or pointer depends on another for validity in a
non-obvious way.
Also, document some basic value-propagation rules
based roughly on the optimization rules for ARC.
Swift SVN r23695
Before this patch there was no dependence visible to the optimizer between a
open_existential and the witness_method allowing the optimizer to reorder the
two instruction. The dependence was implicit in the opened archetype but this
is not a concept model by the SIL optimizer.
%2 = open_existential %0 : $*FooProto to $*@opened("...") FooProto
%3 = witness_method $@opened("...") FooProto,
#FooProto.bar!1 : $@cc(...)
%4 = apply %3<...>(%2)
This patch changes the SIL representation such that witness_methods on opened
archetypes take the open_existential (or the producer of the opened existential)
as an operand preventing the optimizer from reordering them.
%2 = open_existential %0 : $*FooProto to $*@opened("...") FooProto
%3 = witness_method $@opened("...") FooProto,
#FooProto.bar!1,
%2 : $*@opened("...") FooProto : $@cc(...)
%4 = apply %3<...>(%2)
rdar://18984526
Swift SVN r23438
This is a type that has ownership of a reference while allowing access to the
spare bits inside the pointer, but which can also safely hold an ObjC tagged pointer
reference (with no spare bits of course). It additionally blesses one
Foundation-coordinated bit with the meaning of "has swift refcounting" in order
to get a faster short-circuit to native refcounting. It supports the following
builtin operations:
- Builtin.castToBridgeObject<T>(ref: T, bits: Builtin.Word) ->
Builtin.BridgeObject
Creates a BridgeObject that contains the bitwise-OR of the bit patterns of
"ref" and "bits". It is the user's responsibility to ensure "bits" doesn't
interfere with the reference identity of the resulting value. In other words,
it is undefined behavior unless:
castReferenceFromBridgeObject(castToBridgeObject(ref, bits)) === ref
This means "bits" must be zero if "ref" is a tagged pointer. If "ref" is a real
object pointer, "bits" must not have any non-spare bits set (unless they're
already set in the pointer value). The native discriminator bit may only be set
if the object is Swift-refcounted.
- Builtin.castReferenceFromBridgeObject<T>(bo: Builtin.BridgeObject) -> T
Extracts the reference from a BridgeObject.
- Builtin.castBitPatternFromBridgeObject(bo: Builtin.BridgeObject) -> Builtin.Word
Presents the bit pattern of a BridgeObject as a Word.
BridgeObject's bits are set up as follows on the various platforms:
i386, armv7:
No ObjC tagged pointers
Swift native refcounting flag bit: 0x0000_0001
Other available spare bits: 0x0000_0002
x86_64:
Reserved for ObjC tagged pointers: 0x8000_0000_0000_0001
Swift native refcounting flag bit: 0x0000_0000_0000_0002
Other available spare bits: 0x7F00_0000_0000_0004
arm64:
Reserved for ObjC tagged pointers: 0x8000_0000_0000_0000
Swift native refcounting flag bit: 0x4000_0000_0000_0000
Other available spare bits: 0x3F00_0000_0000_0007
TODO: BridgeObject doesn't present any extra inhabitants. It ought to at least provide null as an extra inhabitant for Optional.
Swift SVN r22880
Modeling builtins as first-class function values doesn't really make sense because there's no real function value to emit, and modeling them this way complicates passes that work with builtins because they have to invent function types for builtin invocations. It's much more straightforward to have a single instruction that references the builtin by ID, along with the type information for the necessary values, type parameters, and results, so add a new "builtin" instruction that directly represents a builtin invocation. NFC yet.
Swift SVN r22690
layouts. Introduce new SIL instructions to initialize
and open existential metatype values.
Don't actually, y'know, lift any of the restriction on
existential metatypes; just pointlessly burn extra
memory storing them.
Swift SVN r22592
We currently do not serialize the body of global addressors. To make
"sil-opt swiftmodule" pass verification, we change the linkage for
the deserialized empty global addressors from public to public external.
rdar://18021024
Swift SVN r22370
I can't actually reproduce the buildbot failure that happened last night, so
hopefully it will (a) happen again, so I can investigate, or (b) not happen
again.
Swift SVN r22230
Now the SILLinkage for functions and global variables is according to the swift visibility (private, internal or public).
In addition, the fact whether a function or global variable is considered as fragile, is kept in a separate flag at SIL level.
Previously the linkage was used for this (e.g. no inlining of less visible functions to more visible functions). But it had no effect,
because everything was public anyway.
For now this isFragile-flag is set for public transparent functions and for everything if a module is compiled with -sil-serialize-all,
i.e. for the stdlib.
For details see <rdar://problem/18201785> Set SILLinkage correctly and better handling of fragile functions.
The benefits of this change are:
*) Enable to eliminate unused private and internal functions
*) It should be possible now to use private in the stdlib
*) The symbol linkage is as one would expect (previously almost all symbols were public).
More details:
Specializations from fragile functions (e.g. from the stdlib) now get linkonce_odr,default
linkage instead of linkonce_odr,hidden, i.e. they have public visibility.
The reason is: if such a function is called from another fragile function (in the same module),
then it has to be visible from a third module, in case the fragile caller is inlined but not
the specialized function.
I had to update lots of test files, because many CHECK-LABEL lines include the linkage, which has changed.
The -sil-serialize-all option is now handled at SILGen and not at the Serializer.
This means that test files in sil format which are compiled with -sil-serialize-all
must have the [fragile] attribute set for all functions and globals.
The -disable-access-control option doesn't help anymore if the accessed module is not compiled
with -sil-serialize-all, because the linker will complain about unresolved symbols.
A final note: I tried to consider all the implications of this change, but it's not a low-risk change.
If you have any comments, please let me know.
Swift SVN r22215
conformances (22195 to 22199).
It broke tests:
Failing Tests (4):
Swift :: Interpreter/SDK/Foundation_NSString.swift
Swift :: SIL/Serialization/deserialize_appkit.sil
Swift :: SIL/Serialization/deserialize_foundation.sil
Swift :: stdlib/NSStringAPI.swift
Swift SVN r22214
We add two more fields to SILGlobalVariable: a VarDecl and a flag to see if this
is a declaration. VarDecl is mainly used for debugger support, it is also used
to check if the variable is weak imported.
We also modify the serializer to serialize the extra two fields.
Swift SVN r21883
This is necessary to be able to properly stash values with nontrivial lowerings, such as metatypes and functions, inside existential containers. Modify SILGen to lower values to the proper abstraction level before storing them in an existential container. Part of the fix for rdar://problem/18189508, though runtime problems still remain when trying to actually dynamicCast out a metatype from an Any container.
Swift SVN r21830
We want to be able to work around problems with non-failable
Objective-C initializers actually failing, which can happen when the
API audit data incorrectly marks an initializer as non-failable.
Swift SVN r21711
This will let the performance inliner inline a function even if the costs are too high.
This attribute is only a hint to the inliner.
If the inliner has other good reasons not to inline a function,
it will ignore this attribute. For example if it is a recursive function (which is
currently not supported by the inliner).
Note that setting the inline threshold to 0 does disable performance inlining at all and in
this case also the @inline(__always) has no effect.
Swift SVN r21452
This disables inlining at the SIL level. LLVM inlining is still enabled. We can
use this to expose one function at the SIL level - which can participate in
dominance based optimizations but which is implemented in terms of a cheap check
and an expensive check (function call) that benefits from LLVM's inlining.
Example:
The inline(late) in the example below prevents inlining of the two checks. We
can now perform dominance based optimizations on isClassOrObjExistential.
Without blocking inlining the optimizations would apply to the sizeof check
only and we would have multiple expensive function calls.
@inline(late)
func isClassOrObjExistential(t: Type) -> Bool{
return sizeof(t) == sizeof(AnyObject) &&
swift_isClassOrObjExistential(t)
}
We do want inlining of this function to happen at the LLVM level because the
first check is constant folded away - IRGen replaces sizeof by constants.
rdar://17961249
Swift SVN r21286
*NOTE* This linkage is different from {Public,Hidden}External in that it has no
extra semantic meaning beyond shared.
The use of this linkage is to ensure that we do not serialize deserialized
shared functions. Those shared functions can always be re-deserialized from the
original module. This prevents a whole class of bugs related to the
creation of module cross references since all references to the shared
item go straight to the original module.
<rdar://problem/17772847>
Swift SVN r20375
Enable SIL parsing and SIL serialization of semantics.
We add one more field to SILFunctionLayout for semantics. We should refactor
handling of attributes at SIL level, right now they are in SILFunction as bool
or std::string and in SIL serializer as a 1-bit field or an ID field.
rdar://17525564
Swift SVN r19434
