The new instruction is needed for opaque values mode to allow values to
be extracted from tuples containing packs which will appear for example
as function arguments.
The new instruction wraps a value in a `@sil_weak` box and produces an
owned value. It is only legal in opaque values mode and is transformed
by `AddressLowering` to `store_weak`.
The new instruction unwraps an `@sil_weak` box and produces an owned
value. It is only legal in opaque values mode and is transformed by
`AddressLowering` to `load_weak`.
Since dead-store-elimination is now more accurate, it's important that the `bind_memory` instructions are also defined to _read_ memory.
Otherwise they are not considered as barriers for dead-store-elimination.
Fixes a miscompile.
rdar://112150142
This is code that I am fairly familiar with but it still took a day of
investigation to figure out how it is supposed to be used now in the
presence of bridging.
This primarily involved ruling out the possibity that the mid-level
Swift APIs could at some point call into the lower-level C++ APIs.
The biggest problem was that AliasAnalysis::getMemoryBehaviorOfInst()
was declared as a public interface, and it's name indicates that it
computes the memory behavior. But it is just a wrapper around a Swift
API and never actually calls into any of the C++ logic that is
responsible for computing memory behavior!
The `hop_to_executor` instruction is a synchronization point and any kind of other code might run at this point,
which potentially can release objects.
Fixes a miscompile
rdar://110924258
This instruction is similar to AssignByWrapperInst, but instead of having
a destination operand, the initialization is fully factored into the init
function operand. Like AssignByWrapper, AssignOrInit has partial application
operands of both the initializer and the setter, and DI will lower the
instruction to a call based on whether the assignment is initialization or
a setter call.
Just the $*T -> $*@moveOnly T variant for addresses. Unlike the object version
this acts like a cast rather than something that provides semantics from the
frontend to the optimizer.
The reason why I am using a different instruction for addresses and objects here
is that the object checker doesnt have to deal with things like initialization.
The new alloc_pack_metadata and dealloc_pack_metadata are inserted as
part of IRGen lowering. The former indicates that the next instruction
might result in on-stack pack metadata being emitted. The latter
indicates that this is the position at which metadata emitted on behalf
of its operand should be cleaned up.
This instruction can be inserted by Onone optimizations as a replacement for deleted instructions to
ensure that it's possible to single step on its location.
This allows dynamically indexing into tuples. IRGen not yet
implemented.
I think I'm going to need a type_refine_addr instruction in
order to handle substitutions into the operand type that
eliminate the outer layer of tuple-ness. Gonna handle that
in a follow-up commit.
Having added these, I'm not entirely sure we couldn't just use
alloc_stack and dealloc_stack. Well, if we find ourselves adding
a lot of redundancy with those instructions (e.g. around DI), we
can always go back and rip these out.
This is a dedicated instruction for incrementing a
profiler counter, which lowers to the
`llvm.instrprof.increment` intrinsic. This
replaces the builtin instruction that was
previously used, and ensures that its arguments
are statically known. This ensures that SIL
optimization passes do not invalidate the
instruction, fixing some code coverage cases in
`-O`.
rdar://39146527
* add `DynamicFunctionRefInst` and `PreviousDynamicFunctionRefInst`
* add a common base class to all function-referencing instructions: `FunctionRefBaseInst`
* add `KeyPathInst`
* add `IndexAddrInst.base` and `IndexAddrInst.index` getters
* add `Instruction.visitReferencedFunctions` to visit all functions which are referenced by an instruction
This is exactly like copy_addr except that it is not viewed from the verifiers
perspective as an "invalid" copy of a move only value. It is intended to be used
in two contexts:
1. When the move checker emits a diagnostic since it could not eliminate a copy,
we still need to produce valid SIL without copy_addr on move only types since we
will hit canonical SIL eventually even if we don't actually codegen the SIL. The
pass can just convert said copy_addr to explicit_copy_addr and everyone is
happy.
2. To implement the explicit copy function for address only types.
Specifically this means that rather than always being owned, we now have owned
and guaranteed versions of copyable_to_moveonlywrapper. Similar to
moveonlywrapper_to_copyable, one chooses which variant one gets by using
specific SILBuilder APIs:
create{Owned,Guaranteed}CopyableToMoveOnlyWrapperValueInst. It is still
forwarding and the rest of the forwarding APIs work as expected except that the
forwarding ownership is fixed (and an assertion will result if one attempts to
do so).
NOTE: It is assumed that trivial operands are always passed to the owned
variant.
These instructions have the following attributes:
1. copyably_to_moveonlywrapper takes in a 'T' and maps it to a '@moveOnly
T'. This is semantically used when initializing a new moveOnly binding from a
copyable value. It semantically destroys its input @owned value and returns a
brand new independent @owned @moveOnly value. It also is used to convert a
trivial copyable value with type 'Trivial' into an owned non-trivial value of
type '@moveOnly Trivial'. If one thinks of '@moveOnly' as a monad, this is how
one injects a copyable value into the move only space.
2. moveonlywrapper_to_copyable takes in a '@moveOnly T' and produces a new 'T'
value. This is a 'forwarding' instruction where at parse time, we only allow for
one to choose it to be [owned] or [guaranteed].
* moveonlywrapper_to_copyable [owned] is used to signal the end of lifetime of
the '@moveOnly' wrapper. SILGen inserts these when ever a move only value has
its ownership passed to a situation where a copyable value is needed. Since it
is consuming, we know that the no implicit copy checker will ensure that if we
need a copy for it, the program will emit a diagnostic.
* moveonlywrapper_to_copyable [guaranteed] is used to pass a @moveOnly T value
as a copyable guaranteed parameter with type 'T' to a function. In the case of
using no-implicit-copy checking this is always fine since no-implicit-copy is a
local pattern. This would be an error when performing no escape
checking. Importantly, this instruction also is where in the case of an
@moveOnly trivial type, we convert from the non-trivial representation to the
trivial representation.
Some important notes:
1. In a forthcoming commit, I am going to rebase the no implicit copy checker on
top of these instructions. By using '@moveOnly' in the type system, we can
ensure that later in the SIL pipeline, we can have optimizations easily ignore
the code.
2. Be aware of is that due to SILGen only emitting '@moveOnly T' along immediate
accesses to the variable and always converts to a copyable representation when
calling other code, we can simply eliminate from the IR all moveonly-ness from
the IR using a lowering pass (that I am going to upstream). In the evil scheme
we are accomplishing here, we perform lowering of trivial values right after
ownership lowering and before diagnostics to simplify the pipeline.
On another note, I also fixed a few things in SILParsing around getASTType() vs
getRawASTType().
This is an instruction that I am going to use to drive some of the ownership
based dataflow optimizations that I am writing now. The instruction contains a
kind that allows one to know what type of checking is required and allows the
need to add a bunch of independent instructions for independent checkers. Each
checker is responsible for removing all of its own mark instructions. NOTE:
MarkMustCheckInst is only allowed in Raw SIL since once we are in Canonical SIL
we want to ensure that all such checking has already occurred.
These macros make ApplySite.h and SILNodes.def unreadable. Getting rid
of them will save me (and I'm sure others) a lot of time whenever I
work with ApplySite.
Best practice dictates that the ApplySite abstraction be modeled in
one place. The macros serve no purpose other than obfuscation.
Introduce a new instruction `dealloc_stack_ref ` and remove the `stack` flag from `dealloc_ref`.
The `dealloc_ref [stack]` was confusing, because all it does is to mark the deallocation of the stack space for a stack promoted object.
This instruction is similar to a copy_addr except that it marks a move of an
address that has to be checked. In order to keep the memory lifetime verifier
happy, the semantics before the checker runs are the mark_unresolved_move_addr is
equivalent to copy_addr [init] (not copy_addr [take][init]).
The use of this instruction is that Mandatory Inlining converts builtin "move"
to a mark_unresolved_move_addr when inlining the function "_move" (the only
place said builtin is invoked).
This is then run through a special checker (that is later in this PR) that
either proves that the mark_unresolved_move_addr can actually be a move in which
case it converts it to copy_addr [take][init] or if it can not be a move, emit
an error and convert the instruction to a copy_addr [init]. After this is done
for all instructions, we loop back through again and emit an error on any
mark_unresolved_move_addr that were not processed earlier allowing for us to
know that we have completeness.
NOTE: The move kills checker for addresses is going to run after Mandatory
Inlining, but before predictable memory opts and friends.
* add the IntegerLiteralInst + the Builder function to create it
* add Value.nonDebugUses
* add a general utility Sequence.isEmpty
* add PassContext.replaceAllUses
* add a function to erase all `debug_value` uses in PassContext.erase
Required for UnsafeRawPointer.withMemoryReboud(to:).
%out_token = rebind_memory %0 : $Builtin.RawPointer to %in_token
%0 must be of $Builtin.RawPointer type
%in_token represents a cached set of bound types from a prior memory state.
%out_token is an opaque $Builtin.Word representing the previously bound
types for this memory region.
This instruction's semantics are identical to ``bind_memory``, except
that the types to which memory will be bound, and the extent of the
memory region is unknown at compile time. Instead, the bound-types are
represented by a token that was produced by a prior memory binding
operation. ``%in_token`` must be the result of bind_memory or
Required for UnsafeRawPointer.withMemoryRebound(to:)
%token = bind_memory %0 : $Builtin.RawPointer, %1 : $Builtin.Word to $T
%0 must be of $Builtin.RawPointer type
%1 must be of $Builtin.Word type
%token is an opaque $Builtin.Word representing the previously bound types
for this memory region.
The key thing is that the move checker will not consider the explicit copy value
to be a copy_value that can be rewritten, ensuring that any uses of the result
of the explicit copy_value (consuming or other wise) are not checked.
Similar to the _move operator I recently introduced, this is a transparent
function so we can perform one level of specialization and thus at least be
generic over all concrete types.
* ApplySite.arguments
* BasicBlock != operator
* some Function argument related properties
* Operand.isTypeDependent
* Type.isTrivial
* bridging of raw_ostream::write
This is a new instruction that can be used by SILGen to perform a semantic move
in between two entities that are considered separate variables at the AST
level. I am going to use it to implement an experimental borrow checker.
This PR contains the following:
1. I define move_value, setup parsing, printing, serializing, deserializing,
cloning, and filled in all of the visitors as appropriate.
2. I added createMoveValue and emitMoveValueOperation SILBuilder
APIs. createMoveValue always creates a move and asserts is passed a trivial
type. emitMoveValueOperation in contrast, will short circuit if passed a
trivial value and just return the trivial value.
3. I added IRGen tests to show that we can push this through the entire system.
This is all just scaffolding for the instruction to live in SIL land and as of
this PR doesn't actually do anything.
