Atomic intrinsics : use const generic ordering, part 2

[RalfJung]

This completes what got started in #141507 by using a const generic for the ordering for all intrinsics. It is based on that PR; only the last commit is new.

Blocked on:

• atomic_load intrinsic: use const generic parameter for ordering #141507
• core: unstably expose atomic_compare_exchange so stdarch can use it #141687
• cmpxchg16b: use atomic_compare_exchange from libcore stdarch#1811
• propagating that stdarch change to rustc

r? @bjorn3

[rustbot]

Some changes occurred in compiler/rustc_codegen_gcc

cc @antoyo, @GuillaumeGomez

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 in compiler/rustc_codegen_ssa

cc @WaffleLapkin

The Miri subtree was changed

cc @rust-lang/miri

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

[RalfJung]

@celinval do you know why this intrinsic is handled separately rather than in the big match with all the others?

[bors]

☔ The latest upstream changes (presumably #141716) made this pull request unmergeable. Please resolve the merge conflicts.

[bjorn3]

Can this test use core::intrinsics instead?
Edit: Nope, that would invalidate the test. It seems like it could use a different intrinsic though.
Edit2: This test was added in 22e3a85

[RalfJung]

Yeah I don't know what this is testing so I changed it as little as possible...

[rustbot]

⚠️ Warning ⚠️

• Some commits in this PR modify submodules.

[RalfJung]

Uh, how could this PR possibly break that incremental test... (incremental/issue-39569.rs)?
This reproduces when I try it locally.
Cc @compiler-errors @oli-obk @BoxyUwU
(we desperately need an expert map, I have only a vague idea whom to ping for incremental issues)

[BoxyUwU]

I don't really know much about incremental 🙏 Hope you manage to figure it out

[compiler-errors]

I can look later if you are willing to wait a day or so 🤔

[RalfJung]

The PR is blocked on some other stuff anyway.

[compiler-errors]

This isn't an incremental bug per se, but instead a bug that has to do with debug printing query keys when debug assertions and -Z query-dep-graph is enabled. We end up printing a const (b/c we're using generic const args here) whose debug printing for -Z query-dep-graph requires invoking the same query cyclically 😃

I've pushed a commit which should fix this.

[rust-log-analyzer]

The job aarch64-gnu-llvm-19-1 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

---- [ui] tests/ui/transmutability/structs/repr/transmute_infinitely_recursive_type.rs stdout ----
Saved the actual stderr to `/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/transmutability/structs/repr/transmute_infinitely_recursive_type/transmute_infinitely_recursive_type.stderr`
diff of stderr:

12 error[E0391]: cycle detected when computing layout of `should_pad_explicitly_packed_field::ExplicitlyPadded`
13    |
14    = note: ...which immediately requires computing layout of `should_pad_explicitly_packed_field::ExplicitlyPadded` again
-    = note: cycle used when evaluating trait selection obligation `(): core::mem::transmutability::TransmuteFrom<should_pad_explicitly_packed_field::ExplicitlyPadded, core::mem::transmutability::Assume { alignment: false, lifetimes: false, safety: false, validity: false }>`
+    = note: cycle used when evaluating trait selection obligation `(): core::mem::transmutability::TransmuteFrom<should_pad_explicitly_packed_field::ExplicitlyPadded, ValTree(Branch([Leaf(0x00), Leaf(0x00), Leaf(0x00), Leaf(0x00)]): core::mem::transmutability::Assume)>`
16    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
17 
18 error: aborting due to 2 previous errors


The actual stderr differed from the expected stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args transmutability/structs/repr/transmute_infinitely_recursive_type.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/transmutability/structs/repr/transmute_infinitely_recursive_type.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/transmutability/structs/repr/transmute_infinitely_recursive_type" "-A" "unused" "-A" "internal_features" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error[E0072]: recursive type `ExplicitlyPadded` has infinite size
##[error]  --> /checkout/tests/ui/transmutability/structs/repr/transmute_infinitely_recursive_type.rs:21:5
   |
LL |     struct ExplicitlyPadded(ExplicitlyPadded);
   |     ^^^^^^^^^^^^^^^^^^^^^^^ ---------------- recursive without indirection
   |
help: insert some indirection (e.g., a `Box`, `Rc`, or `&`) to break the cycle
   |
LL |     struct ExplicitlyPadded(Box<ExplicitlyPadded>);
   |                             ++++                +

error[E0391]: cycle detected when computing layout of `should_pad_explicitly_packed_field::ExplicitlyPadded`
   |
   = note: ...which immediately requires computing layout of `should_pad_explicitly_packed_field::ExplicitlyPadded` again
   = note: cycle used when evaluating trait selection obligation `(): core::mem::transmutability::TransmuteFrom<should_pad_explicitly_packed_field::ExplicitlyPadded, ValTree(Branch([Leaf(0x00), Leaf(0x00), Leaf(0x00), Leaf(0x00)]): core::mem::transmutability::Assume)>`
   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0072, E0391.
For more information about an error, try `rustc --explain E0072`.

[bors]

☔ The latest upstream changes (presumably #139118) made this pull request unmergeable. Please resolve the merge conflicts.

[compiler-errors]

Ah, sorry, needs bless tests due to my changes. I can probably pull it out into a separate PR, lemme do that tomorrow.

[RalfJung]

Sounds good, thanks for looking into this. :)