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Type: Enhancement
Resolution: Fixed
Priority: P4
Fix Version/s: 26
Affects Version/s: 22
Component/s: hotspot
Labels:
- c2
- cleanup
- performance

Subcomponent:
compiler
Resolved In Build:
b03

Adding unsigned bounds and known bits to TypeInt/Long has several advantages:

- More tight value constraints increase the strength of GVN and CCP and open more transformations and simplifications.

- Currently we have some specifically crafted analysis such as CmpU of Add/Sub, And of a LShift, etc and we have some potential improvements in JBS such as the sign of an Or. These can be solved elegantly using unsigned bounds and known bits.

- Ability to express TypeInt::CC_NE

blocks

JDK-8359149 C2: Improve the capability to test inference on TypeInt instances

Open

duplicates

JDK-8311597 OrINode/OrLNode::add_ring should track positives

Closed

relates to

JDK-8001436 C2: Implement bitwise constant propagation

Open

JDK-8311597 OrINode/OrLNode::add_ring should track positives

Closed

JDK-8360561 PhaseIdealLoop::create_new_if_for_predicate hits "must be a uct if pattern" assert

Open

links to

Commit(master) openjdk/jdk/991097b7

Review openjdk/jdk/15440

Review(master) openjdk/jdk/17508

(3 links to)

Assignee:: Quan Anh Mai

Reporter:: Quan Anh Mai

Votes:: 0 Vote for this issue

Watchers:: 5 Start watching this issue

Created:: 2023-08-25 20:10

Updated:: Yesterday 03:31

Resolved:: 2025-06-12 18:10

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