[llvm] r218101 - Optimize sext/zext insertion algorithm in back-end.

[Bob Wilson]

Wow, I just noticed the spelling auto-correct for my (apparently) mis-typed “clearing them out”. We should definitely be clevering things out more often!

> On Sep 24, 2014, at 4:29 PM, Eric Christopher <echristo at gmail.com> wrote:
> 
> On Wed, Sep 24, 2014 at 4:26 PM, Kostya Serebryany <kcc at google.com> wrote:
>> 
>> 
>> On Wed, Sep 24, 2014 at 4:25 PM, Bob Wilson <bob.wilson at apple.com> wrote:
>>> 
>>> I don’t think it would have shown up as a leak. The bad code was adding
>>> values to a DenseMap and never clever them out between functions. I don’t
>>> see how lsan could have detected that.
>> 
>> 
>> Yep, no way. We would need a memory profiler and compare the heap profiles
>> between revisions to detect spikes.
>> 
> 
> Agreed. That might be fun though.
> 
> And yeah, I was just responding to the "where are the bots" part of
> the thread :)
> 
> -eric
> 
>>> 
>>> 
>>> On Sep 24, 2014, at 4:23 PM, Kostya Serebryany <kcc at google.com> wrote:
>>> 
>>> 
>>> 
>>> On Wed, Sep 24, 2014 at 4:21 PM, Eric Christopher <echristo at gmail.com>
>>> wrote:
>>>> 
>>>> On Wed, Sep 24, 2014 at 4:20 PM, Kostya Serebryany <kcc at google.com>
>>>> wrote:
>>>>> 
>>>>> 
>>>>> On Wed, Sep 24, 2014 at 2:47 PM, Eric Christopher <echristo at gmail.com>
>>>>> wrote:
>>>>>> 
>>>>>> On Wed, Sep 24, 2014 at 1:16 AM, Renato Golin
>>>>>> <renato.golin at linaro.org>
>>>>>> wrote:
>>>>>>> On 23 September 2014 18:56, Bob Wilson <bob.wilson at apple.com> wrote:
>>>>>>>> We’re seeing significant regressions in memory usage. I think you
>>>>>>>> forgot to clear the PreferredExtendType DenseMap that you added
>>>>>>>> here.
>>>>>>> 
>>>>>>> Seems we're missing some valgrind / sanitizer buildbots to check
>>>>>>> that
>>>>>>> automatically?
>>>>>>> 
>>>>>> 
>>>>>> http://lab.llvm.org:8011/builders/clang-x86_64-linux-vg
>>>>>> 
>>>>>> which appears to be having problems.
>>>>>> 
>>>>>> I know that Kostya has some sanitizer bots, but I'm not sure what the
>>>>>> status is there.
>>>>> 
>>>>> 
>>>>> We have two bots:
>>>>> http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux
>>>>> http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/
>>>>> The second one is red at the moment with some (fresh?) msan reports.
>>>>> What is the problem here?
>>>>> 
>>>> 
>>>> Aha.
>>>> 
>>>> Anyhow as of r218101 we were leaking quite a bit of memory. I don't
>>>> know if the sanitizers reported it or not.
>>> 
>>> 
>>> lsan is silent. repro?
>>> 
>>> 
>>>> 
>>>> 
>>>> -eric
>>>> 
>>>>>> 
>>>>>> 
>>>>>> -eric
>>>>> 
>>>>> 
>>> 
>>> 
>>