crc/internal/cpu_detect.h

0001 // Copyright 2022 The Abseil Authors
0002 //
0003 // Licensed under the Apache License, Version 2.0 (the "License");
0004 // you may not use this file except in compliance with the License.
0005 // You may obtain a copy of the License at
0006 //
0007 //     https://www.apache.org/licenses/LICENSE-2.0
0008 //
0009 // Unless required by applicable law or agreed to in writing, software
0010 // distributed under the License is distributed on an "AS IS" BASIS,
0011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0012 // See the License for the specific language governing permissions and
0013 // limitations under the License.
0014
0015 #ifndef ABSL_CRC_INTERNAL_CPU_DETECT_H_
0016 #define ABSL_CRC_INTERNAL_CPU_DETECT_H_
0017
0018 #include "absl/base/config.h"
0019
0020 namespace absl {
0021 ABSL_NAMESPACE_BEGIN
0022 namespace crc_internal {
0023
0024 // Enumeration of architectures that we have special-case tuning parameters for.
0025 // This set may change over time.
0026 enum class CpuType {
0027   kUnknown,
0028   kIntelHaswell,
0029   kAmdRome,
0030   kAmdNaples,
0031   kAmdMilan,
0032   kAmdGenoa,
0033   kAmdRyzenV3000,
0034   kIntelCascadelakeXeon,
0035   kIntelSkylakeXeon,
0036   kIntelBroadwell,
0037   kIntelSkylake,
0038   kIntelIvybridge,
0039   kIntelSandybridge,
0040   kIntelWestmere,
0041   kArmNeoverseN1,
0042   kArmNeoverseV1,
0043   kAmpereSiryn,
0044   kArmNeoverseN2,
0045   kArmNeoverseV2
0046 };
0047
0048 // Returns the type of host CPU this code is running on.  Returns kUnknown if
0049 // the host CPU is of unknown type, or if detection otherwise fails.
0050 CpuType GetCpuType();
0051
0052 // Returns whether the host CPU supports the CPU features needed for our
0053 // accelerated implementations. The CpuTypes enumerated above apart from
0054 // kUnknown support the required features. On unknown CPUs, we can use
0055 // this to see if it's safe to use hardware acceleration, though without any
0056 // tuning.
0057 bool SupportsArmCRC32PMULL();
0058
0059 }  // namespace crc_internal
0060 ABSL_NAMESPACE_END
0061 }  // namespace absl
0062
0063 #endif  // ABSL_CRC_INTERNAL_CPU_DETECT_H_