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

[Duncan Sands]

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++?  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.

Ciao,

Duncan.