8370922: Template Framework Library: Float16 type and operations

[eme64]

We should test Float16 with Template Framework Tests. For this, I'm now implementing:

• Template Framework Library: add Float16Type that represents Float16. Extend Operations.java with Float16 operations.
• Verify.java: add verification for Float16, and corresponding tests in TestVerifyIncubatorVector.java. We could have done this separately, but it is not much code and completes the pipeline from code generation through execution and finally result verification in the following two tests.
• Adding Float16 to ExpressionFuzzer.java and TestExpressions.java.

---

Progress

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Issue

• JDK-8370922: Template Framework Library: Float16 type and operations (Sub-task - P4)

Reviewers

• Galder Zamarreño (@galderz - Author)
• Benoît Maillard (@benoitmaillard - Committer) Review applies to c87acd90
• Tobias Hartmann (@TobiHartmann - Reviewer)

Reviewing

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[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]

@eme64 This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8370922: Template Framework Library: Float16 type and operations

Reviewed-by: galder, thartmann, bmaillard

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At the time when this comment was updated there had been 23 new commits pushed to the master branch:

• 53ebcdb: 8373627: assert(!is_vthread_transition_disabler()) failed: no suspend allowed for vthread transition disablers
• 41d28c1: 8373561: Replace usages of -verify java launcher option with -Xverify:all JVM option
• 43d4456: 8373570: Javac stack overflow on method-local class with nested record referring to enclosing type
• ... and 20 more: https://git.openjdk.org/jdk/compare/dc1b0b5f81b6c3de85a0234d0315370b6413c077...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[openjdk]

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

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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.

[mlbridge]

Webrevs

• 03: Full - Incremental (8d0d7e7d)
• 02: Full - Incremental (78bd0cc0)
• 01: Full (c7da6b4d)
• 00: Full (c87acd90)

[eme64]

Can someone please review this?

[galderz]

Looks good, just a small question about the name of the test

[galderz]

I have doubts about leaving the "Incubator" name in the test class name as it's temporary. Are you going to refactor the class name when API is not incubator any more? Maybe TestVerifyVectorAPI instead?

[eme64]

Yes, I might refactor it away actually. We could also remove the special handling in verify for foreign classes. Currently I have to do the hack with reflection. I'd like to get rid of that.

This test is here for the cases where we need to include foreign, and because we need @modules jdk.incubator.vector. There is the other test that already exists and does not need this.

[eme64]

@galderz I now renamed it to TestVerifyFloat16.java, I think it is better, even if I eventually have to refactor the internals of the test we don't have to rename the test itself :)

[benoitmaillard]

Looks good to me, nice work! I only have one question.

[benoitmaillard]

What does this loop do? And why do we have only 2 iterations here, but 10 for PRIMITIVE_TYPES?

[eme64]

It Generate[s] expressions with any scalar numeric types. ;)
The question is just how many per (output) type. Here we do 2 for each type.

The 2 vs 10 is quite arbitrary. I did not want to increase the runtime of the test too much. For now, focusing more on the primitive types an operations is probably good, Float16 is still rather niche. But we can change the balance in the future.

[eme64]

Ah yes, and note: even if we start with a type other than Float16 as the output, we can still have Float16 components in the expression, via conversion for example. We can do float -> Float16 -> float for example.

[benoitmaillard]

I meant to ask specificially about the inner loop sorry :)
The explanation makes sense, thanks for explaining a little more. Perhaps we could have a comment for that, or have constants with more explicit names for 2 and 10?

[eme64]

@benoitmaillard I added some extra comments. What do you think, is it better now?

[benoitmaillard]

Great, thank you!

[openjdk]

@eme64 this pull request can not be integrated into master due to one or more merge conflicts. To resolve these merge conflicts and update this pull request you can run the following commands in the local repository for your personal fork:

git checkout JDK-8370922-TemplateFramework-Library-Float16
git fetch https://git.openjdk.org/jdk.git master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push

[galderz]

@eme64 I have one additional question. How did you test this? Did you have HF hardware access or did you emulate it? In a recent chat with @benoitmaillard, I think he mentioned about using QEMU to emulate and do some testing.

[eme64]

@eme64 I have one additional question. How did you test this? Did you have HF hardware access or did you emulate it? In a recent chat with @benoitmaillard, I think he mentioned about using QEMU to emulate and do some testing.

I ran it through out internal testing machines. Some of them do have specific hardware support for Float16 operations :)
I've used QEMU in the past for Float16 and SVE, but it is relatively slow, so I did not bother with that for this PR.

[galderz]

@eme64 Thanks for explanation, all good :)

[eme64]

@benoitmaillard @galderz Thanks for the reviews and approvals!

Now we'll have to get a reviewer rubber-stamp this :)

[TobiHartmann]

Looks good to me.

[eme64]

@benoitmaillard @galderz @TobiHartmann Thanks for the reviews!

/integrate

[openjdk]

Going to push as commit 89e7751.
Since your change was applied there have been 24 commits pushed to the master branch:

• a61394b: 8373789: No PCH release build failure after JDK-8372543
• 53ebcdb: 8373627: assert(!is_vthread_transition_disabler()) failed: no suspend allowed for vthread transition disablers
• 41d28c1: 8373561: Replace usages of -verify java launcher option with -Xverify:all JVM option
• ... and 21 more: https://git.openjdk.org/jdk/compare/dc1b0b5f81b6c3de85a0234d0315370b6413c077...master

Your commit was automatically rebased without conflicts.

[openjdk]

@eme64 Pushed as commit 89e7751.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

[galderz]

Great timing @eme64 with this, the #28895 PR uses the work here :)