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_X86_INSTRUCTION_SET_FEATURES_X86_H_
18 #define ART_RUNTIME_ARCH_X86_INSTRUCTION_SET_FEATURES_X86_H_
19 
20 #include "arch/instruction_set_features.h"
21 
22 #define GET_REX_R       0x04
23 #define GET_REX_X       0x02
24 #define GET_REX_B       0x01
25 #define SET_VEX_R       0x80
26 #define SET_VEX_X       0x40
27 #define SET_VEX_B       0x20
28 #define SET_VEX_M_0F    0x01
29 #define SET_VEX_M_0F_38 0x02
30 #define SET_VEX_M_0F_3A 0x03
31 #define SET_VEX_W       0x80
32 #define SET_VEX_L_128   0x00
33 #define SET_VEL_L_256   0x04
34 #define SET_VEX_PP_NONE 0x00
35 #define SET_VEX_PP_66   0x01
36 #define SET_VEX_PP_F3   0x02
37 #define SET_VEX_PP_F2   0x03
38 #define TWO_BYTE_VEX    0xC5
39 #define THREE_BYTE_VEX  0xC4
40 #define VEX_INIT        0x00
41 
42 namespace art {
43 
44 class X86InstructionSetFeatures;
45 using X86FeaturesUniquePtr = std::unique_ptr<const X86InstructionSetFeatures>;
46 
47 // Instruction set features relevant to the X86 architecture.
48 class X86InstructionSetFeatures : public InstructionSetFeatures {
49  public:
50   // Process a CPU variant string like "atom" or "nehalem" and create InstructionSetFeatures.
51   static X86FeaturesUniquePtr FromVariant(const std::string& variant,
52                                           std::string* error_msg,
53                                           bool x86_64 = false);
54 
55   // Parse a bitmap and create an InstructionSetFeatures.
56   static X86FeaturesUniquePtr FromBitmap(uint32_t bitmap, bool x86_64 = false);
57 
58   // Turn C pre-processor #defines into the equivalent instruction set features.
59   static X86FeaturesUniquePtr FromCppDefines(bool x86_64 = false);
60 
61   // Process /proc/cpuinfo and use kRuntimeISA to produce InstructionSetFeatures.
62   static X86FeaturesUniquePtr FromCpuInfo(bool x86_64 = false);
63 
64   // Process the auxiliary vector AT_HWCAP entry and use kRuntimeISA to produce
65   // InstructionSetFeatures.
66   static X86FeaturesUniquePtr FromHwcap(bool x86_64 = false);
67 
68   // Use assembly tests of the current runtime (ie kRuntimeISA) to determine the
69   // InstructionSetFeatures. This works around kernel bugs in AT_HWCAP and /proc/cpuinfo.
70   static X86FeaturesUniquePtr FromAssembly(bool x86_64 = false);
71 
72   bool Equals(const InstructionSetFeatures* other) const override;
73 
74   bool HasAtLeast(const InstructionSetFeatures* other) const override;
75 
GetInstructionSet()76   InstructionSet GetInstructionSet() const override {
77     return InstructionSet::kX86;
78   }
79 
80   uint32_t AsBitmap() const override;
81 
82   std::string GetFeatureString() const override;
83 
~X86InstructionSetFeatures()84   virtual ~X86InstructionSetFeatures() {}
85 
HasSSE4_1()86   bool HasSSE4_1() const { return has_SSE4_1_; }
87 
HasPopCnt()88   bool HasPopCnt() const { return has_POPCNT_; }
89 
HasAVX2()90   bool HasAVX2() const { return has_AVX2_; }
91 
HasAVX()92   bool HasAVX() const { return has_AVX_; }
93 
94  protected:
95   // Parse a string of the form "ssse3" adding these to a new InstructionSetFeatures.
96   std::unique_ptr<const InstructionSetFeatures>
AddFeaturesFromSplitString(const std::vector<std::string> & features,std::string * error_msg)97       AddFeaturesFromSplitString(const std::vector<std::string>& features,
98                                  std::string* error_msg) const override {
99     return AddFeaturesFromSplitString(features, false, error_msg);
100   }
101 
102   std::unique_ptr<const InstructionSetFeatures>
103       AddFeaturesFromSplitString(const std::vector<std::string>& features,
104                                  bool x86_64,
105                                  std::string* error_msg) const;
106 
X86InstructionSetFeatures(bool has_SSSE3,bool has_SSE4_1,bool has_SSE4_2,bool has_AVX,bool has_AVX2,bool has_POPCNT)107   X86InstructionSetFeatures(bool has_SSSE3,
108                             bool has_SSE4_1,
109                             bool has_SSE4_2,
110                             bool has_AVX,
111                             bool has_AVX2,
112                             bool has_POPCNT)
113       : InstructionSetFeatures(),
114         has_SSSE3_(has_SSSE3),
115         has_SSE4_1_(has_SSE4_1),
116         has_SSE4_2_(has_SSE4_2),
117         has_AVX_(has_AVX),
118         has_AVX2_(has_AVX2),
119         has_POPCNT_(has_POPCNT) {
120   }
121 
122   static X86FeaturesUniquePtr Create(bool x86_64,
123                                      bool has_SSSE3,
124                                      bool has_SSE4_1,
125                                      bool has_SSE4_2,
126                                      bool has_AVX,
127                                      bool has_AVX2,
128                                      bool has_POPCNT);
129 
130  private:
131   // Bitmap positions for encoding features as a bitmap.
132   enum {
133     kSsse3Bitfield = 1 << 0,
134     kSse4_1Bitfield = 1 << 1,
135     kSse4_2Bitfield = 1 << 2,
136     kAvxBitfield = 1 << 3,
137     kAvx2Bitfield = 1 << 4,
138     kPopCntBitfield = 1 << 5,
139   };
140 
141   const bool has_SSSE3_;   // x86 128bit SIMD - Supplemental SSE.
142   const bool has_SSE4_1_;  // x86 128bit SIMD SSE4.1.
143   const bool has_SSE4_2_;  // x86 128bit SIMD SSE4.2.
144   const bool has_AVX_;     // x86 256bit SIMD AVX.
145   const bool has_AVX2_;    // x86 256bit SIMD AVX 2.0.
146   const bool has_POPCNT_;  // x86 population count
147 
148   DISALLOW_COPY_AND_ASSIGN(X86InstructionSetFeatures);
149 };
150 
151 }  // namespace art
152 
153 #endif  // ART_RUNTIME_ARCH_X86_INSTRUCTION_SET_FEATURES_X86_H_
154