Swift Optimizing at Compiler World

@NSSpain 2020 Remote Edition

Transcript

1. Swift Optimizing at Compiler World
   NSSpain 2020: Remote Edition, November 20th 2020
   Yuki Aki from LINE Fukuoka
   

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2. About Me
   Yuki Aki (freddi)
   iOS Engineer at LINE Fukuoka
   

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3. Activity & Community
   Developing LINE Creators Studio at LINE Fukuoka
   

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4. Activity & Community
   Writing Swift for 2 years
   Swift Compiler, XcodeGen etc …
   Contributed to OSS Projects
   As a Speaker at many conferences
   

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5. About Me
   Yuki Aki (freddi)
   iOS Engineer at LINE Fukuoka
   

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6. Swift Optimizing at Compiler World
   

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7. Agenda
   Why need to learn Swift Compiler (Optimizer)?
   Basis of Swift Compiler
   Swift Intermediate Language (SIL)
   SIL Optimizer
   

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8. Agenda
   Why need to learn Swift Compiler (Optimizer)?
   Basis of Swift Compiler
   Swift Intermediate Language (SIL)
   SIL Optimizer
   

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9. Agenda
   Why need to learn Swift Compiler (Optimizer)?
   Basis of Swift Compiler
   Swift Intermediate Language (SIL)
   SIL Optimizer
   

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10. Agenda
    Why need to learn Swift Compiler (Optimizer)?
    Basis of Swift Compiler
    Swift Intermediate Language (SIL)
    SIL Optimizer
    

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11. Agenda
    Why need to learn Swift Compiler (Optimizer)?
    Basis of Swift Compiler
    Swift Intermediate Language (SIL)
    SIL Optimizer
    

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12. Swift Compiler
    

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13. Why need to learn
    Swift Compiler (Optimizer)?
    

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14. Why learn about Swift Compiler?
    Increase ways to solve difficult problems in Swift Coding
    Compiling Time, Compiler Bugs, Effective Code …
    Start Contributing to Swift Language
    So Fun
    

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15. Why learn about Optimizer?
    Easy to learn!
    Helpful to know what happened on Compiling for Product
    And how to try to solve problems related to Optimizer
    

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16. Agenda
    Why need to learn Swift Compiler (Optimizer)?
    Basis of Swift Compiler
    Swift Intermediate Language
    SIL Optimizer
    

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17. Basis of Swift Compiler
    

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18. Basis of Swift Compiler
    Looks Difficult?
    Don’t be afraid! I’ll describe Complier easily!
    

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19. Flow of Compiling Swift Code
    
    App
    

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20. AST AST
    (Typed)
    SIL IR
    (LLVM)
    
    App
    Flow of Compiling Swift Code
    

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21. AST AST
    (Typed)
    SIL IR
    (LLVM)
    
    App
    Flow of Compiling Swift Code
    

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22. AST
    Flow of Compiling Swift Code
    Convert to Abstract Syntax Tree by grammar rule of Swift
    Syntax Tree is a format for compiler to understand Code easy
    Parser
    

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23. AST AST
    (Typed)
    Flow of Compiling Swift Code
    AST to Typed AST
    Checking Type of the Code by generated AST or Type-Error
    Sema
    

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24. AST
    (Typed)
    SIL
    Flow of Compiling Swift Code
    SILGen
    Typed AST to Swift Intermediate Language(SIL)
    IR (Intermediate Representation)
    

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25. SIL IR
    (LLVM)
    Flow of Compiling Swift Code
    IRGen
    Swift Intermediate Language Code to LLVM IR
    LLVM is a backend of Swift
    

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26. IR
    (LLVM)
    
    App
    Flow of Compiling Swift Code
    Convert to executable, like iOS App, Command Line Tools …
    Other compiler phases like Linker are here (not touch today)
    

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27. AST AST
    (Typed)
    SIL IR
    (LLVM)
    
    App
    Flow of Compiling Swift Code
    

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28. AST AST
    (Typed)
    SIL IR
    (LLVM)
    
    App
    Flow of Compiling Swift Code
    

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29. SIL
    SIL is one of topic of talk topic!
    Let’s focus on SIL!
    

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30. Agenda
    Why need to learn Swift Compiler (Optimizer)?
    Basis of Swift Compiler
    Swift Intermediate Language
    SIL Optimizer
    

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31. Swift Intermediate Language
    

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32. AST AST
    (Typed)
    SIL IR
    (LLVM)
    
    App
    Swift Intermediate Language
    

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33. SIL
    Swift Intermediate Language
    Intermediate Representation(IR) of Swift
    Used for specialized optimization for Swift
    

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34. SIL
    Swift Intermediate Language
    LLVM IR is also optimized later
    IR
    (LLVM)
    Some effective optimization cannot be run on LLVM IR
    

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35. Swift Intermediate Language
    Let’s convert this code to SIL!
    print("Hello, World")
    hello.swift
    

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36. SIL
    Two kinds of SIL
    

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37. Two kinds of SIL
    

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38. Two kinds of SIL
    raw
    SIL
    canonical
    SIL
    

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39. raw
    SIL
    canonical
    SIL
    Two kinds of SIL
    raw SIL is generated by SILGen (from AST)
    canonical SIL is optimized raw SIL by SIL Optimizer
    

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40. Swift Intermediate Language
    raw
    SIL
    print("Hello, World")
    hello.swift
    

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42. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    

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43. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    
    

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44. Structure of SIL Code
    SIL Module
    Generated from Swift Source File
    

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45. Structure of SIL Code
    SIL Module
    Meta information
    (Imported libraries, Function signature, Witness Table …)
    

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46. Structure of SIL Code
    SIL Module
    SIL Function
    SIL Function
    SIL Function
    Meta information
    (Imported libraries, Function signature, Witness Table …)
    

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47. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    import Builtin
    import Swift
    import SwiftShims
    sil_stage raw
    

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48. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    sil_stage raw
    raw or canonical
    

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49. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    import Builtin
    import Swift
    import SwiftShims
    

    View Slide

50. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    import Builtin
    import Swift
    import SwiftShims
    

    View Slide

51. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    import Builtin
    import Swift
    import SwiftShims
    $Builtin.Int
    

    View Slide

52. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    import Builtin
    import Swift
    import SwiftShims
    $Builtin.Int
    

    View Slide

53. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    import Builtin
    import Swift
    import SwiftShims
    $Builtin.Int
    My Builtin Literal talk is avalible on YouTube
    

    View Slide

54. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    import Builtin
    import Swift
    import SwiftShims
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    

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55. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    

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56. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    

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57. Structure of SIL Code
    SIL Module
    SIL Function
    SIL Function
    SIL Function
    Meta information
    (imported libraries, vtable, function signature,witness table …)
    

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58. Structure of SIL Code
    Converted from Swift Function
    SIL Function
    

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59. sil_stage raw
    import Builtin
    import Swift
    import SwiftShims
    %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %4
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer) // user: %5
    (%5, %6) = destructure_tuple %4 : $(Array, Builtin.RawPointer) // users: %24, %21, %7
    %7 = pointer_to_address %6 : $Builtin.RawPointer to [strict] $*Any // user: %14
    %8 = string_literal utf8 "Hello, World" // user: %13
    %9 = integer_literal $Builtin.Word, 12 // user: %13
    %10 = integer_literal $Builtin.Int1, -1 // user: %13
    %11 = metatype $@thin String.Type // user: %13
    // function_ref String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    %12 = function_ref @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %13
    %13 = apply %12(%8, %9, %10, %11) : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String // user: %15
    %14 = init_existential_addr %7 : $*Any, $String // user: %15
    store %13 to [init] %14 : $*String // id: %15
    // function_ref default argument 1 of print(_:separator:terminator:)
    %16 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String // user: %17
    %17 = apply %16() : $@convention(thin) () -> @owned String // users: %23, %21
    // function_ref default argument 2 of print(_:separator:terminator:)
    %18 = function_ref @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String // user: %19
    %19 = apply %18() : $@convention(thin) () -> @owned String // users: %22, %21
    // function_ref print(_:separator:terminator:)
    %20 = function_ref @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> () // user: %21
    %21 = apply %20(%5, %17, %19) : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    destroy_value %19 : $String // id: %22
    destroy_value %17 : $String // id: %23
    destroy_value %5 : $Array // id: %24
    %25 = integer_literal $Builtin.Int32, 0 // user: %26
    %26 = struct $Int32 (%25 : $Builtin.Int32) // user: %27
    // _allocateUninitializedArray(_:)
    sil [serialized] [always_inline] [_semantics "array.uninitialized_intrinsic"] @$ss27_allocateUninitializedArrayySayxG_BptBwlF : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned Array<τ_0_0>, Builtin.RawPointer)
    // String.init(_builtinStringLiteral:utf8CodeUnitCount:isASCII:)
    sil [serialized] [always_inline] [readonly] [_semantics "string.makeUTF8"] @$sSS21_builtinStringLiteral17utf8CodeUnitCount7isASCIISSBp_BwBi1_tcfC : $@convention(method) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thin String.Type) -> @owned String
    // default argument 1 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA0_ : $@convention(thin) () -> @owned String
    // default argument 2 of print(_:separator:terminator:)
    sil hidden_external [serialized] @$ss5print_9separator10terminatoryypd_S2StFfA1_ : $@convention(thin) () -> @owned String
    // print(_:separator:terminator:)
    sil @$ss5print_9separator10terminatoryypd_S2StF : $@convention(thin) (@guaranteed Array, @guaranteed String, @guaranteed String) -> ()
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    

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60. …
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    

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61. “main” Function of Swift
    print("Hello, World")
    hello.swift
    Body code is surrounded by Main function
    Main function works as entry point like other languages
    

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62. Structure of SIL Code
    SIL Function
    SIL Basic Block
    SIL Basic Block
    SIL Basic Block
    SIL Basic Block
    SIL Basic Block
    

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63. Structure of SIL Code
    SIL Function
    SIL Basic Block
    SIL Basic Block
    SIL Basic Block
    SIL Basic Block
    SIL Basic Block
    

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64. Structure of SIL Code
    SIL Basic Block
    Basic Block is kind of Scope in Swift Function
    Increased as Conditional Branches of program
    

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65. …
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    

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66. …
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    bb represents Basic Block
    

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67. …
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    Basic Block is increased as Conditional Branches
    bb1 …:
    …
    bb represents Basic Block
    if, while, switch, … in Swift
    

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68. Structure of SIL Code
    SIL Basic Block
    SIL Instruction
    SIL Instruction
    SIL Instruction
    SIL Instruction
    SIL Instruction
    

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69. Structure of SIL Code
    Converted from Swift Code
    SIL Instruction
    

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70. %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF …
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned …)
    …
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    

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71. %2 = integer_literal $Builtin.Word, 1 // user: %4
    // function_ref _allocateUninitializedArray(_:)
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF …
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned …)
    …
    // main
    sil [ossa] @main : $@convention(c) (Int32, UnsafeMutablePointer>>) -> Int32 {
    bb0(%0 : $Int32, %1 : $UnsafeMutablePointer>>):
    return %26 : $Int32 // id: %27
    } // end sil function 'main'
    

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72. Structure of SIL Code
    Converted from Swift Code
    SIL Instruction
    Conformed to Static Single Assignment format
    

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73. Static Single Assignment (SSA)
    Each variable cannot be assigned value twice
    %2 = integer_literal $Builtin.Word, 1
    %3 = function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF …
    %4 = apply %3(%2) : $@convention(thin) <τ_0_0> (Builtin.Word) -> (@owned …)
    A left value starts from % is variable
    Instruction with assigning is %n = instruction
    

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74. Why converting SSA?
    Very easy to track how code is using each variable
    /// Body of SIL Function
    // A: integer variable
    %2 = integer_literal
    %3 = function_ref Int.init(:)
    %4 = apply %3(%2)
    // B: integer variable
    %5 = integer_literal
    %6 = function_ref Int.init(:)
    %7 = apply %5(%6)
    return %7 // return B
    

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75. Why converting SSA?
    Very easy to track how code is using each variable
    /// Body of SIL Function
    // A: integer variable
    %2 = integer_literal
    %3 = function_ref Int.init(:)
    %4 = apply %3(%2)
    // B: integer variable
    %5 = integer_literal
    %6 = function_ref Int.init(:)
    %7 = apply %5(%6)
    return %7 // return B
    Removing Dead(not used) Code of Function
    

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76. Why converting SSA?
    Very easy to track how code is using each variable
    /// Body of SIL Function
    // A: integer variable
    %2 = integer_literal
    %3 = function_ref Int.init(:)
    %4 = apply %3(%2)
    // B: integer variable
    %5 = integer_literal
    %6 = function_ref Int.init(:)
    %7 = apply %5(%6)
    return %7 // return B ← return and %7 should be marked as Live (used) Code
    

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77. Why converting SSA?
    Very easy to track how code is using each variable
    /// Body of SIL Function
    // A: integer variable
    %2 = integer_literal
    %3 = function_ref Int.init(:)
    %4 = apply %3(%2)
    // B: integer variable
    %5 = integer_literal
    %6 = function_ref Int.init(:)
    %7 = apply %5(%6)
    return %7 // return B ← return and %7 should be marked as Live (used) Code
    

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78. Why converting SSA?
    Very easy to track how code is using each variable
    /// Body of SIL Function
    // A: integer variable
    %2 = integer_literal
    %3 = function_ref Int.init(:)
    %4 = apply %3(%2)
    // B: integer variable
    %5 = integer_literal
    %6 = function_ref Int.init(:)
    %7 = apply %5(%6)
    return %7 // return B ← return and %7 should be marked as Live (used) Code
    ← %5 and %6 should be marked as Live (used) Code
    

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79. Why converting SSA?
    Very easy to track how code is using each variable
    /// Body of SIL Function
    // A: integer variable
    %2 = integer_literal
    %3 = function_ref Int.init(:)
    %4 = apply %3(%2)
    // B: integer variable
    %5 = integer_literal
    %6 = function_ref Int.init(:)
    %7 = apply %5(%6)
    return %7 // return B ← return and %7 should be marked as Live (used) Code
    ← %5 and %6 should be marked as Live (used) Code
    

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80. Why converting SSA?
    Very easy to track how code is using each variable
    /// Body of SIL Function
    // A: integer variable
    %2 = integer_literal
    %3 = function_ref Int.init(:)
    %4 = apply %3(%2)
    // B: integer variable
    %5 = integer_literal
    %6 = function_ref Int.init(:)
    %7 = apply %5(%6)
    return %7 // return B ← return and %7 should be marked as Live (used) Code
    ← %5 and %6 should be marked as Live (used) Code
    ← Marked as Dead Code because referred by return
    

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81. Why converting SSA?
    Very easy to track how code is using each variable
    /// Body of SIL Function
    // A: integer variable
    %2 = integer_literal
    %3 = function_ref Int.init(:)
    %4 = apply %3(%2)
    // B: integer variable
    %5 = integer_literal
    %6 = function_ref Int.init(:)
    %7 = apply %5(%6)
    return %7 // return B
    Searching for variable proceeds by Unidirectional flow
    

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82. Dead Code Elimination
    Constant Propagation
    Why converting SSA?
    Very easy to track how code is using each variable
    

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83. Structure of SIL Code
    Converted from Swift Code
    SIL Instruction
    The Code Style is conformed to SSA
    Reference: docs/SIL.rst in apple/swift
    

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84. Recap of SIL
    raw SIL and canonical SIL
    SIL consists of Module, Function, Basic Block and Instruction
    SIL is conformed to Single Static Assignment Format
    

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85. Agenda
    Why need to learn Swift Compiler (Optimizer)?
    Basis of Swift Compiler
    Swift Intermediate Language (SIL)
    SIL Optimizer
    

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86. SIL Optimizer
    

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87. How SIL Optimizer works
    

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88. raw to canonical
    raw
    SIL
    canonical
    SIL
    

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89. raw to canonical
    raw
    SIL
    canonical
    SIL
    SIL Code Optimization
    

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90. raw to canonical
    raw
    SIL
    canonical
    SIL
    SIL Optimizer
    SIL Code Optimization
    

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91. Role of SIL Optimizer
    SIL Optimizer has two important roles on Compiler Phase
    Optimization SIL Code
    Diagnostic SIL Code
    

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92. Role of SIL Optimizer
    SIL Optimizer has two important roles on Compiler Phase
    SIL Code
    Diagnostic SIL Code
    Optimization
    

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93. by SIL Optimizer
    Optimization specialized for Swift Language
    Optimization
    Generic Specialization
    Witness and VTable Devirtualization etc
    

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94. Role of SIL Optimizer
    SIL Optimizer has two important roles on Compiler Phase
    SIL Code
    SIL Code
    Diagnostic
    Optimization
    

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95. by Compiler
    Each phase of Compiler diagnoses your Swift Code
    Checking Grammar on Parser Phase (to AST)
    Checking Type on Sema Phase (to typed AST)
    ??? on SIL Optimizer Phase (to canonical SIL)
    Compiler will show error if diagnostic fails
    Diagnostic
    

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96. func wrongReturnType() -> String {
    return 2020
    }
    wrong-type.swift
    by Compiler
    Diagnostic
    

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97. AST AST
    (Typed)
    SIL IR
    (LLVM)
    
    App
    Diagnostic of Type Check
    

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98. AST AST
    (Typed)
    SIL IR
    (LLVM)
    
    App
    Diagnostic of Type Check
    OK
    NG
    error:
    cannot convert return expression of type 'Int' to return type 'String'
    

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99. func wrongReturnType() -> String {
    return 2020
    }
    wrong-type.swift
    Diagnostic of return
    

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100. func wrongReturnType() -> String {
     }
     wrong-type.swift
     Diagnostic of return
     

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101. SIL
     AST AST
     (Typed)
     IR
     (LLVM)
     
     App
     OK OK OK
     Diagnostic of return
     

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102. raw
     SIL
     canonical
     SIL
     Diagnostic in SIL Optimizer
     NG
     error: missing return in a function expected to return 'String'
     SIL Code Optimization
     

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103. Diagnostic of return
     func wrongReturnType() -> String {
     }
     no-return.swift
     … // some code
     fatalError()
     

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104. AST AST
     (Typed)
     SIL IR
     (LLVM)
     
     App
     OK
     Diagnostic of return
     OK OK OK OK
     No error by fatalError
     

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105. Examples
     Diagnostic of Grammar by Parser
     Diagnostic of validation no-return by SIL Optimizer
     Diagnostic
     Diagnostic of Overflow by SIL Optimizer
     Diagnostic of Type (of return) by Sema
     etc
     

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106. Role of SIL Optimizer
     SIL Optimizer has two important role on Compiler Phase
     Optimizing SIL Code
     SIL Code
     Diagnostic
     Guaranteeing safety as other roles of each phase
     

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107. raw SIL
     raw
     SIL
     canonical
     SIL
     SIL Optimizer
     Optimizing
     

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108. raw SIL
     raw
     SIL
     canonical
     SIL
     Optimizing
     Many Passes optimize your code in order
     Pass Pass
     Pass Pass
     Each Pass has role for optimization and diagnostic
     

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109. Example of Pass in SIL Optimizer
     Dead Code Elimination
     Constant Propagation
     Memory Promotion
     Other Diagnostic etc
     

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110. Pass Pipeline has information that which Pass must be called
     Pass Pipeline
     Pass Pass
     Pass Pass
     SIL Optimizer calls only registered Pass on Pipeline
     is Pass Pipeline
     

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111. How Pass PipeLine is built
     Pass Pass
     Pass Pass
     Pipeline is built from optimization level of Compiler
     -Onone : Minimum optimization for debugging situation
     -O : Optimization for production code
     -Osize : Optimization for reducing size than performance
     

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112. Which Pass is called or not?
     lib/SILOptimizer/PassManager/PassPipeline.cpp
     https://github.com/apple/swift
     

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113. Which Pass is called or not?
     lib/SILOptimizer/PassManager/PassPipeline.cpp
     addMandatoryDiagnosticOptPipeline
     getOnonePassPipeline
     etc
     

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114. List of Passes
     include/swift/SILOptimizer/PassManager/Passes.def
     https://github.com/apple/swift
     

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115. Recap of SIL Optimizer
     SIL Optimizer’s roles are Optimization and Diagnostic
     raw SIL is optimized by Passes in SIL Optimizer
     Pipeline has information which Pass must be called
     Pass Pipeline is built by optimization level
     

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116. SIL Optimizer
     

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117. More Deeper Dive into SIL Optimizer
     

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118. Two kinds of Pass
     For SIL Module
     For SIL Function
     Run by each SIL Module
     Run by each SIL Function
     

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119. Two kinds of Pass
     For SIL Module
     For SIL Function
     Dead Function Elimination
     Global Variable Optimization
     Dead Code Elimination
     Alloc Box to Stack
     etc
     etc
     

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120. How to know what kind of Pass
     Passes are developed by C++ Class in Compiler Code
     Each Pass inherits two kinds of Bass Class
     SILModuleTransform
     SILFunctionTransform
     

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121. How to know what kind of Pass
     For SIL Module
     For SIL Function
     Dead Function Elimination
     Global Variable Optimization
     Dead Code Elimination
     Alloc Box to Stack
     etc
     etc
     

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122. How to know what kind of Pass
     Dead Function Elimination
     class SILDeadFuncElimination : public SILModuleTransform {
     …
     }
     lib/SILOptimizer/IPO/DeadFunctionElimination.cpp
     

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123. How to know what kind of Pass
     Dead Code Elimination
     class DCE : public SILFunctionTransform {
     …
     }
     lib/SILOptimizer/Transforms/DeadCodeElimination.cpp
     

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124. Pass’s implementation
     Making Class from SILModule(Function)Transform
     Implementing run() as Entry Point
     

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125. Reading Pass Code
     For example, let’s read AssumeSingleThreaded Pass
     The smallest Pass in Swift Compiler
     Optimizes program specialized for Single Thread
     

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126. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &BB : *getFunction()) {
     for (auto &I : BB) {
     if (auto RCInst = dyn_cast(&I))
     RCInst->setNonAtomic();
     }
     }
     /// Post treatment
     }
     };
     

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127. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &BB : *getFunction()) {
     for (auto &I : BB) {
     if (auto RCInst = dyn_cast(&I))
     RCInst->setNonAtomic();
     }
     }
     /// Post treatment
     }
     };
     

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128. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &BB : *getFunction()) {
     for (auto &I : BB) {
     if (auto RCInst = dyn_cast(&I))
     RCInst->setNonAtomic();
     }
     }
     /// Post treatment
     }
     };
     

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129. Reading Pass Code
     Easy to understand if we know structure of SIL Code
     SIL Module
     SIL Function
     SIL Basic Block
     SIL Instruction
     

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130. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &BB : *getFunction()) {
     for (auto &I : BB) {
     if (auto RCInst = dyn_cast(&I))
     RCInst->setNonAtomic();
     }
     }
     /// Post treatment
     }
     };
     

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131. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &I : BB) {
     if (auto RCInst = dyn_cast(&I))
     RCInst->setNonAtomic();
     }
     /// Post treatment
     }
     };
     for (auto &BB : *getFunction()) {
     }
     

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132. Reading Pass Code
     getFunction returns current scanning SILFunction
     for (auto &BB : *getFunction()) {
     }
     …
     SILFunction can be treated as SILBasicBlock Collection
     

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133. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &BB : *getFunction()) {
     for (auto &I : BB) {
     if (auto RCInst = dyn_cast(&I))
     RCInst->setNonAtomic();
     }
     }
     /// Post treatment
     }
     };
     for (auto &BB : *getFunction()) {
     }
     

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134. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &BB : *getFunction()) {
     if (auto RCInst = dyn_cast(&I))
     RCInst->setNonAtomic();
     }
     /// Post treatment
     }
     };
     for (auto &I : BB) {
     }
     

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135. Reading Pass Code
     }
     …
     for (auto &I : BB) {
     SILBasicBlock is SILInstruction Collection
     Scanning SILInstruction from top
     

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136. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &BB : *getFunction()) {
     if (auto RCInst = dyn_cast(&I))
     RCInst->setNonAtomic();
     }
     /// Post treatment
     }
     };
     for (auto &I : BB) {
     }
     

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137. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &BB : *getFunction()) {
     if (. )
     RCInst->setNonAtomic();
     }
     /// Post treatment
     }
     };
     for (auto &I : BB) {
     }
     auto RCInst = dyn_cast(&I)
     

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138. Reading Pass Code
     Checking what kind of SILInstruction by casting
     RefCountingInst is instruction related to ARC
     auto RCInst = dyn_cast(&I)
     

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139. Reading Pass Code
     If we want to check instruction is return or not
     Check type-cast by ReturnInst
     auto ReturnInst = dyn_cast(&I)
     

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140. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &BB : *getFunction()) {
     if (. )
     RCInst->setNonAtomic();
     }
     /// Post treatment
     }
     };
     for (auto &I : BB) {
     }
     auto RCInst = dyn_cast(&I)
     

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141. lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp
     class AssumeSingleThreaded : public swift::SILFunctionTransform {
     /// The entry point to the transformation.
     void run() override {
     /// Checking option …
     for (auto &BB : *getFunction()) {
     for (auto &I : BB) {
     if (auto RCInst = dyn_cast(&I))
     }
     }
     /// Post treatment
     }
     };
     RCInst->setNonAtomic();
     

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142. Reading Pass Code
     Setting Reference Count instruction as non Atomic
     RCInst->setNonAtomic();
     

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143. What AssumeSingleThreaded?
     Scanning SIL Instruction related to Reference Count
     Marking Reference Count Instruction as non Atomic
     Called by each SIL Function
     

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144. Now, you can read
     Swift Compiler Code!
     

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145. Using docs/SIL.rst for reference of SIL Instruction
     Understanding C++ and LLVM for more deep dive
     Recap to read SIL Optimizer Code
     Understanding structure of SIL Code
     

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146. For More your learning Compiler
     

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147. Build Swift Compiler!
     You can clone from https://github.com/apple/swift
     It requires more than 60 GB ⚠ to build
     

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148. SIL Optimizer may have bugs which not tracked
     There is many chance to contribute!
     Contribute to Swift Compiler!
     

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149. Talk/Write about Swift Compiler!
     Swift Compiler is difficult topic
     Your talk/article would be helpful for next learner!
     

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150. Thank you!
     Twitter: _ _ _ freddi _ _ _
     Give me a feed back and question!
     

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