Mandatory pass will clean it up and replace it by a copy_block and
is_escaping/cond_fail/release combination on the %closure in follow-up
patches.
The instruction marks the dependence of a block on a closure that is
used as an 'withoutActuallyEscaping' sentinel.
rdar://39682865
To mark when a user of it is known to escape the value. This happens
with materializeForSet arguments which are captured and used in the
write-back. This means we need to keep the context alive until after
the write-back.
Follow-up patches to fully replace the PostponedCleanup hack in SILGen
by a mandatory SIL transformation pass to guarantee the proper lifetime
will use this flag to be more conservative when extending the lifetime.
The problem:
%pa = partial_apply %f(%some_context)
%cvt = convert_escape_to_noescape [not_guaranteed] [escaped] %pa
%ptr = %materialize_for_set(..., %cvt)
... write_back
... // <-- %pa needs to be alive until after write_back
This statically guarantees that the access has no inner conflict within
its own scope.
IRGen will turn this into a "nontracking" access in which an
exclusivity check is performed for conflicts on an outer scope. However,
unlike normal accesses the runtime does not record the access, and the
access will not be checked for subsequent conflicts.
end_unpaired_access [no_nested_conflict] is not currently
supported. Making a begin_unpaired_access [no_nested_conflict] requires
deleting the corresponding end_unpaired_access. Future runtimes
could support this for verification by storing inline data in the
valud buffer. However, the runtime can never assume that a
[no_nested_conflict] begin_unpaired_access will have a corresponding
end_unpaired_access call without adding a new ExclusivityFlag for
that purpose.
Assign the location of a switch statement's subject expression to all of
its case statements.
This improves the debugger's stepping behavior in switch statements.
Stepping into a switch now goes directly to the first matching case
(possibly one with a `where` clause that may or may not match). It's
still possible to set breakpoints within `where` clauses.
rdar://35628672
Check that an ``withoutActuallyEscaping(noescape_closure) { // scope}`` closure
has not escaped in the scope using the ``is_escaping_closure %closure``
instruction.
rdar://35525730
Will be used to verify that withoutActuallyEscaping's block does not
escape the closure.
``%escaping = is_escaping_closure %closure`` tests the reference count. If the
closure is not uniquely referenced it prints out and error message and
returns true. Otherwise, it returns false. The returned result can be
used with a ``cond_fail %escaping`` instruction to abort the program.
rdar://35525730
This patch both makes debug variable information it optional on
alloc_stack and alloc_box instructions, and forced variable
information on debug_value and debug_value_addr instructions. The
change of the interface uncovered a plethora of bugs in SILGen,
SILTransform, and IRGen's LoadableByAddress pass.
Most importantly this fixes the previously commented part of the
DebugInfo/local-vars.swift.gyb testcase.
rdar://problem/37720555
@noescape function types will eventually be trivial. A
convert_escape_to_noescape instruction does not take ownership of its
operand. It is a projection to the trivial value carried by the closure
-- both context and implementation function viewed as a trivial value.
A safe SIL program must ensure that the object that the project value is based
on is live beyond the last use of the trivial value. This will be
achieve by means of making the lifetimes dependent.
For example:
%e = partial_apply [callee_guaranteed] %f(%z) : $@convention(thin) (Builtin.Int64) -> ()
%n = convert_escape_to_noescape %e : $@callee_guaranteed () -> () to $@noescape @callee_guaranteed () -> ()
%n2 = mark_dependence %n : $@noescape @callee_guaranteed () -> () on %e : $@callee_guaranteed () -> ()
%f2 = function_ref @use : $@convention(thin) (@noescape @callee_guaranteed () -> ()) -> ()
apply %f2(%n2) : $@convention(thin) (@noescape @callee_guaranteed () -> ()) -> ()
release_value %e : $@callee_guaranteed () -> ()
Note: This is not yet actually used.
Part of:
SR-5441
rdar://36116691
* Reduce array abstraction on apple platforms dealing with literals
Part of the ongoing quest to reduce swift array literal abstraction
penalties: make the SIL optimizer able to eliminate bridging overhead
when dealing with array literals.
Introduce a new classify_bridge_object SIL instruction to handle the
logic of extracting platform specific bits from a Builtin.BridgeObject
value that indicate whether it contains a ObjC tagged pointer object,
or a normal ObjC object. This allows the SIL optimizer to eliminate
these, which allows constant folding a ton of code. On the example
added to test/SILOptimizer/static_arrays.swift, this results in 4x
less SIL code, and also leads to a lot more commonality between linux
and apple platform codegen when passing an array literal.
This also introduces a couple of SIL combines for patterns that occur
in the array literal passing case.
We can just !SILFunction::hasQualifiedOwnership(). Plus as Andy pointed out,
even ignoring the functional aspects, having APIs with names this close can
create confusion.
This just abstracts the creation of a destructure_store or destructure_tuple
without the caller needing to know.
Just slicing simple code off of a larger commit.
rdar://31521023
Previously in PredMemOpts, we would insert any extracts at the load site, i.e.:
store %foo to %0
...
%1 = struct_element_addr %0, $Type, $Type.field
%2 = load %1
...
apply %use(%2)
would transform to:
store %foo to %0
...
%2 = struct_extract %foo
apply %use(%2)
This framework will not work with Ownership enabled since the value stored is
considered consumed by the store. This change fixes the issue by moving such
non-destructive extracts to occur while %foo is considered live, i.e. before the
store:
%2 = struct_extract %foo
store %foo to %0
...
apply %use(%2)
This means that we have to store insertion points for each store that provides
us with available values and insert the extracts at those points. This creates
some complications in the case where we have multiple stores since we need to
deal with phi nodes. Rather than dealing with it by hand, we just insert the
extracts at each point and then use the SSA updater to insert the relevant phi
nodes.
rdar://31521023
This is just convenient if you want to have a pass work transparently with both
ownership and non-ownership SIL.
Chopped off from the larger pred-memopt update commit to ease review.
rdar://31521023
This will allow us to remove dynamic_method, emitting objc_method
in its place. It will also allow objc_method to be used for
Objective-C protocol method calls, with witness_method used
for Swift native protocol method calls only.
This replaces the '[volatile]' flag. Now, class_method and
super_method are only used for vtable dispatch.
The witness_method instruction is still overloaded for use
with both ObjC protocol requirements and Swift protocol
requirements; the next step is to make it only mean the
latter, also using objc_method for ObjC protocol calls.
Update the SILBuilder and other relevant bits of SILGen s.t we pass
along branch taken counts whenever we create conditional branches.
There is a lot of unfinished work here: we need to teach ParseSIL,
DeserializeSIL, and the SILOptimizer about profile data. And add a
stable AST hasher. And add tests for it all.
Let's skip all of that for now. Next, we'll wire in some actual profile
data.
introduce a common superclass, SILNode.
This is in preparation for allowing instructions to have multiple
results. It is also a somewhat more elegant representation for
instructions that have zero results. Instructions that are known
to have exactly one result inherit from a class, SingleValueInstruction,
that subclasses both ValueBase and SILInstruction. Some care must be
taken when working with SILNode pointers and testing for equality;
please see the comment on SILNode for more information.
A number of SIL passes needed to be updated in order to handle this
new distinction between SIL values and SIL instructions.
Note that the SIL parser is now stricter about not trying to assign
a result value from an instruction (like 'return' or 'strong_retain')
that does not produce any.
