1 //===- SetTheory.cpp - Generate ordered sets from DAG expressions ---------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the SetTheory class that computes ordered sets of
11 // Records from DAG expressions.
13 //===----------------------------------------------------------------------===//
15 #include "SetTheory.h"
16 #include "llvm/TableGen/Error.h"
17 #include "llvm/TableGen/Record.h"
18 #include "llvm/Support/Format.h"
22 // Define the standard operators.
25 typedef SetTheory::RecSet RecSet;
26 typedef SetTheory::RecVec RecVec;
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 ST.evaluate(Expr->arg_begin(), Expr->arg_end(), Elts);
35 // (sub Add, Sub, ...) Set difference.
36 struct 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: " +
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)
50 // (and S1, S2) Set intersection.
51 struct 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();
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)
64 // SetIntBinOp - Abstract base class for (Op S, N) operators.
65 struct SetIntBinOp : public SetTheory::Operator {
66 virtual void apply2(SetTheory &ST, DagInit *Expr,
67 RecSet &Set, int64_t N,
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();
74 ST.evaluate(Expr->arg_begin()[0], Set);
75 IntInit *II = dynamic_cast<IntInit*>(Expr->arg_begin()[1]);
77 throw "Second argument must be an integer: " + Expr->getAsString();
78 apply2(ST, Expr, Set, II->getValue(), Elts);
82 // (shl S, N) Shift left, remove the first N elements.
83 struct ShlOp : public SetIntBinOp {
84 void apply2(SetTheory &ST, DagInit *Expr,
85 RecSet &Set, int64_t N,
88 throw "Positive shift required: " + Expr->getAsString();
89 if (unsigned(N) < Set.size())
90 Elts.insert(Set.begin() + N, Set.end());
94 // (trunc S, N) Truncate after the first N elements.
95 struct TruncOp : public SetIntBinOp {
96 void apply2(SetTheory &ST, DagInit *Expr,
97 RecSet &Set, int64_t N,
100 throw "Positive length required: " + Expr->getAsString();
101 if (unsigned(N) > Set.size())
103 Elts.insert(Set.begin(), Set.begin() + N);
107 // Left/right rotation.
108 struct RotOp : public SetIntBinOp {
111 RotOp(bool Rev) : Reverse(Rev) {}
113 void apply2(SetTheory &ST, DagInit *Expr,
114 RecSet &Set, int64_t N,
118 // N > 0 -> rotate left, N < 0 -> rotate right.
122 N = Set.size() - (-N % Set.size());
125 Elts.insert(Set.begin() + N, Set.end());
126 Elts.insert(Set.begin(), Set.begin() + N);
130 // (decimate S, N) Pick every N'th element of S.
131 struct DecimateOp : public SetIntBinOp {
132 void apply2(SetTheory &ST, DagInit *Expr,
133 RecSet &Set, int64_t N,
136 throw "Positive stride required: " + Expr->getAsString();
137 for (unsigned I = 0; I < Set.size(); I += N)
142 // (sequence "Format", From, To) Generate a sequence of records by name.
143 struct SequenceOp : public SetTheory::Operator {
144 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts) {
145 if (Expr->arg_size() != 3)
146 throw "Bad args to (sequence \"Format\", From, To): " +
149 if (StringInit *SI = dynamic_cast<StringInit*>(Expr->arg_begin()[0]))
150 Format = SI->getValue();
152 throw "Format must be a string: " + Expr->getAsString();
155 if (IntInit *II = dynamic_cast<IntInit*>(Expr->arg_begin()[1]))
156 From = II->getValue();
158 throw "From must be an integer: " + Expr->getAsString();
159 if (From < 0 || From >= (1 << 30))
160 throw "From out of range";
162 if (IntInit *II = dynamic_cast<IntInit*>(Expr->arg_begin()[2]))
165 throw "From must be an integer: " + Expr->getAsString();
166 if (To < 0 || To >= (1 << 30))
167 throw "To out of range";
169 RecordKeeper &Records =
170 dynamic_cast<DefInit&>(*Expr->getOperator()).getDef()->getRecords();
172 int Step = From <= To ? 1 : -1;
173 for (To += Step; From != To; From += Step) {
175 raw_string_ostream OS(Name);
176 OS << format(Format.c_str(), unsigned(From));
177 Record *Rec = Records.getDef(OS.str());
179 throw "No def named '" + Name + "': " + Expr->getAsString();
180 // Try to reevaluate Rec in case it is a set.
181 if (const RecVec *Result = ST.expand(Rec))
182 Elts.insert(Result->begin(), Result->end());
189 // Expand a Def into a set by evaluating one of its fields.
190 struct FieldExpander : public SetTheory::Expander {
193 FieldExpander(StringRef fn) : FieldName(fn) {}
195 void expand(SetTheory &ST, Record *Def, RecSet &Elts) {
196 ST.evaluate(Def->getValueInit(FieldName), Elts);
199 } // end anonymous namespace
201 SetTheory::SetTheory() {
202 addOperator("add", new AddOp);
203 addOperator("sub", new SubOp);
204 addOperator("and", new AndOp);
205 addOperator("shl", new ShlOp);
206 addOperator("trunc", new TruncOp);
207 addOperator("rotl", new RotOp(false));
208 addOperator("rotr", new RotOp(true));
209 addOperator("decimate", new DecimateOp);
210 addOperator("sequence", new SequenceOp);
213 void SetTheory::addOperator(StringRef Name, Operator *Op) {
214 Operators[Name] = Op;
217 void SetTheory::addExpander(StringRef ClassName, Expander *E) {
218 Expanders[ClassName] = E;
221 void SetTheory::addFieldExpander(StringRef ClassName, StringRef FieldName) {
222 addExpander(ClassName, new FieldExpander(FieldName));
225 void SetTheory::evaluate(Init *Expr, RecSet &Elts) {
226 // A def in a list can be a just an element, or it may expand.
227 if (DefInit *Def = dynamic_cast<DefInit*>(Expr)) {
228 if (const RecVec *Result = expand(Def->getDef()))
229 return Elts.insert(Result->begin(), Result->end());
230 Elts.insert(Def->getDef());
234 // Lists simply expand.
235 if (ListInit *LI = dynamic_cast<ListInit*>(Expr))
236 return evaluate(LI->begin(), LI->end(), Elts);
238 // Anything else must be a DAG.
239 DagInit *DagExpr = dynamic_cast<DagInit*>(Expr);
241 throw "Invalid set element: " + Expr->getAsString();
242 DefInit *OpInit = dynamic_cast<DefInit*>(DagExpr->getOperator());
244 throw "Bad set expression: " + Expr->getAsString();
245 Operator *Op = Operators.lookup(OpInit->getDef()->getName());
247 throw "Unknown set operator: " + Expr->getAsString();
248 Op->apply(*this, DagExpr, Elts);
251 const RecVec *SetTheory::expand(Record *Set) {
252 // Check existing entries for Set and return early.
253 ExpandMap::iterator I = Expansions.find(Set);
254 if (I != Expansions.end())
257 // This is the first time we see Set. Find a suitable expander.
259 const std::vector<Record*> &SC = Set->getSuperClasses();
260 for (unsigned i = 0, e = SC.size(); i != e; ++i)
261 if (Expander *Exp = Expanders.lookup(SC[i]->getName())) {
262 // This breaks recursive definitions.
263 RecVec &EltVec = Expansions[Set];
265 Exp->expand(*this, Set, Elts);
266 EltVec.assign(Elts.begin(), Elts.end());
269 } catch (const std::string &Error) {
270 throw TGError(Set->getLoc(), Error);
273 // Set is not expandable.