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      1 /*
      2  * Copyright (C) 2011 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_RUNTIME_ARCH_INSTRUCTION_SET_FEATURES_H_
     18 #define ART_RUNTIME_ARCH_INSTRUCTION_SET_FEATURES_H_
     19 
     20 #include <ostream>
     21 #include <vector>
     22 
     23 #include "base/macros.h"
     24 #include "instruction_set.h"
     25 
     26 namespace art {
     27 
     28 class ArmInstructionSetFeatures;
     29 class Arm64InstructionSetFeatures;
     30 class MipsInstructionSetFeatures;
     31 class Mips64InstructionSetFeatures;
     32 class X86InstructionSetFeatures;
     33 class X86_64InstructionSetFeatures;
     34 
     35 // Abstraction used to describe features of a different instruction sets.
     36 class InstructionSetFeatures {
     37  public:
     38   // Process a CPU variant string for the given ISA and create an InstructionSetFeatures.
     39   static const InstructionSetFeatures* FromVariant(InstructionSet isa,
     40                                                    const std::string& variant,
     41                                                    std::string* error_msg);
     42 
     43   // Parse a bitmap for the given isa and create an InstructionSetFeatures.
     44   static const InstructionSetFeatures* FromBitmap(InstructionSet isa, uint32_t bitmap);
     45 
     46   // Turn C pre-processor #defines into the equivalent instruction set features for kRuntimeISA.
     47   static const InstructionSetFeatures* FromCppDefines();
     48 
     49   // Process /proc/cpuinfo and use kRuntimeISA to produce InstructionSetFeatures.
     50   static const InstructionSetFeatures* FromCpuInfo();
     51 
     52   // Process the auxiliary vector AT_HWCAP entry and use kRuntimeISA to produce
     53   // InstructionSetFeatures.
     54   static const InstructionSetFeatures* FromHwcap();
     55 
     56   // Use assembly tests of the current runtime (ie kRuntimeISA) to determine the
     57   // InstructionSetFeatures. This works around kernel bugs in AT_HWCAP and /proc/cpuinfo.
     58   static const InstructionSetFeatures* FromAssembly();
     59 
     60   // Parse a string of the form "div,-atomic_ldrd_strd" adding and removing these features to
     61   // create a new InstructionSetFeatures.
     62   const InstructionSetFeatures* AddFeaturesFromString(const std::string& feature_list,
     63                                                       std::string* error_msg) const WARN_UNUSED;
     64 
     65   // Are these features the same as the other given features?
     66   virtual bool Equals(const InstructionSetFeatures* other) const = 0;
     67 
     68   // Return the ISA these features relate to.
     69   virtual InstructionSet GetInstructionSet() const = 0;
     70 
     71   // Return a bitmap that represents the features. ISA specific.
     72   virtual uint32_t AsBitmap() const = 0;
     73 
     74   // Return a string of the form "div,lpae" or "none".
     75   virtual std::string GetFeatureString() const = 0;
     76 
     77   // Does the instruction set variant require instructions for correctness with SMP?
     78   bool IsSmp() const {
     79     return smp_;
     80   }
     81 
     82   // Down cast this ArmInstructionFeatures.
     83   const ArmInstructionSetFeatures* AsArmInstructionSetFeatures() const;
     84 
     85   // Down cast this Arm64InstructionFeatures.
     86   const Arm64InstructionSetFeatures* AsArm64InstructionSetFeatures() const;
     87 
     88   // Down cast this MipsInstructionFeatures.
     89   const MipsInstructionSetFeatures* AsMipsInstructionSetFeatures() const;
     90 
     91   // Down cast this Mips64InstructionFeatures.
     92   const Mips64InstructionSetFeatures* AsMips64InstructionSetFeatures() const;
     93 
     94   // Down cast this X86InstructionFeatures.
     95   const X86InstructionSetFeatures* AsX86InstructionSetFeatures() const;
     96 
     97   // Down cast this X86_64InstructionFeatures.
     98   const X86_64InstructionSetFeatures* AsX86_64InstructionSetFeatures() const;
     99 
    100   virtual ~InstructionSetFeatures() {}
    101 
    102  protected:
    103   explicit InstructionSetFeatures(bool smp) : smp_(smp) {}
    104 
    105   // Returns true if variant appears in the array variants.
    106   static bool FindVariantInArray(const char* const variants[], size_t num_variants,
    107                                  const std::string& variant);
    108 
    109   // Add architecture specific features in sub-classes.
    110   virtual const InstructionSetFeatures*
    111       AddFeaturesFromSplitString(bool smp, const std::vector<std::string>& features,
    112                                  std::string* error_msg) const = 0;
    113 
    114  private:
    115   const bool smp_;
    116 
    117   DISALLOW_COPY_AND_ASSIGN(InstructionSetFeatures);
    118 };
    119 std::ostream& operator<<(std::ostream& os, const InstructionSetFeatures& rhs);
    120 
    121 }  // namespace art
    122 
    123 #endif  // ART_RUNTIME_ARCH_INSTRUCTION_SET_FEATURES_H_
    124