
+      return "";
+
+    uint64_t Counter = 0;
+    if (FullCallGraph) {
+      // looks for next call site between Caller and Callee
+      for (User *U : Callee->users()) {
+        auto CS = CallSite(U);
+        if (CS.getCaller() == Caller) {
+          if (VisitedCallSites.count(U))
+            continue;
+          VisitedCallSites.insert(U);
+          Counter = getNumOfCalls(CS, CGInfo->LookupBFI);
+          break;
+        }
+      }
+    } else {
+      Counter = getNumOfCalls(*Caller, *Callee, CGInfo->LookupBFI);
+    }
+
+    const unsigned MaxEdgeWidth = 3;
+
+    double Width =
+        1 + (MaxEdgeWidth - 1) * (double(Counter) / CGInfo->getMaxEdgeCount());
+    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 || F->isDeclaration())
+      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 llvm
 
 namespace {
 
-struct CallGraphViewer
-    : public DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
-                                        AnalysisCallGraphWrapperPassTraits> {
+// Viewer
+
+class CallGraphViewer : public ModulePass {
+public:
   static char ID;
+  CallGraphViewer() : ModulePass(ID) {}
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+  bool runOnModule(Module &M) override;
+
+
 
-  CallGraphViewer()
-      : DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
-                                   AnalysisCallGraphWrapperPassTraits>(
-            "callgraph", ID) {
-    initializeCallGraphViewerPass(*PassRegistry::getPassRegistry());
-  }
+
+};
+
+void CallGraphViewer::getAnalysisUsage(AnalysisUsage &AU) const {
+  ModulePass::getAnalysisUsage(AU);
+  AU.addRequired<BlockFrequencyInfoWrapperPass>();
+  AU.setPreservesAll();
+
+bool CallGraphViewer::runOnModule(Module &M) {
+  auto LookupBFI = [this](Function &F) {
+    return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();
   };
 
-struct CallGraphDOTPrinter : public DOTGraphTraitsModulePrinter<
-                              CallGraphWrapperPass, true, CallGraph *,
-                              AnalysisCallGraphWrapperPassTraits> {
+  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;
 
-  CallGraphDOTPrinter()
-      : DOTGraphTraitsModulePrinter<CallGraphWrapperPass, true, CallGraph *,
-                                    AnalysisCallGraphWrapperPassTraits>(
-            "callgraph", ID) {
-    initializeCallGraphDOTPrinterPass(*PassRegistry::getPassRegistry());
-  }
+
+
+
+};
+
+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 =
+      (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;
 INITIALIZE_PASS(CallGraphViewer, "view-callgraph", "View call graph", false,
                 false)
 
 char CallGraphDOTPrinter::ID = 0;
 INITIALIZE_PASS(CallGraphDOTPrinter, "dot-callgraph",

llvm/lib/Analysis/DomPrinter.cpp

std::string getNodeLabel(DomTreeNode *Node, DomTreeNode *Graph) {
 
     BasicBlock *BB = Node->getBlock();
 
     if (!BB)
       return "Post dominance root node";
 
 
     if (isSimple())
-      return DOTGraphTraits<const Function*>
-        ::getSimpleNodeLabel(BB, BB->getParent());
+      return DOTGraphTraits<CFGDOTInfo*>
+        ::getSimpleNodeLabel(BB, nullptr);
     else
-      return DOTGraphTraits<const Function*>
-        ::getCompleteNodeLabel(BB, BB->getParent());
+      return DOTGraphTraits<CFGDOTInfo*>
+        ::getCompleteNodeLabel(BB, nullptr);
   }
 };
 
 template<>
 struct DOTGraphTraits<DominatorTree*> : public DOTGraphTraits<DomTreeNode*> {
 
   DOTGraphTraits (bool isSimple=false)
     : DOTGraphTraits<DomTreeNode*>(isSimple) {}

llvm/lib/Analysis/HeatUtils.cpp

+//===-- HeatUtils.cpp - Utility for printing heat colors --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Utility for printing heat colors based on heuristics or profiling
+// information.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/HeatUtils.h"
+#include "llvm/IR/Instructions.h"
+
+namespace llvm {
+
+static const unsigned heatSize = 100;
+static const std::string heatPalette[heatSize] = {
+    "#3d50c3", "#4055c8", "#4358cb", "#465ecf", "#4961d2", "#4c66d6", "#4f69d9",
+    "#536edd", "#5572df", "#5977e3", "#5b7ae5", "#5f7fe8", "#6282ea", "#6687ed",
+    "#6a8bef", "#6c8ff1", "#7093f3", "#7396f5", "#779af7", "#7a9df8", "#7ea1fa",
+    "#81a4fb", "#85a8fc", "#88abfd", "#8caffe", "#8fb1fe", "#93b5fe", "#96b7ff",
+    "#9abbff", "#9ebeff", "#a1c0ff", "#a5c3fe", "#a7c5fe", "#abc8fd", "#aec9fc",
+    "#b2ccfb", "#b5cdfa", "#b9d0f9", "#bbd1f8", "#bfd3f6", "#c1d4f4", "#c5d6f2",
+    "#c7d7f0", "#cbd8ee", "#cedaeb", "#d1dae9", "#d4dbe6", "#d6dce4", "#d9dce1",
+    "#dbdcde", "#dedcdb", "#e0dbd8", "#e3d9d3", "#e5d8d1", "#e8d6cc", "#ead5c9",
+    "#ecd3c5", "#eed0c0", "#efcebd", "#f1ccb8", "#f2cab5", "#f3c7b1", "#f4c5ad",
+    "#f5c1a9", "#f6bfa6", "#f7bca1", "#f7b99e", "#f7b599", "#f7b396", "#f7af91",
+    "#f7ac8e", "#f7a889", "#f6a385", "#f5a081", "#f59c7d", "#f4987a", "#f39475",
+    "#f29072", "#f08b6e", "#ef886b", "#ed8366", "#ec7f63", "#e97a5f", "#e8765c",
+    "#e57058", "#e36c55", "#e16751", "#de614d", "#dc5d4a", "#d85646", "#d65244",
+    "#d24b40", "#d0473d", "#cc403a", "#ca3b37", "#c53334", "#c32e31", "#be242e",
+    "#bb1b2c", "#b70d28"};
+
+bool hasProfiling(const Module &M) {
+  for (auto &F : M) {
+    for (auto &BB : F) {
+      auto *TI = BB.getTerminator();
+      if (TI == nullptr)
+        continue;
+      if (TI->getMetadata(llvm::LLVMContext::MD_prof) != nullptr)
+        return true;
+    }
+  }
+  return false;
+}
+
+uint64_t getBlockFreq(const BasicBlock *BB, const BlockFrequencyInfo *BFI,
+                      bool useHeuristic) {
+  uint64_t freqVal = 0;
+  if (!useHeuristic) {
+    Optional<uint64_t> freq = BFI->getBlockProfileCount(BB);
+    if (freq.hasValue())
+      freqVal = freq.getValue();
+  } else {
+    freqVal = BFI->getBlockFreq(BB).getFrequency();
+  }
+  return freqVal;
+}
+
+uint64_t getNumOfCalls(CallSite &CS,
+                       function_ref<BlockFrequencyInfo *(Function &)> LookupBFI,
+                       bool useHeuristic) {
+  if (CS.getInstruction()==nullptr) return 0;
+  if (CS.getInstruction()->getParent()==nullptr) return 0;
+  BasicBlock *BB = CS.getInstruction()->getParent();
+  return getBlockFreq(BB, LookupBFI(*CS.getCaller()));
+}
+
+uint64_t getNumOfCalls(Function &callerFunction, Function &calledFunction,
+                       function_ref<BlockFrequencyInfo *(Function &)> LookupBFI,
+                       bool useHeuristic) {
+  uint64_t counter = 0;
+  for (User *U : calledFunction.users()) {
+    if (isa<CallInst>(U)) {
+      auto CS = CallSite(U);
+      if (CS.getCaller() == (&callerFunction)) {
+        counter += getNumOfCalls(CS, LookupBFI);
+      }
+    }
+  }
+  return counter;
+}
+
+uint64_t getMaxFreq(const Function &F, const BlockFrequencyInfo *BFI,
+                    bool useHeuristic) {
+  uint64_t maxFreq = 0;
+  for (const BasicBlock &BB : F) {
+    uint64_t freqVal = getBlockFreq(&BB, BFI, useHeuristic);
+    if (freqVal >= maxFreq)
+      maxFreq = freqVal;
+  }
+  return maxFreq;
+}
+
+uint64_t getMaxFreq(Module &M,
+                    function_ref<BlockFrequencyInfo *(Function &)> LookupBFI,
+                    bool useHeuristic) {
+  uint64_t maxFreq = 0;
+  for (auto &F : M) {
+    if (F.isDeclaration())
+      continue;
+    uint64_t localMaxFreq = getMaxFreq(F, LookupBFI(F), useHeuristic);
+    if (localMaxFreq >= maxFreq)
+      maxFreq = localMaxFreq;
+  }
+  return maxFreq;
+}
+
+std::string getHeatColor(uint64_t freq, uint64_t maxFreq) {
+  if (freq > maxFreq)
+    freq = maxFreq;
+  double percent = log2(double(freq)) / log2(maxFreq);
+  return getHeatColor(percent);
+}
+
+std::string getHeatColor(double percent) {
+  if (percent > 1.0)
+    percent = 1.0;
+  if (percent < 0.0)
+    percent = 0.0;
+  unsigned colorId = unsigned(round(percent * (heatSize - 1.0)));
+  return heatPalette[colorId];
+}
+
+} // namespace llvm
 No newline at end of file

llvm/lib/Analysis/RegionPrinter.cpp

DOTGraphTraits (bool isSimple=false)
     : DefaultDOTGraphTraits(isSimple) {}
 
   std::string getNodeLabel(RegionNode *Node, RegionNode *Graph) {
 
     if (!Node->isSubRegion()) {
       BasicBlock *BB = Node->getNodeAs<BasicBlock>();
 
       if (isSimple())
-        return DOTGraphTraits<const Function*>
-          ::getSimpleNodeLabel(BB, BB->getParent());
+        return DOTGraphTraits<CFGDOTInfo*>
+          ::getSimpleNodeLabel(BB, nullptr);
       else
-        return DOTGraphTraits<const Function*>
-          ::getCompleteNodeLabel(BB, BB->getParent());
+        return DOTGraphTraits<CFGDOTInfo*>
+          ::getCompleteNodeLabel(BB, nullptr);
     }
 
     return "Not implemented";
   }
 };
 
 template <>
 struct DOTGraphTraits<RegionInfo *> : public DOTGraphTraits<RegionNode *> {

llvm/lib/Passes/PassRegistry.def

 MODULE_PASS("always-inline", AlwaysInlinerPass())
 MODULE_PASS("attributor", AttributorPass())
 MODULE_PASS("called-value-propagation", CalledValuePropagationPass())
 MODULE_PASS("canonicalize-aliases", CanonicalizeAliasesPass())
 MODULE_PASS("cg-profile", CGProfilePass())
 MODULE_PASS("constmerge", ConstantMergePass())
 MODULE_PASS("cross-dso-cfi", CrossDSOCFIPass())
 MODULE_PASS("deadargelim", DeadArgumentEliminationPass())
+MODULE_PASS("dot-cfg", CFGPrinterPass())
+MODULE_PASS("dot-cfg-only", CFGOnlyPrinterPass())
 MODULE_PASS("elim-avail-extern", EliminateAvailableExternallyPass())
 MODULE_PASS("forceattrs", ForceFunctionAttrsPass())
 MODULE_PASS("function-import", FunctionImportPass())
 MODULE_PASS("globaldce", GlobalDCEPass())
 MODULE_PASS("globalopt", GlobalOptPass())
 MODULE_PASS("globalsplit", GlobalSplitPass())
 MODULE_PASS("hotcoldsplit", HotColdSplittingPass())
 MODULE_PASS("hwasan", HWAddressSanitizerPass(false, false))

 MODULE_PASS("wholeprogramdevirt", WholeProgramDevirtPass(nullptr, nullptr))
 MODULE_PASS("verify", VerifierPass())
 MODULE_PASS("asan-module", ModuleAddressSanitizerPass(/*CompileKernel=*/false, false, true, false))
 MODULE_PASS("msan-module", MemorySanitizerPass({}))
 MODULE_PASS("tsan-module", ThreadSanitizerPass())
 MODULE_PASS("kasan-module", ModuleAddressSanitizerPass(/*CompileKernel=*/true, false, true, false))
 MODULE_PASS("sancov-module", ModuleSanitizerCoveragePass())
 MODULE_PASS("poison-checking", PoisonCheckingPass())
+MODULE_PASS("view-cfg", CFGViewerPass())
+MODULE_PASS("view-cfg-only", CFGOnlyViewerPass())
 #undef MODULE_PASS
 
 #ifndef CGSCC_ANALYSIS
 #define CGSCC_ANALYSIS(NAME, CREATE_PASS)
 #endif
 CGSCC_ANALYSIS("no-op-cgscc", NoOpCGSCCAnalysis())
 CGSCC_ANALYSIS("fam-proxy", FunctionAnalysisManagerCGSCCProxy())
 CGSCC_ANALYSIS("pass-instrumentation", PassInstrumentationAnalysis(PIC))

 FUNCTION_PASS("break-crit-edges", BreakCriticalEdgesPass())
 FUNCTION_PASS("callsite-splitting", CallSiteSplittingPass())
 FUNCTION_PASS("consthoist", ConstantHoistingPass())
 FUNCTION_PASS("chr", ControlHeightReductionPass())
 FUNCTION_PASS("correlated-propagation", CorrelatedValuePropagationPass())
 FUNCTION_PASS("dce", DCEPass())
 FUNCTION_PASS("div-rem-pairs", DivRemPairsPass())
 FUNCTION_PASS("dse", DSEPass())
-FUNCTION_PASS("dot-cfg", CFGPrinterPass())
-FUNCTION_PASS("dot-cfg-only", CFGOnlyPrinterPass())
 FUNCTION_PASS("early-cse", EarlyCSEPass(/*UseMemorySSA=*/false))
 FUNCTION_PASS("early-cse-memssa", EarlyCSEPass(/*UseMemorySSA=*/true))
 FUNCTION_PASS("ee-instrument", EntryExitInstrumenterPass(/*PostInlining=*/false))
 FUNCTION_PASS("make-guards-explicit", MakeGuardsExplicitPass())
 FUNCTION_PASS("post-inline-ee-instrument", EntryExitInstrumenterPass(/*PostInlining=*/true))
 FUNCTION_PASS("gvn-hoist", GVNHoistPass())
 FUNCTION_PASS("instcombine", InstCombinePass())
 FUNCTION_PASS("instsimplify", InstSimplifyPass())

 FUNCTION_PASS("unroll-and-jam", LoopUnrollAndJamPass())
 FUNCTION_PASS("verify", VerifierPass())
 FUNCTION_PASS("verify<domtree>", DominatorTreeVerifierPass())
 FUNCTION_PASS("verify<loops>", LoopVerifierPass())
 FUNCTION_PASS("verify<memoryssa>", MemorySSAVerifierPass())
 FUNCTION_PASS("verify<regions>", RegionInfoVerifierPass())
 FUNCTION_PASS("verify<safepoint-ir>", SafepointIRVerifierPass())
 FUNCTION_PASS("verify<scalar-evolution>", ScalarEvolutionVerifierPass())
-FUNCTION_PASS("view-cfg", CFGViewerPass())
-FUNCTION_PASS("view-cfg-only", CFGOnlyViewerPass())
 FUNCTION_PASS("transform-warning", WarnMissedTransformationsPass())
 FUNCTION_PASS("asan", AddressSanitizerPass(false, false, false))
 FUNCTION_PASS("kasan", AddressSanitizerPass(true, false, false))
 FUNCTION_PASS("msan", MemorySanitizerPass({}))
 FUNCTION_PASS("kmsan", MemorySanitizerPass({0, false, /*Kernel=*/true}))
 FUNCTION_PASS("tsan", ThreadSanitizerPass())
 #undef FUNCTION_PASS
 

llvm/lib/Transforms/Scalar/NewGVN.cpp

 bool NewGVN::isBackedge(BasicBlock *From, BasicBlock *To) const {
   return From == To ||
          RPOOrdering.lookup(DT->getNode(From)) >=
              RPOOrdering.lookup(DT->getNode(To));
 }
 
 #ifndef NDEBUG
 static std::string getBlockName(const BasicBlock *B) {
-  return DOTGraphTraits<const Function *>::getSimpleNodeLabel(B, nullptr);
+  return DOTGraphTraits<CFGDOTInfo *>::getSimpleNodeLabel(B, nullptr);
 }
 #endif
 
 // Get a MemoryAccess for an instruction, fake or real.
 MemoryUseOrDef *NewGVN::getMemoryAccess(const Instruction *I) const {
   auto *Result = MSSA->getMemoryAccess(I);
   return Result ? Result : TempToMemory.lookup(I);
 }

llvm/test/Other/2007-06-05-PassID.ll

 ;RUN: opt < %s -analyze -dot-cfg-only 2>/dev/null
 ;RUN: opt < %s -analyze -passes=dot-cfg-only 2>/dev/null
+;RUN: opt < %s -analyze -dot-cfg-only \
+;RUN:          -cfg-heat-colors=true -cfg-weights=true 2>/dev/null
+;RUN: opt < %s -analyze -dot-cfg-only \
+;RUN:          -cfg-heat-colors=false -cfg-weights=false 2>/dev/null
+;RUN: opt < %s -analyze -dot-cfg \
+;RUN:          -cfg-heat-colors=true -cfg-weights=true 2>/dev/null
+;RUN: opt < %s -analyze -dot-cfg \
+;RUN:          -cfg-heat-colors=false -cfg-weights=false 2>/dev/null
 ;PR 1497
 
 define void @foo() {
 entry:
   br label %return
 
 return:   ; preds = %entry
   ret void
 }
 

llvm/test/Other/cfg-printer-branch-weights-percent.ll

+;RUN: opt < %s -analyze -dot-cfg -cfg-weights -cfg-dot-filename-prefix=%t 2>/dev/null
+;RUN: FileCheck %s -input-file=%t.f.dot
+
+define void @f(i32) {
+entry:
+  %check = icmp sgt i32 %0, 0
+  br i1 %check, label %if, label %exit, !prof !0
+
+; CHECK: label="0.50%"
+; CHECK-NOT: ["];
+if:                     ; preds = %entry
+  br label %exit
+; CHECK: label="99.50%"
+; CHECK-NOT: ["];
+exit:                   ; preds = %entry, %if
+  ret void
+}
+
+!0 = !{!"branch_weights", i32 1, i32 200}

llvm/test/Other/cfg-printer-branch-weights.ll

-;RUN: opt < %s -analyze -dot-cfg -cfg-dot-filename-prefix=%t 2>/dev/null
+;RUN: opt < %s -analyze -dot-cfg -cfg-weights -cfg-raw-weights -cfg-dot-filename-prefix=%t 2>/dev/null
 ;RUN: FileCheck %s -input-file=%t.f.dot
 
 define void @f(i32) {
 entry:
   %check = icmp sgt i32 %0, 0
   br i1 %check, label %if, label %exit, !prof !0
 
-; CHECK: label="W:1"
+; CHECK: label="W:7"
 ; CHECK-NOT: ["];
 if:                     ; preds = %entry
   br label %exit
-; CHECK: label="W:200"
+; CHECK: label="W:1600"
 ; CHECK-NOT: ["];
 exit:                   ; preds = %entry, %if
   ret void
 }
 
 !0 = !{!"branch_weights", i32 1, i32 200}

polly/lib/Analysis/ScopGraphPrinter.cpp

 template <> struct DOTGraphTraits<RegionNode *> : public DefaultDOTGraphTraits {
   DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
 
   std::string getNodeLabel(RegionNode *Node, RegionNode *Graph) {
     if (!Node->isSubRegion()) {
       BasicBlock *BB = Node->getNodeAs<BasicBlock>();
 
       if (isSimple())
-        return DOTGraphTraits<const Function *>::getSimpleNodeLabel(
-            BB, BB->getParent());
+        return DOTGraphTraits<CFGDOTInfo*>::getSimpleNodeLabel(BB, nullptr);
+
       else
-        return DOTGraphTraits<const Function *>::getCompleteNodeLabel(
-            BB, BB->getParent());
+        return DOTGraphTraits<CFGDOTInfo*>::getCompleteNodeLabel(BB, nullptr);
     }
 
     return "Not implemented";
   }
 };
 
 template <>
 struct DOTGraphTraits<ScopDetectionWrapperPass *>

polly/lib/Support/RegisterPasses.cpp

#endif
 
   PM.addPass(CodePreparationPass());
   PM.addPass(createFunctionToScopPassAdaptor(std::move(SPM)));
   PM.addPass(PB.buildFunctionSimplificationPipeline(
       Level, PassBuilder::ThinLTOPhase::None)); // Cleanup
 
   assert(!DumpAfter && "This option is not implemented");
   assert(DumpAfterFile.empty() && "This option is not implemented");
-
-  if (CFGPrinter)
-    PM.addPass(llvm::CFGPrinterPass());
 }
 
 /// Register Polly to be available as an optimizer
 ///
 ///
 /// We can currently run Polly at three different points int the pass manager.
 /// a) very early, b) after the canonicalizing loop transformations and c) right
 /// before the vectorizer.
parseTopLevelPipeline(ModulePassManager &MPM,
   }
 
   FPM.addPass(createFunctionToScopPassAdaptor(std::move(SPM)));
   if (VerifyEachPass)
     FPM.addPass(VerifierPass());
   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
   if (VerifyEachPass)
     MPM.addPass(VerifierPass());
-
+  if (CFGPrinter)
+    MPM.addPass(llvm::CFGPrinterPass());
   return true;
 }
 
 void registerPollyPasses(PassBuilder &PB) {
   PB.registerAnalysisRegistrationCallback(registerFunctionAnalyses);
   PB.registerPipelineParsingCallback(parseFunctionPipeline);
   PB.registerPipelineParsingCallback(parseScopPipeline);
   PB.registerParseTopLevelPipelineCallback(parseTopLevelPipeline);