[5.7] Fix OwnershipLiveRange for @owned values getting transformed to none values via switch_enum #60110
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…values via switch_enum rdar://95039799 We are currently not computing OwnershipLiveRange correctly in the presence of switch_enum transforming the owned value to a none value. We can end up with illegal SIL with LoadCopyToLoadBorrowOptimization, due to this. Example: sil [ossa] @switch_enum_test : $@convention(thin) (@inout StructWithEnum) -> () { bb0(%0 : $*StructWithEnum): %1 = struct_element_addr %0 : $*StructWithEnum, #StructWithEnum.val %2 = struct_element_addr %0 : $*StructWithEnum, #StructWithEnum.val %3 = load [copy] %2 : $*EnumA destroy_addr %1 : $*EnumA switch_enum %3 : $EnumA, case #EnumA.sometrivial!enumelt: bb1, case #EnumA.somenontrivial!enumelt:bb2, case #EnumA.none!enumelt: bb3 bb1(%6 : $TrivialStruct): %f = function_ref @get_enum : $@convention(thin) () -> @owned EnumA %r = apply %f() : $@convention(thin) () -> @owned EnumA %ele = struct_element_addr %0 : $*StructWithEnum, #StructWithEnum.val store %r to [init] %ele :$*EnumA %9999 = tuple() return %9999 : $() bb2(%7 : @owned $NonTrivialStruct): unreachable bb3: unreachable } can get transformed to: sil [ossa] @switch_enum_test : $@convention(thin) (@inout StructWithEnum) -> () { bb0(%0 : $*StructWithEnum): %1 = struct_element_addr %0 : $*StructWithEnum, #StructWithEnum.val %2 = struct_element_addr %0 : $*StructWithEnum, #StructWithEnum.val %3 = load_borrow %2 : $*EnumA destroy_addr %1 : $*EnumA switch_enum %3 : $EnumA, case #EnumA.sometrivial!enumelt: bb1, case #EnumA.somenontrivial!enumelt: bb2, case #EnumA.none!enumelt: bb3 bb1(%6 : $TrivialStruct): end_borrow %3 : $EnumA %8 = function_ref @get_enum : $@convention(thin) () -> @owned EnumA %9 = apply %8() : $@convention(thin) () -> @owned EnumA %10 = struct_element_addr %0 : $*StructWithEnum, #StructWithEnum.val store %9 to [init] %10 : $*EnumA %12 = tuple () return %12 : $() bb2(%14 : @guaranteed $NonTrivialStruct): unreachable bb3: unreachable } which is incorrect: Write: destroy_addr %1 : $*EnumA SIL verification failed: Found load borrow that is invalidated by a local write?!: loadBorrowImmutabilityAnalysis.isImmutable(LBI) Verifying instruction: %2 = struct_element_addr %0 : $*StructWithEnum, #StructWithEnum.val -> %3 = load_borrow %2 : $*EnumA switch_enum %3 : $EnumA, case #EnumA.sometrivial!enumelt: bb1, case #EnumA.somenontrivial!enumelt: bb2, case #EnumA.none!enumelt: bb3 end_borrow %3 : $EnumA
|
@swift-ci test |
meg-gupta
changed the title
|
@swift-ci please nominate |
airspeedswift
approved these changes
Jul 22, 2022
AnthonyLatsis
added
🍒 release cherry pick
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Scope: Fixes possible verifier error while using switch on enums with dead ends on non-trivial paths
Main Branch PR: #60101
Resolves: rdar://95039799
Risk: Very low
Reviewed By: Andrew Trick, Michael Gottesman
Testing: Added a regression test-case to the suite.