Comparing Linux C and C++ Compilers: Benchmarks and Analysis

[Scott Robert Ladd]

Richard Guenther wrote:
> You may want to check gcc 4.0s auto-vectorizing capabilities by using
> -ftree-vectorize.  I believe Intel compiler does this by default with your
> optimization settings, and also unrolls loops where profitable (-funroll-loops
> for all gcc versions).  While I personally do not have success with
> auto-vectorizing (neither with Intel nor with gcc), loop unrolling
> shows very positive effects on my numerical codes.

I've had mixed success with unrolling loops in GCC, though I haven't 
tested it thoroughly with 4.0.

I'll likely publish an addendum to the article sometime next week, after 
people's feedback comes in.

Thanks.


-- 
Scott Robert Ladd
site: http://www.coyotegulch.com
blog: http://chaoticcoyote.blogspot.com