text: // Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
  //
  // 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.
  
  #ifndef __COMPARE_SET_H
  #define __COMPARE_SET_H
  
  #include <stdint.h>
  #include <stdbool.h>
  #include "soc/cpu.h"
  #include "soc/soc_memory_layout.h"
  #include "xtensa/xtruntime.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  static inline void __attribute__((always_inline)) compare_and_set_native(volatile uint32_t *addr, uint32_t compare, uint32_t *set)
  {
  #if (XCHAL_HAVE_S32C1I > 0) 
      __asm__ __volatile__ (
          "WSR 	    %2,SCOMPARE1 \n"
          "S32C1I     %0, %1, 0	 \n"
          :"=r"(*set)
          :"r"(addr), "r"(compare), "0"(*set)
      );
  #else
      // No S32C1I, so do this by disabling and re-enabling interrupts (slower)
      uint32_t intlevel, old_value;
      __asm__ __volatile__ ("rsil %0, " XTSTR(XCHAL_EXCM_LEVEL) "\n"
                            : "=r"(intlevel));
  
      old_value = *addr;
      if (old_value == compare) {
          *addr = *set;
      }
  
      __asm__ __volatile__ ("memw \n"
                            "wsr %0, ps\n"
                            :: "r"(intlevel));
  
      *set = old_value;
  #endif
  }
  
  
  void compare_and_set_extram(volatile uint32_t *addr, uint32_t compare, uint32_t *set);
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif