Re: [Qemu-devel] [PATCH 1/3] Add support for target helper functions which don't return

[Stefan Weil]

Am 19.03.2012 11:45, schrieb Andreas Färber:

Am 18.03.2012 23:16, schrieb Stefan Weil:

Most functions which handle exceptions don't return.

With a compiler attribute (added by QEMU_NORETURN),
gcc can optimize the code.

Do you have any numbers?

Yes, of course: for (;;) { printf("%ld\n", random()); } :-)

To be honest, I don't expect large savings of code (some bytes for the function return
which is no longer needed), nor will there be a huge gain in execution speed.

It's more for documentation purposes that this attribute is useful here.
We might also add a compiler warning for missing attributes some day
(-Wsuggest-attribute=noreturn) - it is surprising how many functions never return!

Regards,
Stefan

Signed-off-by: Stefan Weil <address@hidden>

Seems like a sensible optimization,

Reviewed-by: Andreas Färber <address@hidden>

Andreas