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