1 // Copyright 2020 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 #pragma once 15 16 // PW_SYNC_YIELD_CORE_FOR_SMT provides the architecture specific processor hint 17 // to allow the processor to yield in the case of SMT. 18 #if defined(__x86_64__) || defined(__i386__) 19 #include <immintrin.h> 20 #define PW_SYNC_YIELD_CORE_FOR_SMT() _mm_pause() 21 22 #elif defined(__aarch64__) || defined(__arm__) 23 #define PW_SYNC_YIELD_CORE_FOR_SMT() asm volatile("yield" ::: "memory") 24 25 #else 26 #error "No processor yield implementation for this architecture." 27 28 #endif // PW_SYNC_YIELD_CORE_FOR_SMT 29