Fix quadratic performance with lots of use statements
This fixes 2 problems that caused quadratic performance when lots of use-statements were present. After this patch, performance is linear (and very fast) even with 1M uses.
Fixes#43572.
Fixes#43573.
r? @eddyb
Derive `Hash` on `AssociatedKind`.
This is a trivial change useful in downstream code poking in rustc's
innards, in particular the semver verification tool I'm currently working on.
r? @eddyb
Fix the Solaris pthread_t raw type in std to match what's in libc
The old type causes failures when building cargo 0.20.0 after rust-lang/libc@8304e06b5.
rustc: Inline bitwise modification operators
These need to be inlined across crates to avoid showing up as one-instruction
functions in profiles! In the benchmark from #43578 this decreased the
translation item collection step from 30s to 23s, and looks like it also allowed
vectorization elsewhere of the operations!
Thread through the original error when opening archives
This updates the management of opening archives to thread through the original
piece of error information from LLVM over to the end consumer, trans.
Gate LLVMRustHasFeature on LLVM_RUSTLLVM
Commit c4710203c0 in #43492 make `LLVMRustHasFeature` "more robust"
by using `getFeatureTable()`. However, this function is specific to
Rust's own LLVM fork, not upstream LLVM-4.0, so we need to use
`#if LLVM_RUSTLLVM` to guard this call.
Closes#43555.
rustc_mir: don't build unused unwind cleanup blocks
When building a scope exit, don't build unwind cleanup blocks unless they will actually be used by the unwind path of a drop - the unused blocks are removed by SimplifyCfg, but they can cause a significant performance slowdown before they are removed. That fixes#43511.
Also a few other small MIR cleanups & optimizations.
r? @eddyb
add documentation for function pointers as a primitive
This PR adds a new kind of primitive to the standard library documentation: Function pointers. It's useful to be able to discuss them separately from closure-trait-objects, and to have something to point to when discussing function pointers as a *type* and not a *trait*.
Fixes#17104
Run translation and LLVM in parallel when compiling with multiple CGUs
This is still a work in progress but the bulk of the implementation is done, so I thought it would be good to get it in front of more eyes.
This PR makes the compiler start running LLVM while translation is still in progress, effectively allowing for more parallelism towards the end of the compilation pipeline. It also allows the main thread to switch between either translation or running LLVM, which allows to reduce peak memory usage since not all LLVM module have to be kept in memory until linking. This is especially good for incr. comp. but it works just as well when running with `-Ccodegen-units=N`.
In order to help tuning and debugging the work scheduler, the PR adds the `-Ztrans-time-graph` flag which spits out html files that show how work packages where scheduled:
(red is translation, green is llvm)
One side effect here is that `-Ztime-passes` might show something not quite correct because trans and LLVM are not strictly separated anymore. I plan to have some special handling there that will try to produce useful output.
One open question is how to determine whether the trans-thread should switch to intermediate LLVM processing.
TODO:
- [x] Restore `-Z time-passes` output for LLVM.
- [x] Update documentation, esp. for work package scheduling.
- [x] Tune the scheduling algorithm.
cc @alexcrichton @rust-lang/compiler
trans::mir::constant - fix assignment error recovery
trans::mir::constant - fix assignment error recovery
We used to not store anything when the RHS of an assignment returned an error, which caused ICEs downstream.
Fixes#43197.
Instead of finding the next free disambiguator by incrementing it until
you find a place, store the next available disambiguator in an hash-map.
This avoids O(n^2) performance when lots of items have the same
un-disambiguated `DefPathData` - e.g. all `use` items have
`DefPathData::Misc`.
We already had a cache for file contents, but we read the source-file
before testing the cache, causing obvious slowness, so this just avoids
loading the source-file when the cache already has the contents.
add docs for references as a primitive
Just like #43529 did for function pointers, here is a new primitive page for references.
This PR will pull in impls on references if it's a reference to a generic type parameter. Initially i was only able to pull in impls that were re-exported from another crate; crate-local impls got a different representation in the AST, and i had to change how types were resolved when cleaning it. (This is the change at the bottom of `librustdoc/clean/mod.rs`, in `resolve_type`.) I'm unsure the full ramifications of the change, but from what it looks like, it shouldn't impact anything major. Likewise, references to generic type parameters also get the `&'a [mut]` linked to the new page.
cc @rust-lang/docs: Is this sufficient information? The listing of trait impls kinda feels redundant (especially if we can get the automated impl listing sorted again), but i still think it's useful to point out that you can use these in a generic context.
Fixes#15654
