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/MachineConstantPool.h"
  17 #include "llvm/CodeGen/MachineFunction.h"
  18 #include "llvm/CodeGen/SelectionDAG.h"
  19 #include "llvm/CodeGen/TargetRegisterInfo.h"
  20 #include "llvm/IR/Constants.h"
  21 #include "llvm/Support/Debug.h"
  22 #include "llvm/Support/GraphWriter.h"
  23 #include "llvm/Support/raw_ostream.h"
  24 #include "llvm/Target/TargetMachine.h"
  25 using namespace llvm;
  26
  27 #define DEBUG_TYPE "dag-printer"
  28
  29 namespace llvm {
  30   template<>
  31   struct DOTGraphTraits<SelectionDAG*> : public DefaultDOTGraphTraits {
  32
  33     explicit DOTGraphTraits(bool isSimple=false) :
  34       DefaultDOTGraphTraits(isSimple) {}
  35
  36     static bool hasEdgeDestLabels() {
  37       return true;
  38     }
  39
  40     static unsigned numEdgeDestLabels(const void *Node) {
  41       return ((const SDNode *) Node)->getNumValues();
  42     }
  43
  44     static std::string getEdgeDestLabel(const void *Node, unsigned i) {
  45       return ((const SDNode *) Node)->getValueType(i).getEVTString();
  46     }
  47
  48     template<typename EdgeIter>
  49     static std::string getEdgeSourceLabel(const void *Node, EdgeIter I) {
  50       return itostr(I - SDNodeIterator::begin((const SDNode *) Node));
  51     }
  52
  53     /// edgeTargetsEdgeSource - This method returns true if this outgoing edge
  54     /// should actually target another edge source, not a node.  If this method
  55     /// is implemented, getEdgeTarget should be implemented.
  56     template<typename EdgeIter>
  57     static bool edgeTargetsEdgeSource(const void *Node, EdgeIter I) {
  58       return true;
  59     }
  60
  61     /// getEdgeTarget - If edgeTargetsEdgeSource returns true, this method is
  62     /// called to determine which outgoing edge of Node is the target of this
  63     /// edge.
  64     template<typename EdgeIter>
  65     static EdgeIter getEdgeTarget(const void *Node, EdgeIter I) {
  66       SDNode *TargetNode = *I;
  67       SDNodeIterator NI = SDNodeIterator::begin(TargetNode);
  68       std::advance(NI, I.getNode()->getOperand(I.getOperand()).getResNo());
  69       return NI;
  70     }
  71
  72     static std::string getGraphName(const SelectionDAG *G) {
  73       return std::string(G->getMachineFunction().getName());
  74     }
  75
  76     static bool renderGraphFromBottomUp() {
  77       return true;
  78     }
  79
  80     static std::string getNodeIdentifierLabel(const SDNode *Node,
  81                                               const SelectionDAG *Graph) {
  82       std::string R;
  83       raw_string_ostream OS(R);
  84 #ifndef NDEBUG
  85       OS << 't' << Node->PersistentId;
  86 #else
  87       OS << static_cast<const void *>(Node);
  88 #endif
  89       return R;
  90     }
  91
  92     /// If you want to override the dot attributes printed for a particular
  93     /// edge, override this method.
  94     template<typename EdgeIter>
  95     static std::string getEdgeAttributes(const void *Node, EdgeIter EI,
  96                                          const SelectionDAG *Graph) {
  97       SDValue Op = EI.getNode()->getOperand(EI.getOperand());
  98       EVT VT = Op.getValueType();
  99       if (VT == MVT::Glue)
 100         return "color=red,style=bold";
 101       else if (VT == MVT::Other)
 102         return "color=blue,style=dashed";
 103       return "";
 104     }
 105
 106
 107     static std::string getSimpleNodeLabel(const SDNode *Node,
 108                                           const SelectionDAG *G) {
 109       std::string Result = Node->getOperationName(G);
 110       {
 111         raw_string_ostream OS(Result);
 112         Node->print_details(OS, G);
 113       }
 114       return Result;
 115     }
 116     std::string getNodeLabel(const SDNode *Node, const SelectionDAG *Graph);
 117     static std::string getNodeAttributes(const SDNode *N,
 118                                          const SelectionDAG *Graph) {
 119 #ifndef NDEBUG
 120       const std::string &Attrs = Graph->getGraphAttrs(N);
 121       if (!Attrs.empty()) {
 122         if (Attrs.find("shape=") == std::string::npos)
 123           return std::string("shape=Mrecord,") + Attrs;
 124         else
 125           return Attrs;
 126       }
 127 #endif
 128       return "shape=Mrecord";
 129     }
 130
 131     static void addCustomGraphFeatures(SelectionDAG *G,
 132                                        GraphWriter<SelectionDAG*> &GW) {
 133       GW.emitSimpleNode(nullptr, "plaintext=circle", "GraphRoot");
 134       if (G->getRoot().getNode())
 135         GW.emitEdge(nullptr, -1, G->getRoot().getNode(), G->getRoot().getResNo(),
 136                     "color=blue,style=dashed");
 137     }
 138   };
 139 }
 140
 141 std::string DOTGraphTraits<SelectionDAG*>::getNodeLabel(const SDNode *Node,
 142                                                         const SelectionDAG *G) {
 143   return DOTGraphTraits<SelectionDAG*>::getSimpleNodeLabel(Node, G);
 144 }
 145
 146
 147 /// viewGraph - Pop up a ghostview window with the reachable parts of the DAG
 148 /// rendered using 'dot'.
 149 ///
 150 void SelectionDAG::viewGraph(const std::string &Title) {
 151 // This code is only for debugging!
 152 #ifndef NDEBUG
 153   ViewGraph(this, "dag." + getMachineFunction().getName(),
 154             false, Title);
 155 #else
 156   errs() << "SelectionDAG::viewGraph is only available in debug builds on "
 157          << "systems with Graphviz or gv!\n";
 158 #endif  // NDEBUG
 159 }
 160
 161 // This overload is defined out-of-line here instead of just using a
 162 // default parameter because this is easiest for gdb to call.
 163 void SelectionDAG::viewGraph() {
 164   viewGraph("");
 165 }
 166
 167 /// Just dump dot graph to a user-provided path and title.
 168 /// This doesn't open the dot viewer program and
 169 /// helps visualization when outside debugging session.
 170 /// FileName expects absolute path. If provided
 171 /// without any path separators then the file
 172 /// will be created in the current directory.
 173 /// Error will be emitted if the path is insane.
 174 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 175 LLVM_DUMP_METHOD void SelectionDAG::dumpDotGraph(const Twine &FileName,
 176                                                  const Twine &Title) {
 177   dumpDotGraphToFile(this, FileName, Title);
 178 }
 179 #endif
 180
 181 /// clearGraphAttrs - Clear all previously defined node graph attributes.
 182 /// Intended to be used from a debugging tool (eg. gdb).
 183 void SelectionDAG::clearGraphAttrs() {
 184 #ifndef NDEBUG
 185   NodeGraphAttrs.clear();
 186 #else
 187   errs() << "SelectionDAG::clearGraphAttrs is only available in debug builds"
 188          << " on systems with Graphviz or gv!\n";
 189 #endif
 190 }
 191
 192
 193 /// setGraphAttrs - Set graph attributes for a node. (eg. "color=red".)
 194 ///
 195 void SelectionDAG::setGraphAttrs(const SDNode *N, const char *Attrs) {
 196 #ifndef NDEBUG
 197   NodeGraphAttrs[N] = Attrs;
 198 #else
 199   errs() << "SelectionDAG::setGraphAttrs is only available in debug builds"
 200          << " on systems with Graphviz or gv!\n";
 201 #endif
 202 }
 203
 204
 205 /// getGraphAttrs - Get graph attributes for a node. (eg. "color=red".)
 206 /// Used from getNodeAttributes.
 207 std::string SelectionDAG::getGraphAttrs(const SDNode *N) const {
 208 #ifndef NDEBUG
 209   std::map<const SDNode *, std::string>::const_iterator I =
 210     NodeGraphAttrs.find(N);
 211
 212   if (I != NodeGraphAttrs.end())
 213     return I->second;
 214   else
 215     return "";
 216 #else
 217   errs() << "SelectionDAG::getGraphAttrs is only available in debug builds"
 218          << " on systems with Graphviz or gv!\n";
 219   return std::string();
 220 #endif
 221 }
 222
 223 /// setGraphColor - Convenience for setting node color attribute.
 224 ///
 225 void SelectionDAG::setGraphColor(const SDNode *N, const char *Color) {
 226 #ifndef NDEBUG
 227   NodeGraphAttrs[N] = std::string("color=") + Color;
 228 #else
 229   errs() << "SelectionDAG::setGraphColor is only available in debug builds"
 230          << " on systems with Graphviz or gv!\n";
 231 #endif
 232 }
 233
 234 /// setSubgraphColorHelper - Implement setSubgraphColor.  Return
 235 /// whether we truncated the search.
 236 ///
 237 bool SelectionDAG::setSubgraphColorHelper(SDNode *N, const char *Color, DenseSet<SDNode *> &visited,
 238                                           int level, bool &printed) {
 239   bool hit_limit = false;
 240
 241 #ifndef NDEBUG
 242   if (level >= 20) {
 243     if (!printed) {
 244       printed = true;
 245       LLVM_DEBUG(dbgs() << "setSubgraphColor hit max level\n");
 246     }
 247     return true;
 248   }
 249
 250   unsigned oldSize = visited.size();
 251   visited.insert(N);
 252   if (visited.size() != oldSize) {
 253     setGraphColor(N, Color);
 254     for(SDNodeIterator i = SDNodeIterator::begin(N), iend = SDNodeIterator::end(N);
 255         i != iend;
 256         ++i) {
 257       hit_limit = setSubgraphColorHelper(*i, Color, visited, level+1, printed) || hit_limit;
 258     }
 259   }
 260 #else
 261   errs() << "SelectionDAG::setSubgraphColor is only available in debug builds"
 262          << " on systems with Graphviz or gv!\n";
 263 #endif
 264   return hit_limit;
 265 }
 266
 267 /// setSubgraphColor - Convenience for setting subgraph color attribute.
 268 ///
 269 void SelectionDAG::setSubgraphColor(SDNode *N, const char *Color) {
 270 #ifndef NDEBUG
 271   DenseSet<SDNode *> visited;
 272   bool printed = false;
 273   if (setSubgraphColorHelper(N, Color, visited, 0, printed)) {
 274     // Visually mark that we hit the limit
 275     if (strcmp(Color, "red") == 0) {
 276       setSubgraphColorHelper(N, "blue", visited, 0, printed);
 277     } else if (strcmp(Color, "yellow") == 0) {
 278       setSubgraphColorHelper(N, "green", visited, 0, printed);
 279     }
 280   }
 281
 282 #else
 283   errs() << "SelectionDAG::setSubgraphColor is only available in debug builds"
 284          << " on systems with Graphviz or gv!\n";
 285 #endif
 286 }
 287
 288 std::string ScheduleDAGSDNodes::getGraphNodeLabel(const SUnit *SU) const {
 289   std::string s;
 290   raw_string_ostream O(s);
 291   O << "SU(" << SU->NodeNum << "): ";
 292   if (SU->getNode()) {
 293     SmallVector<SDNode *, 4> GluedNodes;
 294     for (SDNode *N = SU->getNode(); N; N = N->getGluedNode())
 295       GluedNodes.push_back(N);
 296     while (!GluedNodes.empty()) {
 297       O << DOTGraphTraits<SelectionDAG*>
 298         ::getSimpleNodeLabel(GluedNodes.back(), DAG);
 299       GluedNodes.pop_back();
 300       if (!GluedNodes.empty())
 301         O << "\n    ";
 302     }
 303   } else {
 304     O << "CROSS RC COPY";
 305   }
 306   return O.str();
 307 }
 308
 309 void ScheduleDAGSDNodes::getCustomGraphFeatures(GraphWriter<ScheduleDAG*> &GW) const {
 310   if (DAG) {
 311     // Draw a special "GraphRoot" node to indicate the root of the graph.
 312     GW.emitSimpleNode(nullptr, "plaintext=circle", "GraphRoot");
 313     const SDNode *N = DAG->getRoot().getNode();
 314     if (N && N->getNodeId() != -1)
 315       GW.emitEdge(nullptr, -1, &SUnits[N->getNodeId()], -1,
 316                   "color=blue,style=dashed");
 317   }
 318 }