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