Use MIR's `Offset` for pointer `add` too
~~Status: draft while waiting for #110822 to land, since this is built atop that.~~
~~r? `@ghost~~`
Canonical Rust code has mostly moved to `add`/`sub` on pointers, which take `usize`, instead of `offset` which takes `isize`. (And, relatedly, when `sub_ptr` was added it turned out it replaced every single in-tree use of `offset_from`, because `usize` is just so much more useful than `isize` in Rust.)
Unfortunately, `intrinsics::offset` could only accept `*const` and `isize`, so there's a *huge* amount of type conversions back and forth being done. They're identity conversions in the backend, but still end up producing quite a lot of unhelpful MIR.
This PR changes `intrinsics::offset` to accept `*const` *and* `*mut` along with `isize` *and* `usize`. Conveniently, the backends and CTFE already handle this, since MIR's `BinOp::Offset` [already supports all four combinations](adaac6b166/compiler/rustc_const_eval/src/transform/validate.rs (L523-L528)).
To demonstrate the difference, I added some `mir-opt/pre-codegen/` tests around slice indexing. Here's the difference to `[T]::get_mut`, since it uses `<*mut _>::add` internally:
```diff
`@@` -79,30 +70,21 `@@` fn slice_get_mut_usize(_1: &mut [u32], _2: usize) -> Option<&mut u32> {
StorageLive(_12); // scope 3 at $SRC_DIR/core/src/slice/index.rs:LL:COL
StorageLive(_9); // scope 6 at $SRC_DIR/core/src/slice/index.rs:LL:COL
_9 = _8 as *mut u32 (PtrToPtr); // scope 11 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageLive(_13); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _13 = _2 as isize (IntToInt); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageLive(_14); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageLive(_15); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _15 = _9 as *const u32 (Pointer(MutToConstPointer)); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _14 = Offset(move _15, _13); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageDead(_15); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _7 = move _14 as *mut u32 (PtrToPtr); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageDead(_14); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageDead(_13); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
+ _7 = Offset(_9, _2); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
StorageDead(_9); // scope 6 at $SRC_DIR/core/src/slice/index.rs:LL:COL
StorageDead(_12); // scope 3 at $SRC_DIR/core/src/slice/index.rs:LL:COL
StorageDead(_11); // scope 3 at $SRC_DIR/core/src/slice/index.rs:LL:COL
```
1c1c8e442a (diff-a841b6a4538657add3f39bc895744331453d0625e7aace128b1f604f0b63c8fdR80)
Nicer ICE for #67981
Provides a slightly nicer ICE for #67981, documenting the problem. A proper fix will be necessary before `#![feature(unsized_fn_params)]` can be stabilized.
The problem is that the design of the `"rust-call"` ABI is fundamentally not compatible with `unsized_fn_params`. `"rust-call"` functions need to collect their arguments into a tuple, but if the arguments are not `Sized`, said tuple is potentially not even a valid type—and if it is, it requires `alloca` to create.
``@rustbot`` label +A-abi +A-codegen +F-unboxed_closures +F-unsized_fn_params
Rollup of 10 pull requests
Successful merges:
- #108760 (Add lint to deny diagnostics composed of static strings)
- #109444 (Change tidy error message for TODOs)
- #110419 (Spelling library)
- #110550 (Suggest deref on comparison binop RHS even if type is not Copy)
- #110641 (Add new rustdoc book chapter to describe in-doc settings)
- #110798 (pass `unused_extern_crates` in `librustdoc::doctest::make_test`)
- #110819 (simplify TrustedLen impls)
- #110825 (diagnostics: add test case for already-solved issue)
- #110835 (Make some region folders a little stricter.)
- #110847 (rustdoc-json: Time serialization.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
They're semantically the same, so this means the backends don't need to handle the intrinsic and means fewer MIR basic blocks in pointer arithmetic code.
Report allocation errors as panics
OOM is now reported as a panic but with a custom payload type (`AllocErrorPanicPayload`) which holds the layout that was passed to `handle_alloc_error`.
This should be review one commit at a time:
- The first commit adds `AllocErrorPanicPayload` and changes allocation errors to always be reported as panics.
- The second commit removes `#[alloc_error_handler]` and the `alloc_error_hook` API.
ACP: https://github.com/rust-lang/libs-team/issues/192Closes#51540Closes#51245
Add offset_of! macro (RFC 3308)
Implements https://github.com/rust-lang/rfcs/pull/3308 (tracking issue #106655) by adding the built in macro `core::mem::offset_of`. Two of the future possibilities are also implemented:
* Nested field accesses (without array indexing)
* DST support (for `Sized` fields)
I wrote this a few months ago, before the RFC merged. Now that it's merged, I decided to rebase and finish it.
cc `@thomcc` (RFC author)
Support AIX-style archive type
Reading facility of AIX big archive has been supported by `object` since 0.30.0.
Writing facility of AIX big archive has already been supported by `ar_archive_writer`, but we need to bump the version to support the new archive type enum.
Add `rustc_fluent_macro` to decouple fluent from `rustc_macros`
Fluent, with all the icu4x it brings in, takes quite some time to compile. `fluent_messages!` is only needed in further downstream rustc crates, but is blocking more upstream crates like `rustc_index`. By splitting it out, we allow `rustc_macros` to be compiled earlier, which speeds up `x check compiler` by about 5 seconds (and even more after the needless dependency on `serde_json` is removed from `rustc_data_structures`).
Encode hashes as bytes, not varint
In a few places, we store hashes as `u64` or `u128` and then apply `derive(Decodable, Encodable)` to the enclosing struct/enum. It is more efficient to encode hashes directly than try to apply some varint encoding. This PR adds two new types `Hash64` and `Hash128` which are produced by `StableHasher` and replace every use of storing a `u64` or `u128` that represents a hash.
Distribution of the byte lengths of leb128 encodings, from `x build --stage 2` with `incremental = true`
Before:
```
( 1) 373418203 (53.7%, 53.7%): 1
( 2) 196240113 (28.2%, 81.9%): 3
( 3) 108157958 (15.6%, 97.5%): 2
( 4) 17213120 ( 2.5%, 99.9%): 4
( 5) 223614 ( 0.0%,100.0%): 9
( 6) 216262 ( 0.0%,100.0%): 10
( 7) 15447 ( 0.0%,100.0%): 5
( 8) 3633 ( 0.0%,100.0%): 19
( 9) 3030 ( 0.0%,100.0%): 8
( 10) 1167 ( 0.0%,100.0%): 18
( 11) 1032 ( 0.0%,100.0%): 7
( 12) 1003 ( 0.0%,100.0%): 6
( 13) 10 ( 0.0%,100.0%): 16
( 14) 10 ( 0.0%,100.0%): 17
( 15) 5 ( 0.0%,100.0%): 12
( 16) 4 ( 0.0%,100.0%): 14
```
After:
```
( 1) 372939136 (53.7%, 53.7%): 1
( 2) 196240140 (28.3%, 82.0%): 3
( 3) 108014969 (15.6%, 97.5%): 2
( 4) 17192375 ( 2.5%,100.0%): 4
( 5) 435 ( 0.0%,100.0%): 5
( 6) 83 ( 0.0%,100.0%): 18
( 7) 79 ( 0.0%,100.0%): 10
( 8) 50 ( 0.0%,100.0%): 9
( 9) 6 ( 0.0%,100.0%): 19
```
The remaining 9 or 10 and 18 or 19 are `u64` and `u128` respectively that have the high bits set. As far as I can tell these are coming primarily from `SwitchTargets`.
Fluent, with all the icu4x it brings in, takes quite some time to
compile. `fluent_messages!` is only needed in further downstream rustc
crates, but is blocking more upstream crates like `rustc_index`. By
splitting it out, we allow `rustc_macros` to be compiled earlier, which
speeds up `x check compiler` by about 5 seconds (and even more after the
needless dependency on `serde_json` is removed from
`rustc_data_structures`).
Preserve argument indexes when inlining MIR
We store argument indexes on VarDebugInfo. Unlike the previous method of relying on the variable index to know whether a variable is an argument, this survives MIR inlining.
We also no longer check if var.source_info.scope is the outermost scope. When a function gets inlined, the arguments to the inner function will no longer be in the outermost scope. What we care about though is whether they were in the outermost scope prior to inlining, which we know by whether we assigned an argument index.
Fixes#83217
I considered using `Option<NonZeroU16>` instead of `Option<u16>` to store the index. I didn't because `TypeFoldable` isn't implemented for `NonZeroU16` and because it looks like due to padding, it currently wouldn't make any difference. But I indexed from 1 anyway because (a) it'll make it easier if later it becomes worthwhile to use a `NonZeroU16` and because the arguments were previously indexed from 1, so it made for a smaller change.
This is my first PR on rust-lang/rust, so apologies if I've gotten anything not quite right.
Initial support for loongarch64-unknown-linux-gnu
Hi, We hope to add a new port in rust for LoongArch.
LoongArch intro
LoongArch is a RISC style ISA which is independently designed by Loongson
Technology in China. It is divided into two versions, the 32-bit version (LA32)
and the 64-bit version (LA64). LA64 applications have application-level
backward binary compatibility with LA32 applications. LoongArch is composed of
a basic part (Loongson Base) and an expanded part. The expansion part includes
Loongson Binary Translation (LBT), Loongson VirtualiZation (LVZ), Loongson SIMD
EXtension (LSX) and Loongson Advanced SIMD EXtension(LASX).
Currently the LA464 processor core supports LoongArch ISA and the Loongson
3A5000 processor integrates 4 64-bit LA464 cores. LA464 is a four-issue 64-bit
high-performance processor core. It can be used as a single core for high-end
embedded and desktop applications, or as a basic processor core to form an
on-chip multi-core system for server and high-performance machine applications.
Documentations:
ISA:
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html
ABI:
https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html
More docs can be found at:
https://loongson.github.io/LoongArch-Documentation/README-EN.html
Since last year, we have locally adapted two versions of rust, rust1.41 and rust1.57, and completed the test locally.
I'm not sure if I'm submitting all the patches at once, so I split up the patches and here's one of the commits
Add support for RISC-V relax target feature
This adds `relax` as an allowed RISC-V target feature. The relax feature in LLVM enables [linker relaxation](https://www.sifive.com/blog/all-aboard-part-3-linker-relaxation-in-riscv-toolchain), an optimization specific to RISC-V that allows global variable accesses to be resolved by the linker by using the global pointer (`gp`) register (rather than constructing the addresses from scratch for each access). Enabling `relax` will cause LLVM to emit relocations in the object file that support this. The feature can be enabled in rustc with `-C target-feature=+relax`.
Currently this feature is disabled by default, but maybe it should be enabled by default since it is an easy performance improvement (but requires the `gp` register to be set up properly). GCC/Clang enable this feature by default (for both hosted/bare-metal targets), and include the `-mno-relax` flag to disable it (see [here](466d554dca/clang/lib/Driver/ToolChains/Arch/RISCV.cpp (L145)) for the code that enables it in Clang). I think it would make sense to enable by default, at least for all hosted targets since the `gp` register should be automatically set up by the runtime. For bare-metal targets, `gp` must be set up manually, so it is probably best to leave off by default to avoid breaking existing applications that do not set up `gp`. Leaving it disabled by default for all targets is also reasonable though.
Let me know your thoughts. Thanks!
Fixes#109426.
We store argument indexes on VarDebugInfo. Unlike the previous method of
relying on the variable index to know whether a variable is an argument,
this survives MIR inlining.
We also no longer check if var.source_info.scope is the outermost scope.
When a function gets inlined, the arguments to the inner function will
no longer be in the outermost scope. What we care about though is
whether they were in the outermost scope prior to inlining, which we
know by whether we assigned an argument index.
Fix a couple ICEs in the new `CastKind::Transmute` code
Check the sizes of the immediates, rather than the overall types, when deciding whether we can convert types without going through memory.
Fixes#110005Fixes#109992Fixes#110032
cc `@matthiaskrgr`
Unify terminology used in unwind action and terminator, and reflect
the fact that a nounwind panic is triggered instead of an immediate
abort is triggered for this terminator.
