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
20 using namespace llvm;
21
22 // Define the standard operators.
23 namespace {
24
25 typedef SetTheory::RecSet RecSet;
26 typedef SetTheory::RecVec RecVec;
27
28 // (add a, b, ...) Evaluate and union all arguments.
29 struct AddOp : public SetTheory::Operator {
apply__anonb23a274a0111::AddOp30 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, ArrayRef<SMLoc> Loc) {
31 ST.evaluate(Expr->arg_begin(), Expr->arg_end(), Elts, Loc);
32 }
33 };
34
35 // (sub Add, Sub, ...) Set difference.
36 struct SubOp : public SetTheory::Operator {
apply__anonb23a274a0111::SubOp37 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, ArrayRef<SMLoc> Loc) {
38 if (Expr->arg_size() < 2)
39 PrintFatalError(Loc, "Set difference needs at least two arguments: " +
40 Expr->getAsString());
41 RecSet Add, Sub;
42 ST.evaluate(*Expr->arg_begin(), Add, Loc);
43 ST.evaluate(Expr->arg_begin() + 1, Expr->arg_end(), Sub, Loc);
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.
51 struct AndOp : public SetTheory::Operator {
apply__anonb23a274a0111::AndOp52 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, ArrayRef<SMLoc> Loc) {
53 if (Expr->arg_size() != 2)
54 PrintFatalError(Loc, "Set intersection requires two arguments: " +
55 Expr->getAsString());
56 RecSet S1, S2;
57 ST.evaluate(Expr->arg_begin()[0], S1, Loc);
58 ST.evaluate(Expr->arg_begin()[1], S2, Loc);
59 for (RecSet::iterator I = S1.begin(), E = S1.end(); I != E; ++I)
60 if (S2.count(*I))
61 Elts.insert(*I);
62 }
63 };
64
65 // SetIntBinOp - Abstract base class for (Op S, N) operators.
66 struct SetIntBinOp : public SetTheory::Operator {
67 virtual void apply2(SetTheory &ST, DagInit *Expr,
68 RecSet &Set, int64_t N,
69 RecSet &Elts, ArrayRef<SMLoc> Loc) =0;
70
apply__anonb23a274a0111::SetIntBinOp71 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, ArrayRef<SMLoc> Loc) {
72 if (Expr->arg_size() != 2)
73 PrintFatalError(Loc, "Operator requires (Op Set, Int) arguments: " +
74 Expr->getAsString());
75 RecSet Set;
76 ST.evaluate(Expr->arg_begin()[0], Set, Loc);
77 IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[1]);
78 if (!II)
79 PrintFatalError(Loc, "Second argument must be an integer: " +
80 Expr->getAsString());
81 apply2(ST, Expr, Set, II->getValue(), Elts, Loc);
82 }
83 };
84
85 // (shl S, N) Shift left, remove the first N elements.
86 struct ShlOp : public SetIntBinOp {
apply2__anonb23a274a0111::ShlOp87 void apply2(SetTheory &ST, DagInit *Expr,
88 RecSet &Set, int64_t N,
89 RecSet &Elts, ArrayRef<SMLoc> Loc) {
90 if (N < 0)
91 PrintFatalError(Loc, "Positive shift required: " +
92 Expr->getAsString());
93 if (unsigned(N) < Set.size())
94 Elts.insert(Set.begin() + N, Set.end());
95 }
96 };
97
98 // (trunc S, N) Truncate after the first N elements.
99 struct TruncOp : public SetIntBinOp {
apply2__anonb23a274a0111::TruncOp100 void apply2(SetTheory &ST, DagInit *Expr,
101 RecSet &Set, int64_t N,
102 RecSet &Elts, ArrayRef<SMLoc> Loc) {
103 if (N < 0)
104 PrintFatalError(Loc, "Positive length required: " +
105 Expr->getAsString());
106 if (unsigned(N) > Set.size())
107 N = Set.size();
108 Elts.insert(Set.begin(), Set.begin() + N);
109 }
110 };
111
112 // Left/right rotation.
113 struct RotOp : public SetIntBinOp {
114 const bool Reverse;
115
RotOp__anonb23a274a0111::RotOp116 RotOp(bool Rev) : Reverse(Rev) {}
117
apply2__anonb23a274a0111::RotOp118 void apply2(SetTheory &ST, DagInit *Expr,
119 RecSet &Set, int64_t N,
120 RecSet &Elts, ArrayRef<SMLoc> Loc) {
121 if (Reverse)
122 N = -N;
123 // N > 0 -> rotate left, N < 0 -> rotate right.
124 if (Set.empty())
125 return;
126 if (N < 0)
127 N = Set.size() - (-N % Set.size());
128 else
129 N %= Set.size();
130 Elts.insert(Set.begin() + N, Set.end());
131 Elts.insert(Set.begin(), Set.begin() + N);
132 }
133 };
134
135 // (decimate S, N) Pick every N'th element of S.
136 struct DecimateOp : public SetIntBinOp {
apply2__anonb23a274a0111::DecimateOp137 void apply2(SetTheory &ST, DagInit *Expr,
138 RecSet &Set, int64_t N,
139 RecSet &Elts, ArrayRef<SMLoc> Loc) {
140 if (N <= 0)
141 PrintFatalError(Loc, "Positive stride required: " +
142 Expr->getAsString());
143 for (unsigned I = 0; I < Set.size(); I += N)
144 Elts.insert(Set[I]);
145 }
146 };
147
148 // (interleave S1, S2, ...) Interleave elements of the arguments.
149 struct InterleaveOp : public SetTheory::Operator {
apply__anonb23a274a0111::InterleaveOp150 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, ArrayRef<SMLoc> Loc) {
151 // Evaluate the arguments individually.
152 SmallVector<RecSet, 4> Args(Expr->getNumArgs());
153 unsigned MaxSize = 0;
154 for (unsigned i = 0, e = Expr->getNumArgs(); i != e; ++i) {
155 ST.evaluate(Expr->getArg(i), Args[i], Loc);
156 MaxSize = std::max(MaxSize, unsigned(Args[i].size()));
157 }
158 // Interleave arguments into Elts.
159 for (unsigned n = 0; n != MaxSize; ++n)
160 for (unsigned i = 0, e = Expr->getNumArgs(); i != e; ++i)
161 if (n < Args[i].size())
162 Elts.insert(Args[i][n]);
163 }
164 };
165
166 // (sequence "Format", From, To) Generate a sequence of records by name.
167 struct SequenceOp : public SetTheory::Operator {
apply__anonb23a274a0111::SequenceOp168 void apply(SetTheory &ST, DagInit *Expr, RecSet &Elts, ArrayRef<SMLoc> Loc) {
169 int Step = 1;
170 if (Expr->arg_size() > 4)
171 PrintFatalError(Loc, "Bad args to (sequence \"Format\", From, To): " +
172 Expr->getAsString());
173 else if (Expr->arg_size() == 4) {
174 if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[3])) {
175 Step = II->getValue();
176 } else
177 PrintFatalError(Loc, "Stride must be an integer: " +
178 Expr->getAsString());
179 }
180
181 std::string Format;
182 if (StringInit *SI = dyn_cast<StringInit>(Expr->arg_begin()[0]))
183 Format = SI->getValue();
184 else
185 PrintFatalError(Loc, "Format must be a string: " + Expr->getAsString());
186
187 int64_t From, To;
188 if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[1]))
189 From = II->getValue();
190 else
191 PrintFatalError(Loc, "From must be an integer: " + Expr->getAsString());
192 if (From < 0 || From >= (1 << 30))
193 PrintFatalError(Loc, "From out of range");
194
195 if (IntInit *II = dyn_cast<IntInit>(Expr->arg_begin()[2]))
196 To = II->getValue();
197 else
198 PrintFatalError(Loc, "From must be an integer: " + Expr->getAsString());
199 if (To < 0 || To >= (1 << 30))
200 PrintFatalError(Loc, "To out of range");
201
202 RecordKeeper &Records =
203 cast<DefInit>(Expr->getOperator())->getDef()->getRecords();
204
205 Step *= From <= To ? 1 : -1;
206 while (true) {
207 if (Step > 0 && From > To)
208 break;
209 else if (Step < 0 && From < To)
210 break;
211 std::string Name;
212 raw_string_ostream OS(Name);
213 OS << format(Format.c_str(), unsigned(From));
214 Record *Rec = Records.getDef(OS.str());
215 if (!Rec)
216 PrintFatalError(Loc, "No def named '" + Name + "': " +
217 Expr->getAsString());
218 // Try to reevaluate Rec in case it is a set.
219 if (const RecVec *Result = ST.expand(Rec))
220 Elts.insert(Result->begin(), Result->end());
221 else
222 Elts.insert(Rec);
223
224 From += Step;
225 }
226 }
227 };
228
229 // Expand a Def into a set by evaluating one of its fields.
230 struct FieldExpander : public SetTheory::Expander {
231 StringRef FieldName;
232
FieldExpander__anonb23a274a0111::FieldExpander233 FieldExpander(StringRef fn) : FieldName(fn) {}
234
expand__anonb23a274a0111::FieldExpander235 void expand(SetTheory &ST, Record *Def, RecSet &Elts) {
236 ST.evaluate(Def->getValueInit(FieldName), Elts, Def->getLoc());
237 }
238 };
239 } // end anonymous namespace
240
anchor()241 void SetTheory::Operator::anchor() { }
242
anchor()243 void SetTheory::Expander::anchor() { }
244
SetTheory()245 SetTheory::SetTheory() {
246 addOperator("add", new AddOp);
247 addOperator("sub", new SubOp);
248 addOperator("and", new AndOp);
249 addOperator("shl", new ShlOp);
250 addOperator("trunc", new TruncOp);
251 addOperator("rotl", new RotOp(false));
252 addOperator("rotr", new RotOp(true));
253 addOperator("decimate", new DecimateOp);
254 addOperator("interleave", new InterleaveOp);
255 addOperator("sequence", new SequenceOp);
256 }
257
addOperator(StringRef Name,Operator * Op)258 void SetTheory::addOperator(StringRef Name, Operator *Op) {
259 Operators[Name] = Op;
260 }
261
addExpander(StringRef ClassName,Expander * E)262 void SetTheory::addExpander(StringRef ClassName, Expander *E) {
263 Expanders[ClassName] = E;
264 }
265
addFieldExpander(StringRef ClassName,StringRef FieldName)266 void SetTheory::addFieldExpander(StringRef ClassName, StringRef FieldName) {
267 addExpander(ClassName, new FieldExpander(FieldName));
268 }
269
evaluate(Init * Expr,RecSet & Elts,ArrayRef<SMLoc> Loc)270 void SetTheory::evaluate(Init *Expr, RecSet &Elts, ArrayRef<SMLoc> Loc) {
271 // A def in a list can be a just an element, or it may expand.
272 if (DefInit *Def = dyn_cast<DefInit>(Expr)) {
273 if (const RecVec *Result = expand(Def->getDef()))
274 return Elts.insert(Result->begin(), Result->end());
275 Elts.insert(Def->getDef());
276 return;
277 }
278
279 // Lists simply expand.
280 if (ListInit *LI = dyn_cast<ListInit>(Expr))
281 return evaluate(LI->begin(), LI->end(), Elts, Loc);
282
283 // Anything else must be a DAG.
284 DagInit *DagExpr = dyn_cast<DagInit>(Expr);
285 if (!DagExpr)
286 PrintFatalError(Loc, "Invalid set element: " + Expr->getAsString());
287 DefInit *OpInit = dyn_cast<DefInit>(DagExpr->getOperator());
288 if (!OpInit)
289 PrintFatalError(Loc, "Bad set expression: " + Expr->getAsString());
290 Operator *Op = Operators.lookup(OpInit->getDef()->getName());
291 if (!Op)
292 PrintFatalError(Loc, "Unknown set operator: " + Expr->getAsString());
293 Op->apply(*this, DagExpr, Elts, Loc);
294 }
295
expand(Record * Set)296 const RecVec *SetTheory::expand(Record *Set) {
297 // Check existing entries for Set and return early.
298 ExpandMap::iterator I = Expansions.find(Set);
299 if (I != Expansions.end())
300 return &I->second;
301
302 // This is the first time we see Set. Find a suitable expander.
303 const std::vector<Record*> &SC = Set->getSuperClasses();
304 for (unsigned i = 0, e = SC.size(); i != e; ++i) {
305 // Skip unnamed superclasses.
306 if (!dyn_cast<StringInit>(SC[i]->getNameInit()))
307 continue;
308 if (Expander *Exp = Expanders.lookup(SC[i]->getName())) {
309 // This breaks recursive definitions.
310 RecVec &EltVec = Expansions[Set];
311 RecSet Elts;
312 Exp->expand(*this, Set, Elts);
313 EltVec.assign(Elts.begin(), Elts.end());
314 return &EltVec;
315 }
316 }
317
318 // Set is not expandable.
319 return 0;
320 }
321
322