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80 lines
2.5 KiB
Swift
80 lines
2.5 KiB
Swift
//===--- SimplifyLoad.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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extension LoadInst : OnoneSimplifyable {
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func simplify(_ context: SimplifyContext) {
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replaceLoadOfGlobalLet(context)
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}
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private func replaceLoadOfGlobalLet(_ context: SimplifyContext) {
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guard let globalInitVal = getGlobalInitValue(address: address) else {
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return
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}
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let builder = Builder(before: self, context)
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guard let initVal = context.copyStaticInitializer(fromInitValue: globalInitVal, to: builder) else {
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return
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}
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uses.replaceAll(with: initVal, context)
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transitivelyErase(load: self, context)
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}
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}
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/// Returns the init value of a global which is loaded from `address`.
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private func getGlobalInitValue(address: Value) -> Value? {
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switch address {
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case let gai as GlobalAddrInst:
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if gai.global.isLet {
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return gai.global.staticInitValue
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}
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case let pta as PointerToAddressInst:
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return globalLoadedViaAddressor(pointer: pta.pointer)?.staticInitValue
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case let sea as StructElementAddrInst:
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if let structVal = getGlobalInitValue(address: sea.struct) as? StructInst {
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return structVal.operands[sea.fieldIndex].value
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}
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case let tea as TupleElementAddrInst:
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if let tupleVal = getGlobalInitValue(address: tea.tuple) as? TupleInst {
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return tupleVal.operands[tea.fieldIndex].value
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}
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case let bai as BeginAccessInst:
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return getGlobalInitValue(address: bai.address)
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default:
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break
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}
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return nil
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}
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private func globalLoadedViaAddressor(pointer: Value) -> GlobalVariable? {
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if let ai = pointer as? ApplyInst,
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let callee = ai.referencedFunction,
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let global = callee.globalOfGlobalInitFunction,
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global.isLet {
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return global
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}
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return nil
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}
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private func transitivelyErase(load: LoadInst, _ context: SimplifyContext) {
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var inst: SingleValueInstruction = load
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while inst.uses.isEmpty {
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if inst.operands.count != 1 {
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context.erase(instruction: inst)
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return
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}
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let operandInst = inst.operands[0].value as! SingleValueInstruction
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context.erase(instruction: inst)
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inst = operandInst
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}
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}
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