Files
swift-mirror/test/SILOptimizer/optional_of_existential.swift
Erik Eckstein 6a9d08793a SILCombine: a peephole optimization to optimize alloc_stack of enums.
Replaces an alloc_stack of an enum by an alloc_stack of the payload if only one enum case (with payload) is stored to that location.

For example:

  %loc = alloc_stack $Optional<T>
  %payload = init_enum_data_addr %loc
  store %value to %payload
  ...
  %take_addr = unchecked_take_enum_data_addr %loc
  %l = load %take_addr

is transformed to

  %loc = alloc_stack $T
  store %value to %loc
  ...
  %l = load %loc

https://bugs.swift.org/browse/SR-12710
2020-06-10 09:23:37 +02:00

27 lines
778 B
Swift

// RUN: %target-swift-frontend -O -module-name=test -emit-sil -primary-file %s | %FileCheck %s
protocol P { associatedtype A = Int }
protocol Q : P {}
protocol B { var x: Int { get } }
struct Y<T> {}
extension Y : B where T : Q { var x: Int { 0 }}
extension P {
var z: Int? { (Y<Self>() as? B)?.x }
}
struct X : Q {
// Check that this getter can be folded to a simple "return 0"
// CHECK-LABEL: sil hidden @$s4test1XV0A2MeSiSgvg : $@convention(method) (X) -> Optional<Int> {
// CHECK: bb0(%0 : $X):
// CHECK-NEXT: integer_literal ${{.*}}, 0
// CHECK-NEXT: struct $Int
// CHECK-NEXT: enum $Optional<Int>, #Optional.some!enumelt
// CHECK-NEXT: return %3 : $Optional<Int>
// CHECK-NEXT: } // end sil function '$s4test1XV0A2MeSiSgvg'
var testMe: Int? { z }
}