This commit stabilizes the `#[wasm_import_module]` attribute as
`#[link(wasm_import_module = "...")]`. Tracked by #52090 this new directive in
the `#[link]` attribute is used to configured the module name that the imports
are listed with. The WebAssembly specification indicates two utf-8 names are
associated with all imported items, one for the module the item comes from and
one for the item itself. The item itself is configurable in Rust via its
identifier or `#[link_name = "..."]`, but the module name was previously not
configurable and defaulted to `"env"`. This commit ensures that this is also
configurable.
Closes#52090
This commit transitions definitions of custom sections on the wasm target from
the unstable `#[wasm_custom_section]` attribute to the
already-stable-for-other-targets `#[link_section]` attribute. Mostly the same
restrictions apply as before, except that this now applies only to statics.
Closes#51088
Remove `ty_to_def_id`
fixes https://github.com/rust-lang/rust/issues/52341
The uses were mostly convenience and generally "too powerful" (would also have worked for types that weren't interesting at the use site)
r? @eddyb
Add the `amdgpu-kernel` ABI.
Technically, there are requirements imposed by the LLVM
`AMDGPUTargetMachine` on functions with this ABI (eg, the return type
must be void), but I'm unsure exactly where this should be enforced.
Technically, there are requirements imposed by the LLVM
`AMDGPUTargetMachine` on functions with this ABI (eg, the return type
must be void), but I'm unsure exactly where this should be enforced.
Preliminary work for incremental ThinLTO.
Since implementing incremental ThinLTO is a bit more involved than I initially thought, I'm splitting out some of the things that already work. This PR (1) adds a way accessing some ThinLTO information in `rustc` and (2) does some cleanup around CGU/object file naming (which makes things quite a bit nicer).
This is probably best reviewed one commit at a time.
nll experiment: compute SCCs instead of iterative region solving
This is an attempt to speed up region solving by replacing the current iterative dataflow with a SCC computation. The idea is to detect cycles (SCCs) amongst region constraints and then compute just one value per cycle. The graph with all cycles removed is of course a DAG, so we can then solve constraints "bottom up" once the liveness values are known.
I kinda ran out of time this morning so the last commit is a bit sloppy but I wanted to get this posted, let travis run on it, and maybe do a perf run, before I clean it up.
rustc_codegen_llvm: replace the first argument early in FnType::new_vtable.
Fixes#51907 by removing the vtable pointer before the `ArgType` is even created.
This allows any ABI to support trait object method calls, regardless of how it passes `*dyn Trait`.
r? @nikomatsakis
Disable LLVM verification by default
Currently -Z no-verify only controls IR verification prior to LLVM codegen, while verification is performed unconditionally both before and after linking with (Thin)LTO.
Also wondering what the sentiment is on disabling verification by default (and e.g. only enabling it on ALT builds with assertions). This does not seem terribly useful outside of rustc development and it does seem to show up in profiles (at something like 3%).
**EDIT:** A table showing the various configurations and what is enabled when.
| Configuration | Dynamic verification performed | LLVM static assertions compiled in |
| --- | --- | --- |
| alt builds | | yes |
| nightly builds | | no |
| stable builds | | no |
| CI builds | | |
| dev builds in a checkout | | |
Upgrade to LLVM's master branch (LLVM 7)
### Current status
~~Blocked on a [performance regression](https://github.com/rust-lang/rust/pull/51966#issuecomment-402320576). The performance regression has an [upstream LLVM issue](https://bugs.llvm.org/show_bug.cgi?id=38047) and has also [been bisected](https://reviews.llvm.org/D44282) to an LLVM revision.~~
Ready to merge!
---
This commit upgrades the main LLVM submodule to LLVM's current master branch.
The LLD submodule is updated in tandem as well as compiler-builtins.
Along the way support was also added for LLVM 7's new features. This primarily
includes the support for custom section concatenation natively in LLD so we now
add wasm custom sections in LLVM IR rather than having custom support in rustc
itself for doing so.
Some other miscellaneous changes are:
* We now pass `--gc-sections` to `wasm-ld`
* The optimization level is now passed to `wasm-ld`
* A `--stack-first` option is passed to LLD to have stack overflow always cause
a trap instead of corrupting static data
* The wasm target for LLVM switched to `wasm32-unknown-unknown`.
* The syntax for aligned pointers has changed in LLVM IR and tests are updated
to reflect this.
* ~~The `thumbv6m-none-eabi` target is disabled due to an [LLVM bug][llbug]~~
Nowadays we've been mostly only upgrading whenever there's a major release of
LLVM but enough changes have been happening on the wasm target that there's been
growing motivation for quite some time now to upgrade out version of LLD. To
upgrade LLD, however, we need to upgrade LLVM to avoid needing to build yet
another version of LLVM on the builders.
The revision of LLVM in use here is arbitrarily chosen. We will likely need to
continue to update it over time if and when we discover bugs. Once LLVM 7 is
fully released we can switch to that channel as well.
[llbug]: https://bugs.llvm.org/show_bug.cgi?id=37382
cc #50543
Correct some codegen stats counter inconsistencies
I noticed some possible typos/inconsistencies in the codegen counters. For example, `fsub` was getting counted as an integer `sub`, whereas `fadd` was counted as an add. And `addincoming` was only being counted on the initial call.
dbd10f8175/src/librustc_codegen_llvm/builder.rs (L831-L841)
Only remaining inconsistencies I can see are things like `fadd_fast` are counted as `fadd`. But the vector versions like `vector_reduce_fmax_fast` are counted as `vector.reduce.fmax_fast` not as their 'base' versions (`vector_reduce_fmax` is counted as `vector.reduce.fmax`).
This commit upgrades the main LLVM submodule to LLVM's current master branch.
The LLD submodule is updated in tandem as well as compiler-builtins.
Along the way support was also added for LLVM 7's new features. This primarily
includes the support for custom section concatenation natively in LLD so we now
add wasm custom sections in LLVM IR rather than having custom support in rustc
itself for doing so.
Some other miscellaneous changes are:
* We now pass `--gc-sections` to `wasm-ld`
* The optimization level is now passed to `wasm-ld`
* A `--stack-first` option is passed to LLD to have stack overflow always cause
a trap instead of corrupting static data
* The wasm target for LLVM switched to `wasm32-unknown-unknown`.
* The syntax for aligned pointers has changed in LLVM IR and tests are updated
to reflect this.
* The `thumbv6m-none-eabi` target is disabled due to an [LLVM bug][llbug]
Nowadays we've been mostly only upgrading whenever there's a major release of
LLVM but enough changes have been happening on the wasm target that there's been
growing motivation for quite some time now to upgrade out version of LLD. To
upgrade LLD, however, we need to upgrade LLVM to avoid needing to build yet
another version of LLVM on the builders.
The revision of LLVM in use here is arbitrarily chosen. We will likely need to
continue to update it over time if and when we discover bugs. Once LLVM 7 is
fully released we can switch to that channel as well.
[llbug]: https://bugs.llvm.org/show_bug.cgi?id=37382
Store scalar pair bools as i8 in memory
We represent `bool` as `i1` in a `ScalarPair`, unlike other aggregates,
to optimize IR for checked operators and the like. With this patch, we
still do so when the pair is an immediate value, but we use the `i8`
memory type when the value is loaded or stored as an LLVM aggregate.
So `(bool, bool)` looks like an `{ i1, i1 }` immediate, but `{ i8, i8 }`
in memory. When a pair is a direct function argument, `PassMode::Pair`,
it is still passed using the immediate `i1` type, but as a return value
it will use the `i8` memory type. Also, `bool`-like` enum tags will now
use scalar pairs when possible, where they were previously excluded due
to optimization issues.
Fixes#51516.
Closes#51566.
r? @eddyb
cc @nox
Mostly fix metadata_only backend and extract some code out of rustc_codegen_llvm
Removes dependency on the `ar` crate and removes the `llvm.enabled` config option in favour of setting `rust.codegen-backends` to `[]`.
When doing linker-plugin based LTO, write LLVM bitcode obj-files instead of embedding the bitcode into the regular object file.
This PR makes the compiler emit LLVM bitcode object files instead of regular object files with the IR embed when compiling for linker-plugin-based LTO. The reasoning for switching the strategy is this:
- Embedding bitcode in a section of the object file actually makes us save bitcode twice in rlibs and Rust dylibs, once for linker-based LTO and once for rustc-based LTO. That's a waste of space.
- When compiling for plugin-based LTO, one usually has no use for the machine code also present in the object file. Generating it is a waste of time.
- When compiling for plugin-based LTO, `rustc` will skip running ThinLTO because the linker will do that anyway. This has the side effect of then generating poorly optimized machine code, which makes it even less useful (and may lead to users not knowing why their code is slow instead of getting an error).
- Not having machine code available makes it impossible for the linker to silently fall back to not inlining stuff across language boundaries.
- This is what Clang does and according to [the documentation](https://llvm.org/docs/BitCodeFormat.html#native-object-file-wrapper-format) is the better supported option.
- The current behavior (minus the runtime performance problems) is still available via `-Z embed-bitcode` (we might want to do this for `libstd` at some point).
r? @alexcrichton
[cross-lang-lto] Allow the linker to choose the LTO-plugin (which is useful when using LLD)
This PR allows for not specifying an LTO-linker plugin but still let `rustc` invoke the linker with the correct plugin arguments. This is useful when using LLD which does not need the `-plugin` argument. Since LLD is the best linker for this scenario anyway, this change should improve ergonomics quite a bit.
r? @alexcrichton
We represent `bool` as `i1` in a `ScalarPair`, unlike other aggregates,
to optimize IR for checked operators and the like. With this patch, we
still do so when the pair is an immediate value, but we use the `i8`
memory type when the value is loaded or stored as an LLVM aggregate.
So `(bool, bool)` looks like an `{ i1, i1 }` immediate, but `{ i8, i8 }`
in memory. When a pair is a direct function argument, `PassMode::Pair`,
it is still passed using the immediate `i1` type, but as a return value
it will use the `i8` memory type. Also, `bool`-like` enum tags will now
use scalar pairs when possible, where they were previously excluded due
to optimization issues.
incr.comp.: Take names of children into account when computing the ICH of a module's HIR.
Fixes#40876. Red-green tracking does not make this a problem anymore. We should verify this via a perf-run though.
r? @nikomatsakis
Do not allow LLVM to increase a TLS's alignment on macOS.
This addresses the various TLS segfault on macOS 10.10.
Fix#51794.
Fix#51758.
Fix#50867.
Fix#48866.
Fix#46355.
Fix#44056.
Disable probestack when GCOV profiling is being used
If I compile Firefox with gcov profiling enabled, Firefox crashes at startup because of probestack.
Since it's disabled for PGO, I think it makes sense to disable it for gcov too.
Currently -Z no-verify only controls IR verification prior to
LLVM codegen, while verification is performed unconditionally
both before and after linking with (Thin)LTO.
Generate br for all two target SwitchInts
Instead of only for booleans. This means that `if let` also becomes a br.
Apart from making the IR slightly simpler, this is supported by FastISel (#4353).
Fix building rustc on and for musl hosts.
This fixes all problems I had when trying to compile rustc on a musl-based distribution (with `crt-static = false` in `config.toml`).
This is a fixed version of what ended up being #50105, making it possible to compile rustc on musl targets.
The differences to the old (now merged and subsequently reverted) pull request are:
- The commit (6d9154a830) that caused the regression for which the original commits were reverted in #50709 is left out. This means the corresponding bug #36710 is still not fixed with `+crt-static`.
- The test for issue 36710 is skipped for musl targets (until the issue is properly fixed).
- Building cargo-vendor if `crt-static = false` is needed was broken (cargo-vendor links to some shared libraries if they exist on the system and this produces broken binaries with `+crt-static`)
CC @alexcrichton
(This is just the data structure changes and some boilerplate match
code that followed from it; the actual emission of these statements
comes in a follow-up commit.)
Add simd math intrinsics and gather/scatter
This PR adds simd math intrinsics for floating-point vectors (sqrt, sin, cos, pow, exp, log, fma, abs, etc.) and the generic simd gather/scatter intrinsics.
std: Ensure OOM is classified as `nounwind`
OOM can't unwind today, and historically it's been optimized as if it can't
unwind. This accidentally regressed with recent changes to the OOM handler, so
this commit adds in a codegen test to assert that everything gets optimized away
after the OOM function is approrpiately classified as nounwind
Closes#50925
OOM can't unwind today, and historically it's been optimized as if it can't
unwind. This accidentally regressed with recent changes to the OOM handler, so
this commit adds in a codegen test to assert that everything gets optimized away
after the OOM function is approrpiately classified as nounwind
Closes#50925
Alex Crichton
csmoe
Michael Woerister
bors
Oliver Schneider
Amanieu d'Antras
Richard Diamond
Niko Matsakis
Mark Rousskov
ljedrz
Guillaume Gomez
gnzlbg
Ben Harris
bjorn3
Jorge Aparicio
kennytm
Josh Stone
Eduard-Mihai Burtescu
CrLF0710
Pietro Albini
est31
Vadim Petrochenkov
John Kåre Alsaker
varkor
Marco Castelluccio
Bastien Orivel
Fabian Drinck
Nikita Popov
Johannes Nixdorf
Felix S. Klock II