Reading value of ccount registry on esp8266 returns probably invalid resut - embedded

Question

I'm trying to read the value of ccount register on esp8266. Though the first read after reset seems to be sensible, the rest values seem to be fishy.
Here is a complete code snippet I'm using
/* Hello World Example
This example code is in the Public Domain (or CC0 licensed, at your option.)
Unless required by applicable law or agreed to in writing, this
software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied.
*/
#include <stdio.h>
#include <stdint.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "esp_spi_flash.h"
static inline uint32_t get_ccount(void)
{
volatile uint32_t r;
__asm__ __volatile__("rsr %0,ccount":"=a" (r));
return r;
}
static void print_ccount()
{
uint32_t c = get_ccount();
printf("ccount: %u\n", c);
}
void app_main()
{
for (int i = 10; i >= 0; i--) {
print_ccount();
vTaskDelay(1000 / portTICK_PERIOD_MS);
}
printf("Restarting now.\n");
fflush(stdout);
esp_restart();
}
First read after reset is usually something like 659430, 110466 etc, but the rest values is usually recurring '1981' value or something similar. Even after reset, all reads after the first read return '1981' value.
Sometimes the output looks like this:
�ccount: 110466
I'm afraid that there is some garbage on the stack but I can't figure out what is the cause.