// RUN: %target-sil-opt -enable-sil-verify-all %s -mem2reg | %FileCheck %s

import Builtin
import Swift

//////////////////
// Declarations //
//////////////////

class Klass {}

struct SmallCodesizeStruct {
  var cls1 : Klass
  var cls2 : Klass
}

struct LargeCodesizeStruct {
  var s1: SmallCodesizeStruct
  var s2: SmallCodesizeStruct
  var s3: SmallCodesizeStruct
  var s4: SmallCodesizeStruct
  var s5: SmallCodesizeStruct
}

struct EmptyStruct {}
struct Pair<T, U> {
  var t: T
  var u: U
}

///////////
// Tests //
///////////

// CHECK-LABEL: sil @store_only_allocas
// CHECK-NOT: alloc_stack
// CHECK: return
// simple.foo0 (c : Swift.Int64) -> ()
sil @store_only_allocas : $@convention(thin) (Int64) -> () {
bb0(%0 : $Int64):
  %1 = alloc_stack $Int64, var, name "c"               // users: %5, %2
  store %0 to %1 : $*Int64                      // id: %2
  // function_ref Swift.print (val : Swift.Int64) -> ()
  %3 = function_ref @_Ts5printFT3valSi_T_ : $@convention(thin) (Int64) -> () // user: %4
  %4 = apply %3(%0) : $@convention(thin) (Int64) -> ()
  dealloc_stack %1 : $*Int64     // id: %5
  %6 = tuple ()                                   // user: %7
  return %6 : $()                                 // id: %7
}

// Swift.print (val : Swift.Int64) -> ()
sil @_Ts5printFT3valSi_T_ : $@convention(thin) (Int64) -> ()

// CHECK-LABEL: sil @multiple_store_vals
// CHECK-NOT: alloc_stack
// CHECK: return
// simple.foo1 (c : Swift.Int64) -> Swift.Int64
sil @multiple_store_vals : $@convention(thin) (Int64) -> Int64 {
bb0(%0 : $Int64):
  %1 = alloc_stack $Int64, var, name "c"               // users: %14, %2
  store %0 to %1 : $*Int64                      // id: %2
  %3 = alloc_stack $Int64, var, name "x"               // users: %12, %11, %13, %6
  %4 = integer_literal $Builtin.Int64, 2          // user: %5
  %5 = struct $Int64 (%4 : $Builtin.Int64)        // user: %6
  store %5 to %3 : $*Int64                      // id: %6
  %7 = integer_literal $Builtin.Int64, 5          // user: %9
  %8 = integer_literal $Builtin.Int1, 0           // user: %10
  %9 = struct $Int64 (%7 : $Builtin.Int64)        // users: %12, %15, %11
  cond_fail %8 : $Builtin.Int1                    // id: %10
  store %9 to %3 : $*Int64                      // id: %11
  store %9 to %3 : $*Int64                      // id: %12
  dealloc_stack %3 : $*Int64     // id: %13
  dealloc_stack %1 : $*Int64     // id: %14
  return %9 : $Int64                              // id: %15
}

// CHECK-LABEL: sil @multiple_store_vals2
// CHECK-NOT: alloc_stack
// CHECK: return
// simple.foo2 (c : Swift.Int64) -> Swift.Int64
sil @multiple_store_vals2 : $@convention(thin) (Int64) -> Int64 {
bb0(%0 : $Int64):
  %1 = alloc_stack $Int64, var, name "c"               // users: %19, %2
  store %0 to %1 : $*Int64                      // id: %2
  %3 = alloc_box $<τ_0_0> { var τ_0_0 } <Int64>, var, name "x"                 // users: %16, %11, %6
  %3a = project_box %3 : $<τ_0_0> { var τ_0_0 } <Int64>, 0
  %4 = integer_literal $Builtin.Int64, 2          // users: %9, %5
  %5 = struct $Int64 (%4 : $Builtin.Int64)        // users: %12, %6
  store %5 to %3a : $*Int64                      // id: %6
  %8 = struct_extract %0 : $Int64, #Int64._value   // user: %9
  %9 = builtin "cmp_sgt_Int64"(%8 : $Builtin.Int64, %4 : $Builtin.Int64) : $Builtin.Int1 // users: %15, %10
  cond_br %9, bb1, bb2                            // id: %10

bb1:                                              // Preds: bb0
  strong_release %3 : $<τ_0_0> { var τ_0_0 } <Int64>    // id: %11
  br bb3(%5 : $Int64)                             // id: %12

bb2:                                              // Preds: bb0
  %13 = integer_literal $Builtin.Int64, 5         // user: %14
  %14 = struct $Int64 (%13 : $Builtin.Int64)      // user: %17
  cond_fail %9 : $Builtin.Int1                    // id: %15
  strong_release %3 : $<τ_0_0> { var τ_0_0 } <Int64>    // id: %16
  br bb3(%14 : $Int64)                            // id: %17

bb3(%18 : $Int64):                                // Preds: bb2 bb1
  dealloc_stack %1 : $*Int64     // id: %19
  return %18 : $Int64                             // id: %20
}

// CHECK-LABEL: sil @with_loads
// simple.foo2 (c : Swift.Int64) -> Swift.Int64
sil @with_loads : $@convention(thin) (Int64) -> Int64 {
bb0(%0 : $Int64):
  %1 = alloc_stack $Int64, var, name "c"               // users: %19, %2, (%20)
  store %0 to %1 : $*Int64                      // id: %2
  %3 = alloc_box $<τ_0_0> { var τ_0_0 } <Int64>, var, name "x"                 // users: %16, %11, %6
  %3a = project_box %3 : $<τ_0_0> { var τ_0_0 } <Int64>, 0
  %4 = integer_literal $Builtin.Int64, 2          // users: %9, %5
  %5 = struct $Int64 (%4 : $Builtin.Int64)        // users: %12, %6
  store %5 to %3a : $*Int64                      // id: %6
  %8 = struct_extract %0 : $Int64, #Int64._value   // user: %9
  %9 = builtin "cmp_sgt_Int64"(%8 : $Builtin.Int64, %4 : $Builtin.Int64) : $Builtin.Int1 // users: %15, %10
  cond_br %9, bb1, bb2                            // id: %10

bb1:                                              // Preds: bb0
  strong_release %3 : $<τ_0_0> { var τ_0_0 } <Int64>    // id: %11
  br bb3(%5 : $Int64)                             // id: %12

bb2:                                              // Preds: bb0
  %13 = integer_literal $Builtin.Int64, 5         // user: %14
  %14 = struct $Int64 (%13 : $Builtin.Int64)      // user: %17
  cond_fail %9 : $Builtin.Int1                    // id: %15
  strong_release %3 : $<τ_0_0> { var τ_0_0 } <Int64>    // id: %16
  br bb3(%14 : $Int64)                            // id: %17

//CHECK: bb3([[RET:%[0-9]+]] : $Int64):
bb3(%18 : $Int64):                                // Preds: bb2 bb1
  dealloc_stack %1 : $*Int64     // id: %19
  %20 = load %1 : $*Int64
//CHECK: return [[RET]]
  return %18 : $Int64                             // id: %20
}

// CHECK-LABEL: sil @basic_block_with_loads_and_stores
// CHECK-NOT: alloc_stack
// CHECK: return
// test.foo3 (c : Swift.Int64) -> ()
sil @basic_block_with_loads_and_stores : $@convention(thin) (Int64) -> () {
bb0(%0 : $Int64):
  %1 = alloc_stack $Int64, var, name "c"               // users: %20, %2
  store %0 to %1 : $*Int64                      // id: %2
  %3 = alloc_stack $Int64, var, name "x"               // users: %14, %19, %6, %17
  %4 = integer_literal $Builtin.Int64, 3          // user: %5
  %5 = struct $Int64 (%4 : $Builtin.Int64)        // user: %6
  store %5 to %3 : $*Int64                      // id: %6
  %7 = integer_literal $Builtin.Int64, 3          // user: %10
  %9 = struct_extract %0 : $Int64, #Int64._value   // user: %10
  %10 = builtin "cmp_sgt_Int64"(%9 : $Builtin.Int64, %7 : $Builtin.Int64) : $Builtin.Int1 // user: %11

  %12 = integer_literal $Builtin.Int64, 2         // user: %13
  %13 = struct $Int64 (%12 : $Builtin.Int64)      // user: %14
  store %13 to %3 : $*Int64                     // id: %14

  // function_ref Swift.print (val : Swift.Int64) -> ()
  %16 = function_ref @_Ts5printFT3valSi_T_ : $@convention(thin) (Int64) -> () // user: %18
  %17 = load %3 : $*Int64                       // user: %18
  %18 = apply %16(%17) : $@convention(thin) (Int64) -> ()
  dealloc_stack %3 : $*Int64     // id: %19
  dealloc_stack %1 : $*Int64     // id: %20
  %21 = tuple ()                                  // user: %22
  return %21 : $()                                // id: %22
}

// CHECK-LABEL: sil @load_uninitialized_empty
// CHECK-NOT: load
// CHECK: return
sil @load_uninitialized_empty : $@convention(thin) (@inout ()) -> () {
bb0(%0 : $*()):
  %1 = alloc_stack $()
  %2 = load %1 : $*()
  store %2 to %0 : $*()
  dealloc_stack %1 : $*()
  %3 = tuple ()
  return %3 : $()
}

// CHECK-LABEL: sil @mem2reg_debug_value
// CHECK-NOT: alloc_stack
// CHECK-NOT: debug_value {{.*}} expr op_deref
// CHECK: debug_value %0
// CHECK: return
sil @mem2reg_debug_value : $@convention(thin) (Int) -> Int {
bb0(%0 : $Int):
  %1 = alloc_stack $Int
  store %0 to %1 : $*Int
  debug_value %1 : $*Int, expr op_deref
  %2 = load %1 : $*Int
  dealloc_stack %1 : $*Int
  return %2 : $Int
}

// CHECK-LABEL: sil @mem2reg_struct_addr
// CHECK-NOT: alloc_stack
// CHECK: struct_extract
// CHECK: return
sil @mem2reg_struct_addr : $@convention(thin) (Int64) -> Builtin.Int64 {
bb0(%0 : $Int64):
  %1 = alloc_stack $Int64
  store %0 to %1 : $*Int64
  %2 = struct_element_addr %1 : $*Int64, #Int64._value
  %3 = load %2 : $*Builtin.Int64
  dealloc_stack %1 : $*Int64
  return %3 : $Builtin.Int64
}

// CHECK-LABEL: sil @mem2reg_tuple_addr
// CHECK-NOT: alloc_stack
// CHECK: tuple_extract {{.*}}, 0
// CHECK: return
sil @mem2reg_tuple_addr : $@convention(thin) (Int64) -> Int64 {
bb0(%0 : $Int64):
  %1 = alloc_stack $(Int64, Int64)
  %2 = tuple (%0 : $Int64, %0 : $Int64)
  store %2 to %1 : $*(Int64, Int64)
  %4 = tuple_element_addr %1 : $*(Int64, Int64), 0
  %5 = load %4 : $*Int64
  dealloc_stack %1 : $*(Int64, Int64)
  return %5 : $Int64
}

// CHECK-LABEL: sil @struct_extract_if_then_else
// CHECK-NOT: alloc_stack
sil @struct_extract_if_then_else : $@convention(thin) (Int64) -> Int64 {
bb0(%0 : $Int64):
  %1 = alloc_stack $Int64
  store %0 to %1 : $*Int64
  %3 = integer_literal $Builtin.Int64, 2
  %4 = struct_extract %0 : $Int64, #Int64._value
  %5 = builtin "cmp_sgt_Int64"(%4 : $Builtin.Int64, %3 : $Builtin.Int64) : $Builtin.Int1
  %6 = struct_element_addr %1 : $*Int64, #Int64._value
  cond_br %5, bb1, bb2

// CHECK: bb1:
// CHECK: struct_extract %0
bb1:
  %8 = load %6 : $*Builtin.Int64
  %9 = integer_literal $Builtin.Int64, 1
  %10 = integer_literal $Builtin.Int1, 0
  %11 = builtin "sadd_with_overflow_Int64"(%8 : $Builtin.Int64, %9 : $Builtin.Int64, %10 : $Builtin.Int1) : $(Builtin.Int64, Builtin.Int1)
  %12 = tuple_extract %11 : $(Builtin.Int64, Builtin.Int1), 0
  br bb3(%12 : $Builtin.Int64)

// CHECK: bb2:
// CHECK: struct_extract %0
bb2:
  %14 = load %6 : $*Builtin.Int64
  %15 = integer_literal $Builtin.Int64, 2
  %16 = integer_literal $Builtin.Int1, 0
  %17 = builtin "sadd_with_overflow_Int64"(%14 : $Builtin.Int64, %15 : $Builtin.Int64, %16 : $Builtin.Int1) : $(Builtin.Int64, Builtin.Int1)
  %18 = tuple_extract %17 : $(Builtin.Int64, Builtin.Int1), 0
  br bb3(%18 : $Builtin.Int64)

// CHECK-NOT: dealloc_stack
bb3(%20 : $Builtin.Int64):
  dealloc_stack %1 : $*Int64
  %22 = struct $Int64 (%20 : $Builtin.Int64)
  return %22 : $Int64
}

sil @first : $@convention(thin) () -> Int
sil @second : $@convention(thin) () -> Int

// CHECK: sil @promote_function_refs
sil @promote_function_refs : $@convention(thin) (Bool) -> Int {
// CHECK: bb0
bb0(%0 : $Bool):
// CHECK-NOT: [[STACK:%.*]] = alloc_stack
  %1 = alloc_stack $@callee_owned () -> Int
  debug_value %0 : $Bool
  %3 = struct_extract %0 : $Bool, #Bool._value
  cond_br %3, bb1, bb2

// CHECK: bb1
bb1:
// CHECK: [[FIRSTREF:%.*]] = function_ref @first
  %5 = function_ref @first : $@convention(thin) () -> Int
// CHECK: [[FIRSTTHICK:%.*]] =  thin_to_thick_function [[FIRSTREF]]
  %6 = thin_to_thick_function %5 : $@convention(thin) () -> Int to $@callee_owned () -> Int
// CHECK-NOT: store
  store %6 to %1 : $*@callee_owned () -> Int
// CHECK: br bb3([[FIRSTTHICK]] : $@callee_owned () -> Int
  br bb3

// CHECK: bb2
bb2:
// CHECK: [[SECONDREF:%.*]] = function_ref @second
  %9 = function_ref @second : $@convention(thin) () -> Int
// CHECK: [[SECONDTHICK:%.*]] =  thin_to_thick_function [[SECONDREF]]
  %10 = thin_to_thick_function %9 : $@convention(thin) () -> Int to $@callee_owned () -> Int
// CHECK-NOT: store
  store %10 to %1 : $*@callee_owned () -> Int
// CHECK: br bb3([[SECONDTHICK]] : $@callee_owned () -> Int)
  br bb3

// CHECK: bb3([[ARG:%.*]] : $@callee_owned () -> Int):
bb3:
// CHECK-NOT: load
  %13 = load %1 : $*@callee_owned () -> Int
// CHECK: strong_retain [[ARG]]
  strong_retain %13 : $@callee_owned () -> Int
// CHECK: [[RESULT:%.*]] = apply [[ARG]]
  %15 = apply %13() : $@callee_owned () -> Int
  br bb4

  // NOTE: This block and the branch above exist to ensure that we
  //       test what happens when %1 hasn't already been loaded in this
  //       block.
// CHECK: bb4
bb4:
// CHECK-NOT: destroy_addr
// CHECK: strong_release [[ARG]]
  destroy_addr %1 : $*@callee_owned () -> Int
// CHECK-NOT: dealloc_stack
  dealloc_stack %1 : $*@callee_owned () -> Int
// CHECK: return [[RESULT]]
  return %15 : $Int
}

// Test cases where the only use is a debug_value_addr
// CHECK-LABEL: sil @no_real_uses
sil @no_real_uses : $@convention(thin) () -> () {
// CHECK: bb0
bb0:
  // CHECK-NOT: alloc_stack
  %0 = alloc_stack $Builtin.Int32
  // CHECK-NOT: debug_value {{.*}} expr op_deref
  debug_value %0 : $*Builtin.Int32, let, name "x", argno 1, expr op_deref
  // CHECK-NOT: dealloc_stack
  dealloc_stack %0 : $*Builtin.Int32
  // CHECK: [[VAL:%.*]] = tuple ()
  %1 = tuple ()
  // CHECK: return [[VAL]]
  return %1 : $()
}

// CHECK-LABEL: sil @keep_release
// CHECK: strong_release %0
// CHECK: return
sil @keep_release : $@convention(thin) (@owned AnyObject) -> () {
bb0(%0 : $AnyObject):
  %1 = alloc_stack $AnyObject
  store %0 to %1 : $*AnyObject
  destroy_addr %1 : $*AnyObject
  dealloc_stack %1 : $*AnyObject
  %7 = tuple ()
  return %7 : $()
}

// Test cases where there are dead address instructions.
// CHECK-LABEL: sil @dead_use
// CHECK-NOT: alloc_stack
sil @dead_use : $@convention(thin) () -> () {
  %0 = alloc_stack $Int64
  %1 = struct_element_addr %0 : $*Int64, #Int64._value
  dealloc_stack %0 : $*Int64
  %2 = alloc_stack $(Int64, Int64)
  %3 = tuple_element_addr %2 : $*(Int64, Int64), 0
  dealloc_stack %2 : $*(Int64, Int64)
  // CHECK: [[VAL:%.*]] = tuple ()
  %4 = tuple ()
  // CHECK: return [[VAL]]
  return %4 : $()
}

// CHECK-LABEL: sil @dont_crash_on_dead_arg_use
// CHECK: bb0{{.*}}:
// CHECK:      tuple ()
// CHECK-NEXT: return
sil @dont_crash_on_dead_arg_use : $@convention(thin) (@inout Int64) -> () {
bb0(%0 : $*Int64):
  %2 = alloc_stack $Int64
  %1 = struct_element_addr %0 : $*Int64, #Int64._value
  %3 = struct_element_addr %2 : $*Int64, #Int64._value
  dealloc_stack %2 : $*Int64
  %4 = tuple ()
  return %4 : $()
}

// Make sure that we do expand destroy_addr appropriately for code-size
// trade-offs.
// CHECK-LABEL: sil @large_struct_test : $@convention(thin) (@owned LargeCodesizeStruct) -> () {
// CHECK: bb0([[ARG0:%.*]] : $LargeCodesizeStruct):
// CHECK:   release_value [[ARG0]]
// CHECK: } // end sil function 'large_struct_test'
sil @large_struct_test : $@convention(thin) (@owned LargeCodesizeStruct) -> () {
bb0(%0 : $LargeCodesizeStruct):
  %1 = alloc_stack $LargeCodesizeStruct
  store %0 to %1 : $*LargeCodesizeStruct
  destroy_addr %1 : $*LargeCodesizeStruct
  dealloc_stack %1 : $*LargeCodesizeStruct
  %7 = tuple ()
  return %7 : $()
}

// CHECK-LABEL: sil @small_struct_test : $@convention(thin) (@owned SmallCodesizeStruct) -> () {
// CHECK: bb0([[ARG0:%.*]] : $SmallCodesizeStruct):
// CHECK:   [[ARG0cls1:%.*]] = struct_extract [[ARG0]]
// CHECK:   strong_release [[ARG0cls1]]
// CHECK:   [[ARG0cls2:%.*]] = struct_extract [[ARG0]]
// CHECK:   strong_release [[ARG0cls2]]
// CHECK: } // end sil function 'small_struct_test'
sil @small_struct_test : $@convention(thin) (@owned SmallCodesizeStruct) -> () {
bb0(%0 : $SmallCodesizeStruct):
  %1 = alloc_stack $SmallCodesizeStruct
  store %0 to %1 : $*SmallCodesizeStruct
  destroy_addr %1 : $*SmallCodesizeStruct
  dealloc_stack %1 : $*SmallCodesizeStruct
  %7 = tuple ()
  return %7 : $()
}

// CHECK-LABEL: sil @dead_address_projections
// CHECK-NOT: alloc_stack
// CHECK: } // end sil function 'dead_address_projections'
sil @dead_address_projections : $@convention(thin) (((), ())) -> ((), ()) {
bb0(%0 : $((), ())):
  %1 = alloc_stack $((), ())
  %200 = tuple_element_addr %1 : $*((), ()), 0
  %300 = tuple_element_addr %1 : $*((), ()), 1
  cond_br undef, bb1, bb2

bb1:
  store %0 to %1 : $*((), ())
  %16 = load %1 : $*((), ())
  dealloc_stack %1 : $*((), ())
  br bb3(%16 : $((), ()))

bb2:
  dealloc_stack %1 : $*((), ())
  br bb3(%0 : $((), ()))

bb3(%20 : $((), ())):
  return %20 : $((), ())
}

// CHECK-LABEL: sil @load_tuple_of_void
// CHECK:   [[T:%[0-9]+]] = tuple (%{{[0-9]+}} : $(), %{{[0-9]+}} : $())
// CHECK:   return [[T]] : $((), ())
// CHECK: } // end sil function 'load_tuple_of_void'
sil @load_tuple_of_void : $@convention(thin) () -> ((), ()) {
bb0:
  %1 = alloc_stack $((), ())
  %16 = load %1 : $*((), ())
  dealloc_stack %1 : $*((), ())
  return %16 : $((), ())
}

// CHECK-LABEL: sil @unchecked_bitwise_cast
// CHECK-NOT: alloc_stack
// CHECK: [[CAST:%.*]] = unchecked_bitwise_cast %0 : $Optional<Klass> to $Klass
// CHECK: release_value [[CAST]]
// CHECK: return
sil @unchecked_bitwise_cast : $@convention(thin) (@owned Optional<Klass>) -> () {
bb0(%0 : $Optional<Klass>):
  %1 = alloc_stack $Optional<Klass>
  store %0 to %1 : $*Optional<Klass>
  %2 = unchecked_addr_cast %1 : $*Optional<Klass> to $*Klass
  %3 = load %2 : $*Klass
  release_value %3 : $Klass
  dealloc_stack %1 : $*Optional<Klass>
  %4 = tuple()
  return %4 : $()
}

// dead args okay in non-ossa
// CHECK-LABEL: sil @multi_basic_block_use_on_one_path :
// CHECK-NOT: alloc_stack
// CHECK: br bb3(undef : $Klass)
// CHECK: bb3([[dead_arg:%.*]]):
sil @multi_basic_block_use_on_one_path : $@convention(thin) (@owned Klass) -> () {
bb0(%0 : $Klass):
  %1 = alloc_stack $Klass
  cond_br undef, bb1, bb2

bb1:
  dealloc_stack %1 : $*Klass
  strong_release %0 : $Klass
  br bb3

bb2:
  store %0 to %1 : $*Klass
  %7 = load %1 : $*Klass
  dealloc_stack %1 : $*Klass
  strong_release %7 : $Klass
  br bb3

bb3:
  %11 = tuple ()
  return %11 : $()
}

// CHECK-LABEL: sil @load_from_uninitialized_empty : {{.*}} {
// CHECK:         [[V_3_0:%[^,]+]] = struct $EmptyStruct
// CHECK:         [[V_3_1:%[^,]+]] = struct $EmptyStruct
// CHECK:         [[V_2_0:%[^,]+]] = struct $Pair{{.*}} ([[V_3_0]]{{.*}}, [[V_3_1]]
// CHECK:         [[V_2_1:%[^,]+]] = struct $EmptyStruct ()
// CHECK:         [[V_1_0:%[^,]+]] = struct $Pair{{.*}} ([[V_2_0]]{{.*}}, [[V_2_1]]
// CHECK:         [[V_2_2:%[^,]+]] = struct $EmptyStruct
// CHECK:         [[V_2_3:%[^,]+]] = struct $EmptyStruct
// CHECK:         [[V_1_1:%[^,]+]] = tuple ([[V_2_2]]{{.*}}, [[V_2_3]]
// CHECK:         [[V_1_2:%[^,]+]] = struct $EmptyStruct
// CHECK:         [[V_0:%[^,]+]] = tuple ([[V_1_0]]{{.*}}, [[V_1_1]]{{.*}}, [[V_1_2]]{{.*}})
// CHECK:         return [[V_0]]
// CHECK-LABEL: } // end sil function 'load_from_uninitialized_empty'
sil @load_from_uninitialized_empty : $@convention(thin) () -> (Pair<Pair<EmptyStruct, EmptyStruct>, EmptyStruct>, (EmptyStruct, EmptyStruct), EmptyStruct) {
  %addr = alloc_stack $(Pair<Pair<EmptyStruct, EmptyStruct>, EmptyStruct>, (EmptyStruct, EmptyStruct), EmptyStruct)
  %value = load %addr : $*(Pair<Pair<EmptyStruct, EmptyStruct>, EmptyStruct>, (EmptyStruct, EmptyStruct), EmptyStruct)
  dealloc_stack %addr : $*(Pair<Pair<EmptyStruct, EmptyStruct>, EmptyStruct>, (EmptyStruct, EmptyStruct), EmptyStruct)
  return %value : $(Pair<Pair<EmptyStruct, EmptyStruct>, EmptyStruct>, (EmptyStruct, EmptyStruct), EmptyStruct)
}


// CHECK-LABEL: sil @dont_canonicalize_undef : {{.*}} {
// CHECK:         [[RETVAL:%[^,]+]] = tuple
// CHECK:         return [[RETVAL]]
// CHECK-LABEL: } // end sil function 'dont_canonicalize_undef'
sil @dont_canonicalize_undef : $@convention(thin) () -> () {
  %addr = alloc_stack $()
  store undef to %addr : $*()
  dealloc_stack %addr : $*()
  %retval = tuple ()
  return %retval : $()
}

// CHECK-LABEL: sil @undef_for_load_of_empty_type_from_nontrivial_aggregate : {{.*}} {
// CHECK:         [[EMPTY:%[^,]+]] = tuple ()
// CHECK:         [[AGGREGATE:%[^,]+]] = tuple (undef : $Builtin.BridgeObject, [[EMPTY]] : $())
// CHECK:         tuple_extract [[AGGREGATE]] : $(Builtin.BridgeObject, ()), 1
// CHECK-LABEL: } // end sil function 'undef_for_load_of_empty_type_from_nontrivial_aggregate'
sil @undef_for_load_of_empty_type_from_nontrivial_aggregate : $@convention(thin) () -> () {
bb0:
  %11 = alloc_stack $(Builtin.BridgeObject, ())
  %12 = tuple_element_addr %11 : $*(Builtin.BridgeObject, ()), 1
  %13 = load %12 : $*()
  %empty = tuple ()
  %14 = tuple (%empty : $(), %13 : $())
  dealloc_stack %11 : $*(Builtin.BridgeObject, ())
  return undef : $()
}