gh-134584: Cleanups for refcount elimination #135860

[Fidget-Spinner]

This cleans up PR #135860.

Mostly just moving code around.

• Issue: Eliminate redundant refcounting in the JIT #134584

[corona10]

lgtm!

[markshannon]

Can you make a separate PRs for fixing the leak? I'd like to get that in ASAP.

For the larger changes:

• There is no need for _POP_TOP_NOT_NULL as it still needs to check for immortal objects and NULL is immortal
• The changes to the code generator need more explanation and maybe a new issue.

[bedevere-app]

When you're done making the requested changes, leave the comment: I have made the requested changes; please review again.

[Fidget-Spinner]

Can you make a separate PRs for fixing the leak? I'd like to get that in ASAP.

I can't without a partial revert. The problem is that we don't allow live inputs at ERROR_IF. This PR simply changes the ERROR_IF behavior to close all live inputs.

The rest of this PR to the cases generator is just moving stuff around if you take a closer look. I mainly had to expose the close_variable function as it was previously a nested one.

[Zheaoli]

Just for personal thought(correct me plz if I'm wrong)

The root cause about this refleak is related with the wrong position about ERROR_IF. In this case, in old generated code, the arg will leak after ERROR_IF

So the core point about this PR is the behavior change "raise an exception when here's live variable on TOS -> close all the live variable"

So we can mark the stack INPUT_DEAD safety after ERROR_IF after this PR

[Fidget-Spinner]

@Zheaoli yes you're right

[Fidget-Spinner]

Can you make a separate PRs for fixing the leak? I'd like to get that in ASAP.

For the larger changes:

• There is no need for _POP_TOP_NOT_NULL as it still needs to check for immortal objects and NULL is immortal
• The changes to the code generator need more explanation and maybe a new issue.

I removed all the changes to the code generator and POP_TOP_NOT_NULL. As such, this review is now stale.

I removed all the changes that were contentious. This PR is now just a re-implementation of #135860. So it's fine now as that was previously approved and merged.

[corona10]

Since the current change is only a reimplementation of _CALL_TUPLE_1 from #135860, it looks good to me.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Windows PGO NoGIL 3.x (tier-1) has failed when building commit e02a35c.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1622/builds/3361) and take a look at the build logs.
4. Check if the failure is related to this commit (e02a35c) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1622/builds/3361

Summary of the results of the build (if available):

Click to see traceback logs

remote: Enumerating objects: 30, done.        
remote: Counting objects:   3% (1/27)        
remote: Counting objects:   7% (2/27)        
remote: Counting objects:  11% (3/27)        
remote: Counting objects:  14% (4/27)        
remote: Counting objects:  18% (5/27)        
remote: Counting objects:  22% (6/27)        
remote: Counting objects:  25% (7/27)        
remote: Counting objects:  29% (8/27)        
remote: Counting objects:  33% (9/27)        
remote: Counting objects:  37% (10/27)        
remote: Counting objects:  40% (11/27)        
remote: Counting objects:  44% (12/27)        
remote: Counting objects:  48% (13/27)        
remote: Counting objects:  51% (14/27)        
remote: Counting objects:  55% (15/27)        
remote: Counting objects:  59% (16/27)        
remote: Counting objects:  62% (17/27)        
remote: Counting objects:  66% (18/27)        
remote: Counting objects:  70% (19/27)        
remote: Counting objects:  74% (20/27)        
remote: Counting objects:  77% (21/27)        
remote: Counting objects:  81% (22/27)        
remote: Counting objects:  85% (23/27)        
remote: Counting objects:  88% (24/27)        
remote: Counting objects:  92% (25/27)        
remote: Counting objects:  96% (26/27)        
remote: Counting objects: 100% (27/27)        
remote: Counting objects: 100% (27/27), done.        
remote: Compressing objects:   7% (1/13)        
remote: Compressing objects:  15% (2/13)        
remote: Compressing objects:  23% (3/13)        
remote: Compressing objects:  30% (4/13)        
remote: Compressing objects:  38% (5/13)        
remote: Compressing objects:  46% (6/13)        
remote: Compressing objects:  53% (7/13)        
remote: Compressing objects:  61% (8/13)        
remote: Compressing objects:  69% (9/13)        
remote: Compressing objects:  76% (10/13)        
remote: Compressing objects:  84% (11/13)        
remote: Compressing objects:  92% (12/13)        
remote: Compressing objects: 100% (13/13)        
remote: Compressing objects: 100% (13/13), done.        
remote: Total 30 (delta 16), reused 14 (delta 14), pack-reused 3 (from 2)        
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HEAD is now at e02a35c3653 gh-134584: Cleanups for GH-135860 (GH-142604)
Switched to and reset branch 'main'

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