Always statically dispatch to C functions imported as members, and
call to the foreign entry point. This gets us through SILGen, but DI
is still deeply unhappy with the resulting SIL.
Bridging thunks don't yet support bridging address-only types, but
ideally they should, so that we can bridge Objective-C types to
resilient value types.
This came up while I was adding @_fixed_layout declarations in
the standard library. To make this easier to figure out in the
future, add the asserts to the bridging logic for now.
Also, to avoid hitting the asserts when we emit a reference to a
C function with an incompatible type, don't emit the foreign
function at all until we determine that the ABI conversion is safe.
Previously IRGen would force all fragile entities to have public linkage.
It makes more sense to do this in SILGen instead, and only when
-sil-serialize-all is on.
If a function is public, and either @_transparent or @inline(__always),
we need to make its body available for inlining in other resilience
domains. The more general concept here is an 'inlineable' function;
once the precise behaviors we want are nailed down, the set of AST
attributes for exposing this will likely change.
At the SIL level, inlineable functions are marked with the [fragile]
attribute. The SIL serializer only serializes [fragile] functions
unless -sil-serialize-all is passed in.
This patch fixes two problems in this area by consolidating some
duplicated logic:
1) Property accesses in Sema did not check for @inline(__always)
functions, or functions nested inside inlineable functions.
This manifested as IRGen crashes if an inlineable function
accessed a property of a resilient type.
2) In SILGen, functions nested inside [fragile] functions were
properly [fragile], but @inline(__always) was not taken into
account. This manifested as SIL serializer crashes where a
[fragile] function could reference a non-public, non-[fragile]
function.
This change is part of the series for building the standard library
without -sil-serialize-all.
This attribute is a stand-in for the versioning annotations
described in docs/LibraryEvolution.rst; right now it's just present
or absent, and its only effect is to make sure versioned internal
decls are treated as public at the SIL level. (This functionality
already existed for -enable-testing, so it can probably be trusted.)
Also, allow inlineable functions to reference transparent and
inline-always functions /if/ they're only called immediately (not used
as values or partial-applied), since they'll be inlined away before
emitting IR. (We should really only allow this /before/ mandatory
inlining, but we don't have a separate SIL stage for that.)
If a thunk is referenced from two different functions, the thunk inherits
the fragile attribute from the first function that forced it to be emitted.
This is wrong, in case the first function might not be fragile, while
the second one is. Copying the fragile attribute to an existing thunk when
checking if it has already been emitted is also wrong, because the thunk
might reference another thunk, and so on.
The correct fix is to have SIL serialization serialize the transitive
closure of all fragile functions and thunks referenced from fragile
functions. Re-work SIL function serialization to use a worklist so that
we can do this.
Part of https://bugs.swift.org/browse/SR-267.
A transparent function might be deserialized and inlined into a function
in another module, which would cause problems if the function referenced
local functions.
Previously we would force local functions to have public linkage instead,
which worked, but was not resilient if the body of the transparent
function changed in the module that contained it.
Add a library evolution test ensuring that such a change is resilient
now.
Part of https://bugs.swift.org/browse/SR-267.
We do clever tricks to avoid having to serialize the full type of a
partial_apply instruction, but those conflicted with our clever tricks
for handling unusual return conventions. Make sure we do all type
calculations for partial_apply in one place. (Credit to Slava for
both introducing the problem and immediately seeing how to fix it.)
This should allow re-application of e6a519f and 86dcce1.
This was mistakenly reverted in an attempt to fix buildbots.
Unfortunately it's now smashed into one commit.
---
Introduce @_specialize(<type list>) internal attribute.
This attribute can be attached to generic functions. The attribute's
arguments must be a list of concrete types to be substituted in the
function's generic signature. Any number of specializations may be
associated with a generic function.
This attribute provides a hint to the compiler. At -O, the compiler
will generate the specified specializations and emit calls to the
specialized code in the original generic function guarded by type
checks.
The current attribute is designed to be an internal tool for
performance experimentation. It does not affect the language or
API. This work may be extended in the future to add user-visible
attributes that do provide API guarantees and/or direct dispatch to
specialized code.
This attribute works on any generic function: a freestanding function
with generic type parameters, a nongeneric method declared in a
generic class, a generic method in a nongeneric class or a generic
method in a generic class. A function's generic signature is a
concatenation of the generic context and the function's own generic
type parameters.
e.g.
struct S<T> {
var x: T
@_specialize(Int, Float)
mutating func exchangeSecond<U>(u: U, _ t: T) -> (U, T) {
x = t
return (u, x)
}
}
// Substitutes: <T, U> with <Int, Float> producing:
// S<Int>::exchangeSecond<Float>(u: Float, t: Int) -> (Float, Int)
---
[SILOptimizer] Introduce an eager-specializer pass.
This pass finds generic functions with @_specialized attributes and
generates specialized code for the attribute's concrete types. It
inserts type checks and guarded dispatch at the beginning of the
generic function for each specialization. Since we don't currently
expose this attribute as API and don't specialize vtables and witness
tables yet, the only way to reach the specialized code is by calling
the generic function which performs the guarded dispatch.
In the future, we can build on this work in several ways:
- cross module dispatch directly to specialized code
- dynamic dispatch directly to specialized code
- automated specialization based on less specific hints
- partial specialization
- and so on...
I reorganized and refactored the optimizer's generic utilities to
support direct function specialization as opposed to apply
specialization.
This split the function signature module pass into 2 functin passes.
By doing so, this allows us to rewrite to using the FSO-optimized
function prior to attempting inlining, but allow us to do a substantial
amount of optimization on the current function before attempting to do
FSO on that function.
And also helps us to move to a model which module pass is NOT used unless
necesary.
I do not see regression nor improvement for on the performance test suite.
functionsignopts.sil and functionsignopt_sroa.sil are modified because the
mangler now takes into account of information in the projection tree.
Temporarily reverting @_specialize because stdlib unit tests are
failing on an internal branch during deserialization.
This reverts commit e2c43cfe14, reversing
changes made to 9078011f93.
Introduce a new SILPrintContext class which is the main handle passed to the SILModule's and SILFunction's print functions.
It also allows to let derived classes implement call backs on instruction printing.
NFC for now, but needed for the upcoming SIL-debuginfo change.
Fix a crash in emitBuiltinCall() which occurs because we drop function
linkage information when creating SILCoverageMaps.
This re-applies 45c7e4e86 with the MachO-specific checks in the test
case removed.
This attribute can be attached to generic functions. The attribute's
arguments must be a list of concrete types to be substituted in the
function's generic signature. Any number of specializations may be
associated with a generic function.
This attribute provides a hint to the compiler. At -O, the compiler
will generate the specified specializations and emit calls to the
specialized code in the original generic function guarded by type
checks.
The current attribute is designed to be an internal tool for
performance experimentation. It does not affect the language or
API. This work may be extended in the future to add user-visible
attributes that do provide API guarantees and/or direct dispatch to
specialized code.
This attribute works on any generic function: a freestanding function
with generic type parameters, a nongeneric method declared in a
generic class, a generic method in a nongeneric class or a generic
method in a generic class. A function's generic signature is a
concatenation of the generic context and the function's own generic
type parameters.
e.g.
struct S<T> {
var x: T
@_specialize(Int, Float)
mutating func exchangeSecond<U>(u: U, _ t: T) -> (U, T) {
x = t
return (u, x)
}
}
// Substitutes: <T, U> with <Int, Float> producing:
// S<Int>::exchangeSecond<Float>(u: Float, t: Int) -> (Float, Int)
Eliminate the String/Array/Dictionary/Set special cases, using
_ObjectiveCBridgeable conformances instead.
Note: Clang update required for the test to success.
Introduce abstraction patterns for curried C-functions-as-methods for type lowering, and plumb the "foreign self parameter index" through call emission so that we emit the "self" parameter in the right position. This gets us handling C functions imported as methods with explicit swift_name attributes in simple, fully-applied cases. There's still more work to be done for properties, partial applications, and initializers introduced by extensions.
