SetTheory.cpp revision 226633
1223013Sdim//===- SetTheory.cpp - Generate ordered sets from DAG expressions ---------===// 2223013Sdim// 3223013Sdim// The LLVM Compiler Infrastructure 4223013Sdim// 5223013Sdim// This file is distributed under the University of Illinois Open Source 6223013Sdim// License. See LICENSE.TXT for details. 7223013Sdim// 8223013Sdim//===----------------------------------------------------------------------===// 9223013Sdim// 10223013Sdim// This file implements the SetTheory class that computes ordered sets of 11223013Sdim// Records from DAG expressions. 12223013Sdim// 13223013Sdim//===----------------------------------------------------------------------===// 14223013Sdim 15223013Sdim#include "SetTheory.h" 16226633Sdim#include "llvm/TableGen/Error.h" 17226633Sdim#include "llvm/TableGen/Record.h" 18223013Sdim#include "llvm/Support/Format.h" 19223013Sdim 20223013Sdimusing namespace llvm; 21223013Sdim 22223013Sdim// Define the standard operators. 23223013Sdimnamespace { 24223013Sdim 25223013Sdimtypedef SetTheory::RecSet RecSet; 26223013Sdimtypedef SetTheory::RecVec RecVec; 27223013Sdim 28223013Sdim// (add a, b, ...) Evaluate and union all arguments. 29223013Sdimstruct AddOp : public SetTheory::Operator { 30223013Sdim void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts) { 31223013Sdim ST.evaluate(Expr->arg_begin(), Expr->arg_end(), Elts); 32223013Sdim } 33223013Sdim}; 34223013Sdim 35223013Sdim// (sub Add, Sub, ...) Set difference. 36223013Sdimstruct SubOp : public SetTheory::Operator { 37223013Sdim void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts) { 38223013Sdim if (Expr->arg_size() < 2) 39223013Sdim throw "Set difference needs at least two arguments: " + 40223013Sdim Expr->getAsString(); 41223013Sdim RecSet Add, Sub; 42223013Sdim ST.evaluate(*Expr->arg_begin(), Add); 43223013Sdim ST.evaluate(Expr->arg_begin() + 1, Expr->arg_end(), Sub); 44223013Sdim for (RecSet::iterator I = Add.begin(), E = Add.end(); I != E; ++I) 45223013Sdim if (!Sub.count(*I)) 46223013Sdim Elts.insert(*I); 47223013Sdim } 48223013Sdim}; 49223013Sdim 50223013Sdim// (and S1, S2) Set intersection. 51223013Sdimstruct AndOp : public SetTheory::Operator { 52223013Sdim void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts) { 53223013Sdim if (Expr->arg_size() != 2) 54223013Sdim throw "Set intersection requires two arguments: " + Expr->getAsString(); 55223013Sdim RecSet S1, S2; 56223013Sdim ST.evaluate(Expr->arg_begin()[0], S1); 57223013Sdim ST.evaluate(Expr->arg_begin()[1], S2); 58223013Sdim for (RecSet::iterator I = S1.begin(), E = S1.end(); I != E; ++I) 59223013Sdim if (S2.count(*I)) 60223013Sdim Elts.insert(*I); 61223013Sdim } 62223013Sdim}; 63223013Sdim 64223013Sdim// SetIntBinOp - Abstract base class for (Op S, N) operators. 65223013Sdimstruct SetIntBinOp : public SetTheory::Operator { 66223013Sdim virtual void apply2(SetTheory &ST, DagInit *Expr, 67223013Sdim RecSet &Set, int64_t N, 68223013Sdim RecSet &Elts) =0; 69223013Sdim 70223013Sdim void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts) { 71223013Sdim if (Expr->arg_size() != 2) 72223013Sdim throw "Operator requires (Op Set, Int) arguments: " + Expr->getAsString(); 73223013Sdim RecSet Set; 74223013Sdim ST.evaluate(Expr->arg_begin()[0], Set); 75223013Sdim IntInit *II = dynamic_cast<IntInit*>(Expr->arg_begin()[1]); 76223013Sdim if (!II) 77223013Sdim throw "Second argument must be an integer: " + Expr->getAsString(); 78223013Sdim apply2(ST, Expr, Set, II->getValue(), Elts); 79223013Sdim } 80223013Sdim}; 81223013Sdim 82223013Sdim// (shl S, N) Shift left, remove the first N elements. 83223013Sdimstruct ShlOp : public SetIntBinOp { 84223013Sdim void apply2(SetTheory &ST, DagInit *Expr, 85223013Sdim RecSet &Set, int64_t N, 86223013Sdim RecSet &Elts) { 87223013Sdim if (N < 0) 88223013Sdim throw "Positive shift required: " + Expr->getAsString(); 89223013Sdim if (unsigned(N) < Set.size()) 90223013Sdim Elts.insert(Set.begin() + N, Set.end()); 91223013Sdim } 92223013Sdim}; 93223013Sdim 94223013Sdim// (trunc S, N) Truncate after the first N elements. 95223013Sdimstruct TruncOp : public SetIntBinOp { 96223013Sdim void apply2(SetTheory &ST, DagInit *Expr, 97223013Sdim RecSet &Set, int64_t N, 98223013Sdim RecSet &Elts) { 99223013Sdim if (N < 0) 100223013Sdim throw "Positive length required: " + Expr->getAsString(); 101223013Sdim if (unsigned(N) > Set.size()) 102223013Sdim N = Set.size(); 103223013Sdim Elts.insert(Set.begin(), Set.begin() + N); 104223013Sdim } 105223013Sdim}; 106223013Sdim 107223013Sdim// Left/right rotation. 108223013Sdimstruct RotOp : public SetIntBinOp { 109223013Sdim const bool Reverse; 110223013Sdim 111223013Sdim RotOp(bool Rev) : Reverse(Rev) {} 112223013Sdim 113223013Sdim void apply2(SetTheory &ST, DagInit *Expr, 114223013Sdim RecSet &Set, int64_t N, 115223013Sdim RecSet &Elts) { 116223013Sdim if (Reverse) 117223013Sdim N = -N; 118223013Sdim // N > 0 -> rotate left, N < 0 -> rotate right. 119223013Sdim if (Set.empty()) 120223013Sdim return; 121223013Sdim if (N < 0) 122223013Sdim N = Set.size() - (-N % Set.size()); 123223013Sdim else 124223013Sdim N %= Set.size(); 125223013Sdim Elts.insert(Set.begin() + N, Set.end()); 126223013Sdim Elts.insert(Set.begin(), Set.begin() + N); 127223013Sdim } 128223013Sdim}; 129223013Sdim 130223013Sdim// (decimate S, N) Pick every N'th element of S. 131223013Sdimstruct DecimateOp : public SetIntBinOp { 132223013Sdim void apply2(SetTheory &ST, DagInit *Expr, 133223013Sdim RecSet &Set, int64_t N, 134223013Sdim RecSet &Elts) { 135223013Sdim if (N <= 0) 136223013Sdim throw "Positive stride required: " + Expr->getAsString(); 137223013Sdim for (unsigned I = 0; I < Set.size(); I += N) 138223013Sdim Elts.insert(Set[I]); 139223013Sdim } 140223013Sdim}; 141223013Sdim 142223013Sdim// (sequence "Format", From, To) Generate a sequence of records by name. 143223013Sdimstruct SequenceOp : public SetTheory::Operator { 144223013Sdim void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts) { 145223013Sdim if (Expr->arg_size() != 3) 146223013Sdim throw "Bad args to (sequence \"Format\", From, To): " + 147223013Sdim Expr->getAsString(); 148223013Sdim std::string Format; 149223013Sdim if (StringInit *SI = dynamic_cast<StringInit*>(Expr->arg_begin()[0])) 150223013Sdim Format = SI->getValue(); 151223013Sdim else 152223013Sdim throw "Format must be a string: " + Expr->getAsString(); 153223013Sdim 154223013Sdim int64_t From, To; 155223013Sdim if (IntInit *II = dynamic_cast<IntInit*>(Expr->arg_begin()[1])) 156223013Sdim From = II->getValue(); 157223013Sdim else 158223013Sdim throw "From must be an integer: " + Expr->getAsString(); 159224145Sdim if (From < 0 || From >= (1 << 30)) 160224145Sdim throw "From out of range"; 161224145Sdim 162223013Sdim if (IntInit *II = dynamic_cast<IntInit*>(Expr->arg_begin()[2])) 163223013Sdim To = II->getValue(); 164223013Sdim else 165223013Sdim throw "From must be an integer: " + Expr->getAsString(); 166224145Sdim if (To < 0 || To >= (1 << 30)) 167224145Sdim throw "To out of range"; 168223013Sdim 169223013Sdim RecordKeeper &Records = 170223013Sdim dynamic_cast<DefInit&>(*Expr->getOperator()).getDef()->getRecords(); 171223013Sdim 172223013Sdim int Step = From <= To ? 1 : -1; 173223013Sdim for (To += Step; From != To; From += Step) { 174223013Sdim std::string Name; 175223013Sdim raw_string_ostream OS(Name); 176224145Sdim OS << format(Format.c_str(), unsigned(From)); 177223013Sdim Record *Rec = Records.getDef(OS.str()); 178223013Sdim if (!Rec) 179223013Sdim throw "No def named '" + Name + "': " + Expr->getAsString(); 180223013Sdim // Try to reevaluate Rec in case it is a set. 181223013Sdim if (const RecVec *Result = ST.expand(Rec)) 182223013Sdim Elts.insert(Result->begin(), Result->end()); 183223013Sdim else 184223013Sdim Elts.insert(Rec); 185223013Sdim } 186223013Sdim } 187223013Sdim}; 188223013Sdim 189223013Sdim// Expand a Def into a set by evaluating one of its fields. 190223013Sdimstruct FieldExpander : public SetTheory::Expander { 191223013Sdim StringRef FieldName; 192223013Sdim 193223013Sdim FieldExpander(StringRef fn) : FieldName(fn) {} 194223013Sdim 195223013Sdim void expand(SetTheory &ST, Record *Def, RecSet &Elts) { 196223013Sdim ST.evaluate(Def->getValueInit(FieldName), Elts); 197223013Sdim } 198223013Sdim}; 199223013Sdim} // end anonymous namespace 200223013Sdim 201223013SdimSetTheory::SetTheory() { 202223013Sdim addOperator("add", new AddOp); 203223013Sdim addOperator("sub", new SubOp); 204223013Sdim addOperator("and", new AndOp); 205223013Sdim addOperator("shl", new ShlOp); 206223013Sdim addOperator("trunc", new TruncOp); 207223013Sdim addOperator("rotl", new RotOp(false)); 208223013Sdim addOperator("rotr", new RotOp(true)); 209223013Sdim addOperator("decimate", new DecimateOp); 210223013Sdim addOperator("sequence", new SequenceOp); 211223013Sdim} 212223013Sdim 213223013Sdimvoid SetTheory::addOperator(StringRef Name, Operator *Op) { 214223013Sdim Operators[Name] = Op; 215223013Sdim} 216223013Sdim 217223013Sdimvoid SetTheory::addExpander(StringRef ClassName, Expander *E) { 218223013Sdim Expanders[ClassName] = E; 219223013Sdim} 220223013Sdim 221223013Sdimvoid SetTheory::addFieldExpander(StringRef ClassName, StringRef FieldName) { 222223013Sdim addExpander(ClassName, new FieldExpander(FieldName)); 223223013Sdim} 224223013Sdim 225223013Sdimvoid SetTheory::evaluate(Init *Expr, RecSet &Elts) { 226223013Sdim // A def in a list can be a just an element, or it may expand. 227223013Sdim if (DefInit *Def = dynamic_cast<DefInit*>(Expr)) { 228223013Sdim if (const RecVec *Result = expand(Def->getDef())) 229223013Sdim return Elts.insert(Result->begin(), Result->end()); 230223013Sdim Elts.insert(Def->getDef()); 231223013Sdim return; 232223013Sdim } 233223013Sdim 234223013Sdim // Lists simply expand. 235223013Sdim if (ListInit *LI = dynamic_cast<ListInit*>(Expr)) 236223013Sdim return evaluate(LI->begin(), LI->end(), Elts); 237223013Sdim 238223013Sdim // Anything else must be a DAG. 239223013Sdim DagInit *DagExpr = dynamic_cast<DagInit*>(Expr); 240223013Sdim if (!DagExpr) 241223013Sdim throw "Invalid set element: " + Expr->getAsString(); 242223013Sdim DefInit *OpInit = dynamic_cast<DefInit*>(DagExpr->getOperator()); 243223013Sdim if (!OpInit) 244223013Sdim throw "Bad set expression: " + Expr->getAsString(); 245223013Sdim Operator *Op = Operators.lookup(OpInit->getDef()->getName()); 246223013Sdim if (!Op) 247223013Sdim throw "Unknown set operator: " + Expr->getAsString(); 248223013Sdim Op->apply(*this, DagExpr, Elts); 249223013Sdim} 250223013Sdim 251223013Sdimconst RecVec *SetTheory::expand(Record *Set) { 252223013Sdim // Check existing entries for Set and return early. 253223013Sdim ExpandMap::iterator I = Expansions.find(Set); 254223013Sdim if (I != Expansions.end()) 255223013Sdim return &I->second; 256223013Sdim 257223013Sdim // This is the first time we see Set. Find a suitable expander. 258223013Sdim try { 259223013Sdim const std::vector<Record*> &SC = Set->getSuperClasses(); 260223013Sdim for (unsigned i = 0, e = SC.size(); i != e; ++i) 261223013Sdim if (Expander *Exp = Expanders.lookup(SC[i]->getName())) { 262223013Sdim // This breaks recursive definitions. 263223013Sdim RecVec &EltVec = Expansions[Set]; 264223013Sdim RecSet Elts; 265223013Sdim Exp->expand(*this, Set, Elts); 266223013Sdim EltVec.assign(Elts.begin(), Elts.end()); 267223013Sdim return &EltVec; 268223013Sdim } 269223013Sdim } catch (const std::string &Error) { 270223013Sdim throw TGError(Set->getLoc(), Error); 271223013Sdim } 272223013Sdim 273223013Sdim // Set is not expandable. 274223013Sdim return 0; 275223013Sdim} 276223013Sdim 277