[PATCH] Induction variables: support arbitrary constant step

[Nadav Rotem]

Hi Alexey, 

Did you verify the correctness and the performance impacts of this patch? You should run the LLVM test suite with your changes. 

This patch looks very suspicious.  The test that you are chancing (example13) has code that looks like this: 

    for (j = 0; j < N; j+=8) {
      diff += (a[i][j] - b[i][j]);
    }

How are you generating consecutive vector loads?   This looks like a bug.  Also, you did not explain what programs you are expecting to vectorize and how. This is a huge patch and you should explain what changes you made and why. 

-Nadav

http://reviews.llvm.org/D6051