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



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



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