From d8deadd787d0f857d701b73aeaa3e0753efd9405 Mon Sep 17 00:00:00 2001 From: Timotej Kapus Date: Thu, 7 Nov 2019 14:27:07 +0000 Subject: [optimize-array] Fix update list read order ArrayExprOptimizer read the UpdateList in the wrong order, which meant that it used least recent update instead of the most recent one. This patch fixes this as well as adds a test to illustrate the issue. --- lib/Expr/ArrayExprOptimizer.cpp | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/Expr/ArrayExprOptimizer.cpp b/lib/Expr/ArrayExprOptimizer.cpp index 1a48adfe..e43530ec 100644 --- a/lib/Expr/ArrayExprOptimizer.cpp +++ b/lib/Expr/ArrayExprOptimizer.cpp @@ -280,8 +280,17 @@ ref ExprOptimizer::getSelectOptExpr( // assume that the UpdateNodes contain ConstantExpr indexes and values assert(read->updates.root->isConstantArray() && "Expected concrete array, found symbolic array"); + + // We need to read updates from lest recent to most recent, therefore + // reverse the list + std::vector us; + us.reserve(read->updates.getSize()); + for (const UpdateNode *un = read->updates.head; un; un = un->next) + us.push_back(un); + auto arrayConstValues = read->updates.root->constantValues; - for (const UpdateNode *un = read->updates.head; un; un = un->next) { + for (auto it = us.rbegin(); it != us.rend(); it++) { + const UpdateNode *un = *it; auto ce = dyn_cast(un->index); assert(ce && "Not a constant expression"); uint64_t index = ce->getAPValue().getZExtValue(); @@ -356,7 +365,16 @@ ref ExprOptimizer::getSelectOptExpr( arrayConstValues.push_back(ConstantExpr::create(0, Expr::Int8)); } } - for (const UpdateNode *un = read->updates.head; un; un = un->next) { + + // We need to read updates from lest recent to most recent, therefore + // reverse the list + std::vector us; + us.reserve(read->updates.getSize()); + for (const UpdateNode *un = read->updates.head; un; un = un->next) + us.push_back(un); + + for (auto it = us.rbegin(); it != us.rend(); it++) { + const UpdateNode *un = *it; auto ce = dyn_cast(un->index); assert(ce && "Not a constant expression"); uint64_t index = ce->getAPValue().getLimitedValue(); -- cgit 1.4.1