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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 #include "instruction_set_features_x86.h"
18 
19 #include <fstream>
20 #include <sstream>
21 
22 #include "android-base/stringprintf.h"
23 #include "android-base/strings.h"
24 
25 #include "arch/x86_64/instruction_set_features_x86_64.h"
26 #include "base/logging.h"
27 
28 namespace art {
29 
30 using android::base::StringPrintf;
31 
32 // Feature-support arrays.
33 
34 static constexpr const char* x86_known_variants[] = {
35     "atom",
36     "silvermont",
37 };
38 
39 static constexpr const char* x86_variants_with_ssse3[] = {
40     "atom",
41     "silvermont",
42 };
43 
44 static constexpr const char* x86_variants_with_sse4_1[] = {
45     "silvermont",
46 };
47 
48 static constexpr const char* x86_variants_with_sse4_2[] = {
49     "silvermont",
50 };
51 
52 static constexpr const char* x86_variants_with_popcnt[] = {
53     "silvermont",
54 };
55 
Create(bool x86_64,bool has_SSSE3,bool has_SSE4_1,bool has_SSE4_2,bool has_AVX,bool has_AVX2,bool has_POPCNT)56 X86FeaturesUniquePtr X86InstructionSetFeatures::Create(bool x86_64,
57                                                        bool has_SSSE3,
58                                                        bool has_SSE4_1,
59                                                        bool has_SSE4_2,
60                                                        bool has_AVX,
61                                                        bool has_AVX2,
62                                                        bool has_POPCNT) {
63   if (x86_64) {
64     return X86FeaturesUniquePtr(new X86_64InstructionSetFeatures(has_SSSE3,
65                                                                  has_SSE4_1,
66                                                                  has_SSE4_2,
67                                                                  has_AVX,
68                                                                  has_AVX2,
69                                                                  has_POPCNT));
70   } else {
71     return X86FeaturesUniquePtr(new X86InstructionSetFeatures(has_SSSE3,
72                                                               has_SSE4_1,
73                                                               has_SSE4_2,
74                                                               has_AVX,
75                                                               has_AVX2,
76                                                               has_POPCNT));
77   }
78 }
79 
FromVariant(const std::string & variant,std::string * error_msg ATTRIBUTE_UNUSED,bool x86_64)80 X86FeaturesUniquePtr X86InstructionSetFeatures::FromVariant(
81     const std::string& variant, std::string* error_msg ATTRIBUTE_UNUSED,
82     bool x86_64) {
83   bool has_SSSE3 = FindVariantInArray(x86_variants_with_ssse3, arraysize(x86_variants_with_ssse3),
84                                       variant);
85   bool has_SSE4_1 = FindVariantInArray(x86_variants_with_sse4_1,
86                                        arraysize(x86_variants_with_sse4_1),
87                                        variant);
88   bool has_SSE4_2 = FindVariantInArray(x86_variants_with_sse4_2,
89                                        arraysize(x86_variants_with_sse4_2),
90                                        variant);
91   bool has_AVX = false;
92   bool has_AVX2 = false;
93 
94   bool has_POPCNT = FindVariantInArray(x86_variants_with_popcnt,
95                                        arraysize(x86_variants_with_popcnt),
96                                        variant);
97 
98   // Verify that variant is known.
99   bool known_variant = FindVariantInArray(x86_known_variants, arraysize(x86_known_variants),
100                                           variant);
101   if (!known_variant && variant != "default") {
102     LOG(WARNING) << "Unexpected CPU variant for X86 using defaults: " << variant;
103   }
104 
105   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
106 }
107 
FromBitmap(uint32_t bitmap,bool x86_64)108 X86FeaturesUniquePtr X86InstructionSetFeatures::FromBitmap(uint32_t bitmap, bool x86_64) {
109   bool has_SSSE3 = (bitmap & kSsse3Bitfield) != 0;
110   bool has_SSE4_1 = (bitmap & kSse4_1Bitfield) != 0;
111   bool has_SSE4_2 = (bitmap & kSse4_2Bitfield) != 0;
112   bool has_AVX = (bitmap & kAvxBitfield) != 0;
113   bool has_AVX2 = (bitmap & kAvxBitfield) != 0;
114   bool has_POPCNT = (bitmap & kPopCntBitfield) != 0;
115   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
116 }
117 
FromCppDefines(bool x86_64)118 X86FeaturesUniquePtr X86InstructionSetFeatures::FromCppDefines(bool x86_64) {
119 #ifndef __SSSE3__
120   const bool has_SSSE3 = false;
121 #else
122   const bool has_SSSE3 = true;
123 #endif
124 
125 #ifndef __SSE4_1__
126   const bool has_SSE4_1 = false;
127 #else
128   const bool has_SSE4_1 = true;
129 #endif
130 
131 #ifndef __SSE4_2__
132   const bool has_SSE4_2 = false;
133 #else
134   const bool has_SSE4_2 = true;
135 #endif
136 
137 #ifndef __AVX__
138   const bool has_AVX = false;
139 #else
140   const bool has_AVX = true;
141 #endif
142 
143 #ifndef __AVX2__
144   const bool has_AVX2 = false;
145 #else
146   const bool has_AVX2 = true;
147 #endif
148 
149 #ifndef __POPCNT__
150   const bool has_POPCNT = false;
151 #else
152   const bool has_POPCNT = true;
153 #endif
154 
155   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
156 }
157 
FromCpuInfo(bool x86_64)158 X86FeaturesUniquePtr X86InstructionSetFeatures::FromCpuInfo(bool x86_64) {
159   // Look in /proc/cpuinfo for features we need.  Only use this when we can guarantee that
160   // the kernel puts the appropriate feature flags in here.  Sometimes it doesn't.
161   bool has_SSSE3 = false;
162   bool has_SSE4_1 = false;
163   bool has_SSE4_2 = false;
164   bool has_AVX = false;
165   bool has_AVX2 = false;
166   bool has_POPCNT = false;
167 
168   std::ifstream in("/proc/cpuinfo");
169   if (!in.fail()) {
170     while (!in.eof()) {
171       std::string line;
172       std::getline(in, line);
173       if (!in.eof()) {
174         LOG(INFO) << "cpuinfo line: " << line;
175         if (line.find("flags") != std::string::npos) {
176           LOG(INFO) << "found flags";
177           if (line.find("ssse3") != std::string::npos) {
178             has_SSSE3 = true;
179           }
180           if (line.find("sse4_1") != std::string::npos) {
181             has_SSE4_1 = true;
182           }
183           if (line.find("sse4_2") != std::string::npos) {
184             has_SSE4_2 = true;
185           }
186           if (line.find("avx") != std::string::npos) {
187             has_AVX = true;
188           }
189           if (line.find("avx2") != std::string::npos) {
190             has_AVX2 = true;
191           }
192           if (line.find("popcnt") != std::string::npos) {
193             has_POPCNT = true;
194           }
195         }
196       }
197     }
198     in.close();
199   } else {
200     LOG(ERROR) << "Failed to open /proc/cpuinfo";
201   }
202   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
203 }
204 
FromHwcap(bool x86_64)205 X86FeaturesUniquePtr X86InstructionSetFeatures::FromHwcap(bool x86_64) {
206   UNIMPLEMENTED(WARNING);
207   return FromCppDefines(x86_64);
208 }
209 
FromAssembly(bool x86_64)210 X86FeaturesUniquePtr X86InstructionSetFeatures::FromAssembly(bool x86_64) {
211   UNIMPLEMENTED(WARNING);
212   return FromCppDefines(x86_64);
213 }
214 
Equals(const InstructionSetFeatures * other) const215 bool X86InstructionSetFeatures::Equals(const InstructionSetFeatures* other) const {
216   if (GetInstructionSet() != other->GetInstructionSet()) {
217     return false;
218   }
219   const X86InstructionSetFeatures* other_as_x86 = other->AsX86InstructionSetFeatures();
220   return (has_SSSE3_ == other_as_x86->has_SSSE3_) &&
221       (has_SSE4_1_ == other_as_x86->has_SSE4_1_) &&
222       (has_SSE4_2_ == other_as_x86->has_SSE4_2_) &&
223       (has_AVX_ == other_as_x86->has_AVX_) &&
224       (has_AVX2_ == other_as_x86->has_AVX2_) &&
225       (has_POPCNT_ == other_as_x86->has_POPCNT_);
226 }
227 
AsBitmap() const228 uint32_t X86InstructionSetFeatures::AsBitmap() const {
229   return (has_SSSE3_ ? kSsse3Bitfield : 0) |
230       (has_SSE4_1_ ? kSse4_1Bitfield : 0) |
231       (has_SSE4_2_ ? kSse4_2Bitfield : 0) |
232       (has_AVX_ ? kAvxBitfield : 0) |
233       (has_AVX2_ ? kAvx2Bitfield : 0) |
234       (has_POPCNT_ ? kPopCntBitfield : 0);
235 }
236 
GetFeatureString() const237 std::string X86InstructionSetFeatures::GetFeatureString() const {
238   std::string result;
239   if (has_SSSE3_) {
240     result += "ssse3";
241   } else {
242     result += "-ssse3";
243   }
244   if (has_SSE4_1_) {
245     result += ",sse4.1";
246   } else {
247     result += ",-sse4.1";
248   }
249   if (has_SSE4_2_) {
250     result += ",sse4.2";
251   } else {
252     result += ",-sse4.2";
253   }
254   if (has_AVX_) {
255     result += ",avx";
256   } else {
257     result += ",-avx";
258   }
259   if (has_AVX2_) {
260     result += ",avx2";
261   } else {
262     result += ",-avx2";
263   }
264   if (has_POPCNT_) {
265     result += ",popcnt";
266   } else {
267     result += ",-popcnt";
268   }
269   return result;
270 }
271 
AddFeaturesFromSplitString(const std::vector<std::string> & features,bool x86_64,std::string * error_msg) const272 std::unique_ptr<const InstructionSetFeatures> X86InstructionSetFeatures::AddFeaturesFromSplitString(
273     const std::vector<std::string>& features, bool x86_64,
274     std::string* error_msg) const {
275   bool has_SSSE3 = has_SSSE3_;
276   bool has_SSE4_1 = has_SSE4_1_;
277   bool has_SSE4_2 = has_SSE4_2_;
278   bool has_AVX = has_AVX_;
279   bool has_AVX2 = has_AVX2_;
280   bool has_POPCNT = has_POPCNT_;
281   for (auto i = features.begin(); i != features.end(); i++) {
282     std::string feature = android::base::Trim(*i);
283     if (feature == "ssse3") {
284       has_SSSE3 = true;
285     } else if (feature == "-ssse3") {
286       has_SSSE3 = false;
287     } else if (feature == "sse4.1") {
288       has_SSE4_1 = true;
289     } else if (feature == "-sse4.1") {
290       has_SSE4_1 = false;
291     } else if (feature == "sse4.2") {
292       has_SSE4_2 = true;
293     } else if (feature == "-sse4.2") {
294       has_SSE4_2 = false;
295     } else if (feature == "avx") {
296       has_AVX = true;
297     } else if (feature == "-avx") {
298       has_AVX = false;
299     } else if (feature == "avx2") {
300       has_AVX2 = true;
301     } else if (feature == "-avx2") {
302       has_AVX2 = false;
303     } else if (feature == "popcnt") {
304       has_POPCNT = true;
305     } else if (feature == "-popcnt") {
306       has_POPCNT = false;
307     } else {
308       *error_msg = StringPrintf("Unknown instruction set feature: '%s'", feature.c_str());
309       return nullptr;
310     }
311   }
312   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
313 }
314 
315 }  // namespace art
316