Messages in this thread | | | Date | Wed, 14 Feb 2018 11:44:08 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: clang asm-goto support (Was Re: [PATCH v2] x86/retpoline: Add clang support) |
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On Wed, 14 Feb 2018, Peter Zijlstra wrote: > On Wed, Feb 14, 2018 at 08:41:43AM +0000, Chandler Carruth wrote: > > Marina, Kees: > > > > I think the combination of LKML and the LLVM developer's list is probably > > too large a set of folks to have a (somewhat) lengthy exploration of > > options and how to go about this and find a good path forward. > > As one of the original authors of the jump-label implementation I'm > saying there are no options. We're not going to do a second parallel > implementation. If you want to build the kernel, you get to implement > asm-goto, teh end.
Amen to that.
As x86 maintainer I'm really interested and willing to support llvm/clang for x86 and the kernel in general, but asm-goto is not longer negotiable.
asm-goto is in the kernel since Oct 2010 and the relevant llvm/clang bug #9295 is open since Feb 2011. All clang/llvm folks came up with in those 7 years is occasional handwaving about better solutions.
We really try to support old tools and tools which lack features for quite a long time, but that's not a free pass for eternity.
That said, I'm not willing to wait another 7 years and I'm going to pull the plug on compilers w/o asm-goto support soon whether llvm/clang gets their act together or not.
Hint: GCC is not the only major compiler which supports asm-goto.
Thanks,
tglx
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