coverage: Deal with unused functions and their names in one place
When coverage codegen creates dummy instances and covfun records for unused functions, we already know that they are unused, so we might as well set up the special array of unused function names at the same time.
---
The first commit only moves code around; all significant changes are in the second commit.
There should be no change in compiler output.
- fix errors caused by the move of `ast::Item::ident` (see #138740)
- move the logic of getting `sig`, `vis`, and `ident` from two seperate
`match` statements into one (less repetition especially with the
nested `match`)
Add `*_value` methods to proc_macro lib
This is the (re-)implementation of https://github.com/rust-lang/libs-team/issues/459.
It allows to get the actual value (unescaped) of the different string literals.
It was originally done in https://github.com/rust-lang/rust/pull/136355 but it broke the artifacts build so we decided to move the crate to crates.io to go around this limitation.
Part of https://github.com/rust-lang/rust/issues/136652.
Considering this is a copy-paste of the originally approved PR, no need to go through the whole process again. \o/
r? `@Urgau`
Refactor Apple version handling in the compiler
Move various Apple version handling code in the compiler out `rustc_codegen_ssa` and into a place where it can be accessed by `rustc_attr_parsing`, which I found to be necessary when doing https://github.com/rust-lang/rust/pull/136867. Thought I'd split it out to make it easier to land, and to make further changes like https://github.com/rust-lang/rust/pull/131477 have fewer conflicts / PR dependencies.
There should be no functional changes in this PR.
`@rustbot` label O-apple
r? rust-lang/compiler
In `simplify_repeated_aggregate`, don't test first element against itself
r? `@saethlin`
Noticed that in `InstSimplifyContext::simplify_repeated_aggregate`, we're accidentally evaluating the first element's value twice, and then comparing it with itself, instead of just checking whether the rest of the elements are equal to the first one.
This will probably save very few cycles, but since `InstSimplify` is always enabled, this might improve perf by a bit.
Update the minimum external LLVM to 19
With this change, we'll have stable support for LLVM 19 and 20.
For reference, the previous increase to LLVM 18 was #130487.
cc `@rust-lang/wg-llvm`
r? nikic
StableMIR: Prepare for refactoring
Temporarily make `stable_mir` "parasitic" on the `rustc_smir` crate.
It aims to resolve the circular dependency that would arise if we directly invert the dependency order between `rustc_smir` and `stable_mir`.
Once the refactoring is complete (`rustc_smir` does not depend on `stable_mir`), we will migrate it back to the `stable_mir` crate. See more details: [here](https://hackmd.io/jBRkZLqAQL2EVgwIIeNMHg).
Folder experiment: Micro-optimize RegionEraserVisitor
**NOTE:** This is one of a series of perf experiments that I've come up with while sick in bed. I'm assigning them to lqd b/c you're a good reviewer and you'll hopefully be awake when these experiments finish, lol.
r? lqd
The region eraser is very hot, so let's see if we can avoid erasing types (and visiting consts and preds that don't have region-ful types) unnecessarily.
hygiene: Avoid recursion in syntax context decoding
#139241 has two components
- Avoiding recursion during syntax context decoding
- Encoding/decoding only the non-redundant data, and recalculating the redundant data again during decoding
Both of these parts may influence compilation times, possibly in opposite directions.
So this PR contains only the first part to evaluate its effect in isolation.
Apply `Recovery::Forbidden` when reparsing pasted macro fragments.
Fixes#137874.
The changes to the output of `tests/ui/associated-consts/issue-93835.rs`
partly undo the changes seen when `NtTy` was removed in #133436, which
is good.
r? ``@petrochenkov``
replace extra_filename with strict version hash in metrics file names
Should resolve the potential issue of overwriting metrics from the same crate when compiled with different features or flags.
r? `````@estebank`````
try-job: test-various
Autodiff batching
Enzyme supports batching, which is especially known from the ML side when training neural networks.
There we would normally have a training loop, where in each iteration we would pass in some data (e.g. an image), and a target vector. Based on how close we are with our prediction we compute our loss, and then use backpropagation to compute the gradients and update our weights.
That's quite inefficient, so what you normally do is passing in a batch of 8/16/.. images and targets, and compute the gradients for those all at once, allowing better optimizations.
Enzyme supports batching in two ways, the first one (which I implemented here) just accepts a Batch size,
and then each Dual/Duplicated argument has not one, but N shadow arguments. So instead of
```rs
for i in 0..100 {
df(x[i], y[i], 1234);
}
```
You can now do
```rs
for i in 0..100.step_by(4) {
df(x[i+0],x[i+1],x[i+2],x[i+3], y[i+0], y[i+1], y[i+2], y[i+3], 1234);
}
```
which will give the same results, but allows better compiler optimizations. See the testcase for details.
There is a second variant, where we can mark certain arguments and instead of having to pass in N shadow arguments, Enzyme assumes that the argument is N times longer. I.e. instead of accepting 4 slices with 12 floats each, we would accept one slice with 48 floats. I'll implement this over the next days.
I will also add more tests for both modes.
For any one preferring some more interactive explanation, here's a video of Tim's llvm dev talk, where he presents his work. https://www.youtube.com/watch?v=edvaLAL5RqU
I'll also add some other docs to the dev guide and user docs in another PR.
r? ghost
Tracking:
- https://github.com/rust-lang/rust/issues/124509
- https://github.com/rust-lang/rust/issues/135283
