[llvm] r246344 - Use UNSUPPORTED instead of XFAIL to disable this test, as it passes on one AArch64 bot.

[Peter Collingbourne via llvm-commits]

Hi Yaron,

Thanks for pointing that out.

A much more minimal way to support LLVM_ENABLE_THREADS=0 would be to add
some magic in llvm/Support/thread.h that declares llvm::thread as either
a typedef of std::thread or a replacement that runs on the main thread
depending on the value of LLVM_ENABLE_THREADS. This should be easy to do;
I'll start working on that.

There shouldn't be any functional changes needed (e.g. -j limitations),
and this way parallel CG tests should pass regardless of whether threads
are enabled.

I'd like to see LLVM_ENABLE_THREADS removed, but that would need to be
proposed separately.

Peter

On Mon, Aug 31, 2015 at 01:06:32AM +0300, Yaron Keren wrote:
> Hi Peter,
> 
> llvm::splitCodeGen() in lib/CodeGen/ParallelCG.cpp (called from this test)
> uses threads even when LLVM was compiled without thread
> support, LLVM_ENABLE_THREADS=0. This does not end well.
> 
> As long as LLVM_ENABLE_THREADS=0 is supported build option (should it go
> away?) the code should not use threads (and thus the test will pass). Maybe
> limit -j to 1 and run everything on the main thread without creating any
> threads?
> 
> Yaron
> 
> 
> 
> 
> 
> 2015-08-29 1:17 GMT+03:00 Peter Collingbourne via llvm-commits <
> llvm-commits at lists.llvm.org>:
> 
> > Author: pcc
> > Date: Fri Aug 28 17:17:29 2015
> > New Revision: 246344
> >
> > URL: http://llvm.org/viewvc/llvm-project?rev=246344&view=rev
> > Log:
> > Use UNSUPPORTED instead of XFAIL to disable this test, as it passes on one
> > AArch64 bot.
> >
> > Modified:
> >     llvm/trunk/test/LTO/X86/parallel.ll
> >
> > Modified: llvm/trunk/test/LTO/X86/parallel.ll
> > URL:
> > http://llvm.org/viewvc/llvm-project/llvm/trunk/test/LTO/X86/parallel.ll?rev=246344&r1=246343&r2=246344&view=diff
> >
> > ==============================================================================
> > --- llvm/trunk/test/LTO/X86/parallel.ll (original)
> > +++ llvm/trunk/test/LTO/X86/parallel.ll Fri Aug 28 17:17:29 2015
> > @@ -4,7 +4,7 @@
> >  ; RUN: llvm-nm %t.o.1 | FileCheck --check-prefix=CHECK1 %s
> >
> >  ; FIXME: Investigate test failures on these architecures.
> > -; XFAIL: mips, mipsel, aarch64
> > +; UNSUPPORTED: mips, mipsel, aarch64
> >
> >  target triple = "x86_64-unknown-linux-gnu"
> >
> >
> >
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> >

-- 
Peter