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source: src/ResolvExpr/ConversionCost.cc @ d411426d

ADTaaron-thesisarm-ehast-experimentalcleanup-dtorsdeferred_resndemanglerenumforall-pointer-decayjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprnew-envno_listpersistent-indexerpthread-emulationqualifiedEnumresolv-newwith_gc

Last change on this file since d411426d was 201aeb9, checked in by Peter A. Buhr <pabuhr@…>, 7 years ago
first attempt at new basic-type int128, and length suffix with explicit size
Property mode set to `100644`
File size: 18.0 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 : Mon Sep 25 15:43:34 2017
13	// Update Count : 10
14	//
15
16	#include "ConversionCost.h"
17
18	#include <cassert> // for assert
19	#include <list> // for list, list<>::const_iterator
20	#include <string> // for operator==, string
21
22	#include "ResolvExpr/Cost.h" // for Cost
23	#include "ResolvExpr/TypeEnvironment.h" // for EqvClass, TypeEnvironment
24	#include "SymTab/Indexer.h" // for Indexer
25	#include "SynTree/Declaration.h" // for TypeDecl, NamedTypeDecl
26	#include "SynTree/Type.h" // for Type, BasicType, TypeInstType
27	#include "typeops.h" // for typesCompatibleIgnoreQualifiers
28
29	namespace ResolvExpr {
30	const Cost Cost::zero = Cost( 0, 0, 0, 0 );
31	const Cost Cost::infinity = Cost( -1, -1, -1, -1 );
32	const Cost Cost::unsafe = Cost( 1, 0, 0, 0 );
33	const Cost Cost::poly = Cost( 0, 1, 0, 0 );
34	const Cost Cost::safe = Cost( 0, 0, 1, 0 );
35	const Cost Cost::reference = Cost( 0, 0, 0, 1 );
36
37	#if 0
38	#define PRINT(x) x
39	#else
40	#define PRINT(x)
41	#endif
42	Cost conversionCost( Type src, Type dest, const SymTab::Indexer &indexer, const TypeEnvironment &env ) {
43	if ( TypeInstType destAsTypeInst = dynamic_cast< TypeInstType >( dest ) ) {
44	EqvClass eqvClass;
45	NamedTypeDecl *namedType;
46	PRINT( std::cerr << "type inst " << destAsTypeInst->get_name(); )
47	if ( env.lookup( destAsTypeInst->get_name(), eqvClass ) ) {
48	if ( eqvClass.type ) {
49	return conversionCost( src, eqvClass.type, indexer, env );
50	} else {
51	return Cost::infinity;
52	}
53	} else if ( ( namedType = indexer.lookupType( destAsTypeInst->get_name() ) ) ) {
54	PRINT( std::cerr << " found" << std::endl; )
55	TypeDecl type = dynamic_cast< TypeDecl >( namedType );
56	// all typedefs should be gone by this point
57	assert( type );
58	if ( type->get_base() ) {
59	return conversionCost( src, type->get_base(), indexer, env ) + Cost::safe;
60	} // if
61	} // if
62	PRINT( std::cerr << " not found" << std::endl; )
63	} // if
64	PRINT(
65	std::cerr << "src is ";
66	src->print( std::cerr );
67	std::cerr << std::endl << "dest is ";
68	dest->print( std::cerr );
69	std::cerr << std::endl << "env is" << std::endl;
70	env.print( std::cerr, 8 );
71	)
72	if ( typesCompatibleIgnoreQualifiers( src, dest, indexer, env ) ) {
73	PRINT( std::cerr << "compatible!" << std::endl; )
74	return Cost::zero;
75	} else if ( dynamic_cast< VoidType* >( dest ) ) {
76	return Cost::safe;
77	} else if ( ReferenceType * refType = dynamic_cast< ReferenceType * > ( dest ) ) {
78	PRINT( std::cerr << "conversionCost: dest is reference" << std::endl; )
79	return convertToReferenceCost( src, refType, indexer, env, [](Type * t1, Type * t2, const TypeEnvironment & env, const SymTab::Indexer &){
80	return ptrsAssignable( t1, t2, env );
81	});
82	} else {
83	ConversionCost converter( dest, indexer, env );
84	src->accept( converter );
85	if ( converter.get_cost() == Cost::infinity ) {
86	return Cost::infinity;
87	} else {
88	return converter.get_cost() + Cost::zero;
89	} // if
90	} // if
91	}
92
93	Cost convertToReferenceCost( Type * src, Type * dest, int diff, const SymTab::Indexer & indexer, const TypeEnvironment & env, PtrsFunction func ) {
94	PRINT( std::cerr << "convert to reference cost... diff " << diff << std::endl; )
95	if ( diff > 0 ) {
96	// TODO: document this
97	Cost cost = convertToReferenceCost( strict_dynamic_cast< ReferenceType * >( src )->get_base(), dest, diff-1, indexer, env, func );
98	cost.incReference();
99	return cost;
100	} else if ( diff < -1 ) {
101	// TODO: document this
102	Cost cost = convertToReferenceCost( src, strict_dynamic_cast< ReferenceType * >( dest )->get_base(), diff+1, indexer, env, func );
103	cost.incReference();
104	return cost;
105	} else if ( diff == 0 ) {
106	ReferenceType * srcAsRef = dynamic_cast< ReferenceType * >( src );
107	ReferenceType * destAsRef = dynamic_cast< ReferenceType * >( dest );
108	if ( srcAsRef && destAsRef ) { // pointer-like conversions between references
109	PRINT( std::cerr << "converting between references" << std::endl; )
110	if ( srcAsRef->get_base()->get_qualifiers() <= destAsRef->get_base()->get_qualifiers() && typesCompatibleIgnoreQualifiers( srcAsRef->get_base(), destAsRef->get_base(), indexer, env ) ) {
111	return Cost::safe;
112	} else { // xxx - this discards reference qualifiers from consideration -- reducing qualifiers is a safe conversion; is this right?
113	int assignResult = func( srcAsRef->get_base(), destAsRef->get_base(), env, indexer );
114	PRINT( std::cerr << "comparing references: " << assignResult << " " << srcAsRef << " " << destAsRef << std::endl; )
115	if ( assignResult < 0 ) {
116	return Cost::safe;
117	} else if ( assignResult > 0 ) {
118	return Cost::unsafe;
119	} // if
120	} // if
121	} else {
122	PRINT( std::cerr << "reference to rvalue conversion" << std::endl; )
123	ConversionCost converter( dest, indexer, env );
124	src->accept( converter );
125	return converter.get_cost();
126	} // if
127	} else {
128	ReferenceType * destAsRef = dynamic_cast< ReferenceType * >( dest );
129	assert( diff == -1 && destAsRef );
130	PRINT( std::cerr << "dest is: " << dest << " / src is: " << src << std::endl; )
131	if ( typesCompatibleIgnoreQualifiers( src, destAsRef->get_base(), indexer, env ) ) {
132	PRINT( std::cerr << "converting compatible base type" << std::endl; )
133	if ( src->get_lvalue() ) {
134	PRINT(
135	std::cerr << "lvalue to reference conversion" << std::endl;
136	std::cerr << src << " => " << destAsRef << std::endl;
137	)
138	// lvalue-to-reference conversion: cv lvalue T => cv T &
139	if ( src->get_qualifiers() == destAsRef->get_base()->get_qualifiers() ) {
140	return Cost::reference; // cost needs to be non-zero to add cast
141	} if ( src->get_qualifiers() < destAsRef->get_base()->get_qualifiers() ) {
142	return Cost::safe; // cost needs to be higher than previous cast to differentiate adding qualifiers vs. keeping same
143	} else {
144	return Cost::unsafe;
145	} // if
146	} else if ( destAsRef->get_base()->get_const() ) {
147	PRINT( std::cerr << "rvalue to const ref conversion" << std::endl; )
148	// rvalue-to-const-reference conversion: T => const T &
149	return Cost::safe;
150	} else {
151	PRINT( std::cerr << "rvalue to non-const reference conversion" << std::endl; )
152	// rvalue-to-reference conversion: T => T &
153	return Cost::unsafe;
154	} // if
155	} // if
156	PRINT( std::cerr << "attempting to convert from incompatible base type -- fail" << std::endl; )
157	}
158	return Cost::infinity;
159	}
160
161	Cost convertToReferenceCost( Type * src, ReferenceType * dest, const SymTab::Indexer & indexer, const TypeEnvironment & env, PtrsFunction func ) {
162	int sdepth = src->referenceDepth(), ddepth = dest->referenceDepth();
163	return convertToReferenceCost( src, dest, sdepth-ddepth, indexer, env, func );
164	}
165
166	ConversionCost::ConversionCost( Type *dest, const SymTab::Indexer &indexer, const TypeEnvironment &env )
167	: dest( dest ), indexer( indexer ), cost( Cost::infinity ), env( env ) {
168	}
169
170	/*
171	Old
172	===
173	Double
174	\|
175	Float
176	\|
177	ULong
178	/ \
179	UInt Long
180	\ /
181	Int
182	\|
183	Ushort
184	\|
185	Short
186	\|
187	Uchar
188	/ \
189	Schar Char
190
191	New
192	===
193	+-----LongDoubleComplex--+
194	LongDouble--+ \| +-LongDoubleImag
195	\| +---DoubleComplex---+ \|
196	Double------+ \| +----DoubleImag
197	\| +-FloatComplex-+ \|
198	Float---------+ +-------FloatImag
199	\|
200	ULongLong
201	\|
202	LongLong
203	\|
204	ULong
205	/ \
206	UInt Long
207	\ /
208	Int
209	\|
210	Ushort
211	\|
212	Short
213	\|
214	Uchar
215	/ \
216	Schar Char
217	\ /
218	Bool
219	*/
220
221	static const int costMatrix[ BasicType::NUMBER_OF_BASIC_TYPES ][ BasicType::NUMBER_OF_BASIC_TYPES ] = {
222	/* Src \ Dest: Bool Char SChar UChar Short UShort Int UInt Long ULong LLong ULLong Float Double LDbl FCplex DCplex LDCplex FImag DImag LDImag I128, U128 */
223	/* Bool */ { 0, 1, 1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 12, 13, 14, 12, 13, 14, -1, -1, -1, 10, 11, },
224	/* Char */ { -1, 0, -1, 1, 2, 3, 4, 5, 5, 6, 7, 8, 11, 12, 13, 11, 12, 13, -1, -1, -1, 9, 10, },
225	/* SChar */ { -1, -1, 0, 1, 2, 3, 4, 5, 5, 6, 7, 8, 11, 12, 13, 11, 12, 13, -1, -1, -1, 9, 10, },
226	/* UChar */ { -1, -1, -1, 0, 1, 2, 3, 4, 4, 5, 6, 7, 10, 11, 12, 10, 11, 12, -1, -1, -1, 8, 9, },
227	/* Short */ { -1, -1, -1, -1, 0, 1, 2, 3, 3, 4, 5, 6, 9, 10, 11, 9, 10, 11, -1, -1, -1, 7, 8, },
228	/* UShort */{ -1, -1, -1, -1, -1, 0, 1, 2, 2, 3, 4, 5, 8, 9, 10, 8, 9, 10, -1, -1, -1, 6, 7, },
229	/* Int */ { -1, -1, -1, -1, -1, -1, 0, 1, 1, 2, 3, 4, 7, 8, 9, 7, 8, 9, -1, -1, -1, 5, 6, },
230	/* UInt */ { -1, -1, -1, -1, -1, -1, -1, 0, -1, 1, 2, 3, 6, 7, 8, 6, 7, 8, -1, -1, -1, 4, 5, },
231	/* Long */ { -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 6, 7, 8, 6, 7, 8, -1, -1, -1, 4, 5, },
232	/* ULong */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 5, 6, 7, 5, 6, 7, -1, -1, -1, 3, 4, },
233	/* LLong */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 4, 5, 6, 4, 5, 6, -1, -1, -1, 2, 3, },
234	/* ULLong */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 3, 4, 5, 3, 4, 5, -1, -1, -1, 1, 2, },
235
236	/* Float */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 1, 2, 3, -1, -1, -1, -1, -1, },
237	/* Double */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, -1, 1, 2, -1, -1, -1, -1, -1, },
238	/* LDbl */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, -1, -1, 1, -1, -1, -1, -1, -1, },
239	/* FCplex */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, -1, -1, -1, -1, -1, },
240	/* DCplex */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, -1, -1, -1, -1, -1, },
241	/* LDCplex */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, -1, -1, -1, -1, -1, },
242	/* FImag */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 3, 0, 1, 2, -1, -1, },
243	/* DImag */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, -1, 0, 1, -1, -1, },
244	/* LDImag */{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, -1, -1, 0, -1, -1, },
245
246	/* I128 */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 2, 3, 4, 3, 4, 5, -1, -1, -1, 0, 1, },
247	/* U128 */ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 3, 2, 3, 4, -1, -1, -1, -1, 0, },
248	};
249
250	void ConversionCost::visit( __attribute((unused)) VoidType *voidType ) {
251	cost = Cost::infinity;
252	}
253
254	void ConversionCost::visit(BasicType *basicType) {
255	if ( BasicType destAsBasic = dynamic_cast< BasicType >( dest ) ) {
256	int tableResult = costMatrix[ basicType->get_kind() ][ destAsBasic->get_kind() ];
257	if ( tableResult == -1 ) {
258	cost = Cost::unsafe;
259	} else {
260	cost = Cost::zero;
261	cost.incSafe( tableResult );
262	} // if
263	} else if ( dynamic_cast< EnumInstType *>( dest ) ) {
264	// xxx - not positive this is correct, but appears to allow casting int => enum
265	cost = Cost::unsafe;
266	} else if ( dynamic_cast< ZeroType* >( dest ) != nullptr \|\| dynamic_cast< OneType* >( dest ) != nullptr ) {
267	cost = Cost::unsafe;
268	} // if
269	}
270
271	void ConversionCost::visit(PointerType *pointerType) {
272	if ( PointerType destAsPtr = dynamic_cast< PointerType >( dest ) ) {
273	PRINT( std::cerr << pointerType << " ===> " << destAsPtr; )
274	Type::Qualifiers tq1 = pointerType->get_base()->get_qualifiers();
275	Type::Qualifiers tq2 = destAsPtr->get_base()->get_qualifiers();
276	if ( tq1 <= tq2 && typesCompatibleIgnoreQualifiers( pointerType->get_base(), destAsPtr->get_base(), indexer, env ) ) {
277	if ( tq1 == tq2 ) {
278	// types are the same
279	cost = Cost::zero;
280	} else {
281	// types are the same, except otherPointer has more qualifiers
282	PRINT( std::cerr << " :: compatible and good qualifiers" << std::endl; )
283	cost = Cost::safe;
284	}
285	} else { // xxx - this discards qualifiers from consideration -- reducing qualifiers is a safe conversion; is this right?
286	int assignResult = ptrsAssignable( pointerType->get_base(), destAsPtr->get_base(), env );
287	PRINT( std::cerr << " :: " << assignResult << std::endl; )
288	if ( assignResult < 0 && pointerType->get_base()->get_qualifiers() <= destAsPtr->get_qualifiers() ) {
289	cost = Cost::safe;
290	} else if ( assignResult > 0 ) {
291	cost = Cost::unsafe;
292	} // if
293	// assignResult == 0 means Cost::Infinity
294	} // if
295	} else if ( dynamic_cast< ZeroType* >( dest ) != nullptr \|\| dynamic_cast< OneType* >( dest ) != nullptr ) {
296	cost = Cost::unsafe;
297	} // if
298	}
299
300	void ConversionCost::visit(__attribute((unused)) ArrayType *arrayType) {}
301
302	void ConversionCost::visit(ReferenceType *refType) {
303	// Note: dest can never be a reference, since it would have been caught in an earlier check
304	assert( ! dynamic_cast< ReferenceType * >( dest ) );
305	// convert reference to rvalue: cv T1 & => T2
306	// recursively compute conversion cost from T1 to T2.
307	// cv can be safely dropped because of 'implicit dereference' behavior.
308	refType->get_base()->accept( *this );
309	if ( refType->get_base()->get_qualifiers() == dest->get_qualifiers() ) {
310	cost.incReference(); // prefer exact qualifiers
311	} else if ( refType->get_base()->get_qualifiers() < dest->get_qualifiers() ) {
312	cost.incSafe(); // then gaining qualifiers
313	} else {
314	cost.incUnsafe(); // lose qualifiers as last resort
315	}
316	PRINT( std::cerr << refType << " ==> " << dest << " " << cost << std::endl; )
317	}
318
319	void ConversionCost::visit(__attribute((unused)) FunctionType *functionType) {}
320
321	void ConversionCost::visit(StructInstType *inst) {
322	if ( StructInstType destAsInst = dynamic_cast< StructInstType >( dest ) ) {
323	if ( inst->get_name() == destAsInst->get_name() ) {
324	cost = Cost::zero;
325	} // if
326	} // if
327	}
328
329	void ConversionCost::visit(UnionInstType *inst) {
330	if ( StructInstType destAsInst = dynamic_cast< StructInstType >( dest ) ) {
331	if ( inst->get_name() == destAsInst->get_name() ) {
332	cost = Cost::zero;
333	} // if
334	} // if
335	}
336
337	void ConversionCost::visit( __attribute((unused)) EnumInstType *inst ) {
338	static Type::Qualifiers q;
339	static BasicType integer( q, BasicType::SignedInt );
340	integer.accept( *this ); // safe if dest >= int
341	if ( cost < Cost::unsafe ) {
342	cost.incSafe();
343	} // if
344	}
345
346	void ConversionCost::visit( __attribute((unused)) TraitInstType *inst) {
347	}
348
349	void ConversionCost::visit(TypeInstType *inst) {
350	EqvClass eqvClass;
351	NamedTypeDecl *namedType;
352	if ( env.lookup( inst->get_name(), eqvClass ) ) {
353	cost = conversionCost( eqvClass.type, dest, indexer, env );
354	} else if ( TypeInstType destAsInst = dynamic_cast< TypeInstType >( dest ) ) {
355	if ( inst->get_name() == destAsInst->get_name() ) {
356	cost = Cost::zero;
357	}
358	} else if ( ( namedType = indexer.lookupType( inst->get_name() ) ) ) {
359	TypeDecl type = dynamic_cast< TypeDecl >( namedType );
360	// all typedefs should be gone by this point
361	assert( type );
362	if ( type->get_base() ) {
363	cost = conversionCost( type->get_base(), dest, indexer, env ) + Cost::safe;
364	} // if
365	} // if
366	}
367
368	void ConversionCost::visit( __attribute((unused)) TupleType *tupleType) {
369	Cost c = Cost::zero;
370	if ( TupleType destAsTuple = dynamic_cast< TupleType >( dest ) ) {
371	std::list< Type* >::const_iterator srcIt = tupleType->get_types().begin();
372	std::list< Type* >::const_iterator destIt = destAsTuple->get_types().begin();
373	while ( srcIt != tupleType->get_types().end() && destIt != destAsTuple->get_types().end() ) {
374	Cost newCost = conversionCost( srcIt++, destIt++, indexer, env );
375	if ( newCost == Cost::infinity ) {
376	return;
377	} // if
378	c += newCost;
379	} // while
380	if ( destIt != destAsTuple->get_types().end() ) {
381	cost = Cost::infinity;
382	} else {
383	cost = c;
384	} // if
385	} // if
386	}
387
388	void ConversionCost::visit( __attribute((unused)) VarArgsType *varArgsType) {
389	if ( dynamic_cast< VarArgsType* >( dest ) ) {
390	cost = Cost::zero;
391	}
392	}
393
394	void ConversionCost::visit( __attribute((unused)) ZeroType *zeroType) {
395	if ( dynamic_cast< ZeroType* >( dest ) ) {
396	cost = Cost::zero;
397	} else if ( BasicType destAsBasic = dynamic_cast< BasicType >( dest ) ) {
398	// copied from visit(BasicType*) for signed int, but +1 for safe conversions
399	int tableResult = costMatrix[ BasicType::SignedInt ][ destAsBasic->get_kind() ];
400	if ( tableResult == -1 ) {
401	cost = Cost::unsafe;
402	} else {
403	cost = Cost::zero;
404	cost.incSafe( tableResult + 1 );
405	}
406	} else if ( dynamic_cast< PointerType* >( dest ) ) {
407	cost = Cost::safe;
408	}
409	}
410
411	void ConversionCost::visit( __attribute((unused)) OneType *oneType) {
412	if ( dynamic_cast< OneType* >( dest ) ) {
413	cost = Cost::zero;
414	} else if ( BasicType destAsBasic = dynamic_cast< BasicType >( dest ) ) {
415	// copied from visit(BasicType*) for signed int, but +1 for safe conversions
416	int tableResult = costMatrix[ BasicType::SignedInt ][ destAsBasic->get_kind() ];
417	if ( tableResult == -1 ) {
418	cost = Cost::unsafe;
419	} else {
420	cost = Cost::zero;
421	cost.incSafe( tableResult + 1 );
422	}
423	}
424	}
425	} // namespace ResolvExpr
426
427	// Local Variables: //
428	// tab-width: 4 //
429	// mode: c++ //
430	// compile-command: "make install" //
431	// End: //

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