alias-analysis.sil

// RUN: %target-sil-opt %s -dump-alias-info -o /dev/null | %FileCheck %s

// General black-box alias analysis tests. White-box unit tests are
// specific to the aa-kind, such as basic-aa.sil and typed-access-tb-aa.sil.

// REQUIRES: asserts

sil_stage canonical

import Swift
import SwiftShims
import Builtin

struct MyStruct {
  @_hasStorage @_hasInitialValue var i: Int64 { get set }
  @_hasStorage @_hasInitialValue var j: Int64 { get set }
}

struct OuterStruct {
  @_hasStorage @_hasInitialValue var s: MyStruct { get set }
}

// Test overlapping access on a different path; the user has misused an index offset
// CHECK-LABEL: @testOffsetBehindProjection
// CHECK:       PAIR #23.
// CHECK-NEXT:    %3 = index_addr %1 : $*Int64, %2 : $Builtin.Word
// CHECK-NEXT:    %5 = struct_element_addr %0 : $*MyStruct, #MyStruct.j
// CHECK-NEXT:    NoAlias
sil shared @testOffsetBehindProjection : $@convention(thin) (@inout MyStruct) -> () {
bb0(%0 : $*MyStruct):
  %1 = struct_element_addr %0 : $*MyStruct, #MyStruct.i
  %2 = integer_literal $Builtin.Word, 1
  %3 = index_addr %1 : $*Int64, %2 : $Builtin.Word
  %4 = load %3 : $*Int64
  // load from a different subobject overlaps
  %5 = struct_element_addr %0 : $*MyStruct, #MyStruct.j
  %6 = load %5 : $*Int64
  %99 = tuple ()
  return %99 : $()
}

// CHECK-LABEL: @testOffsetsBehindProjectionOverlap
// CHECK:       PAIR #21.
// CHECK-NEXT:    %2 = struct_element_addr %1 : $*MyStruct, #MyStruct.i
// CHECK-NEXT:    %6 = struct_element_addr %5 : $*MyStruct, #MyStruct.i
// CHECK-NEXT:    NoAlias
sil shared @testOffsetsBehindProjectionOverlap : $@convention(thin) (@inout OuterStruct) -> () {
bb0(%0 : $*OuterStruct):
  %1 = struct_element_addr %0 : $*OuterStruct, #OuterStruct.s
  %2 = struct_element_addr %1 : $*MyStruct, #MyStruct.i
  %3 = load %2 : $*Int64
  // Loading from a different index within the same subobject still appears to overlap.
  // Indexing from a subobject is always considered an unknown index.
  %4 = integer_literal $Builtin.Word, 1
  %5 = index_addr %1 : $*MyStruct, %4 : $Builtin.Word
  %6 = struct_element_addr %5 : $*MyStruct, #MyStruct.i
  %7 = load %6 : $*Int64
  %99 = tuple ()
  return %99 : $()
}

// CHECK-LABEL: @testIndexOf0
// CHECK:       PAIR #8.
// CHECK-NEXT:    %1 = struct_element_addr %0 : $*MyStruct, #MyStruct.i
// CHECK-NEXT:    %3 = index_addr %0 : $*MyStruct, %2 : $Builtin.Word
// CHECK-NEXT:    MayAlias
// CHECK:       PAIR #9.
// CHECK-NEXT:   %1 = struct_element_addr %0 : $*MyStruct, #MyStruct.i
// CHECK-NEXT:   %4 = struct_element_addr %3 : $*MyStruct, #MyStruct.i
// CHECK-NEXT:   MayAlias
sil @testIndexOf0 : $@convention(thin) (@inout MyStruct) -> () {
bb0(%0 : $*MyStruct):
  %1 = struct_element_addr %0 : $*MyStruct, #MyStruct.i
  %2 = integer_literal $Builtin.Word, 0
  %3 = index_addr %0 : $*MyStruct, %2 : $Builtin.Word
  %4 = struct_element_addr %3 : $*MyStruct, #MyStruct.i
  fix_lifetime %1 : $*Int64
  fix_lifetime %4 : $*Int64
  %99 = tuple ()
  return %99 : $()
}

// CHECK-LABEL: @testUnknownIndex
// CHECK:       PAIR #12.
// CHECK-NEXT:    %2 = struct_element_addr %0 : $*MyStruct, #MyStruct.i
// CHECK-NEXT:    %3 = index_addr %0 : $*MyStruct, %1 : $Builtin.Word
// CHECK-NEXT:    MayAlias
// CHECK:       PAIR #13.
// CHECK-NEXT:    %2 = struct_element_addr %0 : $*MyStruct, #MyStruct.i
// CHECK-NEXT:    %4 = struct_element_addr %3 : $*MyStruct, #MyStruct.i
// CHECK-NEXT:    MayAlias
sil @testUnknownIndex : $@convention(thin) (@inout MyStruct, Builtin.Word) -> () {
bb0(%0 : $*MyStruct, %1 : $Builtin.Word):
  %2 = struct_element_addr %0 : $*MyStruct, #MyStruct.i
  %3 = index_addr %0 : $*MyStruct, %1 : $Builtin.Word
  %4 = struct_element_addr %3 : $*MyStruct, #MyStruct.i
  fix_lifetime %2 : $*Int64
  fix_lifetime %4 : $*Int64
  %99 = tuple ()
  return %99 : $()
}