On 2016-09-17, Nils Asmussen <asmussen.n...@gmx.de> wrote:
> after upgrading to the Version 3.21.92-1, I always get an error stating
> "illegal instruction":
>
> bash$ gnome-photos
> Illegal instruction
>
> The relevant assembly instruction is "rdtscp".
> I checked this by substituting it by "nop"s:
> With a hexeditor I replaced "0F 01 F9" by "90 90 90". As a result I got
> the gnome-photos main screen flashing on my screen for a short time. (I
> didn't see anything of gnome-photos before.)
>
> I conclude that changing the compiler flags to support older cpus would
> fix the problem.
>From gnome-photos' configure.ac:
> AC_MSG_CHECKING([for fast counters with rdtscp])
> AC_RUN_IFELSE([AC_LANG_SOURCE([[
> #include <x86intrin.h>
> int main (int argc, char *argv[]) { int cpu; __builtin_ia32_rdtscp (&cpu);
> return 0; }]])],
> [have_rdtscp=yes],
> [have_rdtscp=no])
> AC_MSG_RESULT([$have_rdtscp])
> AS_IF([test "$have_rdtscp" = "yes"],
> [CFLAGS="$CFLAGS -DEGG_HAVE_RDTSCP"])
It looks like they've recently added something called EggCounter which
which compile-time conditionally uses rdtscp.
