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