For optional chaining a swift_enum is created.
If the sub-projection is ending a begin_access in the some-branch, it also needs to be ended in the none-branch.
Fixes a compiler crash and/or a miscompile.
https://bugs.swift.org/browse/SR-14534
rdar://77224220
I was inconsistently providing initialized or uninitialized memory
to the callback when projecting a settable address, depending on
component type. We should always provide an uninitialized address.
When a computed property returns a generic, the accessor's function
type may involve a type parameter that needs to be resolved using
the key path instruction's substitution map.
We have an optimization in SILCombiner that "inlines" the use of compile-time constant key paths by performing the property access directly instead of calling a runtime function (leading to huge performance gains e.g. for heavy use of @dynamicMemberLookup). However, this optimization previously only supported key paths which solely access stored properties, so computed properties, optional chaining, etc. still had to call a runtime function. This commit generalizes the optimization to support all types of key paths.
I was inconsistently providing initialized or uninitialized memory
to the callback when projecting a settable address, depending on
component type. We should always provide an uninitialized address.
When a computed property returns a generic, the accessor's function
type may involve a type parameter that needs to be resolved using
the key path instruction's substitution map.
We have an optimization in SILCombiner that "inlines" the use of compile-time constant key paths by performing the property access directly instead of calling a runtime function (leading to huge performance gains e.g. for heavy use of @dynamicMemberLookup). However, this optimization previously only supported key paths which solely access stored properties, so computed properties, optional chaining, etc. still had to call a runtime function. This commit generalizes the optimization to support all types of key paths.
