Messages in this thread | | | Date | Thu, 10 Oct 2013 15:10:34 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH, -v2] compiler/gcc4: Add quirk for 'asm goto' miscompilation bug |
| |
On Thu, Oct 10, 2013 at 02:32:36PM +0200, Jakub Jelinek wrote: > On Thu, Oct 10, 2013 at 01:56:17PM +0200, Peter Zijlstra wrote: > > We didn't do version checks for CC_HAVE_ASM_GOTO because of vendor > > backports; can't we detect this in the same way? > > The problem is that it will be harder to check for this as compile time only > check, and for runtime check you'd need to have the assembly string for > every architecture and you couldn't do it for cross-compiling anyway.
> So for >= 4.8.3 just assume no > workaround is needed, otherwise scan assembly.
Right, tedious and error prone it is.. :-)
Would it make sense to create something whereby GCC can tell us about these things? Maybe something like:
__builtin_bug_fixed(58670)
Which would default return 0, and only return 1 when its a known number.
But yes, I also see why you'd not want to do that. I suppose all I'm saying is it would be nice to be able to detect some arbitrary issue being fixed.
> See the follow-up mails, I think placing it immediately after asm goto might > be better.
Duh indeed, must've missed that when I scanned through the thread :/
| |