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[embedded] Avoid use of a metatype in array implementation for embedded Swift #68614

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Merged
merged 1 commit into from
Sep 20, 2023
Merged

[embedded] Avoid use of a metatype in array implementation for embedded Swift #68614

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9 changes: 7 additions & 2 deletions stdlib/public/core/ArrayShared.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -41,9 +41,14 @@ func _allocateUninitializedArray<Element>(_ builtinCount: Builtin.Word)
if count > 0 {
// Doing the actual buffer allocation outside of the array.uninitialized
// semantics function enables stack propagation of the buffer.
let storageType: _ContiguousArrayStorage<Element>.Type
#if !$Embedded
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Would it work to sink this down to getContiguousArrayStorageType()?

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I tried that originally, but the function call that returns a metatype is a problem in embedded Swift. I think we could improve the MandatoryPerfOptimizations to handle that case, but I think I'd like leave that option as a possible follow-up improvement.

storageType = getContiguousArrayStorageType(for: Element.self)
#else
storageType = _ContiguousArrayStorage<Element>.self
#endif
let bufferObject = Builtin.allocWithTailElems_1(
getContiguousArrayStorageType(for: Element.self),
builtinCount, Element.self)
storageType, builtinCount, Element.self)

let (array, ptr) = Array<Element>._adoptStorage(bufferObject, count: count)
return (array, ptr._rawValue)
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9 changes: 7 additions & 2 deletions stdlib/public/core/ContiguousArrayBuffer.swift
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Expand Up @@ -297,9 +297,14 @@ internal struct _ContiguousArrayBuffer<Element>: _ArrayBufferProtocol {
self = _ContiguousArrayBuffer<Element>()
}
else {
let storageType: _ContiguousArrayStorage<Element>.Type
#if !$Embedded
storageType = getContiguousArrayStorageType(for: Element.self)
#else
storageType = _ContiguousArrayStorage<Element>.self
#endif
_storage = Builtin.allocWithTailElems_1(
getContiguousArrayStorageType(for: Element.self),
realMinimumCapacity._builtinWordValue, Element.self)
storageType, realMinimumCapacity._builtinWordValue, Element.self)

let storageAddr = UnsafeMutableRawPointer(Builtin.bridgeToRawPointer(_storage))
let allocSize: Int?
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