From 22df6e9e8618614e8c33700c55705266912500ae Mon Sep 17 00:00:00 2001
From: Tim King <taking@cs.nyu.edu>
Date: Mon, 25 Nov 2013 18:36:06 -0500
Subject: Substantial Changes:

-ITE Simplification
-- Moved the utilities in src/theory/ite_simplifier.{h,cpp} to ite_utilities.
-- Separated simpWithCare from simpITE.
-- Disabled ite simplification on repeat simplification by default. Currently, ite simplification cannot help unless we internally make new constant leaf ites equal to constants.
-- simplifyWithCare() is now only run on QF_AUFBV by default. Speeds up nec benchmarks dramatically.
-- Added a new compress ites pass that is only run on QF_LIA by default.  This targets the perverse structure of ites generated during ite simplification on nec benchmarks.
-- After ite simplification, if the ite simplifier was used many times and the NodeManager's node pool is large enough, this garbage collects: zombies from the NodeManager repeatedly, the ite simplification caches, and the theory rewrite caches.

- TheoryEngine
-- Added TheoryEngine::donePPSimpITE() which orchestrates a number of ite simplifications above.
-- Switched UnconstrainedSimplifier to a pointer.

- RemoveITEs
-- Added a heuristic for checking whether or not a node contains term ites and if not, not bothering to invoke the rest of RemoveITE::run(). This safely changes the type of the cache used on misses of run. This cache can be cleared in the future. Currently disabled pending additional testing.

- TypeChecker
-- added a neverIsConst() rule to the typechecker. Operators that cannot be used in constructing constant expressions by computeIsConst() can now avoid caching on Node::isConst() calls.

- Theory Bool Rewriter
-- Added additional simplifications for boolean ites.

Minor Changes:

- TheoryModel
-- Removed vestigial copy of the ITESimplifier.
- AttributeManager
-- Fixed a garbage collection bug when deleting the node table caused the NodeManager to reclaimZombies() which caused memory corruption by deleting from the attributeManager.

- TypeChecker
-- added a neverIsConst() rule to the typechecker. Operators that cannot be used in constructing constant expressions by computeIsConst() can now avoid caching on Node::isConst() calls.

-NodeManager
-- Added additional functions for reclaiming zombies.
-- Exposed the size of the node pool for heuristics that worry about memory consumption.

- NaryBuilder
-- Added convenience classes for constructing associative and commutative n-ary operators.
-- Added a pass that turns associative and commutative n-ary operators into binary operators. (Mostly for printing expressions for strict parsers.)
---
 src/expr/attribute.cpp | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

(limited to 'src/expr/attribute.cpp')

diff --git a/src/expr/attribute.cpp b/src/expr/attribute.cpp
index 92a21546c..056e68c69 100644
--- a/src/expr/attribute.cpp
+++ b/src/expr/attribute.cpp
@@ -26,6 +26,19 @@ namespace CVC4 {
 namespace expr {
 namespace attr {
 
+AttributeManager::AttributeManager(context::Context* ctxt) :
+  d_cdbools(ctxt),
+  d_cdints(ctxt),
+  d_cdtnodes(ctxt),
+  d_cdnodes(ctxt),
+  d_cdstrings(ctxt),
+  d_cdptrs(ctxt),
+  d_inGarbageCollection(false)
+{}
+
+bool AttributeManager::inGarbageCollection() const {
+  return d_inGarbageCollection;
+}
 
 void AttributeManager::debugHook(int debugFlag) {
   /* DO NOT CHECK IN ANY CODE INTO THE DEBUG HOOKS!
@@ -36,6 +49,7 @@ void AttributeManager::debugHook(int debugFlag) {
 }
 
 void AttributeManager::deleteAllAttributes(NodeValue* nv) {
+  Assert(!inGarbageCollection());
   d_bools.erase(nv);
   deleteFromTable(d_ints, nv);
   deleteFromTable(d_tnodes, nv);
-- 
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