llvm dev - Mar 2013 - [LLVMdev] Help needed on debugging llvm

Are you still having issues with FMA4? I wonder if PR15040 is related. A
fix was just committed.

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
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>

-- 
~Craig
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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
>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>>
>>
>>
>>
>> --
>> ~Craig
>
>
>
>
> --
>  Anitha


-- 
 Anitha