This is the mail archive of the
mailing list for the GCC project.
Re: Comparison of GCC-4.9 and LLVM-3.4 performance on SPECInt2000 for x86-64 and ARM
- From: Renato Golin <renato dot golin at linaro dot org>
- To: Vladimir Makarov <vmakarov at redhat dot com>
- Cc: "gcc.gcc.gnu.org" <gcc at gcc dot gnu dot org>
- Date: Tue, 24 Jun 2014 15:42:58 +0100
- Subject: Re: Comparison of GCC-4.9 and LLVM-3.4 performance on SPECInt2000 for x86-64 and ARM
- Authentication-results: sourceware.org; auth=none
- References: <53A98705 dot 10909 at redhat dot com>
On 24 June 2014 15:11, Vladimir Makarov <email@example.com> wrote:
> A few people asked me about new performance comparison of latest GCC
> and LLVM. So I've finished it and put it on my site
> The comparison is achievable from 2014 link and links under it in
> the left frame.
It's on the same ballpark of my own findings (with SPEC and other
benchmarks) on ARM: +10% performance, but also code size for GCC over
LLVM, and massive compilation time savings on LLVM.
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.
Also interesting to see the impact of LTO being a major drive in
recent performance improvements on both compilers.