xref: /freebsd/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp (revision 9f23cbd6cae82fd77edfad7173432fa8dccd0a95)
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 O.str();
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 }
315