[5.5] CSE: While optimizing lazy property getters, don't inline non-ossa to ossa function (swiftlang#38231)

Fixes rdar://79781904

Cherry-pick of swiftlang#38184

• Explanation: Fixes a bug in optimizing lazy property getters in CSE. Lazy property getters are CSE'ed by inlining their function body. There was no check to skip inlining a non-ossa function into an ossa function which is illegal.

• Scope of Issue: Can lead to crashes or miscompilations

• Risk: Low. The fix is low risk because it is just avoiding the illegal CSE of lazy property getters.

• Reviewed By: Erik Eckstein

• Testing: Added unit tests

Author: meg-gupta

lib/SILOptimizer/Transforms/CSE.cpp

@@ -915,6 +915,10 @@ static bool isLazyPropertyGetter(ApplyInst *ai) {
       !callee->isLazyPropertyGetter())
     return false;
 
+  // We cannot inline a non-ossa function into an ossa function
+  if (ai->getFunction()->hasOwnership() && !callee->hasOwnership())
+    return false;
+
   // Only handle classes, but not structs.
   // Lazy property getters of structs have an indirect inout self parameter.
   // We don't know if the whole struct is overwritten between two getter calls.

lib/SILOptimizer/Utils/SILInliner.cpp

@@ -348,6 +348,9 @@ SILInliner::inlineFullApply(FullApplySite apply,
                             SILInliner::InlineKind inlineKind,
                             SILOptFunctionBuilder &funcBuilder) {
   assert(apply.canOptimize());
+  assert(!apply.getFunction()->hasOwnership() ||
+         apply.getReferencedFunctionOrNull()->hasOwnership());
+
   SmallVector<SILValue, 8> appliedArgs;
   for (const auto arg : apply.getArguments())
     appliedArgs.push_back(arg);

test/SILOptimizer/cse_ossa.sil

@@ -1223,3 +1223,78 @@ bb0(%0 : $*Builtin.Int64, %1 : @guaranteed $Builtin.NativeObject):
   destroy_value %copy : $Builtin.NativeObject
   return %6 : $(Builtin.Int64, Builtin.Int64)
 }
+
+final class LazyKlass {
+  final var lazyProperty: Int64 { get set }
+  @_hasStorage @_hasInitialValue final var lazyPropertyStorage : Int64? { get set }
+  init()
+}
+
+sil private [lazy_getter] [noinline] @lazy_class_getter_nonossa : $@convention(method) (@guaranteed LazyKlass) -> Int64 {
+bb0(%0 : $LazyKlass):
+  %2 = ref_element_addr %0 : $LazyKlass, #LazyKlass.lazyPropertyStorage 
+  %3 = load %2 : $*Optional<Int64>
+  switch_enum %3 : $Optional<Int64>, case #Optional.some!enumelt: bb1, case #Optional.none!enumelt: bb2
+
+bb1(%5 : $Int64):
+  br bb3(%5 : $Int64)
+
+bb2:
+  %9 = integer_literal $Builtin.Int64, 27
+  %10 = struct $Int64 (%9 : $Builtin.Int64)
+  %12 = enum $Optional<Int64>, #Optional.some!enumelt, %10 : $Int64
+  store %12 to %2 : $*Optional<Int64>
+  br bb3(%10 : $Int64)
+
+bb3(%15 : $Int64):
+  return %15 : $Int64
+}
+
+sil private [lazy_getter] [noinline] [ossa] @lazy_class_getter_ossa : $@convention(method) (@guaranteed LazyKlass) -> Int64 {
+bb0(%0 : @guaranteed $LazyKlass):
+  %2 = ref_element_addr %0 : $LazyKlass, #LazyKlass.lazyPropertyStorage 
+  %3 = load [trivial] %2 : $*Optional<Int64>
+  switch_enum %3 : $Optional<Int64>, case #Optional.some!enumelt: bb1, case #Optional.none!enumelt: bb2
+
+bb1(%5 : $Int64):
+  br bb3(%5 : $Int64)
+
+bb2:
+  %9 = integer_literal $Builtin.Int64, 27
+  %10 = struct $Int64 (%9 : $Builtin.Int64)
+  %12 = enum $Optional<Int64>, #Optional.some!enumelt, %10 : $Int64
+  store %12 to [trivial] %2 : $*Optional<Int64>
+  br bb3(%10 : $Int64)
+
+bb3(%15 : $Int64):
+  return %15 : $Int64
+}
+
+// CHECK-LABEL: sil [ossa] @dont_cse_nonossa_getter :
+// CHECK:   [[GETTER:%[0-9]+]] = function_ref @lazy_class_getter_nonossa
+// CHECK:   apply [[GETTER]]
+// CHECK:   apply [[GETTER]]
+// CHECK: } // end sil function 'dont_cse_nonossa_getter'
+sil [ossa] @dont_cse_nonossa_getter : $@convention(thin) (@guaranteed LazyKlass) -> (Int64, Int64) {
+bb0(%0 : @guaranteed $LazyKlass):
+  %getter = function_ref @lazy_class_getter_nonossa : $@convention(method) (@guaranteed LazyKlass) -> Int64
+  %call1 = apply %getter(%0) : $@convention(method) (@guaranteed LazyKlass) -> Int64
+  %call2 = apply %getter(%0) : $@convention(method) (@guaranteed LazyKlass) -> Int64
+  %res = tuple (%call1 : $Int64, %call2 : $Int64)
+  return %res : $(Int64, Int64)
+}
+
+// CHECK-LABEL: sil @cse_ossa_getter :
+// CHECK:   [[GETTER:%[0-9]+]] = function_ref @lazy_class_getter_ossa
+// CHECK:   apply [[GETTER]]
+// CHECK-NOT:   apply [[GETTER]]
+// CHECK: } // end sil function 'cse_ossa_getter'
+sil @cse_ossa_getter : $@convention(thin) (@guaranteed LazyKlass) -> (Int64, Int64) {
+bb0(%0 : $LazyKlass):
+  %1 = function_ref @lazy_class_getter_ossa : $@convention(method) (@guaranteed LazyKlass) -> Int64
+  %2 = apply %1(%0) : $@convention(method) (@guaranteed LazyKlass) -> Int64
+  %3 = apply %1(%0) : $@convention(method) (@guaranteed LazyKlass) -> Int64
+  %4 = tuple (%2 : $Int64, %3 : $Int64)
+  return %4 : $(Int64, Int64)
+}
+