Accelerate vForce (#24152)

* [Accelerate] [vForce] New vForce Overlay

This PR contains a suite of overlays to the vForce transcendental and trigonometric functions on vectors of any length. The overlays simplify the API to the existing functions and accept collections that implement a new protocol called AccelerateBuffer. Conformances are provided for the most useful stdlib Collections.

Author: stephentyrone

stdlib/public/Darwin/Accelerate/Accelerate.swift

@@ -0,0 +1,17 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2019 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+/// An enum that acts as a namespace for Swift overlays to vDSP based functions.
+public enum vDSP {}
+
+/// An enum that acts as a namespace for Swift overlays to vForce based functions.
+public enum vForce {}

stdlib/public/Darwin/Accelerate/CMakeLists.txt

@@ -2,7 +2,10 @@ cmake_minimum_required(VERSION 3.4.3)
 include("../../../../cmake/modules/StandaloneOverlay.cmake")
 
 add_swift_target_library(swiftAccelerate ${SWIFT_SDK_OVERLAY_LIBRARY_BUILD_TYPES} IS_SDK_OVERLAY
+  Accelerate.swift
   Quadrature.swift
+  ContiguousCollection.swift
+  vForce_Operations.swift
 
   "${SWIFT_SOURCE_DIR}/stdlib/linker-support/magic-symbols-for-install-name.c"
 

stdlib/public/Darwin/Accelerate/ContiguousCollection.swift

@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2019 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+/// An object composed of count elements that are stored contiguously in memory.
+///
+/// In practice, most types conforming to this protocol will be Collections,
+/// but they need not be--they need only have an Element type and count, and
+/// provide the withUnsafeBufferPointer function.
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+public protocol AccelerateBuffer {
+  /// The buffer's element type.
+  associatedtype Element
+  
+  /// The number of elements in the buffer.
+  var count: Int { get }
+  
+  /// Calls a closure with a pointer to the object's contiguous storage.
+  func withUnsafeBufferPointer<R>(
+    _ body: (UnsafeBufferPointer<Element>) throws -> R
+  ) rethrows -> R
+}
+
+/// A mutable object composed of count elements that are stored contiguously
+/// in memory.
+///
+/// In practice, most types conforming to this protocol will be
+/// MutableCollections, but they need not be.
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+public protocol AccelerateMutableBuffer: AccelerateBuffer {
+  /// Calls the given closure with a pointer to the object's mutable
+  /// contiguous storage.
+  mutating func withUnsafeMutableBufferPointer<R>(
+    _ body: (inout UnsafeMutableBufferPointer<Element>) throws -> R
+  ) rethrows -> R
+}
+
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+public extension AccelerateBuffer where Self: Collection {
+  func withUnsafeBufferPointer<R>(
+    _ body: (UnsafeBufferPointer<Element>) throws -> R
+  ) rethrows -> R {
+    return try withContiguousStorageIfAvailable(body)!
+  }
+}
+
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+extension AccelerateMutableBuffer where Self: MutableCollection {
+  public mutating func withUnsafeMutableBufferPointer<R>(
+    _ body: (inout UnsafeMutableBufferPointer<Element>) throws -> R
+  ) rethrows -> R {
+    return try withContiguousMutableStorageIfAvailable(body)!
+  }
+}
+
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+extension Array: AccelerateMutableBuffer { }
+
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+extension ContiguousArray: AccelerateMutableBuffer { }
+
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+extension ArraySlice: AccelerateMutableBuffer { }
+
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+extension UnsafeBufferPointer: AccelerateBuffer { }
+
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+extension UnsafeMutableBufferPointer: AccelerateMutableBuffer { }
+
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+extension Slice: AccelerateBuffer where Base: Collection { }
+
+@available(iOS 9999, OSX 9999, tvOS 9999, watchOS 9999, *)
+extension Slice: AccelerateMutableBuffer where Base: MutableCollection { }

stdlib/public/Darwin/Accelerate/Quadrature.swift

@@ -10,8 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-import Accelerate
-
 // MARK: Quadrature
 
 @available(iOS 9999, macOS 9999, tvOS 9999, watchOS 9999, *)