So far single payload enums were implemented in terms of runtime functions which
internally emitted several calls to value witnesses.
This commit adds value witnesses to get and store the enum tag side stepping the
need for witness calls as this information is statically available in many cases
/// int (*getEnumTagSinglePayload)(const T* enum, UINT_TYPE emptyCases)
/// Given an instance of valid single payload enum with a payload of this
/// witness table's type (e.g Optional<ThisType>) , get the tag of the enum.
/// void (*storeEnumTagSinglePayload)(T* enum, INT_TYPE whichCase,
/// UINT_TYPE emptyCases)
/// Given uninitialized memory for an instance of a single payload enum with a
/// payload of this witness table's type (e.g Optional<ThisType>), store the
/// tag.
A simple 'for element in array' loop in generic code operating on a
ContigousArray of Int is ~25% faster on arm64.
rdar://31408033
Integer and Floating literals are aware of their negation but
do not store the sign in the text of the value. Retrieve the
sign bit and properly interpolate the text of the literal value
with it to distinguish negative and positive literals.
LLVM r299341 removed the llvm::integerPart typedef and replaced it
with llvm::APInt::WordType. The integerPartWidth constant was replaced
by llvm::APInt::APINT_BITS_PER_WORD.
A lot of files transitively include Expr.h, because it was
included from SILInstruction.h, SILLocation.h and SILDeclRef.h.
However in reality most of these files don't do anything
with Exprs, especially not anything in IRGen or the SILOptimizer.
Now we're down to 171 files in the frontend which depend on
Expr.h, which is still a lot but much better than before.
This gives big code size wins for unused types and also for types, which are never used in a generic context.
Also it reduces the amount of symbols in the symbol table.
The size wins heavily depend on the project. I have seen binary size reductions from 0 to 20% on real world projects.
rdar://problem/30119960
Use the generic type lowering algorithm described in
"docs/CallingConvention.rst#physical-lowering" to map from IRGen's explosion
type to the type expected by the ABI.
Change IRGen to use the swift calling convention (swiftcc) for native swift
functions.
Use the 'swiftself' attribute on self parameters and for closures contexts.
Use the 'swifterror' parameter for swift error parameters.
Change functions in the runtime that are called as native swift functions to use
the swift calling convention.
rdar://19978563
Storing this separately is unnecessary since we already
serialize the enum element's interface type. Also, this
eliminates one of the few remaining cases where we serialize
archetypes during AST serialization.
Changes:
* Terminate all namespaces with the correct closing comment.
* Make sure argument names in comments match the corresponding parameter name.
* Remove redundant get() calls on smart pointers.
* Prefer using "override" or "final" instead of "virtual". Remove "virtual" where appropriate.
It is technically assigned into dynamically in the loop below, but given
code-refactoring, this invariant could easily be broken yielding a use of an
uninitialized pointer. Better to just initialize and assert.
This attribute is used in the simd overlay. To ensure we can layout
SIMD types correctly, emit a fixed type descriptor instead of a
field type descriptor for these types.
This code is utility code that is just thrown around in the middle of the enum
emission code and makes it difficult to follow. It is something that is large
enough really to stand on its on.
FastISel doesn't like switch, and it's generally more compact code gen to build conditionals for two-target branches instead of switching all the time. There are many popular two-tag enums (Optional, someday Bool, Either) and this should greatly improve the potential for FastISel to kick in at -Onone.
We need to arrange enum type metadata in a way where a client can
fish out generic parameters without knowing if we have a payload
size or not. The payload size is only used inside the module that
defined the enum, and may change if new cases are added.
So put the generic parameters first before the payload size, and
don't crash when an EnumMetadataScanner is used with a resilient
enum.
In practice, this interferes with FastISel and has exposed lots of latent LLVM backend bugs. Using "normal" power-of-two-bytes sized integers is easier to work with and improves code gen performance for nonoptimizing clients like Swift Playgrounds.
This used to crash because the code storing empty payload enum tag values would
use the bit width of the tag (32 bit) as the minimum unit to store to the
payload even if the actual bits required to store the biggest tag value in the
payload was much smaller.
With payload bit-widths < 32bit we would run out of space crashing looking for
new payload to store the value to ...
Instead pass the maximum size of the bits that need storing down.
rdar://26926035
Instead of hooking into nominal type and extension emission
and walking all conformances of those declarations, let's
just directly hook into the logic for emitting conformances.
This fixes an issue where we would apparently emit duplicate
conformances, as well as unnecessary conformances that are
defined elsewhere.
Rather than collection nominal type and extension decls and emit
reflection metadata records in one go, we can emit them as they
are encountered and instead collection builtin types referenced
by those at the end.
specialization to be separately lowered in IRGen, use the mangling
of the specialized type as the name of the llvm::StructType instead
of the base, unspecialized type.
This tends to produce fewer collisions between IR type names.
LLVM does unique the names on its own, so that's not strictly
necessary, but it's still a good idea because it makes the test
output more reliable and somewhat easier to read (modulo the
impact of bigger type names). Collisions will still occur if
the type is specialized at an archetype, since in this case we
will fall back on the unspecialized type.
Properly lower reference counting SIL instructions with nonatomic attribute as invocations of corresponding non-atomic reference counting runtime functions.
Without this, fixed-sized, address-only enums failed to correctly delegate their `getFixedExtraInhabitantMask` implementation to the enum layout strategy, causing a miscompile where switches would test undefined bits of the enum payload. Fixes rdar://problem/24885747.
- Implement emission of type references for nominal type field
reflection, using a small custom encoder resulting in packed
structs, not strings. This will let us embed 7-bit encoded
32-bit relative offsets directly in the structure (not yet
hooked in).
- Use the AST Mangler for encoding type references
Archetypes and internal references were complicating this before, so we
can take the opportunity to reuse this machinery and avoid unique code
and new ABI.
Next up: Tests for reading the reflection sections and converting the
demangle tree into a tree of type references.
Todo: For concrete types, serialize the types for associated types of
their conformances to bootstrap the typeref substitution process.
rdar://problem/15617914
Recent changes added support for resiliently-sized enums, and
enums resilient to changes in implementation strategy.
This patch adds resilient case numbering, fixing the problem
where adding new payload cases would break existing code by
changing the numbering of no-payload cases.
The problem is that internally, enum cases are numbered with payload
cases coming first, followed by no-payload cases. While each list
is itself in declaration order, with new additions coming at the
end, we need to partition it to give us a fast runtime test for
"is this a payload or no-payload case index."
The resilient numbering strategy used here is that the getEnumTag
and destructiveInjectEnumTag value witness functions now take a
tag index in the range [-ElementsWithPayload..ElementsWithNoPayload-1].
Payload elements are numbered in *reverse* declaration order, so
adding new payload cases yields decreasing tag indices, and adding
new no-payload cases yields increasing tag indices, allowing use
sites to be resilient.
This adds the adjustment between 'fragile' and 'resilient' tag
indices in a somewhat unsatisfying manner, because the calculation
could be pushed down further into EnumImplStrategy, simplifying
both the IRGen code and the generated IR. I'll clean this up later.
In the meantime, clean up some other stuff in GenEnum.cpp, mostly
abstracting code that walks cases.
Decrease the size of nominal type descriptors and make them true-const by relative-addressing the other metadata they need to reference, which should all be included in the same image as the descriptor itself. Relative-referencing string constants exposes a bug in the Apple linker, which crashes when resolving relative relocations to coalesceable symbols (rdar://problem/22674524); work around this for now by revoking the `unnamed_addr`-ness of string constants that we take relative references to. (I haven't tested whether GNU ld or gold also have this problem on Linux; it may be possible to conditionalize the workaround to only apply to Darwin targets for now.)
Use them to generate value witnesses when the type has dynamic packing.
Regularize the interface for calling value witnesses.
Not a huge difference yet, although we do re-use local type data
a little more effectively now.
In a few places, we have to be careful about the distinction between
"empty in this resilience domain" versus "empty in all resilience
domains". Make callers think about this by adding a parameter instead
of relying on them to check isFixedSize() as necessary first.
While making this change I noticed that the code for checking if
types are empty when computing extra inhabitants of structs and enums
might be slightly wrong in the face of resilience; I will revisit
this later.
