Stack overflow checks and NPE checks for optimizing.
Change-Id: I59e97448bf29778769b79b51ee4ea43f43493d96
diff --git a/compiler/utils/stack_checks.h b/compiler/utils/stack_checks.h
new file mode 100644
index 0000000..63adbc2
--- /dev/null
+++ b/compiler/utils/stack_checks.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_UTILS_STACK_CHECKS_H_
+#define ART_COMPILER_UTILS_STACK_CHECKS_H_
+
+#include "instruction_set.h"
+
+namespace art {
+
+// Size of a frame that we definitely consider large. Anything larger than this should
+// definitely get a stack overflow check.
+static constexpr size_t kLargeFrameSize = 2 * KB;
+
+// Size of a frame that should be small. Anything leaf method smaller than this should run
+// without a stack overflow check.
+// The constant is from experience with frameworks code.
+static constexpr size_t kSmallFrameSize = 1 * KB;
+
+// Determine whether a frame is small or large, used in the decision on whether to elide a
+// stack overflow check on method entry.
+//
+// A frame is considered large when it's either above kLargeFrameSize, or a quarter of the
+// overflow-usable stack space.
+static inline bool IsLargeFrame(size_t size, InstructionSet isa) {
+ return size >= kLargeFrameSize || size >= GetStackOverflowReservedBytes(isa) / 4;
+}
+
+} // namespace art
+
+#endif // ART_COMPILER_UTILS_STACK_CHECKS_H_