[LLVMdev] PR21302: Vectorize only bottom-tested loops
aschwaighofer at apple.com
Tue Dec 2 14:57:32 PST 2014
On 12/02/14, Michael Zolotukhin wrote:
> 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?
More information about the llvm-dev