Integrated: 8334228: C2 SuperWord: fix JDK-24 regression in VPointer::cmp_for_sort after JDK-8325155

Emanuel Peter epeter at openjdk.org
Mon Jun 17 07:01:20 UTC 2024


On Thu, 13 Jun 2024 13:05:40 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

> This is a small regression from https://git.openjdk.org/jdk/pull/18822.
> 
> An overflow in the subtraction between the offsets means that the offsets are not correctly sorted. This has no correctness impact, but hit a verification assert that checked if the offsets were correctly sorted.
> 
> I now removed the subtractions, and replaced it with two comparisons.
> 
> Just out of an abundance of caution, I also converted all other subtractions into comparisons - even though I could probably make an argument that the values would be guaranteed in ranges that would not underflow the subtraction.

This pull request has now been integrated.

Changeset: 29b63928
Author:    Emanuel Peter <epeter at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/29b63928387a8b6ab387057cb3eac4771b1bfff1
Stats:     75 lines in 2 files changed: 61 ins; 5 del; 9 mod

8334228: C2 SuperWord: fix JDK-24 regression in VPointer::cmp_for_sort after JDK-8325155

Reviewed-by: chagedorn, kvn

-------------

PR: https://git.openjdk.org/jdk/pull/19696


More information about the hotspot-compiler-dev mailing list