Changeset b7175721 for doc/theses

Timestamp:

Feb 27, 2019, 2:41:40 PM (5 years ago)

Author:

Aaron Moss <a3moss@…>

Branches:

ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

e1e3578

Parents:

11b3053

Message:

thesis: incorporate results of vector vs. list data structures investigation

File:

• doc/theses/aaron_moss_PhD/phd/experiments.tex (modified) (1 diff)

doc/theses/aaron_moss_PhD/phd/experiments.tex

@@ -63 +63 @@
 The GC could be used for memory management with few changes to the code-base, but without a substantial re-write to enforce the same ``!const! children'' discipline \CFACC{} could not take advantage of the potential to share sub-objects; without sharing of sub-objects the GC variant of \CFACC{} must do all the same allocations and deletions and garbage-collector overhead degraded performance unacceptably (though it did fix some known memory leaks introduced by failures of the existing manual memory management scheme).
 
-Another minor architectural difference between \CFACC{} and the prototype system is that \CFACC{} makes extensive use of the pointer-chasing !std::list!, !std::set!, and !std::map! data structures, while the prototype uses the array-based !std::vector! and the hash-based !unordered_! variants of !set! and !map! instead. 
-Work is ongoing to port \CFACC{} to use these more efficient data structures.
-% TODO see how Thierry gets on with this
+Another minor architectural difference between \CFACC{} and the prototype system is that \CFACC{} makes extensive use of the pointer-based !std::list!, !std::set!, and !std::map! data structures, while the prototype uses the array-based !std::vector! and the hash-based !unordered_! variants of !set! and !map! instead. 
+Porting the prototype to use the pointer-based data structures resulted in modest performance regressions, whereas preliminary results results from porting \CFACC{} to use !std::vector! over !std::list! also showed performance regressions, in some cases significant.
+The relative performance impact of this architectural difference is unclear, and thus excluded from consideration.
 
 The final difference between \CFACC{} and the resolver prototype is that, as an experiment in language usability, the prototype performs resolution-based rather than unification-based assertion satisfaction, as discussed in Section~\ref{resn-conclusion-sec}.