[optimize-array] Fix hash collisions

The caching maps in ArrayExpr are broken, they only consider hashes
and don't check for structural equality. This can lead to hash collisions
and invalid Expr replacement. This is especially potetent for UpdateLists, who
only put the array name in the hash, so there can be a lot of colisions.

1 files changed, 5 insertions, 5 deletions

diff --git a/lib/Expr/ArrayExprVisitor.cpp b/lib/Expr/ArrayExprVisitor.cpp
index e4ea9a1c..75604104 100644
--- a/lib/Expr/ArrayExprVisitor.cpp
+++ b/lib/Expr/ArrayExprVisitor.cpp
@@ -183,16 +183,16 @@ ExprVisitor::Action IndexTransformationExprVisitor::visitMul(const MulExpr &e) {
 ExprVisitor::Action ArrayReadExprVisitor::visitConcat(const ConcatExpr &ce) {
   ReadExpr *base = ArrayExprHelper::hasOrderedReads(ce);
   if (base) {
-    return inspectRead(ce.hash(), ce.getWidth(), *base);
+    return inspectRead(const_cast<ConcatExpr *>(&ce), ce.getWidth(), *base);
   }
   return Action::doChildren();
 }
 ExprVisitor::Action ArrayReadExprVisitor::visitRead(const ReadExpr &re) {
-  return inspectRead(re.hash(), re.getWidth(), re);
+  return inspectRead(const_cast<ReadExpr *>(&re), re.getWidth(), re);
 }
 // This method is a mess because I want to avoid looping over the UpdateList
 // values twice
-ExprVisitor::Action ArrayReadExprVisitor::inspectRead(unsigned hash,
+ExprVisitor::Action ArrayReadExprVisitor::inspectRead(ref<Expr> hash,
                                                       Expr::Width width,
                                                       const ReadExpr &re) {
   // pre(*): index is symbolic
@@ -243,14 +243,14 @@ ExprVisitor::Action ArrayReadExprVisitor::inspectRead(unsigned hash,
 
 ExprVisitor::Action
 ArrayValueOptReplaceVisitor::visitConcat(const ConcatExpr &ce) {
-  auto found = optimized.find(ce.hash());
+  auto found = optimized.find(const_cast<ConcatExpr *>(&ce));
   if (found != optimized.end()) {
     return Action::changeTo((*found).second.get());
   }
   return Action::doChildren();
 }
 ExprVisitor::Action ArrayValueOptReplaceVisitor::visitRead(const ReadExpr &re) {
-  auto found = optimized.find(re.hash());
+  auto found = optimized.find(const_cast<ReadExpr *>(&re));
   if (found != optimized.end()) {
     return Action::changeTo((*found).second.get());
   }