Hello, On Thu, 23 Jan 2025, Richard Biener wrote:
> When we get a zero distance vector we still have to check for the > situation of a common inner loop with zero distance. But we can > still allow a zero distance for the loop we distribute > (gcc.dg/tree-ssa/ldist-33.c is such a case). This is because > zero distances in non-outermost loops are a misrepresentation > of dependence by dependence analysis. I think as long as that is the case your proposed changes makes sense. But perhaps it's worth a comment to that effect, i.e. that because dependence analysis is wonky (sometime using zero as unknown) we do these "strange" tests. At least for the occasional reader it will be unintuitive why the obvious tests aren't working. Ciao, Michael.
