[LLVMdev] PR21302: Vectorize only bottom-tested loops

[Arnold Schwaighofer]

LGTM.

Thanks!

On 12/02/14, Michael Zolotukhin   wrote:
> Hi,
> 
> This patch fixes the problem described in PR21302.
> 
> The issue is that currently vectorizer sometimes vectorizes loops that are not bottom-tested, i.e. in which each iteration starts from checking the termination condition. That causes an extra-iteration to be executed in vectorized version in some cases.
> 
> The patch consists of two parts:
> 1) Update three existing tests, that contained loop in such forms. After the fix these loops aren’t vectorized any longer, so I applied loop-rotate+simplifycfg to them. This change is quite mechanical.
> 2) The fix itself and a regression test.
> 
> 
> 
> 
> 
> Do they look ok?
> 
> Thanks,
> Michael