[ThinLTO] Implement summary visualizer

Differential revision: https://reviews.llvm.org/D41297

llvm-svn: 323062

1 files changed, 244 insertions, 0 deletions

diff --git a/llvm/lib/IR/ModuleSummaryIndex.cpp b/llvm/lib/IR/ModuleSummaryIndex.cpp
index 51c4bae3332..a0b963e7af3 100644
--- a/llvm/lib/IR/ModuleSummaryIndex.cpp
+++ b/llvm/lib/IR/ModuleSummaryIndex.cpp
@@ -14,6 +14,7 @@
 
 #include "llvm/IR/ModuleSummaryIndex.h"
 #include "llvm/ADT/StringMap.h"
+#include "llvm/Support/Path.h"
 using namespace llvm;
 
 // Collect for the given module the list of function it defines
@@ -69,3 +70,246 @@ bool ModuleSummaryIndex::isGUIDLive(GlobalValue::GUID GUID) const {
       return true;
   return false;
 }
+
+namespace {
+struct Attributes {
+  void add(const Twine &Name, const Twine &Value,
+           const Twine &Comment = Twine());
+  std::string getAsString() const;
+
+  std::vector<std::string> Attrs;
+  std::string Comments;
+};
+
+struct Edge {
+  uint64_t SrcMod;
+  int Hotness;
+  GlobalValue::GUID Src;
+  GlobalValue::GUID Dst;
+};
+}
+
+void Attributes::add(const Twine &Name, const Twine &Value,
+                     const Twine &Comment) {
+  std::string A = Name.str();
+  A += "=\"";
+  A += Value.str();
+  A += "\"";
+  Attrs.push_back(A);
+  if (!Comment.isTriviallyEmpty()) {
+    if (Comments.empty())
+      Comments = " // ";
+    else
+      Comments += ", ";
+    Comments += Comment.str();
+  }
+}
+
+std::string Attributes::getAsString() const {
+  if (Attrs.empty())
+    return "";
+
+  std::string Ret = "[";
+  for (auto &A : Attrs)
+    Ret += A + ",";
+  Ret.pop_back();
+  Ret += "];";
+  Ret += Comments;
+  return Ret;
+}
+
+static std::string linkageToString(GlobalValue::LinkageTypes LT) {
+  switch (LT) {
+  case GlobalValue::ExternalLinkage:
+    return "extern";
+  case GlobalValue::AvailableExternallyLinkage:
+    return "av_ext";
+  case GlobalValue::LinkOnceAnyLinkage:
+    return "linkonce";
+  case GlobalValue::LinkOnceODRLinkage:
+    return "linkonce_odr";
+  case GlobalValue::WeakAnyLinkage:
+    return "weak";
+  case GlobalValue::WeakODRLinkage:
+    return "weak_odr";
+  case GlobalValue::AppendingLinkage:
+    return "appending";
+  case GlobalValue::InternalLinkage:
+    return "internal";
+  case GlobalValue::PrivateLinkage:
+    return "private";
+  case GlobalValue::ExternalWeakLinkage:
+    return "extern_weak";
+  case GlobalValue::CommonLinkage:
+    return "common";
+  }
+
+  return "<unknown>";
+}
+
+static std::string fflagsToString(FunctionSummary::FFlags F) {
+  auto FlagValue = [](unsigned V) { return V ? '1' : '0'; };
+  char FlagRep[] = {FlagValue(F.ReadNone), FlagValue(F.ReadOnly),
+                    FlagValue(F.NoRecurse), FlagValue(F.ReturnDoesNotAlias), 0};
+
+  return FlagRep;
+}
+
+// Get string representation of function instruction count and flags.
+static std::string getSummaryAttributes(GlobalValueSummary* GVS) {
+  auto *FS = dyn_cast_or_null<FunctionSummary>(GVS);
+  if (!FS)
+    return "";
+
+  return std::string("inst: ") + std::to_string(FS->instCount()) +
+         ", ffl: " + fflagsToString(FS->fflags());
+}
+
+static std::string getNodeVisualName(const ValueInfo &VI) {
+  return VI.name().empty() ? std::string("@") + std::to_string(VI.getGUID())
+                           : VI.name().str();
+}
+
+static std::string getNodeLabel(const ValueInfo &VI, GlobalValueSummary *GVS) {
+  if (isa<AliasSummary>(GVS))
+    return getNodeVisualName(VI);
+
+  std::string Attrs = getSummaryAttributes(GVS);
+  std::string Label =
+      getNodeVisualName(VI) + "|" + linkageToString(GVS->linkage());
+  if (!Attrs.empty())
+    Label += std::string(" (") + Attrs + ")";
+  Label += "}";
+
+  return Label;
+}
+
+// Write definition of external node, which doesn't have any
+// specific module associated with it. Typically this is function
+// or variable defined in native object or library.
+static void defineExternalNode(raw_ostream &OS, const char *Pfx,
+                               const ValueInfo &VI) {
+  auto StrId = std::to_string(VI.getGUID());
+  OS << "  " << StrId << " [label=\"" << getNodeVisualName(VI)
+     << "\"]; // defined externally\n";
+}
+
+void ModuleSummaryIndex::exportToDot(raw_ostream& OS) const {
+  std::vector<Edge> CrossModuleEdges;
+  DenseMap<GlobalValue::GUID, std::vector<uint64_t>> NodeMap;
+  StringMap<GVSummaryMapTy> ModuleToDefinedGVS;
+  collectDefinedGVSummariesPerModule(ModuleToDefinedGVS);
+
+  // Get node identifier in form MXXX_<GUID>. The MXXX prefix is required,
+  // because we may have multiple linkonce functions summaries.
+  auto NodeId = [](uint64_t ModId, GlobalValue::GUID Id) {
+    return ModId == (uint64_t)-1 ? std::to_string(Id)
+                                 : std::string("M") + std::to_string(ModId) +
+                                       "_" + std::to_string(Id);
+  };
+
+  auto DrawEdge = [&](const char *Pfx, int SrcMod, GlobalValue::GUID SrcId,
+                      int DstMod, GlobalValue::GUID DstId, int TypeOrHotness) {
+    // 0 corresponds to alias edge, 1 to ref edge, 2 to call with unknown
+    // hotness, ...
+    TypeOrHotness += 2;
+    static const char *EdgeAttrs[] = {
+        " [style=dotted]; // alias",
+        " [style=dashed]; // ref",
+        " // call (hotness : Unknown)",
+        " [color=blue]; // call (hotness : Cold)",
+        " // call (hotness : None)",
+        " [color=brown]; // call (hotness : Hot)",
+        " [style=bold,color=red]; // call (hotness : Critical)"};
+
+    assert(static_cast<size_t>(TypeOrHotness) <
+           sizeof(EdgeAttrs) / sizeof(EdgeAttrs[0]));
+    OS << Pfx << NodeId(SrcMod, SrcId) << " -> " << NodeId(DstMod, DstId)
+       << EdgeAttrs[TypeOrHotness] << "\n";
+  };
+
+  OS << "digraph Summary {\n";
+  for (auto &ModIt : ModuleToDefinedGVS) {
+    auto ModId = getModuleId(ModIt.first());
+    OS << "  // Module: " << ModIt.first() << "\n";
+    OS << "  subgraph cluster_" << std::to_string(ModId) << " {\n";
+    OS << "    style = filled;\n";
+    OS << "    color = lightgrey;\n";
+    OS << "    label = \"" << sys::path::filename(ModIt.first()) << "\";\n";
+    OS << "    node [style=filled,fillcolor=lightblue];\n";
+
+    auto &GVSMap = ModIt.second;
+    auto Draw = [&](GlobalValue::GUID IdFrom, GlobalValue::GUID IdTo, int Hotness) {
+      if (!GVSMap.count(IdTo)) {
+        CrossModuleEdges.push_back({ModId, Hotness, IdFrom, IdTo});
+        return;
+      }
+      DrawEdge("    ", ModId, IdFrom, ModId, IdTo, Hotness);
+    };
+
+    for (auto &SummaryIt : GVSMap) {
+      NodeMap[SummaryIt.first].push_back(ModId);
+      auto Flags = SummaryIt.second->flags();
+      Attributes A;
+      if (isa<FunctionSummary>(SummaryIt.second)) {
+        A.add("shape", "record", "function");
+      } else if (isa<AliasSummary>(SummaryIt.second)) {
+        A.add("style", "dotted,filled", "alias");
+        A.add("shape", "box");
+      } else {
+        A.add("shape", "Mrecord", "variable");
+      }
+
+      auto VI = getValueInfo(SummaryIt.first);
+      A.add("label", getNodeLabel(VI, SummaryIt.second));
+      if (!Flags.Live)
+        A.add("fillcolor", "red", "dead");
+      else if (Flags.NotEligibleToImport)
+        A.add("fillcolor", "yellow", "not eligible to import");
+
+      OS << "    " << NodeId(ModId, SummaryIt.first) << " " << A.getAsString()
+         << "\n";
+    }
+    OS << "    // Edges:\n";
+
+    for (auto &SummaryIt : GVSMap) {
+      auto *GVS = SummaryIt.second;
+      for (auto &R : GVS->refs())
+        Draw(SummaryIt.first, R.getGUID(), -1);
+
+      if (auto *AS = dyn_cast_or_null<AliasSummary>(SummaryIt.second)) {
+        auto AliaseeOrigId = AS->getAliasee().getOriginalName();
+        auto AliaseeId = getGUIDFromOriginalID(AliaseeOrigId);
+
+        Draw(SummaryIt.first, AliaseeId ? AliaseeId : AliaseeOrigId, -2);
+        continue;
+      }
+
+      if (auto *FS = dyn_cast_or_null<FunctionSummary>(SummaryIt.second))
+        for (auto &CGEdge : FS->calls())
+          Draw(SummaryIt.first, CGEdge.first.getGUID(),
+               static_cast<int>(CGEdge.second.Hotness));
+    }
+    OS << "  }\n";
+  }
+
+  for (auto &E : CrossModuleEdges) {
+    auto &ModList = NodeMap[E.Dst];
+    if (ModList.empty()) {
+      defineExternalNode(OS, "  ", getValueInfo(E.Dst));
+      // Add fake module to the list to draw an edge to an external node
+      // in the loop below.
+      ModList.push_back(-1);
+    }
+    for (auto DstMod : ModList)
+      // The edge representing call or ref is drawn to every module where target
+      // symbol is defined. When target is a linkonce symbol there can be
+      // multiple edges representing a single call or ref, both intra-module and
+      // cross-module. As we've already drawn all intra-module edges before we
+      // skip it here.
+      if (DstMod != E.SrcMod)
+        DrawEdge("  ", E.SrcMod, E.Src, DstMod, E.Dst, E.Hotness);
+  }
+
+  OS << "}";
+}