Comparison of GCC-4.9 and LLVM-3.4 performance on SPECInt2000 for x86-64 and ARM

[Ramana Radhakrishnan]

> I wonder how much of that is due to auto-vectorization (on LLVM, -O2+
> turns it on, I suppose GCC is only on -O3?). From Ramana's point,
> there may be nothing serious if you haven't enabled NEON, though.

Auto-vec is turned off when you have -mfpu=vfpv3-d16 . That implies No Neon.

Ramana

>
> Also interesting to see the impact of LTO being a major drive in
> recent performance improvements on both compilers.
>
> cheers,
> --renato
>