[patch] implement simd loops in trunk (OMP_SIMD)

[Aldy Hernandez <aldyh at redhat dot com>]

Hi folks.

I have distilled the relevant machinery to implement and handle simd 
loops from the gomp-4_0-branch.  This will be used by both gomp4 
(#pragma omp simd) and Cilk Plus (#pragma simd).

All of it is Jakub's code.  There is nothing new here, as I believe 
Jakub and the Richards have talked about all this at length.  Included 
in the patch are the vectorizer changes that have been previously 
discussed, all from the gomp-4_0-branch.

It would be ideal to get an ok from either Mr. Biener or Mr. Henderson 
on the vectorizer changes.

The patch I am formally submitting is the attached patch named OMP_SIMD. 
 I am including the second (CILK_SIMD), which I will submit 
independently, as reference to how it will be used (if for some reason 
it isn't clear from the gomp4 branch usage of OMP_SIMD).

Tested on x86-64 Linux with and without the Cilk Plus bits, not to 
mention that this has been extensively tested on the gomp4 branch.

OK for trunk?

Attachment: OMP_SIMD
Description: Text document

Attachment: CILK_SIMD
Description: Text document