Messages in this thread | | | From | Arnd Bergmann <> | Date | Wed, 1 Jul 2020 12:59:36 +0200 | Subject | Re: [PATCH 18/18] arm64: lto: Strengthen READ_ONCE() to acquire when CLANG_LTO=y |
| |
On Wed, Jul 1, 2020 at 12:19 PM Will Deacon <will@kernel.org> wrote: > On Tue, Jun 30, 2020 at 09:25:03PM +0200, Arnd Bergmann wrote: > > On Tue, Jun 30, 2020 at 7:39 PM Will Deacon <will@kernel.org> wrote: > > Once we make gcc-4.9 the minimum version, > > this could be further improved to > > > > __auto_type __x = &(x); > > Is anybody working on moving to 4.9? I've seen the mails from Linus > championing it, but I thought there was a RHEL in support that people > might care about?
I don't think there was a serious discussion about it so far, and we only just moved to gcc-4.8.
I think moving to gnu11 (gcc-4.9 or clang) instead of gnu99 has other benefits as well, so we may well want to do it anyway when something else comes up.
For __auto_type(), we could do it like
#if (clang or gcc-4.9+) #define auto_typeof(x) __auto_type #else #define auto_typeof(x) typeof(x) #endif
which could be used in a lot of macros.
Arnd
| |