runtime/arch/x86/instruction_set_features_x86.cc - platform/art - Git at Google

 /*
  * Copyright (C) 2014 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "instruction_set_features_x86.h"

 #include <fstream>
 #include <sstream>

 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>

 #include "arch/x86_64/instruction_set_features_x86_64.h"

 #include <cpu_features_macros.h>

 #ifdef CPU_FEATURES_ARCH_X86
 // This header can only be included on x86 targets,
 // as determined by cpu_features own define.
 #include <cpuinfo_x86.h>
 #endif

 namespace art {

 using android::base::StringPrintf;

 // Feature-support arrays.

 static constexpr const char* x86_known_variants[] = {
     "atom",
     "sandybridge",
     "silvermont",
     "kabylake",
 };

 static constexpr const char* x86_variants_with_ssse3[] = {
     "atom",
     "sandybridge",
     "silvermont",
     "kabylake",
 };

 static constexpr const char* x86_variants_with_sse4_1[] = {
     "sandybridge",
     "silvermont",
     "kabylake",
 };

 static constexpr const char* x86_variants_with_sse4_2[] = {
     "sandybridge",
     "silvermont",
     "kabylake",
 };

 static constexpr const char* x86_variants_with_popcnt[] = {
     "sandybridge",
     "silvermont",
     "kabylake",
 };
 static constexpr const char* x86_variants_with_avx[] = {
     "kabylake",
 };

 static constexpr const char* x86_variants_with_avx2[] = {
     "kabylake",
 };

 X86FeaturesUniquePtr X86InstructionSetFeatures::Create(bool x86_64,
                                                        bool has_SSSE3,
                                                        bool has_SSE4_1,
                                                        bool has_SSE4_2,
                                                        bool has_AVX,
                                                        bool has_AVX2,
                                                        bool has_POPCNT) {
   if (x86_64) {
     return X86FeaturesUniquePtr(new X86_64InstructionSetFeatures(has_SSSE3,
                                                                  has_SSE4_1,
                                                                  has_SSE4_2,
                                                                  has_AVX,
                                                                  has_AVX2,
                                                                  has_POPCNT));
   } else {
     return X86FeaturesUniquePtr(new X86InstructionSetFeatures(has_SSSE3,
                                                               has_SSE4_1,
                                                               has_SSE4_2,
                                                               has_AVX,
                                                               has_AVX2,
                                                               has_POPCNT));
   }
 }

 X86FeaturesUniquePtr X86InstructionSetFeatures::FromVariant(
     const std::string& variant, std::string* error_msg ATTRIBUTE_UNUSED,
     bool x86_64) {
   const bool is_runtime_isa =
       kRuntimeISA == (x86_64 ? InstructionSet::kX86_64 : InstructionSet::kX86);
   if (is_runtime_isa && variant == "default") {
     return FromCppDefines(x86_64);
   }

   bool has_SSSE3 = FindVariantInArray(x86_variants_with_ssse3, arraysize(x86_variants_with_ssse3),
                                       variant);
   bool has_SSE4_1 = FindVariantInArray(x86_variants_with_sse4_1,
                                        arraysize(x86_variants_with_sse4_1),
                                        variant);
   bool has_SSE4_2 = FindVariantInArray(x86_variants_with_sse4_2,
                                        arraysize(x86_variants_with_sse4_2),
                                        variant);
   bool has_AVX = FindVariantInArray(x86_variants_with_avx,
                                     arraysize(x86_variants_with_avx),
                                     variant);
   bool has_AVX2 = FindVariantInArray(x86_variants_with_avx2,
                                     arraysize(x86_variants_with_avx2),
                                     variant);
   bool has_POPCNT = FindVariantInArray(x86_variants_with_popcnt,
                                        arraysize(x86_variants_with_popcnt),
                                        variant);

   // Verify that variant is known.
   bool known_variant = FindVariantInArray(x86_known_variants, arraysize(x86_known_variants),
                                           variant);
   if (!known_variant && variant != "default") {
     LOG(WARNING) << "Unexpected CPU variant for X86 using defaults: " << variant;
   }

   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
 }

 X86FeaturesUniquePtr X86InstructionSetFeatures::FromBitmap(uint32_t bitmap, bool x86_64) {
   bool has_SSSE3 = (bitmap & kSsse3Bitfield) != 0;
   bool has_SSE4_1 = (bitmap & kSse4_1Bitfield) != 0;
   bool has_SSE4_2 = (bitmap & kSse4_2Bitfield) != 0;
   bool has_AVX = (bitmap & kAvxBitfield) != 0;
   bool has_AVX2 = (bitmap & kAvxBitfield) != 0;
   bool has_POPCNT = (bitmap & kPopCntBitfield) != 0;
   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
 }

 X86FeaturesUniquePtr X86InstructionSetFeatures::FromCppDefines(bool x86_64) {
 #ifndef __SSSE3__
   const bool has_SSSE3 = false;
 #else
   const bool has_SSSE3 = true;
 #endif

 #ifndef __SSE4_1__
   const bool has_SSE4_1 = false;
 #else
   const bool has_SSE4_1 = true;
 #endif

 #ifndef __SSE4_2__
   const bool has_SSE4_2 = false;
 #else
   const bool has_SSE4_2 = true;
 #endif

 #ifndef __AVX__
   const bool has_AVX = false;
 #else
   const bool has_AVX = true;
 #endif

 #ifndef __AVX2__
   const bool has_AVX2 = false;
 #else
   const bool has_AVX2 = true;
 #endif

 #ifndef __POPCNT__
   const bool has_POPCNT = false;
 #else
   const bool has_POPCNT = true;
 #endif

   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
 }

 X86FeaturesUniquePtr X86InstructionSetFeatures::FromCpuInfo(bool x86_64) {
   // Look in /proc/cpuinfo for features we need.  Only use this when we can guarantee that
   // the kernel puts the appropriate feature flags in here.  Sometimes it doesn't.
   bool has_SSSE3 = false;
   bool has_SSE4_1 = false;
   bool has_SSE4_2 = false;
   bool has_AVX = false;
   bool has_AVX2 = false;
   bool has_POPCNT = false;

   std::ifstream in("/proc/cpuinfo");
   if (!in.fail()) {
     while (!in.eof()) {
       std::string line;
       std::getline(in, line);
       if (!in.eof()) {
         LOG(INFO) << "cpuinfo line: " << line;
         if (line.find("flags") != std::string::npos) {
           LOG(INFO) << "found flags";
           if (line.find("ssse3") != std::string::npos) {
             has_SSSE3 = true;
           }
           if (line.find("sse4_1") != std::string::npos) {
             has_SSE4_1 = true;
           }
           if (line.find("sse4_2") != std::string::npos) {
             has_SSE4_2 = true;
           }
           if (line.find("avx") != std::string::npos) {
             has_AVX = true;
           }
           if (line.find("avx2") != std::string::npos) {
             has_AVX2 = true;
           }
           if (line.find("popcnt") != std::string::npos) {
             has_POPCNT = true;
           }
         }
       }
     }
     in.close();
   } else {
     LOG(ERROR) << "Failed to open /proc/cpuinfo";
   }
   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
 }

 X86FeaturesUniquePtr X86InstructionSetFeatures::FromHwcap(bool x86_64) {
   UNIMPLEMENTED(WARNING);
   return FromCppDefines(x86_64);
 }

 X86FeaturesUniquePtr X86InstructionSetFeatures::FromAssembly(bool x86_64) {
   UNIMPLEMENTED(WARNING);
   return FromCppDefines(x86_64);
 }


 X86FeaturesUniquePtr X86InstructionSetFeatures::FromCpuFeatures(bool x86_64) {
 #ifdef CPU_FEATURES_ARCH_X86
   cpu_features::X86Features features = cpu_features::GetX86Info().features;
   return Create(x86_64,
     features.ssse3,
     features.sse4_1,
     features.sse4_2,
     features.avx,
     features.avx2,
     features.popcnt);
 #else
   UNIMPLEMENTED(WARNING);
   return FromCppDefines(x86_64);
 #endif
 }


 bool X86InstructionSetFeatures::Equals(const InstructionSetFeatures* other) const {
   if (GetInstructionSet() != other->GetInstructionSet()) {
     return false;
   }
   const X86InstructionSetFeatures* other_as_x86 = other->AsX86InstructionSetFeatures();
   return (has_SSSE3_ == other_as_x86->has_SSSE3_) &&
       (has_SSE4_1_ == other_as_x86->has_SSE4_1_) &&
       (has_SSE4_2_ == other_as_x86->has_SSE4_2_) &&
       (has_AVX_ == other_as_x86->has_AVX_) &&
       (has_AVX2_ == other_as_x86->has_AVX2_) &&
       (has_POPCNT_ == other_as_x86->has_POPCNT_);
 }

 bool X86InstructionSetFeatures::HasAtLeast(const InstructionSetFeatures* other) const {
   if (GetInstructionSet() != other->GetInstructionSet()) {
     return false;
   }
   const X86InstructionSetFeatures* other_as_x86 = other->AsX86InstructionSetFeatures();
   return (has_SSSE3_ || !other_as_x86->has_SSSE3_) &&
       (has_SSE4_1_ || !other_as_x86->has_SSE4_1_) &&
       (has_SSE4_2_ || !other_as_x86->has_SSE4_2_) &&
       (has_AVX_ || !other_as_x86->has_AVX_) &&
       (has_AVX2_ || !other_as_x86->has_AVX2_) &&
       (has_POPCNT_ || !other_as_x86->has_POPCNT_);
 }

 uint32_t X86InstructionSetFeatures::AsBitmap() const {
   return (has_SSSE3_ ? kSsse3Bitfield : 0) |
       (has_SSE4_1_ ? kSse4_1Bitfield : 0) |
       (has_SSE4_2_ ? kSse4_2Bitfield : 0) |
       (has_AVX_ ? kAvxBitfield : 0) |
       (has_AVX2_ ? kAvx2Bitfield : 0) |
       (has_POPCNT_ ? kPopCntBitfield : 0);
 }

 std::string X86InstructionSetFeatures::GetFeatureString() const {
   std::string result;
   if (has_SSSE3_) {
     result += "ssse3";
   } else {
     result += "-ssse3";
   }
   if (has_SSE4_1_) {
     result += ",sse4.1";
   } else {
     result += ",-sse4.1";
   }
   if (has_SSE4_2_) {
     result += ",sse4.2";
   } else {
     result += ",-sse4.2";
   }
   if (has_AVX_) {
     result += ",avx";
   } else {
     result += ",-avx";
   }
   if (has_AVX2_) {
     result += ",avx2";
   } else {
     result += ",-avx2";
   }
   if (has_POPCNT_) {
     result += ",popcnt";
   } else {
     result += ",-popcnt";
   }
   return result;
 }

 std::unique_ptr<const InstructionSetFeatures> X86InstructionSetFeatures::AddFeaturesFromSplitString(
     const std::vector<std::string>& features, bool x86_64,
     std::string* error_msg) const {
   bool has_SSSE3 = has_SSSE3_;
   bool has_SSE4_1 = has_SSE4_1_;
   bool has_SSE4_2 = has_SSE4_2_;
   bool has_AVX = has_AVX_;
   bool has_AVX2 = has_AVX2_;
   bool has_POPCNT = has_POPCNT_;
   for (const std::string& feature : features) {
     DCHECK_EQ(android::base::Trim(feature), feature)
         << "Feature name is not trimmed: '" << feature << "'";
     if (feature == "ssse3") {
       has_SSSE3 = true;
     } else if (feature == "-ssse3") {
       has_SSSE3 = false;
     } else if (feature == "sse4.1") {
       has_SSE4_1 = true;
     } else if (feature == "-sse4.1") {
       has_SSE4_1 = false;
     } else if (feature == "sse4.2") {
       has_SSE4_2 = true;
     } else if (feature == "-sse4.2") {
       has_SSE4_2 = false;
     } else if (feature == "avx") {
       has_AVX = true;
     } else if (feature == "-avx") {
       has_AVX = false;
     } else if (feature == "avx2") {
       has_AVX2 = true;
     } else if (feature == "-avx2") {
       has_AVX2 = false;
     } else if (feature == "popcnt") {
       has_POPCNT = true;
     } else if (feature == "-popcnt") {
       has_POPCNT = false;
     } else {
       *error_msg = StringPrintf("Unknown instruction set feature: '%s'", feature.c_str());
       return nullptr;
     }
   }
   return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
 }

 }  // namespace art
	/*
	* Copyright (C) 2014 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "instruction_set_features_x86.h"

	#include <fstream>
	#include <sstream>

	#include <android-base/logging.h>
	#include <android-base/stringprintf.h>
	#include <android-base/strings.h>

	#include "arch/x86_64/instruction_set_features_x86_64.h"

	#include <cpu_features_macros.h>

	#ifdef CPU_FEATURES_ARCH_X86
	// This header can only be included on x86 targets,
	// as determined by cpu_features own define.
	#include <cpuinfo_x86.h>
	#endif

	namespace art {

	using android::base::StringPrintf;

	// Feature-support arrays.

	static constexpr const char* x86_known_variants[] = {
	"atom",
	"sandybridge",
	"silvermont",
	"kabylake",
	};

	static constexpr const char* x86_variants_with_ssse3[] = {
	"atom",
	"sandybridge",
	"silvermont",
	"kabylake",
	};

	static constexpr const char* x86_variants_with_sse4_1[] = {
	"sandybridge",
	"silvermont",
	"kabylake",
	};

	static constexpr const char* x86_variants_with_sse4_2[] = {
	"sandybridge",
	"silvermont",
	"kabylake",
	};

	static constexpr const char* x86_variants_with_popcnt[] = {
	"sandybridge",
	"silvermont",
	"kabylake",
	};
	static constexpr const char* x86_variants_with_avx[] = {
	"kabylake",
	};

	static constexpr const char* x86_variants_with_avx2[] = {
	"kabylake",
	};

	X86FeaturesUniquePtr X86InstructionSetFeatures::Create(bool x86_64,
	bool has_SSSE3,
	bool has_SSE4_1,
	bool has_SSE4_2,
	bool has_AVX,
	bool has_AVX2,
	bool has_POPCNT) {
	if (x86_64) {
	return X86FeaturesUniquePtr(new X86_64InstructionSetFeatures(has_SSSE3,
	has_SSE4_1,
	has_SSE4_2,
	has_AVX,
	has_AVX2,
	has_POPCNT));
	} else {
	return X86FeaturesUniquePtr(new X86InstructionSetFeatures(has_SSSE3,
	has_SSE4_1,
	has_SSE4_2,
	has_AVX,
	has_AVX2,
	has_POPCNT));
	}
	}

	X86FeaturesUniquePtr X86InstructionSetFeatures::FromVariant(
	const std::string& variant, std::string* error_msg ATTRIBUTE_UNUSED,
	bool x86_64) {
	const bool is_runtime_isa =
	kRuntimeISA == (x86_64 ? InstructionSet::kX86_64 : InstructionSet::kX86);
	if (is_runtime_isa && variant == "default") {
	return FromCppDefines(x86_64);
	}

	bool has_SSSE3 = FindVariantInArray(x86_variants_with_ssse3, arraysize(x86_variants_with_ssse3),
	variant);
	bool has_SSE4_1 = FindVariantInArray(x86_variants_with_sse4_1,
	arraysize(x86_variants_with_sse4_1),
	variant);
	bool has_SSE4_2 = FindVariantInArray(x86_variants_with_sse4_2,
	arraysize(x86_variants_with_sse4_2),
	variant);
	bool has_AVX = FindVariantInArray(x86_variants_with_avx,
	arraysize(x86_variants_with_avx),
	variant);
	bool has_AVX2 = FindVariantInArray(x86_variants_with_avx2,
	arraysize(x86_variants_with_avx2),
	variant);
	bool has_POPCNT = FindVariantInArray(x86_variants_with_popcnt,
	arraysize(x86_variants_with_popcnt),
	variant);

	// Verify that variant is known.
	bool known_variant = FindVariantInArray(x86_known_variants, arraysize(x86_known_variants),
	variant);
	if (!known_variant && variant != "default") {
	LOG(WARNING) << "Unexpected CPU variant for X86 using defaults: " << variant;
	}

	return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
	}

	X86FeaturesUniquePtr X86InstructionSetFeatures::FromBitmap(uint32_t bitmap, bool x86_64) {
	bool has_SSSE3 = (bitmap & kSsse3Bitfield) != 0;
	bool has_SSE4_1 = (bitmap & kSse4_1Bitfield) != 0;
	bool has_SSE4_2 = (bitmap & kSse4_2Bitfield) != 0;
	bool has_AVX = (bitmap & kAvxBitfield) != 0;
	bool has_AVX2 = (bitmap & kAvxBitfield) != 0;
	bool has_POPCNT = (bitmap & kPopCntBitfield) != 0;
	return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
	}

	X86FeaturesUniquePtr X86InstructionSetFeatures::FromCppDefines(bool x86_64) {
	#ifndef __SSSE3__
	const bool has_SSSE3 = false;
	#else
	const bool has_SSSE3 = true;
	#endif

	#ifndef __SSE4_1__
	const bool has_SSE4_1 = false;
	#else
	const bool has_SSE4_1 = true;
	#endif

	#ifndef __SSE4_2__
	const bool has_SSE4_2 = false;
	#else
	const bool has_SSE4_2 = true;
	#endif

	#ifndef __AVX__
	const bool has_AVX = false;
	#else
	const bool has_AVX = true;
	#endif

	#ifndef __AVX2__
	const bool has_AVX2 = false;
	#else
	const bool has_AVX2 = true;
	#endif

	#ifndef __POPCNT__
	const bool has_POPCNT = false;
	#else
	const bool has_POPCNT = true;
	#endif

	return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
	}

	X86FeaturesUniquePtr X86InstructionSetFeatures::FromCpuInfo(bool x86_64) {
	// Look in /proc/cpuinfo for features we need. Only use this when we can guarantee that
	// the kernel puts the appropriate feature flags in here. Sometimes it doesn't.
	bool has_SSSE3 = false;
	bool has_SSE4_1 = false;
	bool has_SSE4_2 = false;
	bool has_AVX = false;
	bool has_AVX2 = false;
	bool has_POPCNT = false;

	std::ifstream in("/proc/cpuinfo");
	if (!in.fail()) {
	while (!in.eof()) {
	std::string line;
	std::getline(in, line);
	if (!in.eof()) {
	LOG(INFO) << "cpuinfo line: " << line;
	if (line.find("flags") != std::string::npos) {
	LOG(INFO) << "found flags";
	if (line.find("ssse3") != std::string::npos) {
	has_SSSE3 = true;
	}
	if (line.find("sse4_1") != std::string::npos) {
	has_SSE4_1 = true;
	}
	if (line.find("sse4_2") != std::string::npos) {
	has_SSE4_2 = true;
	}
	if (line.find("avx") != std::string::npos) {
	has_AVX = true;
	}
	if (line.find("avx2") != std::string::npos) {
	has_AVX2 = true;
	}
	if (line.find("popcnt") != std::string::npos) {
	has_POPCNT = true;
	}
	}
	}
	}
	in.close();
	} else {
	LOG(ERROR) << "Failed to open /proc/cpuinfo";
	}
	return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
	}

	X86FeaturesUniquePtr X86InstructionSetFeatures::FromHwcap(bool x86_64) {
	UNIMPLEMENTED(WARNING);
	return FromCppDefines(x86_64);
	}

	X86FeaturesUniquePtr X86InstructionSetFeatures::FromAssembly(bool x86_64) {
	UNIMPLEMENTED(WARNING);
	return FromCppDefines(x86_64);
	}


	X86FeaturesUniquePtr X86InstructionSetFeatures::FromCpuFeatures(bool x86_64) {
	#ifdef CPU_FEATURES_ARCH_X86
	cpu_features::X86Features features = cpu_features::GetX86Info().features;
	return Create(x86_64,
	features.ssse3,
	features.sse4_1,
	features.sse4_2,
	features.avx,
	features.avx2,
	features.popcnt);
	#else
	UNIMPLEMENTED(WARNING);
	return FromCppDefines(x86_64);
	#endif
	}


	bool X86InstructionSetFeatures::Equals(const InstructionSetFeatures* other) const {
	if (GetInstructionSet() != other->GetInstructionSet()) {
	return false;
	}
	const X86InstructionSetFeatures* other_as_x86 = other->AsX86InstructionSetFeatures();
	return (has_SSSE3_ == other_as_x86->has_SSSE3_) &&
	(has_SSE4_1_ == other_as_x86->has_SSE4_1_) &&
	(has_SSE4_2_ == other_as_x86->has_SSE4_2_) &&
	(has_AVX_ == other_as_x86->has_AVX_) &&
	(has_AVX2_ == other_as_x86->has_AVX2_) &&
	(has_POPCNT_ == other_as_x86->has_POPCNT_);
	}

	bool X86InstructionSetFeatures::HasAtLeast(const InstructionSetFeatures* other) const {
	if (GetInstructionSet() != other->GetInstructionSet()) {
	return false;
	}
	const X86InstructionSetFeatures* other_as_x86 = other->AsX86InstructionSetFeatures();
	return (has_SSSE3_ \|\| !other_as_x86->has_SSSE3_) &&
	(has_SSE4_1_ \|\| !other_as_x86->has_SSE4_1_) &&
	(has_SSE4_2_ \|\| !other_as_x86->has_SSE4_2_) &&
	(has_AVX_ \|\| !other_as_x86->has_AVX_) &&
	(has_AVX2_ \|\| !other_as_x86->has_AVX2_) &&
	(has_POPCNT_ \|\| !other_as_x86->has_POPCNT_);
	}

	uint32_t X86InstructionSetFeatures::AsBitmap() const {
	return (has_SSSE3_ ? kSsse3Bitfield : 0) \|
	(has_SSE4_1_ ? kSse4_1Bitfield : 0) \|
	(has_SSE4_2_ ? kSse4_2Bitfield : 0) \|
	(has_AVX_ ? kAvxBitfield : 0) \|
	(has_AVX2_ ? kAvx2Bitfield : 0) \|
	(has_POPCNT_ ? kPopCntBitfield : 0);
	}

	std::string X86InstructionSetFeatures::GetFeatureString() const {
	std::string result;
	if (has_SSSE3_) {
	result += "ssse3";
	} else {
	result += "-ssse3";
	}
	if (has_SSE4_1_) {
	result += ",sse4.1";
	} else {
	result += ",-sse4.1";
	}
	if (has_SSE4_2_) {
	result += ",sse4.2";
	} else {
	result += ",-sse4.2";
	}
	if (has_AVX_) {
	result += ",avx";
	} else {
	result += ",-avx";
	}
	if (has_AVX2_) {
	result += ",avx2";
	} else {
	result += ",-avx2";
	}
	if (has_POPCNT_) {
	result += ",popcnt";
	} else {
	result += ",-popcnt";
	}
	return result;
	}

	std::unique_ptr<const InstructionSetFeatures> X86InstructionSetFeatures::AddFeaturesFromSplitString(
	const std::vector<std::string>& features, bool x86_64,
	std::string* error_msg) const {
	bool has_SSSE3 = has_SSSE3_;
	bool has_SSE4_1 = has_SSE4_1_;
	bool has_SSE4_2 = has_SSE4_2_;
	bool has_AVX = has_AVX_;
	bool has_AVX2 = has_AVX2_;
	bool has_POPCNT = has_POPCNT_;
	for (const std::string& feature : features) {
	DCHECK_EQ(android::base::Trim(feature), feature)
	<< "Feature name is not trimmed: '" << feature << "'";
	if (feature == "ssse3") {
	has_SSSE3 = true;
	} else if (feature == "-ssse3") {
	has_SSSE3 = false;
	} else if (feature == "sse4.1") {
	has_SSE4_1 = true;
	} else if (feature == "-sse4.1") {
	has_SSE4_1 = false;
	} else if (feature == "sse4.2") {
	has_SSE4_2 = true;
	} else if (feature == "-sse4.2") {
	has_SSE4_2 = false;
	} else if (feature == "avx") {
	has_AVX = true;
	} else if (feature == "-avx") {
	has_AVX = false;
	} else if (feature == "avx2") {
	has_AVX2 = true;
	} else if (feature == "-avx2") {
	has_AVX2 = false;
	} else if (feature == "popcnt") {
	has_POPCNT = true;
	} else if (feature == "-popcnt") {
	has_POPCNT = false;
	} else {
	*error_msg = StringPrintf("Unknown instruction set feature: '%s'", feature.c_str());
	return nullptr;
	}
	}
	return Create(x86_64, has_SSSE3, has_SSE4_1, has_SSE4_2, has_AVX, has_AVX2, has_POPCNT);
	}

	} // namespace art