Implement Integer funnel shifts

[sayantn]

Tracking issue: #145686
ACP: rust-lang/libs-team#642

This implements funnel shifts on primitive integer types. Implements this for cg_llvm, with a fallback impl for everything else

Thanks @folkertdev for the fixes and tests

cc @rust-lang/libs-api

[rustbot]

r? @tgross35

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[rustbot]

Some changes occurred to the intrinsics. Make sure the CTFE / Miri interpreter
gets adapted for the changes, if necessary.

cc @rust-lang/miri, @RalfJung, @oli-obk, @lcnr

Some changes occurred to the CTFE / Miri interpreter

cc @rust-lang/miri

Some changes occurred to the CTFE machinery

cc @RalfJung, @oli-obk, @lcnr

[tgross35]

I see there is a tracking issue, but not an ACP for this. Could you create one? It's an issue template at https://github.com/rust-lang/libs-team/issues.

[rustbot]

This PR was rebased onto a different master commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[rustbot]

Some changes occurred in compiler/rustc_codegen_gcc

cc @antoyo, @GuillaumeGomez

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

[tgross35]

Just a few tiny requests from me then I think this looks good, as long as @RalfJung doesn't have anything else.

Per usual, please squash. You can also (optionally) drop the CABs from the commit messages assuming they come from the GH suggestion, as typically review feedback is given without need for authorship attribution - bit misleading that GH adds these automatically for what are usually typo fixes (unless @folkertdev authored more of this patch then I'm realizing 🙂)

View changes since this review

[sayantn]

@folkertdev did author a significant part of the patches, including the tests and (although removed now) gcc, clif and const-eval implementations. Also, is a squash really needed, I believe the current commit structure is helpful for reviewers as it clearly separates the different objectives (libs impl, cg_llvm and tests)

[tgross35]

@folkertdev did author a significant part of the patches, including the tests and (although removed now) gcc, clif and const-eval implementations.

I didn't have this context, makes sense 👍 thanks for including in that case

Also, is a squash really needed, I believe the current commit structure is helpful for reviewers as it clearly separates the different objectives (libs impl, cg_llvm and tests)

If it's not a big number of tests then it's always good to have them in the same commit as whatever enables / fixes them, so you can look at a single point in history and see "x changed and produced y visible results" (tests are already separated enough by file/directory). So ideally I'd suggest reordering from current commits 1,2,3 to 2,squash(1,3), which also avoids the fact that adding library support before compiler support just crashes (using the pedantic repo's litmus test of what happens if git bisect happens to drop you between two commits and try to run tests - yes, not super relevant for our repo because bisect has --first-parent).

But we don't have strict history requirements, so I ofc won't insist on that. At a minimum though, please update the commit message "Add tests" to at least specify what tests; that's never the most insightful message to see in the log :)

[sayantn]

Makes sense, I'd just squash the commits (lazy lol)

[tgross35]

Thanks! r=me after CI passes

View changes since this review

[sayantn]

@bors r=tgross35

[bors]

📌 Commit 62b4347 has been approved by tgross35

It is now in the queue for this repository.

[bors]

⌛ Testing commit 62b4347 with merge 45b9d13...

[tgross35]

@bors r-
Why does it keep doing that...

[Zalathar]

Bors, please, it's already merged.

@bors r- retry