I have two examples here that do exactly the same thing. The gcc compiler apparently produces the same assembly code for both variants:

Example 1 with if else:

    #include <stdio.h>
    #include <stdlib.h>
    #include <checkcpu.h>
    
    int main(int argc, char *argv[])
    {
      if (!check386()) {
        printf("This program does require a 386 or better.n");
        exit(EXIT_SUCCESS);
      } else {
        innerMain();
      }
      return 0;
    }

Example 2 with only if without else. The code that is executed in the Else block is simply appended after the if.:

#include <stdio.h>
#include <stdlib.h>
#include <checkcpu.h>

int main(int argc, char *argv[])
{
  if (!check386()) {
    printf("This program does require a 386 or better.n");
    exit(EXIT_SUCCESS);
  }
  innerMain();
  return 0;
}

Are there reasons to prefer one variant over the other?
For example, are there older compilers where this makes a difference?
Which one is easier to read and therefore better design?