ProtocolConformanceRef already has an invalid state. Drop all of the
uses of Optional<ProtocolConformanceRef> and just use
ProtocolConformanceRef::forInvalid() to represent it. Mechanically
translate all of the callers and callsites to use this new
representation.
https://forums.swift.org/t/improving-the-representation-of-polymorphic-interfaces-in-sil-with-substituted-function-types/29711
This prepares SIL to be able to more accurately preserve the calling convention of
polymorphic generic interfaces by letting the type system represent "substituted function types".
We add a couple of fields to SILFunctionType to support this:
- A substitution map, accessed by `getSubstitutions()`, which maps the generic signature
of the function to its concrete implementation. This will allow, for instance, a protocol
witness for a requirement of type `<Self: P> (Self, ...) -> ...` for a concrete conforming
type `Foo` to express its type as `<Self: P> (Self, ...) -> ... for <Foo>`, preserving the relation
to the protocol interface without relying on the pile of hacks that is the `witness_method`
protocol.
- A bool for whether the generic signature of the function is "implied" by the substitutions.
If true, the generic signature isn't really part of the calling convention of the function.
This will allow closure types to distinguish a closure being passed to a generic function, like
`<T, U> in (*T, *U) -> T for <Int, String>`, from the concrete type `(*Int, *String) -> Int`,
which will make it easier for us to differentiate the representation of those as types, for
instance by giving them different pointer authentication discriminators to harden arm64e
code.
This patch is currently NFC, it just introduces the new APIs and takes a first pass at updating
code to use them. Much more work will need to be done once we start exercising these new
fields.
This does bifurcate some existing APIs:
- SILFunctionType now has two accessors to get its generic signature.
`getSubstGenericSignature` gets the generic signature that is used to apply its
substitution map, if any. `getInvocationGenericSignature` gets the generic signature
used to invoke the function at apply sites. These differ if the generic signature is
implied.
- SILParameterInfo and SILResultInfo values carry the unsubstituted types of the parameters
and results of the function. They now have two APIs to get that type. `getInterfaceType`
returns the unsubstituted type of the generic interface, and
`getArgumentType`/`getReturnValueType` produce the substituted type that is used at
apply sites.
The optimizer can generate a thin_to_thick_function conversion from a throwing thin to a non-throwing thick function (in case it can prove that the function is actually not throwing).
Therefore, when removing such a conversion from the callee-argument of an apply, we have to check if the new callee (= the argument of the thin_to_thick_function) is a throwing function and set the not-throwing flag in this case.
This fixes a SILVerifier crash.
rdar://problem/56358645
The XXOptUtils.h convention is already established and parallels
the SIL/XXUtils convention.
New:
- InstOptUtils.h
- CFGOptUtils.h
- BasicBlockOptUtils.h
- ValueLifetime.h
Removed:
- Local.h
- Two conflicting CFG.h files
This reorganization is helpful before I introduce more
utilities for block cloning similar to SinkAddressProjections.
Move the control flow utilies out of Local.h, which was an
unreadable, unprincipled mess. Rename it to InstOptUtils.h, and
confine it to small APIs for working with individual instructions.
These are the optimizer's additions to /SIL/InstUtils.h.
Rename CFG.h to CFGOptUtils.h and remove the one in /Analysis. Now
there is only SIL/CFG.h, resolving the naming conflict within the
swift project (this has always been a problem for source tools). Limit
this header to low-level APIs for working with branches and CFG edges.
Add BasicBlockOptUtils.h for block level transforms (it makes me sad
that I can't use BBOptUtils.h, but SIL already has
BasicBlockUtils.h). These are larger APIs for cloning or removing
whole blocks.
In the previous commit, various methods for adding, replacing, and
removing instructions were duplicate from SILCombiner into
SILInstructionWorklist. Here, SILCombiner is modified to call through
to the methods which were added to SILInstructionWorklist.
- Replaced usage of raw map and vector with the type that wraps the
combination (BlotSetVector); that provided a significant deduplication
since a sizeable portion of the worklist's implementation was in
vector and map management now provided by the BlotSetVector.
- Templated over the type of map and vector used by the blot set vector.
- Added SmallSILInstructionWorklist where the map and vector are
specified to be SmallDenseMap and SmallVector respectively.
- Replaced usages of bare ValueBase with usages of SILValue.
- Renamed zap to resetChecked.
Added a bit of functionality to BlotSetVector, specifically to support
SILInstructionWorklist:
- Made insert return not just the index that the potentially-inserted
item is at on return but additionally whether an insertion occurred,
matching the behavior of llvm::DenseMap::insert.
- Added a method to reserve capacity in the backing vector and map:
BlotSetVector::reserve.
- Added a method to free extra storage used by the backing vector and
map: BlotSetVector::clear.
- Modified SmallBlotSetVector's template parameters so that only a value
and size can be specified--that type will always use SmallVector and
SmallDenseMap for its superclass' VectorT and MapT template
parameters.
- Updated variable names.
In the previous commit, SILInstructionWorklist was added as a verbatim
extraction (modulo some minor style tweaks) of SILCombineWorklist.
Here, SILCombine is moved over to using that renamed type.
Returns `true` if `T.Type` is known to refer to a concrete type. The
implementation allows for the optimizer to specialize this at -O and
eliminate conditional code.
Includes `Swift._isConcrete<T>(T.Type) -> Bool` wrapper function.
NOTE:
1. To test this I changed UnaryOp_match to use this under the hood.
2. These types of m_##ID##Inst matchers now will only accept compound types and
I added a static assert to verify that this mistake doesn't happen. We
previously had matchers that would take an int or the like to match tuple
extract patterns. I converted those to use TupleExtractOperation that also
properly handles destructures.
The SIL generation for this builtin also changes: instead of generating the cond_fail instructions upfront, let the optimizer generate it, if the operand is a static string literal.
In worst case, if the second operand is not a static string literal, the Builtin.condfail is lowered at the end of the optimization pipeline with a default message: "unknown program error".
The SIL generation for this builtin also changes: instead of generating the cond_fail instructions upfront, let the optimizer generate it, if the operand is a static string literal.
In worst case, if the second operand is not a static string literal, the Builtin.condfail is lowered at the end of the optimization pipeline with a default message: "unknown program error".
With the advent of dynamic_function_ref the actual callee of such a ref
my vary. Optimizations should not assume to know the content of a
function referenced by dynamic_function_ref. Introduce
getReferencedFunctionOrNull which will return null for such function
refs. And getInitialReferencedFunction to return the referenced
function.
Use as appropriate.
rdar://50959798
Handle calling conventions and cleanups in all the places (hopefully).
- when ExistentialSpecializer copies the specialized concrete arg into the
original existential value
- when ExistentialSpecializer generates a think
- when SILCombine substitutes concrete values in place of the opened
existential.
One particularly nasty problem is the existential boxes need to be
destroyed. It is not ok to simply destroy their value. The "leaks"
tool does not catch this problem.
Ownership SIL will make this all much more robust.
Fixes <rdar://problem/50595630> Multiple leaks detected - Swift Perf
If the keypath argument of a keypath access function is a keypath literal instruction, generate the projection inline and remove the access function.
For example, replaces (simplified SIL):
%kp = keypath ... stored_property #Foo.bar
apply %keypath_runtime_function(%root_object, %kp, %addr)
with:
%addr = struct_element_addr %root_object, #Foo.bar
load/store %addr
Currently this only handles stored property patterns.
rdar://problem/36244734
This is the complement to load canonicalization. Although store
canonicalization is not required before diagnostics, it should be
defined in the same utility.
CanonicalizeInstruction will be a superset of
simplifyInstruction (once all the transforms are fixed for ownership
SIL). Additionally, it will also include simple SSA-based
canonicalization that requires new instruction creation. It may not
perform any optimization that interferes with diagnostics or increases
compile time.
Canonicalization replaces simplifyInstruction in SILCombine so we can
easily factor some existing SILCombine transforms into canonicalization.
This is a large patch; I couldn't split it up further while still
keeping things working. There are four things being changed at
once here:
- Places that call SILType::isAddressOnly()/isLoadable() now call
the SILFunction overload and not the SILModule one.
- SILFunction's overloads of getTypeLowering() and getLoweredType()
now pass the function's resilience expansion down, instead of
hardcoding ResilienceExpansion::Minimal.
- Various other places with '// FIXME: Expansion' now use a better
resilience expansion.
- A few tests were updated to reflect SILGen's improved code
generation, and some new tests are added to cover more code paths
that previously were uncovered and only manifested themselves as
standard library build failures while I was working on this change.
Optimizing applies that take existential arguments is a complex
process with multiple transformations. If the apply isn't rewritten,
earlier transformations need to be undone.
SILCombine is obviously the wrong place to implement type propagation,
as I point out every time I need to fix it.
Fixes <rdar://problem/49336444> SILCombine infinite loop.
Previously, we based it off of whether or not the original apply had a nothrow
bit. This is incorrect in the case where we added an error result to a function
without an error result. In such a case, we need to /not/ put on the nothrow
bit. This commit generalizes this idea slightly by assuming that if we are asked
to perform this transformation we should just match what the underlying
function_ref (i.e. setting nothrow if the underlying function type has an error
result and not setting nothrow if the underlying function type does not have an
error result).
rdar://47828439
NOTE: I changed all places that the CastOptimizer is created to just pass in
nullptr for now so this is NFC.
----
Right now the interface of the CastOptimizer is muddled and confused. Sometimes
it is returning a value that should be used by the caller, other times it is
returning an instruction that is meant to be reprocessed by the caller.
This series of patches is attempting to clean this up by switching to the
following model:
1. If we are optimizing a cast of a value, we return a SILValue. If the cast
fails, we return an empty SILValue().
2. If we are optimizing a cast of an address, we return a boolean value to show
success/failure and require the user to use the SILBuilderContext to get the
cast if they need to.
This disables a bunch of passes when ownership is enabled. This will allow me to
keep transparent functions in ossa and skip most of the performance pipeline without
being touched by passes that have not been updated for ownership.
This is important so that we can in -Onone code import transparent functions and
inline them into other ossa functions (you can't inline from ossa => non-ossa).
This code was force casting the address of the opened existential to
the lowered SIL type of the known conformance. This is superficially
incorrect because values are stored in existentials with maximal
reabstraction.
Bail on any concrete types that require reabstraction. I don't think
we will hit this currently because there is an earlier check that
prevents optimizing a conformance on a generic types. In theory
someone could add that functionality later for internal generic types
with a single instantiation.
More importantly, we don't want anyone copying this logic and assuming
it's generally correct.
Generalizes the ConcreteExistentialInfo abstraction so it can be used
both by the ExistentialSpecializer and SILCombine, allowing redundant
code in ExistentialSpecializer.cpp to be deleted.
Splits OpenedArchetypeInfo from ConcreteExistentialInfo. Adds a
ConcreteOpenedArchetypeInfo convenience wrapper around them both, for
use wherever we were originally using ConcreteExistentialInfo.
Splits getAddressOfStackInit into getStackInitInst, This is cleaner and
allows both the ExistentialSpecializer and SILCombine to handle more
interesting cases in the future, like unconditional_checked_cast.
Creates utilities, initializeSubstitutionMap, and
initializeConcreteTypeDef to simplify an generalize
ConcreteExistentialInfo.
While rewriting ExistentialSpecializer to use the new
abstraction, I fixed a latent bug in which is was using a SIL
argument index as a function type parameter index (this would
have broken up if/when we decide to enable calls with indirect
results).
This cannot be correctly done as a SILCombine because it must create
new instructions at a previous location. Move the optimization into
CastOptimizer. Insert the new metatype instructions in the correct
spot. And manually do the replaceAllUsesWith and eraseInstruction
steps.
Fixes <rdar://problem/46746188> crash in swift_getObjCClassFromObject.
Basically the pattern to optimize is:
inject_enum_addr %stackloc, #SomeCase
switch_enum_addr %stackloc ...
This works even if the enum is resilient and the case does not have a payload. As long as we don't have opaque values in SIL we need this peephole to optimize the pattern.
This change fixes the code generation for Float.rounded().
rdar://problem/46353885
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
This allows Swift code to implement a fast path via a protocol type
check as follows:
if let existentialVal = genericVal as? SomeProtocol {
// do something fast.
}
Fixes <rdar://problem/46322928> Failure to devirtualize a protocol
method applied to an opened existential blocks implemention of
DataProtocol.
Note: the approach of devirtualization via backward pattern matching
is fundamentally wrong and will never be fully general. It should be a
forward type propagation.
