[LLVMdev] [llvm-testresults] cfarm-x86-64 x86_64 nightly tester results

[Chris Lattner]

On Mar 10, 2009, at 8:24 AM, Duncan Sands wrote:

> Hi Chris,
>
>> Can you check to see if the stepanov_container/fftbench regressions
>> are real?  If so, it would be very interesting to know what is "going
>> wrong" on them.
>
> I think these may not be real.  This version of llvm-gcc was built  
> with
> checking enabled - does this turn on checking in libstdc++?

I don't know if it turns on checking in libstdc++, but I would be very  
surprised by that.

> It seems that
> a bunch of linkonce libstdc++ checking code is now being inlined  
> (presumably
> because it compiled to something smaller than before).  Previously  
> it was
> not being inlined so was discarded, and the version from the system  
> libstdc++
> was used instead.  My guess is that the system libstdc++ version is  
> faster
> because it doesn't do any checking.  To test this theory I've told  
> this
> nightly tester to build llvm-gcc with checking disabled.  If I'm  
> correct
> then stepanov_container/fftbench will speed up hugely in a few days  
> time
> when the tester starts using the new llvm-gcc.

Sounds great, thanks for hunting this down Duncan!

-Chris