8386597: C2: TestTruncationWrapFuzzer.java‎ for CountedLoop detection of subword truncated iv

[eme64]

This template fuzzer was originally motivated by #31395, but it quickly found other bugs, and so I decided to make it a separate RFE.

Bugs that are covered by this fuzzer up to now:

• JDK-8385855 C2: IfNode::filtered_int_type should only allow CmpI
• JDK-8386482 C2 CountedLoopConverter::filtered_type_from_dominators: assert(_base == Int) failed: Not an Int
• JDK-8386591 C2: wrong result because of broken truncation check in CountedLoopConverter::TruncatedIncrement::build

---

• I confirm that I make this contribution in accordance with the OpenJDK Interim AI Policy.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed (2 reviews required, with at least 1 Reviewer, 1 Author)

Issue

• JDK-8386597: C2: TestTruncationWrapFuzzer.java‎ for CountedLoop detection of subword truncated iv (Enhancement - P4)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/31501/head:pull/31501
$ git checkout pull/31501

Update a local copy of the PR:
$ git checkout pull/31501
$ git pull https://git.openjdk.org/jdk.git pull/31501/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 31501

View PR using the GUI difftool:
$ git pr show -t 31501

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/31501.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back epeter! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

@eme64 The following label will be automatically applied to this pull request:

• hotspot-compiler

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[openjdk]

The total number of required reviews for this PR has been set to 2 based on the presence of this label: hotspot-compiler. This can be overridden with the /reviewers command.

[mlbridge]

Webrevs

• 01: Full - Incremental (aafaf2c2)
• 00: Full (618d5788)