[CMake] VS2012 builds using v3.1.0 are a lot slower than v2.8.12

[Brad King]

On 01/16/2015 05:24 AM, Yves Frederix wrote:
> 3.1.0:
>         ALL                 Crypto          Crypto_s        Crypto_test
> real    0m38.211s           0m14.023s       0m7.003s        0m14.691s
> 
> 2.8.12:
>         ALL                 Crypto          Crypto_s        Crypto_test
> real    0m27.230s           0m17.110s       0m10.231s       0m18.618s

Interesting, thanks for the timings.

> This made me wonder if it maybe had to do with default settings for
> parallelization in the builds. So I tried, and if I explicitly "set
> CL=/MP" for the 3.1.0 build, build time reduces from 38 seconds to 24
> seconds which is what I would expect. Could this be the cause and was
> there a change in default settings?

I don't think such a change was made intentionally.  To help narrow
it down, could you please do the timings for CMake 3.0.2 as well?

Thanks,
-Brad