wasm32: Default to a "static" relocation model
LLVM 9 is adding support for a "pic" relocation model for wasm code,
which is quite different than the current model. In order to preserve
the mode of compilation that we have today default to "static" to ensure
that we don't accidentally start creating experimental relocatable
binaries.
improve worst-case performance of HashSet.is_subset
One more simple optimization opportunity for HashSet that was applied in BTreeSet in #59186 (and wasn't in #57043). Already covered by the existing unit test.
r? @KodrAus
std: Upgrade `compiler_builtins` to fix wasi linkage
Turns out we needed to exclude a number of math functions on the
`wasm32-unknown-wasi` target, and this was fixed in 0.1.9 of
compiler-builtins and this is pulling in the fix to libstd's own build.
ci: Update FreeBSD tarball downloads
These appear to have disappeared from the original server, so I acquired
the contents from a different mirror and uploaded them to our S3 bucket
This increases the size of some important types, such as `ast::Expr` and
`mir::Statement`. However, it drastically reduces how much the interner
is used, and the fields are more natural sizes that don't require bit
operations to extract.
As a result, instruction counts drop across a range of workloads, by as
much as 12% for incremental "check" builds of `script-servo`.
Peak memory usage goes up a little for some cases, but down by more for
some other cases -- as much as 18% for non-incremental builds of
`packed-simd`.
The commit also:
- removes the `repr(packed)`, because it has negligible effect, but can
cause undefined behaviour;
- replaces explicit impls of common traits (`Copy`, `PartialEq`, etc.)
with derived ones.
LLVM 9 is adding support for a "pic" relocation model for wasm code,
which is quite different than the current model. In order to preserve
the mode of compilation that we have today default to "static" to ensure
that we don't accidentally start creating experimental relocatable
binaries.
Turns out we needed to exclude a number of math functions on the
`wasm32-unknown-wasi` target, and this was fixed in 0.1.9 of
compiler-builtins and this is pulling in the fix to libstd's own build.
std: Avoid usage of `Once` in `Instant`
This commit removes usage of `Once` from the internal implementation of
time utilities on OSX and Windows. It turns out that we accidentally hit
a deadlock today (#59020) via events that look like:
* A thread invokes `park_timeout`
* Internally, only on OSX, `park_timeout` calls `Instant::elapsed`
* Inside of `Instant::elapsed` on OSX we enter a `Once` to initialize
global timer data
* Inside of `Once`, it attempts to `park`
This means on the same stack frame, when there's contention, we're
calling `park` from inside `park_timeout`, causing a deadlock!
The solution implemented in this commit was to remove usage of `Once`
and instead just do a small dance with atomics. There's no real need we
need to guarantee that the global information is only learned once, only
that it's only *stored* once. This implementation may have multiple
threads invoke `mach_timebase_info`, but only one will store the global
information which will amortize the cost for all other threads.
A similar fix has been applied to windows to be uniform across our
implementations, but looking at the code on Windows no deadlock was
possible. This is purely just a consistency update for Windows and in
theory a slightly leaner implementation.
Closes#59020
A comment in one match arm make a blanket statement about "reads/reservations", but in fact the whole point of this PR is that reservations are *not* handled by that particular arm anymore.
This commit removes usage of `Once` from the internal implementation of
time utilities on OSX and Windows. It turns out that we accidentally hit
a deadlock today (#59020) via events that look like:
* A thread invokes `park_timeout`
* Internally, only on OSX, `park_timeout` calls `Instant::elapsed`
* Inside of `Instant::elapsed` on OSX we enter a `Once` to initialize
global timer data
* Inside of `Once`, it attempts to `park`
This means on the same stack frame, when there's contention, we're
calling `park` from inside `park_timeout`, causing a deadlock!
The solution implemented in this commit was to remove usage of `Once`
and instead just do a small dance with atomics. There's no real need we
need to guarantee that the global information is only learned once, only
that it's only *stored* once. This implementation may have multiple
threads invoke `mach_timebase_info`, but only one will store the global
information which will amortize the cost for all other threads.
A similar fix has been applied to windows to be uniform across our
implementations, but looking at the code on Windows no deadlock was
possible. This is purely just a consistency update for Windows and in
theory a slightly leaner implementation.
Closes#59020
Make some of lexer's API private
Lexer is a `pub` type, so it feels wrong that its fields are just pub (I guess it wasn't exported initially), so let's minimize visibility.
Context: I am looking into extracting rust-lexer into a library, which can be shared by rust-analyzer and rustc. I hope that a simple interface like `fn next_token(src: &str) -> (TokenKind, usize)` would work, but to try this out I need to understand what is the current API of the lexer.
