source: src/ResolvExpr/ConversionCost.cc@ b46e3bd

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors deferred_resn demangler enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr new-env no_list persistent-indexer pthread-emulation qualifiedEnum resolv-new stuck-waitfor-destruct with_gc
Last change on this file since b46e3bd was b46e3bd, checked in by Rob Schluntz <rschlunt@…>, 9 years ago

Update Cost structure to include static unsafe, poly, safe members
  • Property mode set to 100644
File size: 14.3 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// ConversionCost.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Sun May 17 07:06:19 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Wed Mar 2 17:35:46 2016
13// Update Count : 6
14//
15
16#include "ConversionCost.h"
17#include "typeops.h"
18#include "SynTree/Type.h"
19#include "SynTree/Visitor.h"
20#include "SymTab/Indexer.h"
21
22namespace ResolvExpr {
23 const Cost Cost::zero = Cost( 0, 0, 0 );
24 const Cost Cost::infinity = Cost( -1, -1, -1 );
25 const Cost Cost::unsafe = Cost( 1, 0, 0 );
26 const Cost Cost::poly = Cost( 0, 1, 0 );
27 const Cost Cost::safe = Cost( 0, 0, 1 );
28
29
30 Cost conversionCost( Type *src, Type *dest, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
31 if ( TypeInstType *destAsTypeInst = dynamic_cast< TypeInstType* >( dest ) ) {
32 EqvClass eqvClass;
33 NamedTypeDecl *namedType;
34/// std::cout << "type inst " << destAsTypeInst->get_name();
35 if ( env.lookup( destAsTypeInst->get_name(), eqvClass ) ) {
36 if ( eqvClass.type ) {
37 return conversionCost( src, eqvClass.type, indexer, env );
38 } else {
39 return Cost::infinity;
40 }
41 } else if ( ( namedType = indexer.lookupType( destAsTypeInst->get_name() ) ) ) {
42/// std::cout << " found" << std::endl;
43 TypeDecl *type = dynamic_cast< TypeDecl* >( namedType );
44 // all typedefs should be gone by this point
45 assert( type );
46 if ( type->get_base() ) {
47 return conversionCost( src, type->get_base(), indexer, env ) + Cost( 0, 0, 1 );
48 } // if
49 } // if
50/// std::cout << " not found" << std::endl;
51 } // if
52/// std::cout << "src is ";
53/// src->print( std::cout );
54/// std::cout << std::endl << "dest is ";
55/// dest->print( std::cout );
56/// std::cout << std::endl << "env is" << std::endl;
57/// env.print( std::cout, 8 );
58 if ( typesCompatibleIgnoreQualifiers( src, dest, indexer, env ) ) {
59/// std::cout << "compatible!" << std::endl;
60 return Cost( 0, 0, 0 );
61 } else if ( dynamic_cast< VoidType* >( dest ) ) {
62 return Cost( 0, 0, 1 );
63 } else if ( ReferenceType * refType = dynamic_cast< ReferenceType * > ( dest ) ) {
64 // std::cerr << "conversionCost: dest is reference" << std::endl;
65 return convertToReferenceCost( src, refType, indexer, env );
66 } else {
67 ConversionCost converter( dest, indexer, env );
68 src->accept( converter );
69 if ( converter.get_cost() == Cost::infinity ) {
70 return Cost::infinity;
71 } else {
72 return converter.get_cost() + Cost( 0, 0, 0 );
73 } // if
74 } // if
75 }
76
77 Cost convertToReferenceCost( Type * src, ReferenceType * dest, const SymTab::Indexer & indexer, const TypeEnvironment & env ) {
78 // std::cerr << "convert to reference cost..." << std::endl;
79 if ( ReferenceType *srcAsRef = dynamic_cast< ReferenceType * >( src ) ) { // pointer-like conversions between references
80 // std::cerr << "converting between references" << std::endl;
81 if ( srcAsRef->get_base()->get_qualifiers() <= dest->get_base()->get_qualifiers() && typesCompatibleIgnoreQualifiers( srcAsRef->get_base(), dest->get_base(), indexer, env ) ) {
82 return Cost( 0, 0, 1 );
83 } else { // xxx - this discards reference qualifiers from consideration -- reducing qualifiers is a safe conversion; is this right?
84 int assignResult = ptrsAssignable( srcAsRef->get_base(), dest->get_base(), env );
85 if ( assignResult < 0 ) {
86 return Cost( 0, 0, 1 );
87 } else if ( assignResult > 0 ) {
88 return Cost( 1, 0, 0 );
89 } // if
90 } // if
91 } else if ( typesCompatibleIgnoreQualifiers( src, dest->get_base(), indexer, env ) ) {
92 // std::cerr << "converting compatible base type" << std::endl;
93 if ( src->get_lvalue() ) {
94 // std::cerr << "lvalue to reference conversion" << std::endl;
95 // lvalue-to-reference conversion: cv lvalue T => cv T &
96 if ( src->get_qualifiers() == dest->get_base()->get_qualifiers() ) {
97 return Cost( 0, 0, 1 ); // cost needs to be non-zero to add cast
98 } if ( src->get_qualifiers() < dest->get_base()->get_qualifiers() ) {
99 return Cost( 0, 0, 2 ); // cost needs to be higher than previous cast to differentiate adding qualifiers vs. keeping same
100 } else {
101 return Cost( 1, 0, 0 );
102 }
103 } else if ( dest->get_base()->get_const() ) {
104 // std::cerr << "rvalue to const ref conversion" << std::endl;
105 // rvalue-to-const-reference conversion: T => const T &
106 return Cost( 0, 0, 1 );
107 } else {
108 // std::cerr << "rvalue to non-const reference conversion" << std::endl;
109 // rvalue-to-reference conversion: T => T &
110 return Cost( 1, 0, 0 );
111 }
112 } else {
113 // std::cerr << "attempting to convert from incompatible base type -- fail" << std::endl;
114 }
115 return Cost::infinity;
116 }
117
118 ConversionCost::ConversionCost( Type *dest, const SymTab::Indexer &indexer, const TypeEnvironment &env )
119 : dest( dest ), indexer( indexer ), cost( Cost::infinity ), env( env ) {
120 }
121
122/*
123 Old
124 ===
125 Double
126 |
127 Float
128 |
129 ULong
130 / \
131 UInt Long
132 \ /
133 Int
134 |
135 Ushort
136 |
137 Short
138 |
139 Uchar
140 / \
141 Schar Char
142
143 New
144 ===
145 +-----LongDoubleComplex--+
146 LongDouble--+ | +-LongDoubleImag
147 | +---DoubleComplex---+ |
148 Double------+ | +----DoubleImag
149 | +-FloatComplex-+ |
150 Float---------+ +-------FloatImag
151 |
152 ULongLong
153 |
154 LongLong
155 |
156 ULong
157 / \
158 UInt Long
159 \ /
160 Int
161 |
162 Ushort
163 |
164 Short
165 |
166 Uchar
167 / \
168 Schar Char
169 \ /
170 Bool
171*/
172
173 static const int costMatrix[ BasicType::NUMBER_OF_BASIC_TYPES ][ BasicType::NUMBER_OF_BASIC_TYPES ] =
174 {
175 /* Src \ Dest: Bool Char SChar UChar Short UShort Int UInt Long ULong LLong ULLong Float Double LDbl FCplex DCplex LDCplex FImag DImag LDImag */
176 /* Bool */ { 0, 1, 1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 10, 11, 12, 11, 12, 13, -1, -1, -1 },
177 /* Char */ { -1, 0, -1, 1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 10, 11, 10, 11, 12, -1, -1, -1 },
178 /* SChar */ { -1, -1, 0, 1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 10, 11, 10, 11, 12, -1, -1, -1 },
179 /* UChar */ { -1, -1, -1, 0, 1, 2, 3, 4, 4, 5, 6, 7, 8, 9, 10, 9, 10, 11, -1, -1, -1 },
180 /* Short */ { -1, -1, -1, -1, 0, 1, 2, 3, 3, 4, 5, 6, 7, 8, 9, 8, 9, 10, -1, -1, -1 },
181 /* UShort */{ -1, -1, -1, -1, -1, 0, 1, 2, 2, 3, 4, 5, 6, 7, 8, 7, 8, 9, -1, -1, -1 },
182 /* Int */ { -1, -1, -1, -1, -1, -1, 0, 1, 1, 2, 3, 4, 5, 6, 7, 6, 7, 8, -1, -1, -1 },
183 /* UInt */ { -1, -1, -1, -1, -1, -1, -1, 0, -1, 1, 2, 3, 4, 5, 6, 5, 6, 7, -1, -1, -1 },
184 /* Long */ { -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 5, 6, 7, -1, -1, -1 },
185 /* ULong */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 4, 5, 6, -1, -1, -1 },
186 /* LLong */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 3, 4, 5, -1, -1, -1 },
187 /* ULLong */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 2, 3, 4, -1, -1, -1 },
188 /* Float */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 1, 2, 3, -1, -1, -1 },
189 /* Double */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, -1, 1, 2, -1, -1, -1 },
190 /* LDbl */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, -1, -1, 1, -1, -1, -1 },
191 /* FCplex */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, -1, -1, -1 },
192 /* DCplex */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, -1, -1, -1 },
193 /* LDCplex */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, -1, -1, -1 },
194 /* FImag */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 3, 0, 1, 2 },
195 /* DImag */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, -1, 0, 1 },
196 /* LDImag */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, -1, -1, 0 }
197 };
198
199 void ConversionCost::visit( __attribute((unused)) VoidType *voidType ) {
200 cost = Cost::infinity;
201 }
202
203 void ConversionCost::visit(BasicType *basicType) {
204 if ( BasicType *destAsBasic = dynamic_cast< BasicType* >( dest ) ) {
205 int tableResult = costMatrix[ basicType->get_kind() ][ destAsBasic->get_kind() ];
206 if ( tableResult == -1 ) {
207 cost = Cost( 1, 0, 0 );
208 } else {
209 cost = Cost( 0, 0, tableResult );
210 } // if
211 } else if ( dynamic_cast< EnumInstType *>( dest ) ) {
212 // xxx - not positive this is correct, but appears to allow casting int => enum
213 cost = Cost( 1, 0, 0 );
214 } else if ( dynamic_cast< ZeroType* >( dest ) != nullptr || dynamic_cast< OneType* >( dest ) != nullptr ) {
215 cost = Cost( 1, 0, 0 );
216 } // if
217 }
218
219 void ConversionCost::visit(PointerType *pointerType) {
220 if ( PointerType *destAsPtr = dynamic_cast< PointerType* >( dest ) ) {
221 if ( pointerType->get_base()->get_qualifiers() <= destAsPtr->get_base()->get_qualifiers() && typesCompatibleIgnoreQualifiers( pointerType->get_base(), destAsPtr->get_base(), indexer, env ) ) {
222 cost = Cost( 0, 0, 1 );
223 } else { // xxx - this discards pointer qualifiers from consideration -- reducing qualifiers is a safe conversion; is this right?
224 int assignResult = ptrsAssignable( pointerType->get_base(), destAsPtr->get_base(), env );
225 if ( assignResult < 0 ) {
226 cost = Cost( 0, 0, 1 );
227 } else if ( assignResult > 0 ) {
228 cost = Cost( 1, 0, 0 );
229 } // if
230 } // if
231 } else if ( dynamic_cast< ZeroType* >( dest ) != nullptr || dynamic_cast< OneType* >( dest ) != nullptr ) {
232 cost = Cost( 1, 0, 0 );
233 } // if
234 }
235
236 void ConversionCost::visit(__attribute((unused)) ArrayType *arrayType) {}
237
238 void ConversionCost::visit(ReferenceType *refType) {
239 // Note: dest can never be a reference, since it would have been caught in an earlier check
240 assert( ! dynamic_cast< ReferenceType * >( dest ) );
241 // convert reference to rvalue: cv T1 & => T2
242 // recursively compute conversion cost from T1 to T2.
243 // cv can be safely dropped because of 'implicit dereference' behavior.
244 refType->get_base()->accept( *this );
245 }
246
247 void ConversionCost::visit(__attribute((unused)) FunctionType *functionType) {}
248
249 void ConversionCost::visit(StructInstType *inst) {
250 if ( StructInstType *destAsInst = dynamic_cast< StructInstType* >( dest ) ) {
251 if ( inst->get_name() == destAsInst->get_name() ) {
252 cost = Cost::zero;
253 } // if
254 } // if
255 }
256
257 void ConversionCost::visit(UnionInstType *inst) {
258 if ( StructInstType *destAsInst = dynamic_cast< StructInstType* >( dest ) ) {
259 if ( inst->get_name() == destAsInst->get_name() ) {
260 cost = Cost::zero;
261 } // if
262 } // if
263 }
264
265 void ConversionCost::visit( __attribute((unused)) EnumInstType *inst ) {
266 static Type::Qualifiers q;
267 static BasicType integer( q, BasicType::SignedInt );
268 integer.accept( *this ); // safe if dest >= int
269 if ( cost < Cost( 1, 0, 0 ) ) {
270 cost.incSafe();
271 } // if
272 }
273
274 void ConversionCost::visit( __attribute((unused)) TraitInstType *inst) {
275 }
276
277 void ConversionCost::visit(TypeInstType *inst) {
278 EqvClass eqvClass;
279 NamedTypeDecl *namedType;
280 if ( env.lookup( inst->get_name(), eqvClass ) ) {
281 cost = conversionCost( eqvClass.type, dest, indexer, env );
282 } else if ( TypeInstType *destAsInst = dynamic_cast< TypeInstType* >( dest ) ) {
283 if ( inst->get_name() == destAsInst->get_name() ) {
284 cost = Cost::zero;
285 }
286 } else if ( ( namedType = indexer.lookupType( inst->get_name() ) ) ) {
287 TypeDecl *type = dynamic_cast< TypeDecl* >( namedType );
288 // all typedefs should be gone by this point
289 assert( type );
290 if ( type->get_base() ) {
291 cost = conversionCost( type->get_base(), dest, indexer, env ) + Cost( 0, 0, 1 );
292 } // if
293 } // if
294 }
295
296 void ConversionCost::visit( __attribute((unused)) TupleType *tupleType) {
297 Cost c;
298 if ( TupleType *destAsTuple = dynamic_cast< TupleType* >( dest ) ) {
299 std::list< Type* >::const_iterator srcIt = tupleType->get_types().begin();
300 std::list< Type* >::const_iterator destIt = destAsTuple->get_types().begin();
301 while ( srcIt != tupleType->get_types().end() && destIt != destAsTuple->get_types().end() ) {
302 Cost newCost = conversionCost( *srcIt++, *destIt++, indexer, env );
303 if ( newCost == Cost::infinity ) {
304 return;
305 } // if
306 c += newCost;
307 } // while
308 if ( destIt != destAsTuple->get_types().end() ) {
309 cost = Cost::infinity;
310 } else {
311 cost = c;
312 } // if
313 } // if
314 }
315
316 void ConversionCost::visit( __attribute((unused)) VarArgsType *varArgsType) {
317 if ( dynamic_cast< VarArgsType* >( dest ) ) {
318 cost = Cost::zero;
319 }
320 }
321
322 void ConversionCost::visit( __attribute((unused)) ZeroType *zeroType) {
323 if ( dynamic_cast< ZeroType* >( dest ) ) {
324 cost = Cost::zero;
325 } else if ( BasicType *destAsBasic = dynamic_cast< BasicType* >( dest ) ) {
326 // copied from visit(BasicType*) for signed int, but +1 for safe conversions
327 int tableResult = costMatrix[ BasicType::SignedInt ][ destAsBasic->get_kind() ];
328 if ( tableResult == -1 ) {
329 cost = Cost( 1, 0, 0 );
330 } else {
331 cost = Cost( 0, 0, tableResult + 1 );
332 }
333 } else if ( dynamic_cast< PointerType* >( dest ) ) {
334 cost = Cost( 0, 0, 1 );
335 }
336 }
337
338 void ConversionCost::visit( __attribute((unused)) OneType *oneType) {
339 if ( dynamic_cast< OneType* >( dest ) ) {
340 cost = Cost::zero;
341 } else if ( BasicType *destAsBasic = dynamic_cast< BasicType* >( dest ) ) {
342 // copied from visit(BasicType*) for signed int, but +1 for safe conversions
343 int tableResult = costMatrix[ BasicType::SignedInt ][ destAsBasic->get_kind() ];
344 if ( tableResult == -1 ) {
345 cost = Cost( 1, 0, 0 );
346 } else {
347 cost = Cost( 0, 0, tableResult + 1 );
348 }
349 }
350 }
351} // namespace ResolvExpr
352
353// Local Variables: //
354// tab-width: 4 //
355// mode: c++ //
356// compile-command: "make install" //
357// End: //
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