1 //===- RewriterGen.cpp - MLIR pattern rewriter generator ------------===// 2 // 3 // Copyright 2019 The MLIR Authors. 4 // 5 // Licensed under the Apache License, Version 2.0 (the "License"); 6 // you may not use this file except in compliance with the License. 7 // You may obtain a copy of the License at 8 // 9 // http://www.apache.org/licenses/LICENSE-2.0 10 // 11 // Unless required by applicable law or agreed to in writing, software 12 // distributed under the License is distributed on an "AS IS" BASIS, 13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 // See the License for the specific language governing permissions and 15 // limitations under the License. 16 // ============================================================================= 17 // 18 // RewriterGen uses pattern rewrite definitions to generate rewriter matchers. 19 // 20 //===----------------------------------------------------------------------===// 21 22 #include "mlir/TableGen/GenInfo.h" 23 #include "mlir/TableGen/Operator.h" 24 #include "llvm/ADT/StringExtras.h" 25 #include "llvm/ADT/StringSet.h" 26 #include "llvm/Support/CommandLine.h" 27 #include "llvm/Support/FormatVariadic.h" 28 #include "llvm/Support/PrettyStackTrace.h" 29 #include "llvm/Support/Signals.h" 30 #include "llvm/TableGen/Error.h" 31 #include "llvm/TableGen/Main.h" 32 #include "llvm/TableGen/Record.h" 33 #include "llvm/TableGen/TableGenBackend.h" 34 35 using namespace llvm; 36 using namespace mlir; 37 38 namespace { 39 40 // Wrapper around dag argument. 41 struct DagArg { 42 DagArg(Init *init) : init(init){}; 43 bool isAttr(); 44 45 Init *init; 46 }; 47 48 } // end namespace 49 50 bool DagArg::isAttr() { 51 if (auto defInit = dyn_cast<DefInit>(init)) 52 return defInit->getDef()->isSubClassOf("Attr"); 53 return false; 54 } 55 56 namespace { 57 class Pattern { 58 public: 59 static void emit(StringRef rewriteName, Record *p, raw_ostream &os); 60 61 private: 62 Pattern(Record *pattern, raw_ostream &os) : pattern(pattern), os(os){}; 63 64 // Emit the rewrite pattern named `rewriteName`. 65 void emit(StringRef rewriteName); 66 67 // Emit the matcher. 68 void emitMatcher(DagInit *tree); 69 70 // Emits the value of constant attribute to `os`. 71 void emitAttributeValue(Record *constAttr); 72 73 // Collect bound arguments. 74 void collectBoundArguments(DagInit *tree); 75 76 // Map from bound argument name to DagArg. 77 StringMap<DagArg> boundArguments; 78 79 // Number of the operations in the input pattern. 80 int numberOfOpsMatched = 0; 81 82 Record *pattern; 83 raw_ostream &os; 84 }; 85 } // end namespace 86 87 void Pattern::emitAttributeValue(Record *constAttr) { 88 Record *attr = constAttr->getValueAsDef("attr"); 89 auto value = constAttr->getValue("value"); 90 Record *type = attr->getValueAsDef("type"); 91 auto storageType = attr->getValueAsString("storageType").trim(); 92 93 // For attributes stored as strings we do not need to query builder etc. 94 if (storageType == "StringAttr") { 95 os << formatv("rewriter.getStringAttr({0})", 96 value->getValue()->getAsString()); 97 return; 98 } 99 100 // Construct the attribute based on storage type and builder. 101 if (auto b = type->getValue("builderCall")) { 102 if (isa<UnsetInit>(b->getValue())) 103 PrintFatalError(pattern->getLoc(), 104 "no builder specified for " + type->getName()); 105 CodeInit *builder = cast<CodeInit>(b->getValue()); 106 // TODO(jpienaar): Verify the constants here 107 os << formatv("{0}::get(rewriter.{1}, {2})", storageType, 108 builder->getValue(), 109 value->getValue()->getAsUnquotedString()); 110 return; 111 } 112 113 PrintFatalError(pattern->getLoc(), "unable to emit attribute"); 114 } 115 116 void Pattern::collectBoundArguments(DagInit *tree) { 117 ++numberOfOpsMatched; 118 // TODO(jpienaar): Expand to multiple matches. 119 for (int i = 0, e = tree->getNumArgs(); i != e; ++i) { 120 auto arg = tree->getArg(i); 121 if (auto argTree = dyn_cast<DagInit>(arg)) { 122 collectBoundArguments(argTree); 123 continue; 124 } 125 auto name = tree->getArgNameStr(i); 126 if (name.empty()) 127 continue; 128 boundArguments.try_emplace(name, arg); 129 } 130 } 131 132 // Helper function to match patterns. 133 static void matchOp(DagInit *tree, int depth, raw_ostream &os) { 134 Operator op(cast<DefInit>(tree->getOperator())->getDef()); 135 int indent = 4 + 2 * depth; 136 // Skip the operand matching at depth 0 as the pattern rewriter already does. 137 if (depth != 0) { 138 // Skip if there is no defining instruction (e.g., arguments to function). 139 os.indent(indent) << formatv("if (!op{0}) return matchFailure();\n", depth); 140 os.indent(indent) << formatv( 141 "if (!op{0}->isa<{1}>()) return matchFailure();\n", depth, 142 op.qualifiedCppClassName()); 143 } 144 for (int i = 0, e = tree->getNumArgs(); i != e; ++i) { 145 auto arg = tree->getArg(i); 146 if (auto argTree = dyn_cast<DagInit>(arg)) { 147 os.indent(indent) << "{\n"; 148 os.indent(indent + 2) << formatv( 149 "auto op{0} = op{1}->getOperand({2})->getDefiningInst();\n", 150 depth + 1, depth, i); 151 matchOp(argTree, depth + 1, os); 152 os.indent(indent) << "}\n"; 153 continue; 154 } 155 auto name = tree->getArgNameStr(i); 156 if (name.empty()) 157 continue; 158 os.indent(indent) << "state->" << name << " = op" << depth 159 << "->getOperand(" << i << ");\n"; 160 } 161 } 162 163 void Pattern::emitMatcher(DagInit *tree) { 164 // Emit the heading. 165 os << R"( 166 PatternMatchResult match(OperationInst *op0) const override { 167 // TODO: This just handle 1 result 168 if (op0->getNumResults() != 1) return matchFailure(); 169 auto state = std::make_unique<MatchedState>();)" 170 << "\n"; 171 matchOp(tree, 0, os); 172 os.indent(4) << "return matchSuccess(std::move(state));\n }\n"; 173 } 174 175 void Pattern::emit(StringRef rewriteName) { 176 DagInit *tree = pattern->getValueAsDag("PatternToMatch"); 177 // Collect bound arguments and compute number of ops matched. 178 // TODO(jpienaar): the benefit metric is simply number of ops matched at the 179 // moment, revise. 180 collectBoundArguments(tree); 181 182 // Emit RewritePattern for Pattern. 183 DefInit *root = cast<DefInit>(tree->getOperator()); 184 auto *rootName = cast<StringInit>(root->getDef()->getValueInit("opName")); 185 os << formatv(R"(struct {0} : public RewritePattern { 186 {0}(MLIRContext *context) : RewritePattern({1}, {2}, context) {{})", 187 rewriteName, rootName->getAsString(), numberOfOpsMatched) 188 << "\n"; 189 190 // Emit matched state. 191 os << " struct MatchedState : public PatternState {\n"; 192 for (auto &arg : boundArguments) { 193 if (arg.second.isAttr()) { 194 DefInit *defInit = cast<DefInit>(arg.second.init); 195 os.indent(4) << defInit->getDef()->getValueAsString("storageType").trim() 196 << " " << arg.first() << ";\n"; 197 } else { 198 os.indent(4) << "Value* " << arg.first() << ";\n"; 199 } 200 } 201 os << " };\n"; 202 203 emitMatcher(tree); 204 ListInit *resultOps = pattern->getValueAsListInit("ResultOps"); 205 if (resultOps->size() != 1) 206 PrintFatalError("only single result rules supported"); 207 DagInit *resultTree = cast<DagInit>(resultOps->getElement(0)); 208 209 // TODO(jpienaar): Expand to multiple results. 210 for (auto result : resultTree->getArgs()) { 211 if (isa<DagInit>(result)) 212 PrintFatalError(pattern->getLoc(), "only single op result supported"); 213 } 214 215 DefInit *resultRoot = cast<DefInit>(resultTree->getOperator()); 216 Operator resultOp(*resultRoot->getDef()); 217 auto resultOperands = resultRoot->getDef()->getValueAsDag("arguments"); 218 219 os << formatv(R"( 220 void rewrite(OperationInst *op, std::unique_ptr<PatternState> state, 221 PatternRewriter &rewriter) const override { 222 auto& s = *static_cast<MatchedState *>(state.get()); 223 rewriter.replaceOpWithNewOp<{0}>(op, op->getResult(0)->getType())", 224 resultOp.cppClassName()); 225 if (resultOperands->getNumArgs() != resultTree->getNumArgs()) { 226 PrintFatalError(pattern->getLoc(), 227 Twine("mismatch between arguments of resultant op (") + 228 Twine(resultOperands->getNumArgs()) + 229 ") and arguments provided for rewrite (" + 230 Twine(resultTree->getNumArgs()) + Twine(')')); 231 } 232 233 // Create the builder call for the result. 234 // Add operands. 235 int i = 0; 236 for (auto operand : resultOp.getOperands()) { 237 // Start each operand on its own line. 238 (os << ",\n").indent(6); 239 240 auto name = resultTree->getArgNameStr(i); 241 if (boundArguments.find(name) == boundArguments.end()) 242 PrintFatalError(pattern->getLoc(), 243 Twine("referencing unbound variable '") + name + "'"); 244 if (operand.name) 245 os << "/*" << operand.name->getAsUnquotedString() << "=*/"; 246 os << "s." << name; 247 // TODO(jpienaar): verify types 248 ++i; 249 } 250 251 // Add attributes. 252 for (int e = resultTree->getNumArgs(); i != e; ++i) { 253 // Start each attribute on its own line. 254 (os << ",\n").indent(6); 255 256 // The argument in the result DAG pattern. 257 auto name = resultOp.getArgName(i); 258 auto defInit = dyn_cast<DefInit>(resultTree->getArg(i)); 259 auto *value = defInit ? defInit->getDef()->getValue("value") : nullptr; 260 if (!value) 261 PrintFatalError(pattern->getLoc(), 262 Twine("attribute '") + name + 263 "' needs to be constant initialized"); 264 265 // TODO(jpienaar): Refactor out into map to avoid recomputing these. 266 auto argument = resultOp.getArg(i); 267 if (!argument.is<mlir::Operator::Attribute *>()) 268 PrintFatalError(pattern->getLoc(), 269 Twine("expected attribute ") + Twine(i)); 270 271 if (!name.empty()) 272 os << "/*" << name << "=*/"; 273 emitAttributeValue(defInit->getDef()); 274 // TODO(jpienaar): verify types 275 } 276 os << "\n );\n }\n};\n"; 277 } 278 279 void Pattern::emit(StringRef rewriteName, Record *p, raw_ostream &os) { 280 Pattern pattern(p, os); 281 pattern.emit(rewriteName); 282 } 283 284 static void emitRewriters(const RecordKeeper &recordKeeper, raw_ostream &os) { 285 emitSourceFileHeader("Rewriters", os); 286 const auto &patterns = recordKeeper.getAllDerivedDefinitions("Pattern"); 287 288 // Ensure unique patterns simply by appending unique suffix. 289 std::string baseRewriteName = "GeneratedConvert"; 290 int rewritePatternCount = 0; 291 for (Record *p : patterns) { 292 Pattern::emit(baseRewriteName + llvm::utostr(rewritePatternCount++), p, os); 293 } 294 295 // Emit function to add the generated matchers to the pattern list. 296 os << "void populateWithGenerated(MLIRContext *context, " 297 << "OwningRewritePatternList *patterns) {\n"; 298 for (unsigned i = 0; i != rewritePatternCount; ++i) { 299 os.indent(2) << "patterns->push_back(std::make_unique<" << baseRewriteName 300 << i << ">(context));\n"; 301 } 302 os << "}\n"; 303 } 304 305 mlir::GenRegistration 306 genRewriters("gen-rewriters", "Generate pattern rewriters", 307 [](const RecordKeeper &records, raw_ostream &os) { 308 emitRewriters(records, os); 309 return false; 310 }); 311