1 //===- SetTheory.cpp - Generate ordered sets from DAG expressions ---------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements the SetTheory class that computes ordered sets of 11 // Records from DAG expressions. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "llvm/ADT/ArrayRef.h" 16 #include "llvm/ADT/SmallVector.h" 17 #include "llvm/ADT/STLExtras.h" 18 #include "llvm/ADT/StringRef.h" 19 #include "llvm/Support/Casting.h" 20 #include "llvm/Support/Format.h" 21 #include "llvm/Support/SMLoc.h" 22 #include "llvm/Support/raw_ostream.h" 23 #include "llvm/TableGen/Error.h" 24 #include "llvm/TableGen/Record.h" 25 #include "llvm/TableGen/SetTheory.h" 26 #include <algorithm> 27 #include <cstdint> 28 #include <string> 29 #include <utility> 30 31 using namespace llvm; 32 33 // Define the standard operators. 34 namespace { 35 36 using RecSet = SetTheory::RecSet; 37 using RecVec = SetTheory::RecVec; 38 39 // (add a, b, ...) Evaluate and union all arguments. 40 struct AddOp : public SetTheory::Operator { 41 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 42 ArrayRef<SMLoc> Loc) override { 43 ST.evaluate(Expr->arg_begin(), Expr->arg_end(), Elts, Loc); 44 } 45 }; 46 47 // (sub Add, Sub, ...) Set difference. 48 struct SubOp : public SetTheory::Operator { 49 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 50 ArrayRef<SMLoc> Loc) override { 51 if (Expr->arg_size() < 2) 52 PrintFatalError(Loc, "Set difference needs at least two arguments: " + 53 Expr->getAsString()); 54 RecSet Add, Sub; 55 ST.evaluate(*Expr->arg_begin(), Add, Loc); 56 ST.evaluate(Expr->arg_begin() + 1, Expr->arg_end(), Sub, Loc); 57 for (RecSet::iterator I = Add.begin(), E = Add.end(); I != E; ++I) 58 if (!Sub.count(*I)) 59 Elts.insert(*I); 60 } 61 }; 62 63 // (and S1, S2) Set intersection. 64 struct AndOp : public SetTheory::Operator { 65 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 66 ArrayRef<SMLoc> Loc) override { 67 if (Expr->arg_size() != 2) 68 PrintFatalError(Loc, "Set intersection requires two arguments: " + 69 Expr->getAsString()); 70 RecSet S1, S2; 71 ST.evaluate(Expr->arg_begin()[0], S1, Loc); 72 ST.evaluate(Expr->arg_begin()[1], S2, Loc); 73 for (RecSet::iterator I = S1.begin(), E = S1.end(); I != E; ++I) 74 if (S2.count(*I)) 75 Elts.insert(*I); 76 } 77 }; 78 79 // SetIntBinOp - Abstract base class for (Op S, N) operators. 80 struct SetIntBinOp : public SetTheory::Operator { 81 virtual void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N, 82 RecSet &Elts, ArrayRef<SMLoc> Loc) = 0; 83 84 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 85 ArrayRef<SMLoc> Loc) override { 86 if (Expr->arg_size() != 2) 87 PrintFatalError(Loc, "Operator requires (Op Set, Int) arguments: " + 88 Expr->getAsString()); 89 RecSet Set; 90 ST.evaluate(Expr->arg_begin()[0], Set, Loc); 91 IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[1]); 92 if (!II) 93 PrintFatalError(Loc, "Second argument must be an integer: " + 94 Expr->getAsString()); 95 apply2(ST, Expr, Set, II->getValue(), Elts, Loc); 96 } 97 }; 98 99 // (shl S, N) Shift left, remove the first N elements. 100 struct ShlOp : public SetIntBinOp { 101 void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N, 102 RecSet &Elts, ArrayRef<SMLoc> Loc) override { 103 if (N < 0) 104 PrintFatalError(Loc, "Positive shift required: " + 105 Expr->getAsString()); 106 if (unsigned(N) < Set.size()) 107 Elts.insert(Set.begin() + N, Set.end()); 108 } 109 }; 110 111 // (trunc S, N) Truncate after the first N elements. 112 struct TruncOp : public SetIntBinOp { 113 void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N, 114 RecSet &Elts, ArrayRef<SMLoc> Loc) override { 115 if (N < 0) 116 PrintFatalError(Loc, "Positive length required: " + 117 Expr->getAsString()); 118 if (unsigned(N) > Set.size()) 119 N = Set.size(); 120 Elts.insert(Set.begin(), Set.begin() + N); 121 } 122 }; 123 124 // Left/right rotation. 125 struct RotOp : public SetIntBinOp { 126 const bool Reverse; 127 128 RotOp(bool Rev) : Reverse(Rev) {} 129 130 void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N, 131 RecSet &Elts, ArrayRef<SMLoc> Loc) override { 132 if (Reverse) 133 N = -N; 134 // N > 0 -> rotate left, N < 0 -> rotate right. 135 if (Set.empty()) 136 return; 137 if (N < 0) 138 N = Set.size() - (-N % Set.size()); 139 else 140 N %= Set.size(); 141 Elts.insert(Set.begin() + N, Set.end()); 142 Elts.insert(Set.begin(), Set.begin() + N); 143 } 144 }; 145 146 // (decimate S, N) Pick every N'th element of S. 147 struct DecimateOp : public SetIntBinOp { 148 void apply2(SetTheory &ST, DagInit *Expr, RecSet &Set, int64_t N, 149 RecSet &Elts, ArrayRef<SMLoc> Loc) override { 150 if (N <= 0) 151 PrintFatalError(Loc, "Positive stride required: " + 152 Expr->getAsString()); 153 for (unsigned I = 0; I < Set.size(); I += N) 154 Elts.insert(Set[I]); 155 } 156 }; 157 158 // (interleave S1, S2, ...) Interleave elements of the arguments. 159 struct InterleaveOp : public SetTheory::Operator { 160 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 161 ArrayRef<SMLoc> Loc) override { 162 // Evaluate the arguments individually. 163 SmallVector<RecSet, 4> Args(Expr->getNumArgs()); 164 unsigned MaxSize = 0; 165 for (unsigned i = 0, e = Expr->getNumArgs(); i != e; ++i) { 166 ST.evaluate(Expr->getArg(i), Args[i], Loc); 167 MaxSize = std::max(MaxSize, unsigned(Args[i].size())); 168 } 169 // Interleave arguments into Elts. 170 for (unsigned n = 0; n != MaxSize; ++n) 171 for (unsigned i = 0, e = Expr->getNumArgs(); i != e; ++i) 172 if (n < Args[i].size()) 173 Elts.insert(Args[i][n]); 174 } 175 }; 176 177 // (sequence "Format", From, To) Generate a sequence of records by name. 178 struct SequenceOp : public SetTheory::Operator { 179 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, 180 ArrayRef<SMLoc> Loc) override { 181 int Step = 1; 182 if (Expr->arg_size() > 4) 183 PrintFatalError(Loc, "Bad args to (sequence \"Format\", From, To): " + 184 Expr->getAsString()); 185 else if (Expr->arg_size() == 4) { 186 if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[3])) { 187 Step = II->getValue(); 188 } else 189 PrintFatalError(Loc, "Stride must be an integer: " + 190 Expr->getAsString()); 191 } 192 193 std::string Format; 194 if (StringInit *SI = dyn_cast<StringInit>(Expr->arg_begin()[0])) 195 Format = SI->getValue(); 196 else 197 PrintFatalError(Loc, "Format must be a string: " + Expr->getAsString()); 198 199 int64_t From, To; 200 if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[1])) 201 From = II->getValue(); 202 else 203 PrintFatalError(Loc, "From must be an integer: " + Expr->getAsString()); 204 if (From < 0 || From >= (1 << 30)) 205 PrintFatalError(Loc, "From out of range"); 206 207 if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[2])) 208 To = II->getValue(); 209 else 210 PrintFatalError(Loc, "To must be an integer: " + Expr->getAsString()); 211 if (To < 0 || To >= (1 << 30)) 212 PrintFatalError(Loc, "To out of range"); 213 214 RecordKeeper &Records = 215 cast<DefInit>(Expr->getOperator())->getDef()->getRecords(); 216 217 Step *= From <= To ? 1 : -1; 218 while (true) { 219 if (Step > 0 && From > To) 220 break; 221 else if (Step < 0 && From < To) 222 break; 223 std::string Name; 224 raw_string_ostream OS(Name); 225 OS << format(Format.c_str(), unsigned(From)); 226 Record *Rec = Records.getDef(OS.str()); 227 if (!Rec) 228 PrintFatalError(Loc, "No def named '" + Name + "': " + 229 Expr->getAsString()); 230 // Try to reevaluate Rec in case it is a set. 231 if (const RecVec *Result = ST.expand(Rec)) 232 Elts.insert(Result->begin(), Result->end()); 233 else 234 Elts.insert(Rec); 235 236 From += Step; 237 } 238 } 239 }; 240 241 // Expand a Def into a set by evaluating one of its fields. 242 struct FieldExpander : public SetTheory::Expander { 243 StringRef FieldName; 244 245 FieldExpander(StringRef fn) : FieldName(fn) {} 246 247 void expand(SetTheory &ST, Record *Def, RecSet &Elts) override { 248 ST.evaluate(Def->getValueInit(FieldName), Elts, Def->getLoc()); 249 } 250 }; 251 252 } // end anonymous namespace 253 254 // Pin the vtables to this file. 255 void SetTheory::Operator::anchor() {} 256 void SetTheory::Expander::anchor() {} 257 258 SetTheory::SetTheory() { 259 addOperator("add", llvm::make_unique<AddOp>()); 260 addOperator("sub", llvm::make_unique<SubOp>()); 261 addOperator("and", llvm::make_unique<AndOp>()); 262 addOperator("shl", llvm::make_unique<ShlOp>()); 263 addOperator("trunc", llvm::make_unique<TruncOp>()); 264 addOperator("rotl", llvm::make_unique<RotOp>(false)); 265 addOperator("rotr", llvm::make_unique<RotOp>(true)); 266 addOperator("decimate", llvm::make_unique<DecimateOp>()); 267 addOperator("interleave", llvm::make_unique<InterleaveOp>()); 268 addOperator("sequence", llvm::make_unique<SequenceOp>()); 269 } 270 271 void SetTheory::addOperator(StringRef Name, std::unique_ptr<Operator> Op) { 272 Operators[Name] = std::move(Op); 273 } 274 275 void SetTheory::addExpander(StringRef ClassName, std::unique_ptr<Expander> E) { 276 Expanders[ClassName] = std::move(E); 277 } 278 279 void SetTheory::addFieldExpander(StringRef ClassName, StringRef FieldName) { 280 addExpander(ClassName, llvm::make_unique<FieldExpander>(FieldName)); 281 } 282 283 void SetTheory::evaluate(Init *Expr, RecSet &Elts, ArrayRef<SMLoc> Loc) { 284 // A def in a list can be a just an element, or it may expand. 285 if (DefInit *Def = dyn_cast<DefInit>(Expr)) { 286 if (const RecVec *Result = expand(Def->getDef())) 287 return Elts.insert(Result->begin(), Result->end()); 288 Elts.insert(Def->getDef()); 289 return; 290 } 291 292 // Lists simply expand. 293 if (ListInit *LI = dyn_cast<ListInit>(Expr)) 294 return evaluate(LI->begin(), LI->end(), Elts, Loc); 295 296 // Anything else must be a DAG. 297 DagInit *DagExpr = dyn_cast<DagInit>(Expr); 298 if (!DagExpr) 299 PrintFatalError(Loc, "Invalid set element: " + Expr->getAsString()); 300 DefInit *OpInit = dyn_cast<DefInit>(DagExpr->getOperator()); 301 if (!OpInit) 302 PrintFatalError(Loc, "Bad set expression: " + Expr->getAsString()); 303 auto I = Operators.find(OpInit->getDef()->getName()); 304 if (I == Operators.end()) 305 PrintFatalError(Loc, "Unknown set operator: " + Expr->getAsString()); 306 I->second->apply(*this, DagExpr, Elts, Loc); 307 } 308 309 const RecVec *SetTheory::expand(Record *Set) { 310 // Check existing entries for Set and return early. 311 ExpandMap::iterator I = Expansions.find(Set); 312 if (I != Expansions.end()) 313 return &I->second; 314 315 // This is the first time we see Set. Find a suitable expander. 316 ArrayRef<std::pair<Record *, SMRange>> SC = Set->getSuperClasses(); 317 for (const auto &SCPair : SC) { 318 // Skip unnamed superclasses. 319 if (!isa<StringInit>(SCPair.first->getNameInit())) 320 continue; 321 auto I = Expanders.find(SCPair.first->getName()); 322 if (I != Expanders.end()) { 323 // This breaks recursive definitions. 324 RecVec &EltVec = Expansions[Set]; 325 RecSet Elts; 326 I->second->expand(*this, Set, Elts); 327 EltVec.assign(Elts.begin(), Elts.end()); 328 return &EltVec; 329 } 330 } 331 332 // Set is not expandable. 333 return nullptr; 334 } 335
