xcrun swiftc -emit-sil indirect.swift -o -|xcrun swift-demangle > indirect.sil

indirect.sil

sil_stage canonical

import Builtin
import Swift
import SwiftShims

// static Swift.Process._argc : Swift.Int32
sil_global [fragile] @static Swift.Process._argc : Swift.Int32 : $Int32

// globalinit_33_1BDF70FFC18749BAB495A73B459ED2F0_token5
sil_global private_external [fragile] @globalinit_33_1BDF70FFC18749BAB495A73B459ED2F0_token5 : $Builtin.Word

// static Swift.Process._unsafeArgv : Swift.UnsafeMutablePointer<Swift.UnsafeMutablePointer<Swift.Int8>>
sil_global [fragile] @static Swift.Process._unsafeArgv : Swift.UnsafeMutablePointer<Swift.UnsafeMutablePointer<Swift.Int8>> : $UnsafeMutablePointer<UnsafeMutablePointer<Int8>>

// main
sil @main : $@convention(c) (Int32, UnsafeMutablePointer<UnsafeMutablePointer<Int8>>) -> Int32 {
bb0(%0 : $Int32, %1 : $UnsafeMutablePointer<UnsafeMutablePointer<Int8>>):
  %2 = global_addr @static Swift.Process._argc : Swift.Int32 : $*Int32 // user: %3
  store %0 to %2 : $*Int32                        // id: %3
  %4 = global_addr @globalinit_33_1BDF70FFC18749BAB495A73B459ED2F0_token5 : $*Builtin.Word // user: %5
  %5 = address_to_pointer %4 : $*Builtin.Word to $Builtin.RawPointer // user: %7
  // function_ref globalinit_33_1BDF70FFC18749BAB495A73B459ED2F0_func5
  %6 = function_ref @globalinit_33_1BDF70FFC18749BAB495A73B459ED2F0_func5 : $@convention(thin) () -> () // user: %7
  %7 = builtin "once"(%5 : $Builtin.RawPointer, %6 : $@convention(thin) () -> ()) : $()
  %8 = global_addr @static Swift.Process._unsafeArgv : Swift.UnsafeMutablePointer<Swift.UnsafeMutablePointer<Swift.Int8>> : $*UnsafeMutablePointer<UnsafeMutablePointer<Int8>> // user: %9
  store %1 to %8 : $*UnsafeMutablePointer<UnsafeMutablePointer<Int8>> // id: %9
  %10 = tuple ()
  %11 = integer_literal $Builtin.Int32, 0         // user: %12
  %12 = struct $Int32 (%11 : $Builtin.Int32)      // user: %13
  return %12 : $Int32                             // id: %13
}

// Swift._didEnterMain (Swift.Int32, argv : Swift.UnsafeMutablePointer<Swift.UnsafeMutablePointer<Swift.Int8>>) -> ()
sil [transparent] [fragile] @Swift._didEnterMain (Swift.Int32, argv : Swift.UnsafeMutablePointer<Swift.UnsafeMutablePointer<Swift.Int8>>) -> () : $@convention(thin) (Int32, UnsafeMutablePointer<UnsafeMutablePointer<Int8>>) -> ()

// main.NoIndirect.A <A> (main.NoIndirect<A>.Type)(A) -> main.NoIndirect<A>
sil hidden [transparent] @main.NoIndirect.A <A> (main.NoIndirect<A>.Type)(A) -> main.NoIndirect<A> : $@convention(thin) <T> (@out NoIndirect<T>, @in T, @thin NoIndirect<T>.Type) -> () {
bb0(%0 : $*NoIndirect<T>, %1 : $*T, %2 : $@thin NoIndirect<T>.Type):
  %3 = init_enum_data_addr %0 : $*NoIndirect<T>, #NoIndirect.A!enumelt.1 // user: %4
  copy_addr [take] %1 to [initialization] %3 : $*T // id: %4
  inject_enum_addr %0 : $*NoIndirect<T>, #NoIndirect.A!enumelt.1 // id: %5
  %6 = tuple ()                                   // user: %7
  return %6 : $()                                 // id: %7
}

// main.NoIndirect.B <A> (main.NoIndirect<A>.Type)(A) -> main.NoIndirect<A>
sil hidden [transparent] @main.NoIndirect.B <A> (main.NoIndirect<A>.Type)(A) -> main.NoIndirect<A> : $@convention(thin) <T> (@out NoIndirect<T>, @in T, @thin NoIndirect<T>.Type) -> () {
bb0(%0 : $*NoIndirect<T>, %1 : $*T, %2 : $@thin NoIndirect<T>.Type):
  %3 = init_enum_data_addr %0 : $*NoIndirect<T>, #NoIndirect.B!enumelt.1 // user: %4
  copy_addr [take] %1 to [initialization] %3 : $*T // id: %4
  inject_enum_addr %0 : $*NoIndirect<T>, #NoIndirect.B!enumelt.1 // id: %5
  %6 = tuple ()                                   // user: %7
  return %6 : $()                                 // id: %7
}

// main.NoIndirect.C <A> (main.NoIndirect<A>.Type)(A) -> main.NoIndirect<A>
sil hidden [transparent] @main.NoIndirect.C <A> (main.NoIndirect<A>.Type)(A) -> main.NoIndirect<A> : $@convention(thin) <T> (@out NoIndirect<T>, @in T, @thin NoIndirect<T>.Type) -> () {
bb0(%0 : $*NoIndirect<T>, %1 : $*T, %2 : $@thin NoIndirect<T>.Type):
  %3 = init_enum_data_addr %0 : $*NoIndirect<T>, #NoIndirect.C!enumelt.1 // user: %4
  copy_addr [take] %1 to [initialization] %3 : $*T // id: %4
  inject_enum_addr %0 : $*NoIndirect<T>, #NoIndirect.C!enumelt.1 // id: %5
  %6 = tuple ()                                   // user: %7
  return %6 : $()                                 // id: %7
}

// main.Indirect.A <A> (main.Indirect<A>.Type)(A) -> main.Indirect<A>
sil hidden [transparent] @main.Indirect.A <A> (main.Indirect<A>.Type)(A) -> main.Indirect<A> : $@convention(thin) <T> (@in T, @thin Indirect<T>.Type) -> @owned Indirect<T> {
bb0(%0 : $*T, %1 : $@thin Indirect<T>.Type):
  %2 = alloc_box $T                               // users: %3, %4
  copy_addr [take] %0 to [initialization] %2#1 : $*T // id: %3
  %4 = enum $Indirect<T>, #Indirect.A!enumelt.1, %2#0 : $@box T // user: %5
  return %4 : $Indirect<T>                        // id: %5
}

// main.Indirect.B <A> (main.Indirect<A>.Type)(A) -> main.Indirect<A>
sil hidden [transparent] @main.Indirect.B <A> (main.Indirect<A>.Type)(A) -> main.Indirect<A> : $@convention(thin) <T> (@in T, @thin Indirect<T>.Type) -> @owned Indirect<T> {
bb0(%0 : $*T, %1 : $@thin Indirect<T>.Type):
  %2 = alloc_box $T                               // users: %3, %4
  copy_addr [take] %0 to [initialization] %2#1 : $*T // id: %3
  %4 = enum $Indirect<T>, #Indirect.B!enumelt.1, %2#0 : $@box T // user: %5
  return %4 : $Indirect<T>                        // id: %5
}

// main.Indirect.C <A> (main.Indirect<A>.Type)(A) -> main.Indirect<A>
sil hidden [transparent] @main.Indirect.C <A> (main.Indirect<A>.Type)(A) -> main.Indirect<A> : $@convention(thin) <T> (@in T, @thin Indirect<T>.Type) -> @owned Indirect<T> {
bb0(%0 : $*T, %1 : $@thin Indirect<T>.Type):
  %2 = alloc_box $T                               // users: %3, %4
  copy_addr [take] %0 to [initialization] %2#1 : $*T // id: %3
  %4 = enum $Indirect<T>, #Indirect.C!enumelt.1, %2#0 : $@box T // user: %5
  return %4 : $Indirect<T>                        // id: %5
}

// main.NoIndirectA () -> ()
sil hidden @main.NoIndirectA () -> () : $@convention(thin) () -> () {
bb0:
  %0 = integer_literal $Builtin.Int64, 1          // user: %1
  %1 = struct $Int (%0 : $Builtin.Int64)          // user: %4
  %2 = alloc_stack $NoIndirect<Int>               // users: %3, %5, %7, %16, %19
  %3 = init_enum_data_addr %2#1 : $*NoIndirect<Int>, #NoIndirect.A!enumelt.1 // user: %4
  store %1 to %3 : $*Int                          // id: %4
  inject_enum_addr %2#1 : $*NoIndirect<Int>, #NoIndirect.A!enumelt.1 // id: %5
  %6 = tuple ()
  %7 = load %2#1 : $*NoIndirect<Int>              // user: %8
  switch_enum %7 : $NoIndirect<Int>, case #NoIndirect.A!enumelt.1: bb1, default bb2 // id: %8

bb1(%9 : $Int):                                   // Preds: bb0
  debug_value %9 : $Int  // let a                 // id: %10
  // function_ref Swift.print <A> (A) -> ()
  %11 = function_ref @Swift.print <A> (A) -> () : $@convention(thin) <τ_0_0> (@in τ_0_0) -> () // user: %14
  %12 = alloc_stack $Int                          // users: %13, %14, %15
  store %9 to %12#1 : $*Int                       // id: %13
  %14 = apply %11<Int>(%12#1) : $@convention(thin) <τ_0_0> (@in τ_0_0) -> ()
  dealloc_stack %12#0 : $*@local_storage Int      // id: %15
  dealloc_stack %2#0 : $*@local_storage NoIndirect<Int> // id: %16
  br bb4                                          // id: %17

bb2:                                              // Preds: bb0
  br bb3                                          // id: %18

bb3:                                              // Preds: bb2
  dealloc_stack %2#0 : $*@local_storage NoIndirect<Int> // id: %19
  br bb4                                          // id: %20

bb4:                                              // Preds: bb1 bb3
  %21 = tuple ()                                  // user: %22
  return %21 : $()                                // id: %22
}

// Swift.Int.init (Swift.Int.Type)(_builtinIntegerLiteral : Builtin.Int2048) -> Swift.Int
sil [transparent] [fragile] @Swift.Int.init (Swift.Int.Type)(_builtinIntegerLiteral : Builtin.Int2048) -> Swift.Int : $@convention(thin) (Builtin.Int2048, @thin Int.Type) -> Int

// Swift.print <A> (A) -> ()
sil [noinline] [_semantics "stdlib_binary_only"] @Swift.print <A> (A) -> () : $@convention(thin) <τ_0_0> (@in τ_0_0) -> ()

// main.IndirectA () -> ()
sil hidden @main.IndirectA () -> () : $@convention(thin) () -> () {
bb0:
  %0 = integer_literal $Builtin.Int64, 1          // user: %1
  %1 = struct $Int (%0 : $Builtin.Int64)          // user: %3
  %2 = alloc_box $Int                             // users: %3, %5, %13
  store %1 to %2#1 : $*Int                        // id: %3
  br bb1                                          // id: %4

bb1:                                              // Preds: bb0
  %5 = project_box %2#0 : $@box Int               // user: %6
  %6 = load %5 : $*Int                            // users: %7, %10
  debug_value %6 : $Int  // let a                 // id: %7
  // function_ref Swift.print <A> (A) -> ()
  %8 = function_ref @Swift.print <A> (A) -> () : $@convention(thin) <τ_0_0> (@in τ_0_0) -> () // user: %11
  %9 = alloc_stack $Int                           // users: %10, %11, %12
  store %6 to %9#1 : $*Int                        // id: %10
  %11 = apply %8<Int>(%9#1) : $@convention(thin) <τ_0_0> (@in τ_0_0) -> ()
  dealloc_stack %9#0 : $*@local_storage Int       // id: %12
  strong_release %2#0 : $@box Int                 // id: %13
  br bb2                                          // id: %14

bb2:                                              // Preds: bb1
  %15 = tuple ()                                  // user: %16
  return %15 : $()                                // id: %16
}

// globalinit_33_1BDF70FFC18749BAB495A73B459ED2F0_func5
sil private_external [fragile] @globalinit_33_1BDF70FFC18749BAB495A73B459ED2F0_func5 : $@convention(thin) () -> ()

indirect.swift

enum NoIndirect<T> {
    case A(T)
    case B(T)
    case C(T)
}

indirect enum Indirect<T> {
    case A(T)
    case B(T)
    case C(T)
}


func NoIndirectA() {
    switch NoIndirect.A(1) {
    case .A(let a):
        print(a)
    default:()
    }
}

func IndirectA() {
    switch Indirect.A(1) {
    case .A(let a):
        print(a)
    default:()
    }
}