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      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_RUNTIME_ARCH_MIPS_INSTRUCTION_SET_FEATURES_MIPS_H_
     18 #define ART_RUNTIME_ARCH_MIPS_INSTRUCTION_SET_FEATURES_MIPS_H_
     19 
     20 #include <android-base/logging.h>
     21 
     22 #include "arch/instruction_set_features.h"
     23 #include "base/macros.h"
     24 
     25 namespace art {
     26 
     27 class MipsInstructionSetFeatures;
     28 using MipsFeaturesUniquePtr = std::unique_ptr<const MipsInstructionSetFeatures>;
     29 
     30 // Instruction set features relevant to the MIPS architecture.
     31 class MipsInstructionSetFeatures FINAL : public InstructionSetFeatures {
     32  public:
     33   // Process a CPU variant string like "r4000" and create InstructionSetFeatures.
     34   static MipsFeaturesUniquePtr FromVariant(const std::string& variant, std::string* error_msg);
     35 
     36   // Parse a bitmap and create an InstructionSetFeatures.
     37   static MipsFeaturesUniquePtr FromBitmap(uint32_t bitmap);
     38 
     39   // Turn C pre-processor #defines into the equivalent instruction set features.
     40   static MipsFeaturesUniquePtr FromCppDefines();
     41 
     42   // Process /proc/cpuinfo and use kRuntimeISA to produce InstructionSetFeatures.
     43   static MipsFeaturesUniquePtr FromCpuInfo();
     44 
     45   // Process the auxiliary vector AT_HWCAP entry and use kRuntimeISA to produce
     46   // InstructionSetFeatures.
     47   static MipsFeaturesUniquePtr FromHwcap();
     48 
     49   // Use assembly tests of the current runtime (ie kRuntimeISA) to determine the
     50   // InstructionSetFeatures. This works around kernel bugs in AT_HWCAP and /proc/cpuinfo.
     51   static MipsFeaturesUniquePtr FromAssembly();
     52 
     53   bool Equals(const InstructionSetFeatures* other) const OVERRIDE;
     54 
     55   InstructionSet GetInstructionSet() const OVERRIDE {
     56     return InstructionSet::kMips;
     57   }
     58 
     59   uint32_t AsBitmap() const OVERRIDE;
     60 
     61   std::string GetFeatureString() const OVERRIDE;
     62 
     63   // Is this an ISA revision greater than 2 opening up new opcodes.
     64   bool IsMipsIsaRevGreaterThanEqual2() const {
     65     return mips_isa_gte2_;
     66   }
     67 
     68   // Floating point double registers are encoded differently based on whether the Status.FR bit is
     69   // set. When the FR bit is 0 then the FPU is 32-bit, 1 its 64-bit. Return true if the code should
     70   // be generated assuming Status.FR is 0.
     71   bool Is32BitFloatingPoint() const {
     72     return fpu_32bit_;
     73   }
     74 
     75   bool IsR6() const {
     76     return r6_;
     77   }
     78 
     79   // Does it have MSA (MIPS SIMD Architecture) support.
     80   bool HasMsa() const {
     81     return msa_;
     82   }
     83 
     84   virtual ~MipsInstructionSetFeatures() {}
     85 
     86  protected:
     87   // Parse a vector of the form "fpu32", "mips2" adding these to a new MipsInstructionSetFeatures.
     88   std::unique_ptr<const InstructionSetFeatures>
     89       AddFeaturesFromSplitString(const std::vector<std::string>& features,
     90                                  std::string* error_msg) const OVERRIDE;
     91 
     92  private:
     93   MipsInstructionSetFeatures(bool fpu_32bit, bool mips_isa_gte2, bool r6, bool msa)
     94       : InstructionSetFeatures(),
     95         fpu_32bit_(fpu_32bit),
     96         mips_isa_gte2_(mips_isa_gte2),
     97         r6_(r6),
     98         msa_(msa) {
     99     // Sanity checks.
    100     if (r6) {
    101       CHECK(mips_isa_gte2);
    102       CHECK(!fpu_32bit);
    103     }
    104     if (!mips_isa_gte2) {
    105       CHECK(fpu_32bit);
    106     }
    107   }
    108 
    109   // Bitmap positions for encoding features as a bitmap.
    110   enum {
    111     kFpu32Bitfield = 1 << 0,
    112     kIsaRevGte2Bitfield = 1 << 1,
    113     kR6 = 1 << 2,
    114     kMsaBitfield = 1 << 3,
    115   };
    116 
    117   const bool fpu_32bit_;
    118   const bool mips_isa_gte2_;
    119   const bool r6_;
    120   const bool msa_;
    121 
    122   DISALLOW_COPY_AND_ASSIGN(MipsInstructionSetFeatures);
    123 };
    124 
    125 }  // namespace art
    126 
    127 #endif  // ART_RUNTIME_ARCH_MIPS_INSTRUCTION_SET_FEATURES_MIPS_H_
    128