dead_alloc_elim.sil

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

import Swift
import Builtin

//////////
// Data //
//////////

class TrivialDestructor {
  var int : Builtin.Int32
  var ptr : Builtin.NativeObject
  init()
  deinit { }
}

sil @_TFC4main17TrivialDestructorD : $@convention(method) (@owned TrivialDestructor) -> () {
bb0(%0 : $TrivialDestructor):
  // Alloc/Dealloc stack should not disrupt elimination of the
  // alloc_ref.
  %1 = alloc_stack $Builtin.Int64
  dealloc_stack %1#0 : $*@local_storage Builtin.Int64

  // Storing into the struct should not disrupt elimination of the
  // alloc_ref.
  %2 = ref_element_addr %0 : $TrivialDestructor, #TrivialDestructor.int
  %3 = integer_literal $Builtin.Int32, 1
  store %3 to %2 : $*Builtin.Int32

  // Calling a builtin without side effects should not disrupt
  // elimination of the alloc_ref.
  %4 = integer_literal $Builtin.Int32, 0
  %6 = builtin "xor_Int32" (%4 : $Builtin.Int32, %3 : $Builtin.Int32) : $Builtin.Int32

  // Calling dealloc ref on self should not disrupt elimination of the
  // alloc_ref.
  dealloc_ref %0 : $TrivialDestructor

  %7 = tuple()
  return %7 : $()
}

sil @ptr_user : $@convention(thin) (Builtin.NativeObject) -> ()
sil @int_user : $@convention(thin) (Builtin.Int32) -> ()

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

// Trivial case. Remove the alloc_ref.
//
// CHECK-LABEL: sil @trivial_destructor_trivial : $@convention(thin) () -> () {
// CHECK: bb0
// CHECK-NEXT: tuple
// CHECK-NEXT: return
sil @trivial_destructor_trivial : $@convention(thin) () -> () {
  %0 = alloc_ref $TrivialDestructor
  strong_release %0 : $TrivialDestructor
  %1 = tuple()
  return %1 : $()
}

// We load/use a pointer from the alloc_ref, do nothing.
//
// CHECK-LABEL: sil @trivial_destructor_load : $@convention(thin) () -> () {
// CHECK: bb0
// CHECK-NEXT: alloc_ref
// CHECK-NEXT: ref_element_addr
// CHECK-NEXT: load
// CHECK-NEXT: function_ref
// CHECK-NEXT: function_ref
// CHECK-NEXT: apply
// CHECK-NEXT: strong_release
// CHECK-NEXT: tuple
// CHECK-NEXT: return
sil @trivial_destructor_load : $@convention(thin) () -> () {
  %0 = alloc_ref $TrivialDestructor
  %1 = ref_element_addr %0 : $TrivialDestructor, #TrivialDestructor.int
  %2 = load %1 : $*Builtin.Int32
  %3 = function_ref @int_user : $@convention(thin) (Builtin.Int32) -> ()
  apply %3 (%2) : $@convention(thin) (Builtin.Int32) -> ()
  strong_release %0 : $TrivialDestructor
  %4 = tuple()
  return %4 : $()
}

// We store into the alloc_ref, eliminate it!
//
// CHECK-LABEL: sil @trivial_destructor_store_into : $@convention(thin) () -> () {
// CHECK: bb0
// CHECK-NEXT: integer_literal
// CHECK-NEXT: tuple
// CHECK-NEXT: return
sil @trivial_destructor_store_into : $@convention(thin) () -> () {
  %0 = alloc_ref $TrivialDestructor
  %1 = ref_element_addr %0 : $TrivialDestructor, #TrivialDestructor.int
  %2 = integer_literal $Builtin.Int32, 5
  store %2 to %1 : $*Builtin.Int32
  strong_release %0 : $TrivialDestructor
  %4 = tuple()
  return %4 : $()
}

// We store a pointer from the alloc_ref, dont do anything!
//
// CHECK-LABEL: sil @trivial_destructor_store_ptr
// CHECK: bb0
// CHECK-NEXT: alloc_ref
// CHECK-NEXT: ref_element_addr
// CHECK-NEXT: address_to_pointer
// CHECK-NEXT: store
// CHECK-NEXT: strong_release
// CHECK-NEXT: tuple
// CHECK-NEXT: return
sil @trivial_destructor_store_ptr : $@convention(thin) (@inout Builtin.RawPointer) -> () {
bb0(%0 : $*Builtin.RawPointer):
  %1 = alloc_ref $TrivialDestructor
  %2 = ref_element_addr %1 : $TrivialDestructor, #TrivialDestructor.int
  %3 = address_to_pointer %2 : $*Builtin.Int32 to $Builtin.RawPointer
  store %3 to %0 : $*Builtin.RawPointer
  strong_release %1 : $TrivialDestructor
  %4 = tuple()
  return %4 : $()
}

// We are returning the alloc_ref, do nothing.
//
// CHECK-LABEL: sil @trivial_destructor_return_value_use : $@convention(thin) () -> TrivialDestructor {
// CHECK: bb0
// CHECK-NEXT: alloc_ref
// CHECK-NEXT: return
sil @trivial_destructor_return_value_use : $@convention(thin) () -> TrivialDestructor {
  %0 = alloc_ref $TrivialDestructor
  return %0 : $TrivialDestructor
}

// Retains/releases on the alloc_ref can be ignored.
//
// CHECK-LABEL: sil @trivial_destructor_refcount_inst_on_value : $@convention(thin) () -> () {
// CHECK: bb0
// CHECK-NEXT: tuple
// CHECK-NEXT: return
sil @trivial_destructor_refcount_inst_on_value : $@convention(thin) () -> () {
  %0 = alloc_ref $TrivialDestructor
  strong_retain %0 : $TrivialDestructor
  strong_release %0 : $TrivialDestructor
  strong_release %0 : $TrivialDestructor
  %1 = tuple()
  return %1 : $()
}

// Retains/Releases on a different value in the use list implies abort.
//
// CHECK-LABEL: sil @trivial_destructor_refcount_inst_on_diff_value : $@convention(thin) (Builtin.NativeObject) -> () {
// CHECK: bb0
// CHECK-NEXT: alloc_ref
// CHECK-NEXT: ref_element_addr
// CHECK-NEXT: store
// CHECK-NEXT: load
// CHECK-NEXT: strong_release
// CHECK-NEXT: strong_release
// CHECK-NEXT: tuple
// CHECK-NEXT: return
sil @trivial_destructor_refcount_inst_on_diff_value : $@convention(thin) (Builtin.NativeObject) -> () {
bb0(%0 : $Builtin.NativeObject):
  %1 = alloc_ref $TrivialDestructor
  %2 = ref_element_addr %1 : $TrivialDestructor, #TrivialDestructor.ptr
  store %0 to %2 : $*Builtin.NativeObject
  %3 = load %2 : $*Builtin.NativeObject
  strong_release %3 : $Builtin.NativeObject
  strong_release %1 : $TrivialDestructor
  %4 = tuple()
  return %4 : $()
}

/*
sil @trivial_destructor_apply_use

sil @trivial_destructor_side_effect_use
*/

//sil @non_trivial_destructor

class NonTrivialDestructor {
  var ptr : Builtin.NativeObject

  init()
  deinit { }
}

sil @_TFC4main17NonTrivialDestructorD : $@convention(method) (@owned NonTrivialDestructor) -> () {
bb0(%0 : $NonTrivialDestructor):
  %1 = ref_element_addr %0 : $NonTrivialDestructor, #NonTrivialDestructor.ptr
  %2 = load %1 : $*Builtin.NativeObject
  strong_retain %2 : $Builtin.NativeObject
  dealloc_ref %0 : $NonTrivialDestructor
  %3 = tuple()
  return %3 : $()
}

// Make sure that a ref count operation on a different value in the
// destructor disrupts the algorithm.
//
// CHECK-LABEL: sil @non_trivial_destructor_refcount_on_different_value : $@convention(thin) () -> () {
// CHECK: bb0
// CHECK-NEXT: alloc_ref
// CHECK-NEXT: strong_release
// CHECK-NEXT: tuple
// CHECK-NEXT: return
sil @non_trivial_destructor_refcount_on_different_value : $@convention(thin) () -> () {
  %0 = alloc_ref $NonTrivialDestructor
  strong_release %0 : $NonTrivialDestructor
  %1 = tuple()
  return %1 : $()
}

class NonTrivialDestructor2 {
  var ptr : NonTrivialDestructor

  init()
  deinit { }
}

// Test if dealloc_ref on a different value disrupts the algorithm.
sil @_TFC4main17NonTrivialDestructor2D : $@convention(method) (@owned NonTrivialDestructor2) -> () {
bb0(%0 : $NonTrivialDestructor2):
  %1 = ref_element_addr %0 : $NonTrivialDestructor2, #NonTrivialDestructor2.ptr
  %2 = load %1 : $*NonTrivialDestructor
  dealloc_ref %2 : $NonTrivialDestructor
  dealloc_ref %0 : $NonTrivialDestructor2
  %3 = tuple()
  return %3 : $()
}

// CHECK-LABEL: sil @non_trivial_destructor_deallocref_on_different_value : $@convention(thin) () -> () {
// CHECK: bb0
// CHECK-NEXT: alloc_ref
// CHECK-NEXT: strong_release
// CHECK-NEXT: tuple
// CHECK-NEXT: return
sil @non_trivial_destructor_deallocref_on_different_value : $@convention(thin) () -> () {
  %0 = alloc_ref $NonTrivialDestructor
  strong_release %0 : $NonTrivialDestructor
  %1 = tuple()
  return %1 : $()
}

class NonTrivialDestructor3 {
  var ptr : Builtin.NativeObject

  init()
  deinit { }
}

// Make sure a non-builtin apply disrupts the algorithm.
sil @_TFC4main17NonTrivialDestructor3D : $@convention(method) (@owned NonTrivialDestructor3) -> () {
bb0(%0 : $NonTrivialDestructor3):
  %1 = ref_element_addr %0 : $NonTrivialDestructor3, #NonTrivialDestructor3.ptr
  %2 = load %1 : $*Builtin.NativeObject
  %3 = function_ref @ptr_user : $@convention(thin) (Builtin.NativeObject) -> ()
  apply %3 (%2) : $@convention(thin) (Builtin.NativeObject) -> ()
  dealloc_ref %0 : $NonTrivialDestructor3
  %4 = tuple()
  return %4 : $()
}

// CHECK-LABEL: sil @non_trivial_destructor_unknown_apply : $@convention(thin) () -> () {
// CHECK: bb0
// CHECK-NEXT: alloc_ref
// CHECK-NEXT: strong_release
// CHECK-NEXT: tuple
// CHECK-NEXT: return
sil @non_trivial_destructor_unknown_apply : $@convention(thin) () -> () {
  %0 = alloc_ref $NonTrivialDestructor
  strong_release %0 : $NonTrivialDestructor
  %1 = tuple()
  return %1 : $()
}

class NonTrivialObjCDestructor {
  var ptr : Builtin.NativeObject

  init() { }
  deinit { }
}

// Make sure we do not handle objc_methods
sil @_TFC4main17NonTrivialObjCDestructorD : $@convention(objc_method) (@owned NonTrivialObjCDestructor) -> () {
bb0(%0 : $NonTrivialObjCDestructor):
  dealloc_ref %0 : $NonTrivialObjCDestructor
  %1 = tuple()
  return %1 : $()
}

// CHECK-LABEL: sil @non_trivial_destructor_objc_destructor : $@convention(thin) () -> () {
// CHECK: bb0
// CHECK-NEXT: alloc_ref
// CHECK-NEXT: strong_release
// CHECK-NEXT: tuple
// CHECK-NEXT: return
sil @non_trivial_destructor_objc_destructor : $@convention(thin) () -> () {
  %0 = alloc_ref $NonTrivialObjCDestructor
  strong_release %0 : $NonTrivialObjCDestructor
  %1 = tuple()
  return %1 : $()
}

// CHECK-LABEL: sil @non_trivial_destructor_on_stack : $@convention(thin) () -> () {
// CHECK: alloc_stack
// CHECK: return
sil @non_trivial_destructor_on_stack : $@convention(thin) () -> () {
  %0 = alloc_stack $NonTrivialDestructor
  dealloc_stack %0#0 : $*@local_storage NonTrivialDestructor
  %1 = tuple()
  return %1 : $()
}

// CHECK-LABEL: sil @trivial_destructor_on_stack : $@convention(thin) () -> () {
// CHECK-NOT: alloc_stack
// CHECK-NOT: dealloc_stack
// CHECK: return
sil @trivial_destructor_on_stack : $@convention(thin) () -> () {
  %0 = alloc_stack $Int
  destroy_addr %0#1 : $*Int
  dealloc_stack %0#0 : $*@local_storage Int
  %1 = tuple()
  return %1 : $()
}

// If we have an instruction that mayTrap that uses the alloc_ref, we can't
// eliminate it.
//
// CHECK-LABEL: sil @trivial_destructor_may_trap : $@convention(thin) () -> () {
// CHECK: alloc_ref
sil @trivial_destructor_may_trap : $@convention(thin) () -> () {
  %0 = alloc_ref $TrivialDestructor
  %1 = unconditional_checked_cast %0 : $TrivialDestructor to $AnyObject
  strong_release %0 : $TrivialDestructor
  %4 = tuple()
  return %4 : $()
}