Extend SwiftDtoa to provide optimal formatting for Float16 and use that for `Float16.description` and `Float16.debugDescription`.
Notes on signaling NaNs: LLVM's Float16 support passes Float16s on x86
by legalizing to Float32. This works well for most purposes but incidentally
loses the signaling marker from any NaN (because it's a conversion as far
as the hardware is concerned), with a side effect that the print code never
actually sees a true sNaN. This is similar to what happens with Float and
Double on i386 backends. The earlier code here tried to detect sNaN in a
different way, but that approach isn't guaranteed to work so we decided to
make this code use the correct detection logic -- sNaN printing will just be
broken until we can get a better argument passing convention.
Resolves rdar://61414101
Add concrete overloads for ~= for String/Substring
combinations. SR-12457 tracks making this generic after we understand
the expression type checker impact.
module to contain only code necessary for testing the compiler
optimizations and diagnostics. This commit comprises the following changes:
1. Rename the OSLogPrototype module to OSLogTestHelper and rename the files.
2. Make the private module: OSLogTestHelper independent of os overlay.
3. Simplify the os log test suites and make them not perform logging.
4. Enable the os log test suites on all platforms.
<rdar://problem/60542172>
This commit focuses the basics: setting up the relevant stanzas in
lit.cfg and adding platform conditionals for importing Glibc. Future
commits will deal with other portability fixes.
Previously we were using `getPlainType` to match
the parameter type against the key path's base
type. This gave us the external parameter type,
which would be the element type for a variadic
parameter. However the code we generate expects
the internal parameter type, which is provided by
`getParameterType`.
Resolves rdar://problem/59445486.
In order to allow this, I've had to rework the syntax of substituted function types; what was previously spelled `<T> in () -> T for <X>` is now spelled `@substituted <T> () -> T for <X>`. I think this is a nice improvement for readability, but it did require me to churn a lot of test cases.
Distinguishing the substitutions has two chief advantages over the existing representation. First, the semantics seem quite a bit clearer at use points; the `implicit` bit was very subtle and not always obvious how to use. More importantly, it allows the expression of generic function types that must satisfy a particular generic abstraction pattern, which was otherwise impossible to express.
As an example of the latter, consider the following protocol conformance:
```
protocol P { func foo() }
struct A<T> : P { func foo() {} }
```
The lowered signature of `P.foo` is `<Self: P> (@in_guaranteed Self) -> ()`. Without this change, the lowered signature of `A.foo`'s witness would be `<T> (@in_guaranteed A<T>) -> ()`, which does not preserve information about the conformance substitution in any useful way. With this change, the lowered signature of this witness could be `<T> @substituted <Self: P> (@in_guaranteed Self) -> () for <A<T>>`, which nicely preserves the exact substitutions which relate the witness to the requirement.
When we adopt this, it will both obviate the need for the special witness-table conformance field in SILFunctionType and make it far simpler for the SILOptimizer to devirtualize witness methods. This patch does not actually take that step, however; it merely makes it possible to do so.
As another piece of unfinished business, while `SILFunctionType::substGenericArgs()` conceptually ought to simply set the given substitutions as the invocation substitutions, that would disturb a number of places that expect that method to produce an unsubstituted type. This patch only set invocation arguments when the generic type is a substituted type, which we currently never produce in type-lowering.
My plan is to start by producing substituted function types for accessors. Accessors are an important case because the coroutine continuation function is essentially an implicit component of the function type which the current substitution rules simply erase the intended abstraction of. They're also used in narrower ways that should exercise less of the optimizer.
* Don't allocate breadrumbs pointer if under threshold
* Increase breadrumbs threshold
* Linear 16-byte bucketing until 128 bytes, malloc_size after
* Allow cap less than _SmallString.capacity (bridging non-ASCII)
This change decreases the amount of heap usage for moderate-length
strings (< 64 UTF-8 code units in length) and increases the amount of
spare code unit capacity available (less growth needed).
Average improvements for moderate-length strings:
* 64-bit: on average, 8 bytes saved and 4 bytes of extra capacity
* 32-bit: on average, 4 bytes saved and 6 bytes of extra capacity
Additionally, on 32-bit, large-length strings also gain an average of
6 bytes of extra spare capacity.
Details:
On 64-bit, half of moderate-length allocations will save 16 bytes
while the other half get an extra 8 bytes of spare capacity.
On 32-bit, a quarter of moderate-length allocations will save 16
bytes, and the rest get an extra 4 bytes of spare
capacity. Additionally, 32-bit string's storage class now claims its
full allocation, which is its birthright. Prior to this change, we'd
have on average 1.5 bytes of spare capacity, and now we have 7.5 bytes
of spare capacity.
Breadcrumbs threshold is increased from the super-conservative 32 to
the pretty-conservative 64. Some speed improvements are incorporated
in this change, but more are in flight. Even without those eventual
improvements, this is a worthwhile change (ASCII is still fast-pathed
and irrelevant to breadcrumbing).
For a complex real-world workload, this amounts to around a 5%
improvement to transient heap usage due to all strings and a 4%
improvement to peak heap usage due to all strings. For moderate-length
strings specifically, this gives around 11% improvement to both.
These should hopefully all be uncontroversial, minimal changes to deal
with progressing the build to completion on OpenBSD or addressing minor
portability issues. This is not the full set of changes to get a
successful build; other portability issues will be addressed in future
commits.
Most of this is just adding the relevant clauses to the ifdefs, but of
note in this commit:
* StdlibUnittest.swift: the default conditional in _getOSVersion assumes
an Apple platform, therefore the explicit conditional and the relevant
enums need filling out. The default conditional should be #error, but
we'll fix this in a different commit.
* tgmath.swift.gyb: inexplicably, OpenBSD is missing just lgammal_r.
Tests are updated correspondingly.
* ThreadLocalStorage.h: we use the pthread implementation, so it
seems we should typedef __swift_thread_key_t as pthread_key_t.
However, that's also a tweak for another commit.
The format specifier constructed by the os log implementation uses '*' for
width and precision, and passes those values to the os_log ABIs as additional
arguments of the message. (The precision/alignment arguments have the
type: count).
Update tests to handle this change.
This adds the RangeSet and DiscontiguousSlice types, as well as collection
operations for working with discontiguous ranges of elements. This also adds
a COWLoggingArray type to the test suite to verify that mutable collection
algorithms don't perform unexpected copy-on-write operations when mutating
slices mid-operation.
If an enum has a payload case with zero size, we treat it as an empty case
for ABI purposes. Unfortunately, this meant that reflection metadata was
incomplete for such cases, with a Mirror reporting that the enum value
had zero children.
Tweak the field type metadata emission slightly to preserve the payload
type for such enum cases.
Fixes <https://bugs.swift.org/browse/SR-12044> / <rdar://problem/58861157>.
getDescription takes its argument at +1, but the implementation was passing the value directly. This caused the contained error value to be destroyed.
rdar://problem/59512630
These objects can escape into ObjC without their class being realized first, which can cause a crash if the unrealized class gets passed into the ObjC runtime.
rdar://problem/59295395
calls over arrays created from array literals. This enables optimizing
further the output of the OSLogOptimization pass, and results in
highly-compact and optimized IR for calls to the new os log API.
<rdar://58928427>
