[LLVMdev] Help needed on debugging llvm

[Anitha B Gollamudi]

On 11 March 2013 10:06, Anitha B Gollamudi <anitha.boyapati at gmail.com> wrote:
> On 23 January 2013 00:20, Craig Topper <craig.topper at gmail.com> wrote:
>>
>> Are you still having issues with FMA4? I wonder if PR15040 is related. A
>> fix was just committed.

Unfortunately r173176 does not fix this. I have updated the trunk and
ran...Miscompare still persists.

Going by http://llvm.org/bugs/show_bug.cgi?id=14185#c12 , I am
inclined to think that it is an optimization. (If it is an encoding
issue, dragonegg would have failed as well...). or maybe I am missing
something here.


-Anitha









>
> It seems to be so! I will look into it immediately.
>
> Apologies for the late e-mail. I ran out of time devoted for this PR
> and moved on. Coincidentally, only today I came back to this PR for
> further debugging.
>
>
> Thanks!
>
>
>>
>> On Wed, Nov 7, 2012 at 3:22 AM, Anitha Boyapati
>> <anitha.boyapati at gmail.com> wrote:
>>>
>>>
>>>
>>> On 7 November 2012 15:29, Duncan Sands <baldrick at free.fr> wrote:
>>>>
>>>>
>>>> That way the output should be exactly the same as the output dragonegg
>>>> would
>>>> normally run the LLVM optimizers on, e.g. GCC constant folding and other
>>>> such
>>>> optimizations which get turned on at -O2 will still have happened
>>>> (dragonegg
>>>> turns off almost all GCC optimizations by default, but turning
>>>> everything off
>>>> isn't practical).
>>>>
>>>> Running the output through "opt -O2" should then do the same
>>>> optimizations as
>>>> dragonegg would have done.  I say "should" because in my experience this
>>>> isn't
>>>> always true, though it is supposed to be true.
>>>
>>>
>>> Ok.
>>>
>>>>
>>>>
>>>> Next comes the codegen stage, which you can emulate using llc (or clang
>>>> like
>>>> you do below, but llc is more direct).  It isn't that easy finding out
>>>> exactly
>>>> what flags dragonegg passes to llc, so this might be a bit painful.
>>>
>>>
>>> Yes. This is probably what I need now. Code Generation options used by
>>> dragonegg vs clang (or llc as I referred to in last email).
>>>
>>> Thanks for all the suggestions.
>>>
>>>
>>> - Anitha
>>>
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>>>
>>
>>
>>
>> --
>> ~Craig
>
>
>
>
> --
>  Anitha



-- 
 Anitha