[llvm-commits] [PATCH v2] review for fix of profiling test failures on ARM

[David Tweed]

Thanks. I missed your review due to email client issues I'm hopefully fixing. Could someone commit this patch for me as I don't (yet) have commit rights please?

Thanks,
David

-----Original Message-----
From: Kaylor, Andrew [mailto:andrew.kaylor at intel.com]
Sent: 28 September 2012 18:43
To: David Tweed; 'NAKAMURA Takumi'
Cc: llvm-commits at cs.uiuc.edu
Subject: RE: [llvm-commits] [PATCH v2] review for fix of profiling test failures on ARM

Has anyone objected to this?

I'm not sure if my review (posted Wednesday) is sufficient to make the code owners happy, but I think this should be OK to commit.

-Andy

-----Original Message-----
From: llvm-commits-bounces at cs.uiuc.edu [mailto:llvm-commits-bounces at cs.uiuc.edu] On Behalf Of David Tweed
Sent: Friday, September 28, 2012 9:17 AM
To: David Tweed; David Tweed; 'NAKAMURA Takumi'
Cc: llvm-commits at cs.uiuc.edu
Subject: Re: [llvm-commits] [PATCH v2] review for fix of profiling test failures on ARM

Hi. As this patch takes the approach suggested by Andrew Kaylor in a previous mailing list patch discussion and fixes 3 regression test failures on ARM can this be moved towards application please? Various people have fixed quite a few of the ARM regressions recently as part of a push towards getting them to have a baseline of green.

Cheers,
David

-----Original Message-----
From: David Tweed [mailto:david.tweed at arm.com]
Sent: 26 September 2012 16:53
To: David Tweed; 'NAKAMURA Takumi'
Cc: llvm-commits at cs.uiuc.edu
Subject: RE: [llvm-commits] [PATCH v2] review for fix of profiling test failures on ARM

Ping on comments/commit please?

This is part of a short-term effort to resolve some long-standing issues to get the LLVM regression tests to pass on the ARM platform, so that a non-green ARM buildbot signals a new problem. Clearly there's a bigger issue regarding how to test the JIT itself, but this patch follows a suggested approach for making the tests of Profiling functionality pass and seems the an appropriate way to achieve this immediate goal.

Many thanks,
Dave

-----Original Message-----
From: David Tweed
Sent: 25 September 2012 09:07
To: David Tweed; 'NAKAMURA Takumi'
Cc: llvm-commits at cs.uiuc.edu
Subject: RE: [llvm-commits] [PATCH v2] review for fix of profiling test failures on ARM

Ping?

-----Original Message-----
From: llvm-commits-bounces at cs.uiuc.edu
[mailto:llvm-commits-bounces at cs.uiuc.edu] On Behalf Of David Tweed
Sent: 21 September 2012 16:18
To: 'NAKAMURA Takumi'
Cc: llvm-commits at cs.uiuc.edu
Subject: Re: [llvm-commits] [PATCH v2] review for fix of profiling test failures on ARM

Discussion about making the default JIT lli uses for the general user depend on target triple suggested at the very least it requires further clean up and analysis, so while that avenue will be pursued for its own sake, here's a patch that (following David Kaylor's suggestion):

As part of the push to make the ARM buildbots baseline be green, this adds a "%defaultjit" lit macro that (currently) becomes "-use-mcjit=true" on ARM, "-use-mcjit=false" elsewhere. (This is to be explicit; defining it to just be "" for platforms using the old jit would give something that, if lli gets triple-based jit defaulting, would undergo a behaviour change for the case of defaultjit not using MCJIT while no behaviour change the other way around. This kind of asymmetry is a debugging nightmare.) Iprovides an abstraction that tests which need to use the jit, but aren't explicitly testing a particular kind of it, can specify, so that what they want to test gets covered as well as possible with the currently "most robust" jit engine. The patch only uses it on the 3 profiling tests that were failing, but I'll look to see if there are other tests it would be appropriate.

Tested on ARM and x86-64.

Please review with a view to committing.

Many thanks,
David Tweed

-----Original Message-----
From: NAKAMURA Takumi [mailto:geek4civic at gmail.com]
Sent: 13 September 2012 10:39
To: David Tweed
Cc: llvm-commits at cs.uiuc.edu
Subject: Re: [llvm-commits] [PATCH] review for fix of profiling test failures on ARM

2012/9/13 David Tweed <david.tweed at arm.com>:
> Fair enough: I clearly didn't research the MCJIT status deeply enough.
> Out of curiousity, do the profiling tests pass on those platforms as
> it
stands?
> (I can't find any of those platforms listed on the buildbot page.)

They have been suppressed on Win32-based builders.
I can reproduce crash manually.
http://llvm.org/bugs/show_bug.cgi?id=13830

> | What would happen if -use-mcjit were set by default for arm-elf?
>
> That's a good question, one I don't know the complete answer to yet.
> In general the old JIT doesn't compile runnable code on ARM and the
> MCJIT
does,
> but I don't know if there are any cases where the reverse is true. My
> current focus is looking at the regression test failures as reported
> by
the
> buildbots and seeing how many can be "properly" resolved so they pass
> and
we
> get closer to a more useful default green build on ARM. I'm happy to
> turn
on
> mcjit for ARM Elf in some regression tests that are really testing the
> profiling instruction insertion, but I'd need to do some more
comprehensive
> testing before I was happy turning it on for users by default.

I think test/ExecutionEngine should cover then.

> Supposing I was to figure out some magic way to add the -use-mcjit
> option for those tests only on ARM-Linux, would that be a valid way to
> fix the issue in the main tree?

I don't think so. It would be better when -use-mcjit could be turned on for certain targets.

...Takumi



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