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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     "sandybridge",
37     "silvermont",
38 };
39 
40 static constexpr const char* x86_variants_with_ssse3[] = {
41     "atom",
42     "sandybridge",
43     "silvermont",
44 };
45 
46 static constexpr const char* x86_variants_with_sse4_1[] = {
47     "sandybridge",
48     "silvermont",
49 };
50 
51 static constexpr const char* x86_variants_with_sse4_2[] = {
52     "sandybridge",
53     "silvermont",
54 };
55 
56 static constexpr const char* x86_variants_with_popcnt[] = {
57     "sandybridge",
58     "silvermont",
59 };
60 
Create(bool x86_64,bool has_SSSE3,bool has_SSE4_1,bool has_SSE4_2,bool has_AVX,bool has_AVX2,bool has_POPCNT)61 X86FeaturesUniquePtr X86InstructionSetFeatures::Create(bool x86_64,
62                                                        bool has_SSSE3,
63                                                        bool has_SSE4_1,
64                                                        bool has_SSE4_2,
65                                                        bool has_AVX,
66                                                        bool has_AVX2,
67                                                        bool has_POPCNT) {
68   if (x86_64) {
69     return X86FeaturesUniquePtr(new X86_64InstructionSetFeatures(has_SSSE3,
70                                                                  has_SSE4_1,
71                                                                  has_SSE4_2,
72                                                                  has_AVX,
73                                                                  has_AVX2,
74                                                                  has_POPCNT));
75   } else {
76     return X86FeaturesUniquePtr(new X86InstructionSetFeatures(has_SSSE3,
77                                                               has_SSE4_1,
78                                                               has_SSE4_2,
79                                                               has_AVX,
80                                                               has_AVX2,
81                                                               has_POPCNT));
82   }
83 }
84 
FromVariant(const std::string & variant,std::string * error_msg ATTRIBUTE_UNUSED,bool x86_64)85 X86FeaturesUniquePtr X86InstructionSetFeatures::FromVariant(
86     const std::string& variant, std::string* error_msg ATTRIBUTE_UNUSED,
87     bool x86_64) {
88   bool has_SSSE3 = FindVariantInArray(x86_variants_with_ssse3, arraysize(x86_variants_with_ssse3),
89                                       variant);
90   bool has_SSE4_1 = FindVariantInArray(x86_variants_with_sse4_1,
91                                        arraysize(x86_variants_with_sse4_1),
92                                        variant);
93   bool has_SSE4_2 = FindVariantInArray(x86_variants_with_sse4_2,
94                                        arraysize(x86_variants_with_sse4_2),
95                                        variant);
96   bool has_AVX = false;
97   bool has_AVX2 = false;
98 
99   bool has_POPCNT = FindVariantInArray(x86_variants_with_popcnt,
100                                        arraysize(x86_variants_with_popcnt),
101                                        variant);
102 
103   // Verify that variant is known.
104   bool known_variant = FindVariantInArray(x86_known_variants, arraysize(x86_known_variants),
105                                           variant);
106   if (!known_variant && variant != "default") {
107     LOG(WARNING) << "Unexpected CPU variant for X86 using defaults: " << variant;
108   }
109 
110   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
111 }
112 
FromBitmap(uint32_t bitmap,bool x86_64)113 X86FeaturesUniquePtr X86InstructionSetFeatures::FromBitmap(uint32_t bitmap, bool x86_64) {
114   bool has_SSSE3 = (bitmap & kSsse3Bitfield) != 0;
115   bool has_SSE4_1 = (bitmap & kSse4_1Bitfield) != 0;
116   bool has_SSE4_2 = (bitmap & kSse4_2Bitfield) != 0;
117   bool has_AVX = (bitmap & kAvxBitfield) != 0;
118   bool has_AVX2 = (bitmap & kAvxBitfield) != 0;
119   bool has_POPCNT = (bitmap & kPopCntBitfield) != 0;
120   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
121 }
122 
FromCppDefines(bool x86_64)123 X86FeaturesUniquePtr X86InstructionSetFeatures::FromCppDefines(bool x86_64) {
124 #ifndef __SSSE3__
125   const bool has_SSSE3 = false;
126 #else
127   const bool has_SSSE3 = true;
128 #endif
129 
130 #ifndef __SSE4_1__
131   const bool has_SSE4_1 = false;
132 #else
133   const bool has_SSE4_1 = true;
134 #endif
135 
136 #ifndef __SSE4_2__
137   const bool has_SSE4_2 = false;
138 #else
139   const bool has_SSE4_2 = true;
140 #endif
141 
142 #ifndef __AVX__
143   const bool has_AVX = false;
144 #else
145   const bool has_AVX = true;
146 #endif
147 
148 #ifndef __AVX2__
149   const bool has_AVX2 = false;
150 #else
151   const bool has_AVX2 = true;
152 #endif
153 
154 #ifndef __POPCNT__
155   const bool has_POPCNT = false;
156 #else
157   const bool has_POPCNT = true;
158 #endif
159 
160   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
161 }
162 
FromCpuInfo(bool x86_64)163 X86FeaturesUniquePtr X86InstructionSetFeatures::FromCpuInfo(bool x86_64) {
164   // Look in /proc/cpuinfo for features we need.  Only use this when we can guarantee that
165   // the kernel puts the appropriate feature flags in here.  Sometimes it doesn't.
166   bool has_SSSE3 = false;
167   bool has_SSE4_1 = false;
168   bool has_SSE4_2 = false;
169   bool has_AVX = false;
170   bool has_AVX2 = false;
171   bool has_POPCNT = false;
172 
173   std::ifstream in("/proc/cpuinfo");
174   if (!in.fail()) {
175     while (!in.eof()) {
176       std::string line;
177       std::getline(in, line);
178       if (!in.eof()) {
179         LOG(INFO) << "cpuinfo line: " << line;
180         if (line.find("flags") != std::string::npos) {
181           LOG(INFO) << "found flags";
182           if (line.find("ssse3") != std::string::npos) {
183             has_SSSE3 = true;
184           }
185           if (line.find("sse4_1") != std::string::npos) {
186             has_SSE4_1 = true;
187           }
188           if (line.find("sse4_2") != std::string::npos) {
189             has_SSE4_2 = true;
190           }
191           if (line.find("avx") != std::string::npos) {
192             has_AVX = true;
193           }
194           if (line.find("avx2") != std::string::npos) {
195             has_AVX2 = true;
196           }
197           if (line.find("popcnt") != std::string::npos) {
198             has_POPCNT = true;
199           }
200         }
201       }
202     }
203     in.close();
204   } else {
205     LOG(ERROR) << "Failed to open /proc/cpuinfo";
206   }
207   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
208 }
209 
FromHwcap(bool x86_64)210 X86FeaturesUniquePtr X86InstructionSetFeatures::FromHwcap(bool x86_64) {
211   UNIMPLEMENTED(WARNING);
212   return FromCppDefines(x86_64);
213 }
214 
FromAssembly(bool x86_64)215 X86FeaturesUniquePtr X86InstructionSetFeatures::FromAssembly(bool x86_64) {
216   UNIMPLEMENTED(WARNING);
217   return FromCppDefines(x86_64);
218 }
219 
Equals(const InstructionSetFeatures * other) const220 bool X86InstructionSetFeatures::Equals(const InstructionSetFeatures* other) const {
221   if (GetInstructionSet() != other->GetInstructionSet()) {
222     return false;
223   }
224   const X86InstructionSetFeatures* other_as_x86 = other->AsX86InstructionSetFeatures();
225   return (has_SSSE3_ == other_as_x86->has_SSSE3_) &&
226       (has_SSE4_1_ == other_as_x86->has_SSE4_1_) &&
227       (has_SSE4_2_ == other_as_x86->has_SSE4_2_) &&
228       (has_AVX_ == other_as_x86->has_AVX_) &&
229       (has_AVX2_ == other_as_x86->has_AVX2_) &&
230       (has_POPCNT_ == other_as_x86->has_POPCNT_);
231 }
232 
AsBitmap() const233 uint32_t X86InstructionSetFeatures::AsBitmap() const {
234   return (has_SSSE3_ ? kSsse3Bitfield : 0) |
235       (has_SSE4_1_ ? kSse4_1Bitfield : 0) |
236       (has_SSE4_2_ ? kSse4_2Bitfield : 0) |
237       (has_AVX_ ? kAvxBitfield : 0) |
238       (has_AVX2_ ? kAvx2Bitfield : 0) |
239       (has_POPCNT_ ? kPopCntBitfield : 0);
240 }
241 
GetFeatureString() const242 std::string X86InstructionSetFeatures::GetFeatureString() const {
243   std::string result;
244   if (has_SSSE3_) {
245     result += "ssse3";
246   } else {
247     result += "-ssse3";
248   }
249   if (has_SSE4_1_) {
250     result += ",sse4.1";
251   } else {
252     result += ",-sse4.1";
253   }
254   if (has_SSE4_2_) {
255     result += ",sse4.2";
256   } else {
257     result += ",-sse4.2";
258   }
259   if (has_AVX_) {
260     result += ",avx";
261   } else {
262     result += ",-avx";
263   }
264   if (has_AVX2_) {
265     result += ",avx2";
266   } else {
267     result += ",-avx2";
268   }
269   if (has_POPCNT_) {
270     result += ",popcnt";
271   } else {
272     result += ",-popcnt";
273   }
274   return result;
275 }
276 
AddFeaturesFromSplitString(const std::vector<std::string> & features,bool x86_64,std::string * error_msg) const277 std::unique_ptr<const InstructionSetFeatures> X86InstructionSetFeatures::AddFeaturesFromSplitString(
278     const std::vector<std::string>& features, bool x86_64,
279     std::string* error_msg) const {
280   bool has_SSSE3 = has_SSSE3_;
281   bool has_SSE4_1 = has_SSE4_1_;
282   bool has_SSE4_2 = has_SSE4_2_;
283   bool has_AVX = has_AVX_;
284   bool has_AVX2 = has_AVX2_;
285   bool has_POPCNT = has_POPCNT_;
286   for (auto i = features.begin(); i != features.end(); i++) {
287     std::string feature = android::base::Trim(*i);
288     if (feature == "ssse3") {
289       has_SSSE3 = true;
290     } else if (feature == "-ssse3") {
291       has_SSSE3 = false;
292     } else if (feature == "sse4.1") {
293       has_SSE4_1 = true;
294     } else if (feature == "-sse4.1") {
295       has_SSE4_1 = false;
296     } else if (feature == "sse4.2") {
297       has_SSE4_2 = true;
298     } else if (feature == "-sse4.2") {
299       has_SSE4_2 = false;
300     } else if (feature == "avx") {
301       has_AVX = true;
302     } else if (feature == "-avx") {
303       has_AVX = false;
304     } else if (feature == "avx2") {
305       has_AVX2 = true;
306     } else if (feature == "-avx2") {
307       has_AVX2 = false;
308     } else if (feature == "popcnt") {
309       has_POPCNT = true;
310     } else if (feature == "-popcnt") {
311       has_POPCNT = false;
312     } else {
313       *error_msg = StringPrintf("Unknown instruction set feature: '%s'", feature.c_str());
314       return nullptr;
315     }
316   }
317   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
318 }
319 
320 }  // namespace art
321