Today, loads and stores are treated as having @unowned(unsafe) ownership
semantics. This leaves the user to specify ownership changes on the loaded or
stored value independently of the load/store by inserting ARC operations. With
the change to Semantic SIL, this will no longer be true. Instead loads, stores
have ownership semantics that one must reason about such as copy, take, and
trivial.
This change moves us closer to that world by eliminating the default
OwnershipQualification argument from create{Load,Store}. This means that the
compiler developer cannot ignore reasoning about the ownership semantics of the
memory operation that they are creating.
Operationally, this is a NFC change since I have just gone through the compiler
and updated all places where we create loads, stores to pass in the former
default argument ({Load,Store}OwnershipQualifier::Unqualified), to
SILBuilder::create{Load,Store}(...). For now, one can just do that in situations
where one needs to create loads/stores, but over time, I am going to tighten the
semantics up via the verifier.
rdar://28685236
This reverts commit r30272.
There's a way to fix Builtin.reinterpretCast that preserves SILGen
RValue invariants better according to JohnM. So although these changes
are valid, there will be no way for me to test them.
After reverting this, I will roll back in the change to
emitImplicitValueConstructor because I think the old code was
violating SILGen invariants.
Swift SVN r30306
This is required in order to fix Builtin.reinterpretCast for
address-only types. That upcoming fix will include a test case that
exposes this SILGen path.
Swift SVN r30272
completely destroyed when forwarded.
Also, make forwarding a cleanup a first-class operation
on cleanups, rather than setting the cleanup state directly.
Swift SVN r19332
We won't have any types where copying has an effect on the bit pattern (except for blocks, which need special handling anyway), and copy_value having a result makes optimizations more complex, so remove it.
Swift SVN r15640
