llvm/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp

   1 //===-- SelectionDAGPrinter.cpp - Implement SelectionDAG::viewGraph() -----===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This implements the SelectionDAG::viewGraph method.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "ScheduleDAGSDNodes.h"
  14 #include "llvm/ADT/DenseSet.h"
  15 #include "llvm/ADT/StringExtras.h"
  16 #include "llvm/CodeGen/MachineFunction.h"
  17 #include "llvm/CodeGen/SelectionDAG.h"
  18 #include "llvm/Support/Debug.h"
  19 #include "llvm/Support/GraphWriter.h"
  20 #include "llvm/Support/raw_ostream.h"
  21 using namespace llvm;
  22
  23 #define DEBUG_TYPE "dag-printer"
  24
  25 namespace llvm {
  26   template<>
  27   struct DOTGraphTraits<SelectionDAG*> : public DefaultDOTGraphTraits {
  28
  29     explicit DOTGraphTraits(bool isSimple=false) :
  30       DefaultDOTGraphTraits(isSimple) {}
  31
  32     static bool hasEdgeDestLabels() {
  33       return true;
  34     }
  35
  36     static unsigned numEdgeDestLabels(const void *Node) {
  37       return ((const SDNode *) Node)->getNumValues();
  38     }
  39
  40     static std::string getEdgeDestLabel(const void *Node, unsigned i) {
  41       return ((const SDNode *) Node)->getValueType(i).getEVTString();
  42     }
  43
  44     template<typename EdgeIter>
  45     static std::string getEdgeSourceLabel(const void *Node, EdgeIter I) {
  46       return itostr(I - SDNodeIterator::begin((const SDNode *) Node));
  47     }
  48
  49     /// edgeTargetsEdgeSource - This method returns true if this outgoing edge
  50     /// should actually target another edge source, not a node.  If this method
  51     /// is implemented, getEdgeTarget should be implemented.
  52     template<typename EdgeIter>
  53     static bool edgeTargetsEdgeSource(const void *Node, EdgeIter I) {
  54       return true;
  55     }
  56
  57     /// getEdgeTarget - If edgeTargetsEdgeSource returns true, this method is
  58     /// called to determine which outgoing edge of Node is the target of this
  59     /// edge.
  60     template<typename EdgeIter>
  61     static EdgeIter getEdgeTarget(const void *Node, EdgeIter I) {
  62       SDNode *TargetNode = *I;
  63       SDNodeIterator NI = SDNodeIterator::begin(TargetNode);
  64       std::advance(NI, I.getNode()->getOperand(I.getOperand()).getResNo());
  65       return NI;
  66     }
  67
  68     static std::string getGraphName(const SelectionDAG *G) {
  69       return std::string(G->getMachineFunction().getName());
  70     }
  71
  72     static bool renderGraphFromBottomUp() {
  73       return true;
  74     }
  75
  76     static std::string getNodeIdentifierLabel(const SDNode *Node,
  77                                               const SelectionDAG *Graph) {
  78       std::string R;
  79       raw_string_ostream OS(R);
  80 #ifndef NDEBUG
  81       OS << 't' << Node->PersistentId;
  82 #else
  83       OS << static_cast<const void *>(Node);
  84 #endif
  85       return R;
  86     }
  87
  88     /// If you want to override the dot attributes printed for a particular
  89     /// edge, override this method.
  90     template<typename EdgeIter>
  91     static std::string getEdgeAttributes(const void *Node, EdgeIter EI,
  92                                          const SelectionDAG *Graph) {
  93       SDValue Op = EI.getNode()->getOperand(EI.getOperand());
  94       EVT VT = Op.getValueType();
  95       if (VT == MVT::Glue)
  96         return "color=red,style=bold";
  97       else if (VT == MVT::Other)
  98         return "color=blue,style=dashed";
  99       return "";
 100     }
 101
 102
 103     static std::string getSimpleNodeLabel(const SDNode *Node,
 104                                           const SelectionDAG *G) {
 105       std::string Result = Node->getOperationName(G);
 106       {
 107         raw_string_ostream OS(Result);
 108         Node->print_details(OS, G);
 109       }
 110       return Result;
 111     }
 112     std::string getNodeLabel(const SDNode *Node, const SelectionDAG *Graph);
 113     static std::string getNodeAttributes(const SDNode *N,
 114                                          const SelectionDAG *Graph) {
 115 #ifndef NDEBUG
 116       const std::string &Attrs = Graph->getGraphAttrs(N);
 117       if (!Attrs.empty()) {
 118         if (Attrs.find("shape=") == std::string::npos)
 119           return std::string("shape=Mrecord,") + Attrs;
 120         else
 121           return Attrs;
 122       }
 123 #endif
 124       return "shape=Mrecord";
 125     }
 126
 127     static void addCustomGraphFeatures(SelectionDAG *G,
 128                                        GraphWriter<SelectionDAG*> &GW) {
 129       GW.emitSimpleNode(nullptr, "plaintext=circle", "GraphRoot");
 130       if (G->getRoot().getNode())
 131         GW.emitEdge(nullptr, -1, G->getRoot().getNode(), G->getRoot().getResNo(),
 132                     "color=blue,style=dashed");
 133     }
 134   };
 135 }
 136
 137 std::string DOTGraphTraits<SelectionDAG*>::getNodeLabel(const SDNode *Node,
 138                                                         const SelectionDAG *G) {
 139   return DOTGraphTraits<SelectionDAG*>::getSimpleNodeLabel(Node, G);
 140 }
 141
 142
 143 /// viewGraph - Pop up a ghostview window with the reachable parts of the DAG
 144 /// rendered using 'dot'.
 145 ///
 146 void SelectionDAG::viewGraph(const std::string &Title) {
 147 // This code is only for debugging!
 148 #ifndef NDEBUG
 149   ViewGraph(this, "dag." + getMachineFunction().getName(),
 150             false, Title);
 151 #else
 152   errs() << "SelectionDAG::viewGraph is only available in debug builds on "
 153          << "systems with Graphviz or gv!\n";
 154 #endif  // NDEBUG
 155 }
 156
 157 // This overload is defined out-of-line here instead of just using a
 158 // default parameter because this is easiest for gdb to call.
 159 void SelectionDAG::viewGraph() {
 160   viewGraph("");
 161 }
 162
 163 /// Just dump dot graph to a user-provided path and title.
 164 /// This doesn't open the dot viewer program and
 165 /// helps visualization when outside debugging session.
 166 /// FileName expects absolute path. If provided
 167 /// without any path separators then the file
 168 /// will be created in the current directory.
 169 /// Error will be emitted if the path is insane.
 170 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 171 LLVM_DUMP_METHOD void SelectionDAG::dumpDotGraph(const Twine &FileName,
 172                                                  const Twine &Title) {
 173   dumpDotGraphToFile(this, FileName, Title);
 174 }
 175 #endif
 176
 177 /// clearGraphAttrs - Clear all previously defined node graph attributes.
 178 /// Intended to be used from a debugging tool (eg. gdb).
 179 void SelectionDAG::clearGraphAttrs() {
 180 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
 181   NodeGraphAttrs.clear();
 182 #else
 183   errs() << "SelectionDAG::clearGraphAttrs is only available in builds with "
 184          << "ABI breaking checks enabled on systems with Graphviz or gv!\n";
 185 #endif
 186 }
 187
 188
 189 /// setGraphAttrs - Set graph attributes for a node. (eg. "color=red".)
 190 ///
 191 void SelectionDAG::setGraphAttrs(const SDNode *N, const char *Attrs) {
 192 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
 193   NodeGraphAttrs[N] = Attrs;
 194 #else
 195   errs() << "SelectionDAG::setGraphAttrs is only available in builds with "
 196          << "ABI breaking checks enabled on systems with Graphviz or gv!\n";
 197 #endif
 198 }
 199
 200
 201 /// getGraphAttrs - Get graph attributes for a node. (eg. "color=red".)
 202 /// Used from getNodeAttributes.
 203 std::string SelectionDAG::getGraphAttrs(const SDNode *N) const {
 204 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
 205   std::map<const SDNode *, std::string>::const_iterator I =
 206     NodeGraphAttrs.find(N);
 207
 208   if (I != NodeGraphAttrs.end())
 209     return I->second;
 210   else
 211     return "";
 212 #else
 213   errs() << "SelectionDAG::getGraphAttrs is only available in builds with "
 214          << "ABI breaking checks enabled on systems with Graphviz or gv!\n";
 215   return std::string();
 216 #endif
 217 }
 218
 219 /// setGraphColor - Convenience for setting node color attribute.
 220 ///
 221 void SelectionDAG::setGraphColor(const SDNode *N, const char *Color) {
 222 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
 223   NodeGraphAttrs[N] = std::string("color=") + Color;
 224 #else
 225   errs() << "SelectionDAG::setGraphColor is only available in builds with "
 226          << "ABI breaking checks enabled on systems with Graphviz or gv!\n";
 227 #endif
 228 }
 229
 230 /// setSubgraphColorHelper - Implement setSubgraphColor.  Return
 231 /// whether we truncated the search.
 232 ///
 233 bool SelectionDAG::setSubgraphColorHelper(SDNode *N, const char *Color, DenseSet<SDNode *> &visited,
 234                                           int level, bool &printed) {
 235   bool hit_limit = false;
 236
 237 #ifndef NDEBUG
 238   if (level >= 20) {
 239     if (!printed) {
 240       printed = true;
 241       LLVM_DEBUG(dbgs() << "setSubgraphColor hit max level\n");
 242     }
 243     return true;
 244   }
 245
 246   unsigned oldSize = visited.size();
 247   visited.insert(N);
 248   if (visited.size() != oldSize) {
 249     setGraphColor(N, Color);
 250     for(SDNodeIterator i = SDNodeIterator::begin(N), iend = SDNodeIterator::end(N);
 251         i != iend;
 252         ++i) {
 253       hit_limit = setSubgraphColorHelper(*i, Color, visited, level+1, printed) || hit_limit;
 254     }
 255   }
 256 #else
 257   errs() << "SelectionDAG::setSubgraphColor is only available in debug builds"
 258          << " on systems with Graphviz or gv!\n";
 259 #endif
 260   return hit_limit;
 261 }
 262
 263 /// setSubgraphColor - Convenience for setting subgraph color attribute.
 264 ///
 265 void SelectionDAG::setSubgraphColor(SDNode *N, const char *Color) {
 266 #ifndef NDEBUG
 267   DenseSet<SDNode *> visited;
 268   bool printed = false;
 269   if (setSubgraphColorHelper(N, Color, visited, 0, printed)) {
 270     // Visually mark that we hit the limit
 271     if (strcmp(Color, "red") == 0) {
 272       setSubgraphColorHelper(N, "blue", visited, 0, printed);
 273     } else if (strcmp(Color, "yellow") == 0) {
 274       setSubgraphColorHelper(N, "green", visited, 0, printed);
 275     }
 276   }
 277
 278 #else
 279   errs() << "SelectionDAG::setSubgraphColor is only available in debug builds"
 280          << " on systems with Graphviz or gv!\n";
 281 #endif
 282 }
 283
 284 std::string ScheduleDAGSDNodes::getGraphNodeLabel(const SUnit *SU) const {
 285   std::string s;
 286   raw_string_ostream O(s);
 287   O << "SU(" << SU->NodeNum << "): ";
 288   if (SU->getNode()) {
 289     SmallVector<SDNode *, 4> GluedNodes;
 290     for (SDNode *N = SU->getNode(); N; N = N->getGluedNode())
 291       GluedNodes.push_back(N);
 292     while (!GluedNodes.empty()) {
 293       O << DOTGraphTraits<SelectionDAG*>
 294         ::getSimpleNodeLabel(GluedNodes.back(), DAG);
 295       GluedNodes.pop_back();
 296       if (!GluedNodes.empty())
 297         O << "\n    ";
 298     }
 299   } else {
 300     O << "CROSS RC COPY";
 301   }
 302   return s;
 303 }
 304
 305 void ScheduleDAGSDNodes::getCustomGraphFeatures(GraphWriter<ScheduleDAG*> &GW) const {
 306   if (DAG) {
 307     // Draw a special "GraphRoot" node to indicate the root of the graph.
 308     GW.emitSimpleNode(nullptr, "plaintext=circle", "GraphRoot");
 309     const SDNode *N = DAG->getRoot().getNode();
 310     if (N && N->getNodeId() != -1)
 311       GW.emitEdge(nullptr, -1, &SUnits[N->getNodeId()], -1,
 312                   "color=blue,style=dashed");
 313   }
 314 }