A port of ESP32 Arduino PR espressif/arduino-esp32#3165 (#6477)

Author: dok-net

Diff for: cores/esp8266/Esp.h

@@ -201,9 +201,10 @@ class EspClass {
         bool eraseConfig();
 
 #ifndef CORE_MOCK
-        inline
-#endif
+        inline uint32_t getCycleCount() __attribute__((always_inline));
+#else
         uint32_t getCycleCount();
+#endif
 };
 
 #ifndef CORE_MOCK

Diff for: cores/esp8266/core_esp8266_features.h

@@ -85,7 +85,8 @@ namespace arduino
 #define xt_rsil(level) (__extension__({uint32_t state; __asm__ __volatile__("rsil %0," __STRINGIFY(level) : "=a" (state) :: "memory"); state;}))
 #define xt_wsr_ps(state)  __asm__ __volatile__("wsr %0,ps; isync" :: "a" (state) : "memory")
 
-inline uint32_t esp_get_cycle_count() {
+inline uint32_t esp_get_cycle_count() __attribute__((always_inline));
+inline uint32_t esp_get_cycle_count() {
   uint32_t ccount;
   __asm__ __volatile__("rsr %0,ccount":"=a"(ccount));
   return ccount;