From f12feb8e0e857f2832545b3f28d31bad5a9d3903 Mon Sep 17 00:00:00 2001 From: Nicolas Geoffray Date: Thu, 17 Jul 2014 18:32:41 +0100 Subject: Stack overflow checks and NPE checks for optimizing. Change-Id: I59e97448bf29778769b79b51ee4ea43f43493d96 --- compiler/utils/stack_checks.h | 44 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 compiler/utils/stack_checks.h (limited to 'compiler/utils/stack_checks.h') diff --git a/compiler/utils/stack_checks.h b/compiler/utils/stack_checks.h new file mode 100644 index 0000000000..63adbc2328 --- /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_ -- cgit v1.2.3-59-g8ed1b