Added unit tests for ReadExpr::create() to check that constant folding is correctly applied

1 files changed, 151 insertions, 0 deletions

diff --git a/unittests/Expr/ExprTest.cpp b/unittests/Expr/ExprTest.cpp
index 25129d8e..b1f593a5 100644
--- a/unittests/Expr/ExprTest.cpp
+++ b/unittests/Expr/ExprTest.cpp
@@ -113,4 +113,155 @@ TEST(ExprTest, ExtractConcat) {
   EXPECT_EQ(Expr::Extract, concat2->getKid(1)->getKind());
 }
 
+TEST(ExprTest, ReadExprFoldingBasic) {
+  unsigned size = 5;
+
+  // Constant array
+  std::vector<ref<ConstantExpr> > Contents(size);
+  for (unsigned i = 0; i < size; ++i)
+    Contents[i] = ConstantExpr::create(i + 1, Expr::Int8);
+  ArrayCache ac;
+  const Array *array =
+      ac.CreateArray("arr", size, &Contents[0], &Contents[0] + size);
+
+  // Basic constant folding rule
+  UpdateList ul(array, 0);
+  ref<Expr> read;
+
+  for (unsigned i = 0; i < size; ++i) {
+    // Constant index (i)
+    read = ReadExpr::create(ul, ConstantExpr::create(i, Expr::Int32));
+    EXPECT_EQ(Expr::Constant, read.get()->getKind());
+    // Read - should be constant folded to Contents[i]
+    // Check that constant folding worked
+    ConstantExpr *c = static_cast<ConstantExpr *>(read.get());
+    EXPECT_EQ(Contents[i]->getZExtValue(), c->getZExtValue());
+  }
+}
+
+TEST(ExprTest, ReadExprFoldingIndexOutOfBound) {
+  unsigned size = 5;
+
+  // Constant array
+  std::vector<ref<ConstantExpr> > Contents(size);
+  for (unsigned i = 0; i < size; ++i)
+    Contents[i] = ConstantExpr::create(i + 1, Expr::Int8);
+  ArrayCache ac;
+  const Array *array =
+      ac.CreateArray("arr", size, &Contents[0], &Contents[0] + size);
+
+  // Constant folding rule with index-out-of-bound
+  // Constant index (128)
+  ref<Expr> index = ConstantExpr::create(128, Expr::Int32);
+  UpdateList ul(array, 0);
+  ref<Expr> read = ReadExpr::create(ul, index);
+  // Read - should not be constant folded
+  // Check that constant folding was not applied
+  EXPECT_EQ(Expr::Read, read.get()->getKind());
+}
+
+TEST(ExprTest, ReadExprFoldingConstantUpdate) {
+  unsigned size = 5;
+
+  // Constant array
+  std::vector<ref<ConstantExpr> > Contents(size);
+  for (unsigned i = 0; i < size; ++i)
+    Contents[i] = ConstantExpr::create(i + 1, Expr::Int8);
+  ArrayCache ac;
+  const Array *array =
+      ac.CreateArray("arr", size, &Contents[0], &Contents[0] + size);
+
+  // Constant folding rule with constant update
+  // Constant index (0)
+  ref<Expr> index = ConstantExpr::create(0, Expr::Int32);
+  UpdateList ul(array, 0);
+  ref<Expr> updateValue = ConstantExpr::create(32, Expr::Int8);
+  ul.extend(index, updateValue);
+  ref<Expr> read = ReadExpr::create(ul, index);
+  // Read - should be constant folded to 32
+  // Check that constant folding worked
+  EXPECT_EQ(Expr::Constant, read.get()->getKind());
+  ConstantExpr *c = static_cast<ConstantExpr *>(read.get());
+  EXPECT_EQ(32, c->getZExtValue());
+}
+
+TEST(ExprTest, ReadExprFoldingConstantMultipleUpdate) {
+  unsigned size = 5;
+
+  // Constant array
+  std::vector<ref<ConstantExpr> > Contents(size);
+  for (unsigned i = 0; i < size; ++i)
+    Contents[i] = ConstantExpr::create(i + 1, Expr::Int8);
+  ArrayCache ac;
+  const Array *array =
+      ac.CreateArray("arr", size, &Contents[0], &Contents[0] + size);
+
+  // Constant folding rule with constant update
+  // Constant index (0)
+  ref<Expr> index = ConstantExpr::create(0, Expr::Int32);
+  UpdateList ul(array, 0);
+  ref<Expr> updateValue = ConstantExpr::create(32, Expr::Int8);
+  ref<Expr> updateValue2 = ConstantExpr::create(64, Expr::Int8);
+  ul.extend(index, updateValue);
+  ul.extend(index, updateValue2);
+  ref<Expr> read = ReadExpr::create(ul, index);
+  // Read - should be constant folded to 64
+  // Check that constant folding worked
+  EXPECT_EQ(Expr::Constant, read.get()->getKind());
+  ConstantExpr *c = static_cast<ConstantExpr *>(read.get());
+  EXPECT_EQ(64, c->getZExtValue());
+}
+
+TEST(ExprTest, ReadExprFoldingSymbolicValueUpdate) {
+  unsigned size = 5;
+
+  // Constant array
+  std::vector<ref<ConstantExpr> > Contents(size);
+  for (unsigned i = 0; i < size; ++i)
+    Contents[i] = ConstantExpr::create(i + 1, Expr::Int8);
+  ArrayCache ac;
+  const Array *array =
+      ac.CreateArray("arr", size, &Contents[0], &Contents[0] + size);
+
+  // Constant folding rule with symbolic update (value)
+  // Constant index (0)
+  ref<Expr> index = ConstantExpr::create(0, Expr::Int32);
+  UpdateList ul(array, 0);
+  const Array *array2 = ac.CreateArray("arr2", 256);
+  ref<Expr> updateValue = ReadExpr::createTempRead(array2, Expr::Int8);
+  ul.extend(index, updateValue);
+  ref<Expr> read = ReadExpr::create(ul, index);
+  // Read - should be constant folded to the symbolic value
+  // Check that constant folding worked
+  EXPECT_EQ(Expr::Read, read.get()->getKind());
+  EXPECT_EQ(updateValue, read);
+}
+
+TEST(ExprTest, ReadExprFoldingSymbolicIndexUpdate) {
+  unsigned size = 5;
+
+  // Constant array
+  std::vector<ref<ConstantExpr> > Contents(size);
+  for (unsigned i = 0; i < size; ++i)
+    Contents[i] = ConstantExpr::create(i + 1, Expr::Int8);
+  ArrayCache ac;
+  const Array *array =
+      ac.CreateArray("arr", size, &Contents[0], &Contents[0] + size);
+
+  // Constant folding rule with symbolic update (index)
+  UpdateList ul(array, 0);
+  const Array *array2 = ac.CreateArray("arr2", 256);
+  ref<Expr> updateIndex = ReadExpr::createTempRead(array2, Expr::Int32);
+  ref<Expr> updateValue = ConstantExpr::create(12, Expr::Int8);
+  ul.extend(updateIndex, updateValue);
+  ref<Expr> read;
+
+  for (unsigned i = 0; i < size; ++i) {
+    // Constant index (i)
+    read = ReadExpr::create(ul, ConstantExpr::create(i, Expr::Int32));
+    // Read - should not be constant folded
+    // Check that constant folding was not applied
+    EXPECT_EQ(Expr::Read, read.get()->getKind());
+  }
+}
 }