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9aff288be4
Which consists of * removing redundant `address_to_pointer`-`pointer_to_address` pairs * optimize `index_raw_pointer` of a manually computed stride to `index_addr` * remove or increase the alignment based on a "assumeAlignment" builtin This is a big code cleanup but also has some functional differences for the `address_to_pointer`-`pointer_to_address` pair removal: * It's not done if the resulting SIL would result in a (detectable) use-after-dealloc_stack memory lifetime failure. * It's not done if `copy_value`s must be inserted or borrow-scopes must be extended to comply with ownership rules (this was the task of the OwnershipRAUWHelper). Inserting copies is bad anyway. Extending borrow-scopes would only be required if the original lifetime of the pointer extends a borrow scope - which shouldn't happen in save code. Therefore this is a very rare case which is not worth handling.
98 lines
3.0 KiB
Swift
98 lines
3.0 KiB
Swift
//===--- Worklist.swift ---------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2023 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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import SIL
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/// A utility for processing entities in a worklist.
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///
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/// A `Worklist` is basically a combination of a stack and a set.
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/// It can be used for typical worklist-processing algorithms.
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///
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/// This type should be a move-only type, but unfortunately we don't have move-only
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/// types yet. Therefore it's needed to call `deinitialize()` explicitly to
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/// destruct this data structure, e.g. in a `defer {}` block.
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struct Worklist<Set: IntrusiveSet> : CustomStringConvertible, NoReflectionChildren {
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typealias Element = Set.Element
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private var worklist: Stack<Element>
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private var pushedElements: Set
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init(_ context: some Context) {
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self.worklist = Stack(context)
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self.pushedElements = Set(context)
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}
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mutating func pop() -> Element? { return worklist.pop() }
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/// Pop and allow the popped element to be pushed again to the worklist.
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mutating func popAndForget() -> Element? {
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if let element = worklist.pop() {
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pushedElements.erase(element)
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return element
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}
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return nil
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}
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mutating func pushIfNotVisited(_ element: Element) {
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if pushedElements.insert(element) {
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worklist.append(element)
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}
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}
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mutating func pushIfNotVisited<S: Sequence>(contentsOf other: S) where S.Element == Element {
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for element in other {
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pushIfNotVisited(element)
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}
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}
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/// Returns true if \p element was pushed to the worklist, regardless if it's already popped or not.
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func hasBeenPushed(_ element: Element) -> Bool { pushedElements.contains(element) }
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var isEmpty: Bool { worklist.isEmpty }
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var description: String {
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"""
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worklist: \(worklist)
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pushed: \(pushedElements)
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"""
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}
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/// TODO: once we have move-only types, make this a real deinit.
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mutating func deinitialize() {
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pushedElements.deinitialize()
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worklist.deinitialize()
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}
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}
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typealias BasicBlockWorklist = Worklist<BasicBlockSet>
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typealias InstructionWorklist = Worklist<InstructionSet>
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typealias SpecificInstructionWorklist<InstType: Instruction> = Worklist<SpecificInstructionSet<InstType>>
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typealias ValueWorklist = Worklist<ValueSet>
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typealias OperandWorklist = Worklist<OperandSet>
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extension InstructionWorklist {
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mutating func pushPredecessors(of inst: Instruction, ignoring ignoreInst: Instruction) {
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if let prev = inst.previous {
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if prev != ignoreInst {
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pushIfNotVisited(prev)
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}
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} else {
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for predBlock in inst.parentBlock.predecessors {
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let termInst = predBlock.terminator
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if termInst != ignoreInst {
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pushIfNotVisited(termInst)
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}
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}
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}
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}
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}
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