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/*
* Copyright (C) 2015 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.
*/
#include "instruction_simplifier_arm64.h"
#include "mirror/array-inl.h"
namespace art {
namespace arm64 {
void InstructionSimplifierArm64Visitor::TryExtractArrayAccessAddress(HInstruction* access,
HInstruction* array,
HInstruction* index,
int access_size) {
if (index->IsConstant() ||
(index->IsBoundsCheck() && index->AsBoundsCheck()->GetIndex()->IsConstant())) {
// When the index is a constant all the addressing can be fitted in the
// memory access instruction, so do not split the access.
return;
}
if (access->IsArraySet() &&
access->AsArraySet()->GetValue()->GetType() == Primitive::kPrimNot) {
// The access may require a runtime call or the original array pointer.
return;
}
// Proceed to extract the base address computation.
ArenaAllocator* arena = GetGraph()->GetArena();
HIntConstant* offset =
GetGraph()->GetIntConstant(mirror::Array::DataOffset(access_size).Uint32Value());
HArm64IntermediateAddress* address =
new (arena) HArm64IntermediateAddress(array, offset, kNoDexPc);
access->GetBlock()->InsertInstructionBefore(address, access);
access->ReplaceInput(address, 0);
// Both instructions must depend on GC to prevent any instruction that can
// trigger GC to be inserted between the two.
access->AddSideEffects(SideEffects::DependsOnGC());
DCHECK(address->GetSideEffects().Includes(SideEffects::DependsOnGC()));
DCHECK(access->GetSideEffects().Includes(SideEffects::DependsOnGC()));
// TODO: Code generation for HArrayGet and HArraySet will check whether the input address
// is an HArm64IntermediateAddress and generate appropriate code.
// We would like to replace the `HArrayGet` and `HArraySet` with custom instructions (maybe
// `HArm64Load` and `HArm64Store`). We defer these changes because these new instructions would
// not bring any advantages yet.
// Also see the comments in
// `InstructionCodeGeneratorARM64::VisitArrayGet()` and
// `InstructionCodeGeneratorARM64::VisitArraySet()`.
RecordSimplification();
}
void InstructionSimplifierArm64Visitor::VisitArrayGet(HArrayGet* instruction) {
TryExtractArrayAccessAddress(instruction,
instruction->GetArray(),
instruction->GetIndex(),
Primitive::ComponentSize(instruction->GetType()));
}
void InstructionSimplifierArm64Visitor::VisitArraySet(HArraySet* instruction) {
TryExtractArrayAccessAddress(instruction,
instruction->GetArray(),
instruction->GetIndex(),
Primitive::ComponentSize(instruction->GetComponentType()));
}
} // namespace arm64
} // namespace art
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