On 2011-04-02 00:20, Michael Hope wrote:
On Sat, Apr 2, 2011 at 1:50 AM,<omalleys(a)msu.edu> wrote:
> Did anyone ever get llvm/clang working?
>
> It -says- it is fast, good optimization, faster binaries, aimed at
> generating better errors, and has good tools for debugging. :) the
> darwin-arm (and x86 ports are production quality.
> There isn't support for EABI or< armv6 in the ARM-backend yet.
I'm having a bit of a look at this for Linaro at the moment. LLVM is
quite respectable, and generates code that is slower than GCC but
generally in the same ballpark. Of the three benchmarks I've tried,
two took 8 % longer to run on an A9 and pybench took more like 40 %
longer to run. pybench is sensitive to having a good inner loop
though.
-- Michael
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https://admin.fedoraproject.org/mailman/listinfo/arm Hi Michael!
For what I know, LLVM defaults to ARMv4t code generation unless it gets
told that it are allowed to use newer code generation.
This llvm bug tracked how llvm and clang implemented X86 cpu feature
autodetection code to make clang generate the best code available for
any given host when using -march=native.
http://www.llvm.org/bugs/show_bug.cgi?id=5389
I have added an initial cpu features auto-detection code for ARM to that
bug-report for the LLVM part.
Do you get better performance on your A9 tests when running clang with
clang -mcpu=generic -mattr=+neon,-thumb2,+v6,+vfp2
?
Cheers
Xerxes