1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_COMPILER_UTILS_STACK_CHECKS_H_
18 #define ART_COMPILER_UTILS_STACK_CHECKS_H_
19 
20 #include "arch/instruction_set.h"
21 
22 namespace art {
23 
24 // Size of a frame that we definitely consider large. Anything larger than this should
25 // definitely get a stack overflow check.
26 static constexpr size_t kLargeFrameSize = 2 * KB;
27 
28 // Size of a frame that should be small. Anything leaf method smaller than this should run
29 // without a stack overflow check.
30 // The constant is from experience with frameworks code.
31 static constexpr size_t kSmallFrameSize = 1 * KB;
32 
33 // Determine whether a frame is small or large, used in the decision on whether to elide a
34 // stack overflow check on method entry.
35 //
36 // A frame is considered large when it's above kLargeFrameSize.
FrameNeedsStackCheck(size_t size,InstructionSet isa ATTRIBUTE_UNUSED)37 static inline bool FrameNeedsStackCheck(size_t size, InstructionSet isa ATTRIBUTE_UNUSED) {
38   return size >= kLargeFrameSize;
39 }
40 
41 }  // namespace art
42 
43 #endif  // ART_COMPILER_UTILS_STACK_CHECKS_H_
44