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/*
* 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_RUNTIME_ARCH_ARM64_INSTRUCTION_SET_FEATURES_ARM64_H_
#define ART_RUNTIME_ARCH_ARM64_INSTRUCTION_SET_FEATURES_ARM64_H_
#include "arch/instruction_set_features.h"
namespace art {
class Arm64InstructionSetFeatures;
using Arm64FeaturesUniquePtr = std::unique_ptr<const Arm64InstructionSetFeatures>;
// Instruction set features relevant to the ARM64 architecture.
class Arm64InstructionSetFeatures final : public InstructionSetFeatures {
public:
// Process a CPU variant string like "krait" or "cortex-a15" and create InstructionSetFeatures.
static Arm64FeaturesUniquePtr FromVariant(const std::string& variant, std::string* error_msg);
// Parse a bitmap and create an InstructionSetFeatures.
static Arm64FeaturesUniquePtr FromBitmap(uint32_t bitmap);
// Turn C pre-processor #defines into the equivalent instruction set features.
static Arm64FeaturesUniquePtr FromCppDefines();
// Process /proc/cpuinfo and use kRuntimeISA to produce InstructionSetFeatures.
static Arm64FeaturesUniquePtr FromCpuInfo();
// Process the auxiliary vector AT_HWCAP entry and use kRuntimeISA to produce
// InstructionSetFeatures.
static Arm64FeaturesUniquePtr FromHwcap();
// Use assembly tests of the current runtime (ie kRuntimeISA) to determine the
// InstructionSetFeatures. This works around kernel bugs in AT_HWCAP and /proc/cpuinfo.
static Arm64FeaturesUniquePtr FromAssembly();
bool Equals(const InstructionSetFeatures* other) const override;
// Note that newer CPUs do not have a53 erratum 835769 and 843419,
// so the two a53 fix features (fix_cortex_a53_835769 and fix_cortex_a53_843419)
// are not tested for HasAtLeast.
bool HasAtLeast(const InstructionSetFeatures* other) const override;
InstructionSet GetInstructionSet() const override {
return InstructionSet::kArm64;
}
uint32_t AsBitmap() const override;
// Return a string of the form "a53" or "none".
std::string GetFeatureString() const override;
// Generate code addressing Cortex-A53 erratum 835769?
bool NeedFixCortexA53_835769() const {
return fix_cortex_a53_835769_;
}
// Generate code addressing Cortex-A53 erratum 843419?
bool NeedFixCortexA53_843419() const {
return fix_cortex_a53_843419_;
}
bool HasCRC() const {
return has_crc_;
}
bool HasLSE() const {
return has_lse_;
}
bool HasFP16() const {
return has_fp16_;
}
// Are Dot Product instructions (UDOT/SDOT) available?
bool HasDotProd() const {
return has_dotprod_;
}
virtual ~Arm64InstructionSetFeatures() {}
protected:
// Parse a vector of the form "a53" adding these to a new ArmInstructionSetFeatures.
std::unique_ptr<const InstructionSetFeatures>
AddFeaturesFromSplitString(const std::vector<std::string>& features,
std::string* error_msg) const override;
private:
Arm64InstructionSetFeatures(bool needs_a53_835769_fix,
bool needs_a53_843419_fix,
bool has_crc,
bool has_lse,
bool has_fp16,
bool has_dotprod)
: InstructionSetFeatures(),
fix_cortex_a53_835769_(needs_a53_835769_fix),
fix_cortex_a53_843419_(needs_a53_843419_fix),
has_crc_(has_crc),
has_lse_(has_lse),
has_fp16_(has_fp16),
has_dotprod_(has_dotprod) {
}
// Bitmap positions for encoding features as a bitmap.
enum {
kA53Bitfield = 1 << 0,
kCRCBitField = 1 << 1,
kLSEBitField = 1 << 2,
kFP16BitField = 1 << 3,
kDotProdBitField = 1 << 4,
};
const bool fix_cortex_a53_835769_;
const bool fix_cortex_a53_843419_;
const bool has_crc_; // optional in ARMv8.0, mandatory in ARMv8.1.
const bool has_lse_; // ARMv8.1 Large System Extensions.
const bool has_fp16_; // ARMv8.2 FP16 extensions.
const bool has_dotprod_; // optional in ARMv8.2, mandatory in ARMv8.4.
DISALLOW_COPY_AND_ASSIGN(Arm64InstructionSetFeatures);
};
} // namespace art
#endif // ART_RUNTIME_ARCH_ARM64_INSTRUCTION_SET_FEATURES_ARM64_H_