text: /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
  │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
  ╞══════════════════════════════════════════════════════════════════════════════╡
  │ Copyright 2020 Justine Alexandra Roberts Tunney                              │
  │                                                                              │
  │ Permission to use, copy, modify, and/or distribute this software for         │
  │ any purpose with or without fee is hereby granted, provided that the         │
  │ above copyright notice and this permission notice appear in all copies.      │
  │                                                                              │
  │ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
  │ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
  │ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
  │ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
  │ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
  │ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
  │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
  │ PERFORMANCE OF THIS SOFTWARE.                                                │
  ╚─────────────────────────────────────────────────────────────────────────────*/
  #include "libc/stdio/stdio.h"
  #include "libc/testlib/ezbench.h"
  #include "libc/testlib/testlib.h"
  
  static bool once;
  static int64_t g_ezbenchcontrol;
  
  int64_t __testlib_ezbenchcontrol(void) {
    if (!once) {
      int Core, Tries, Interrupts;
      Tries = 0;
      do {
        __testlib_yield();
        Core = __testlib_getcore();
        Interrupts = __testlib_getinterrupts();
        g_ezbenchcontrol =
            BENCHLOOP(__startbench, __endbench, 128, donothing, (void)0);
      } while (++Tries < 10 && (__testlib_getcore() != Core &&
                                __testlib_getinterrupts() > Interrupts));
      if (Tries == 10) {
        fputs("warning: failed to accurately benchmark control\n", stderr);
      }
      fprintf(stderr, "will subtract benchmark overhead of %ld cycles\n\n",
              g_ezbenchcontrol);
      once = true;
    }
    return g_ezbenchcontrol;
  }
  