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 <memory> 21 #include <ostream> 22 #include <vector> 23 24 #include "base/macros.h" 25 #include "instruction_set.h" 26 27 namespace art { 28 29 class ArmInstructionSetFeatures; 30 class Arm64InstructionSetFeatures; 31 class MipsInstructionSetFeatures; 32 class Mips64InstructionSetFeatures; 33 class X86InstructionSetFeatures; 34 class X86_64InstructionSetFeatures; 35 36 // Abstraction used to describe features of a different instruction sets. 37 class InstructionSetFeatures { 38 public: 39 // Process a CPU variant string for the given ISA and create an InstructionSetFeatures. 40 static std::unique_ptr<const InstructionSetFeatures> FromVariant(InstructionSet isa, 41 const std::string& variant, 42 std::string* error_msg); 43 44 // Parse a bitmap for the given isa and create an InstructionSetFeatures. 45 static std::unique_ptr<const InstructionSetFeatures> FromBitmap(InstructionSet isa, 46 uint32_t bitmap); 47 48 // Turn C pre-processor #defines into the equivalent instruction set features for kRuntimeISA. 49 static std::unique_ptr<const InstructionSetFeatures> FromCppDefines(); 50 51 // Process /proc/cpuinfo and use kRuntimeISA to produce InstructionSetFeatures. 52 static std::unique_ptr<const InstructionSetFeatures> FromCpuInfo(); 53 54 // Process the auxiliary vector AT_HWCAP entry and use kRuntimeISA to produce 55 // InstructionSetFeatures. 56 static std::unique_ptr<const InstructionSetFeatures> FromHwcap(); 57 58 // Use assembly tests of the current runtime (ie kRuntimeISA) to determine the 59 // InstructionSetFeatures. This works around kernel bugs in AT_HWCAP and /proc/cpuinfo. 60 static std::unique_ptr<const InstructionSetFeatures> FromAssembly(); 61 62 // Parse a string of the form "div,-atomic_ldrd_strd" adding and removing these features to 63 // create a new InstructionSetFeatures. 64 std::unique_ptr<const InstructionSetFeatures> AddFeaturesFromString( 65 const std::string& feature_list, std::string* error_msg) const WARN_UNUSED; 66 67 // Are these features the same as the other given features? 68 virtual bool Equals(const InstructionSetFeatures* other) const = 0; 69 70 // For testing purposes we want to make sure that the system we run on has at 71 // least the options we claim it has. In this cases Equals() does not 72 // suffice and will cause the test to fail, since the runtime cpu feature 73 // detection claims more capabilities then statically specified from the 74 // build system. 75 // 76 // A good example of this is the armv8 ART test target that declares 77 // "CPU_VARIANT=generic". If the generic target is specified and the code 78 // is run on a platform with enhanced capabilities, the 79 // instruction_set_features test will fail if we resort to using Equals() 80 // between statically defined cpu features and runtime cpu features. 81 // 82 // For now we default this to Equals() in case the architecture does not 83 // provide it. HasAtLeast(const InstructionSetFeatures * other)84 virtual bool HasAtLeast(const InstructionSetFeatures* other) const { 85 return Equals(other); 86 } 87 88 // Return the ISA these features relate to. 89 virtual InstructionSet GetInstructionSet() const = 0; 90 91 // Return a bitmap that represents the features. ISA specific. 92 virtual uint32_t AsBitmap() const = 0; 93 94 // Return a string of the form "div,lpae" or "none". 95 virtual std::string GetFeatureString() const = 0; 96 97 // Down cast this ArmInstructionFeatures. 98 const ArmInstructionSetFeatures* AsArmInstructionSetFeatures() const; 99 100 // Down cast this Arm64InstructionFeatures. 101 const Arm64InstructionSetFeatures* AsArm64InstructionSetFeatures() const; 102 103 // Down cast this MipsInstructionFeatures. 104 const MipsInstructionSetFeatures* AsMipsInstructionSetFeatures() const; 105 106 // Down cast this Mips64InstructionFeatures. 107 const Mips64InstructionSetFeatures* AsMips64InstructionSetFeatures() const; 108 109 // Down cast this X86InstructionFeatures. 110 const X86InstructionSetFeatures* AsX86InstructionSetFeatures() const; 111 112 // Down cast this X86_64InstructionFeatures. 113 const X86_64InstructionSetFeatures* AsX86_64InstructionSetFeatures() const; 114 ~InstructionSetFeatures()115 virtual ~InstructionSetFeatures() {} 116 117 protected: InstructionSetFeatures()118 InstructionSetFeatures() {} 119 120 // Returns true if variant appears in the array variants. 121 static bool FindVariantInArray(const char* const variants[], size_t num_variants, 122 const std::string& variant); 123 124 // Add architecture specific features in sub-classes. 125 virtual std::unique_ptr<const InstructionSetFeatures> 126 AddFeaturesFromSplitString(const std::vector<std::string>& features, 127 std::string* error_msg) const = 0; 128 129 private: 130 DISALLOW_COPY_AND_ASSIGN(InstructionSetFeatures); 131 }; 132 std::ostream& operator<<(std::ostream& os, const InstructionSetFeatures& rhs); 133 134 } // namespace art 135 136 #endif // ART_RUNTIME_ARCH_INSTRUCTION_SET_FEATURES_H_ 137