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//===--- SimplifyPointerToAddress.swift -----------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2023 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
//
//===----------------------------------------------------------------------===//
import SIL
extension PointerToAddressInst : OnoneSimplifyable {
/// For a redundant pair of pointer-address conversions, e.g.
///
/// %2 = address_to_pointer %1
/// %3 = pointer_to_address %2 [strict]
///
/// replace all uses of %3 with %1.
///
func simplify(_ context: SimplifyContext) {
if let atp = self.pointer as? AddressToPointerInst,
atp.address.type == self.type,
self.isStrict,
// If the pointer is within an ownership scope, the transformation can break ownership rules, e.g.
// %2 = begin_borrow %1
// %3 = ref_tail_addr %2
// %4 = address_to_pointer %3
// end_borrow %2
// %5 = pointer_to_address %4 <- cannot replace %5 with %3!
//
!atp.address.accessBase.hasLocalOwnershipLifetime
{
self.uses.replaceAll(with: atp.address, context)
}
}
}
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