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