Integrated: 8315066: Add unsigned bounds and known bits to TypeInt/Long

[Quan Anh Mai]

On Sat, 20 Jan 2024 19:23:23 GMT, Quan Anh Mai <qamai at openjdk.org> wrote:

> Hi,
> 
> This patch adds unsigned bounds and known bits constraints to TypeInt and TypeLong. This opens more transformation opportunities in an elegant manner as well as helps avoid some ad-hoc rules in Hotspot.
> 
> In general, a `TypeInt/Long` represents a set of values `x` that satisfies: `x s>= lo && x s<= hi && x u>= ulo && x u<= uhi && (x & zeros) == 0 && (x & ones) == ones`. These constraints are not independent, e.g. an int that lies in [0, 3] in signed domain must also lie in [0, 3] in unsigned domain and have all bits but the last 2 being unset. As a result, we must canonicalize the constraints (tighten the constraints so that they are optimal) before constructing a `TypeInt/Long` instance.
> 
> This is extracted from #15440 , node value transformations are left for later PRs. I have also added unit tests to verify the soundness of constraint normalization.
> 
> Please kindly review, thanks a lot.
> 
> Testing
> 
> - [x] GHA
> - [x] Linux x64, tier 1-4

This pull request has now been integrated.

Changeset: 991097b7
Author:    Quan Anh Mai <qamai at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/991097b7bf08cc1a4ceedb0c555b12948ae71885
Stats:     2570 lines in 13 files changed: 2007 ins; 331 del; 232 mod

8315066: Add unsigned bounds and known bits to TypeInt/Long

Co-authored-by: Emanuel Peter <epeter at openjdk.org>
Reviewed-by: epeter, kvn, jbhateja

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PR: https://git.openjdk.org/jdk/pull/17508