Before this change, given a CFG like the following:
bb0:
%0 = enum $Optional<Cls>, #Optional.None!enumelt
br bb1(%0 : $Optional<Cls>)
bb1(%1 : $Optional<Cls>):
%2 = alloc_ref $Cls
retain_value %2 : $Cls
release_value %1 : $Optional<Cls>
%3 = enum $Optional<Cls>, #Optional.Some!enumelt.1, %2 : $Cls
cond_br undef, bb1(%3 : $Optional<Cls>), bb2
bb2:
...
We would pair up the retain, release even though they are from different
iterations. The reason we were doing this is that we were recursively
stripping off the Phi node before checking dominance instead of
vis-a-versa.
rdar://18367606
Swift SVN r22892
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
This reverts r22044, reapplying commit r22006.
I think Arnold found the bug behind why this originally was failing (that we
were too aggressive with stripping off certain types of pointers). Re-enable
it.
This gives us another 5% on Richards.
Swift SVN r22809
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
Make unique reference checking available to users, making ManagedBuffer
a complete facility for building COW value types. Also rationalize the
way we name and organize the runtime primitives we ultimately call.
Swift SVN r22594
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
llvm::Optional lives in "llvm/ADT/Optional.h". Like Clang, we can get
Optional in the 'swift' namespace by including "swift/Basic/LLVM.h".
We're now fully switched over to llvm::Optional!
Swift SVN r22477
When simplifying an 'enum' instruction that appears in a block that is
the destination of a switch_enum, we need to ensure that the block with
the 'enum' instruction is uniquely chosen based on the same enum tag
that the 'enum' instruction uses, not just that we'll reach that
destination block with the same enum tag (since we could have multiple
tags target the same block, and could have a default case).
Fixes rdar://problem/18330952.
Swift SVN r22065
This reverts commit r22006. Turns out this did expose other issues. I am just
going to revert it for now since I don't have time to mess with it now. *sigh*.
Swift SVN r22044
This reduces the number of retain, release operations in the dylib from 38512 to
16041. That is a reduction of 60%. Most of the code paths affected by this were
in the cocoa part of the stdlib so when I measured the perf test suite I did not
see a huge boost in perf.
rdar://18327670
Swift SVN r21934
This is important since to be more aggressive we are ignoring incoming values
that are no-payload enums since as far as we are concerned they do not matter
since retains, releases on those values are no-ops.
Swift SVN r21932
Currently, the pass just calls a local version of that function. After OzU, I
will enable the full pass (which is currently disabled behind a flag).
Swift SVN r21894
The cache is needed to ensure we do not run into compile time problems once we
start looking through Phi Nodes.
The analysis is currently disabled and just returns
SILValue::stripRCIdentityPreservingOps. I am going to thread it through the rest
of the passes that use that call. Then I am going to hide
stripRCIdentityPreservingArgs. Finally post OzU, I am going to enable the pass.
rdar://18300069
Swift SVN r21891
This follows the model of dominance info and allows me to create reachability
methods on SILBasicBlock without creating dependencies from swiftSIL to
swiftSILAnalysis.
Swift SVN r21866
If we have an argument that is guaranteed, the optimizer should always treat it
as known safe. This is good to do since we will eventually if I understand
correctly mark self as @guaranteed in methods. For now it will only be exposed
via function signature optimization.
rdar://18289318
Swift SVN r21834
This will hopefully make it clearer as we onboard people that
SimplifyInstruction should not add instructions to the IR by making it clearer
that it is an analysis, not a pass.
Swift SVN r21752
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
The old call graph remains, but the new call graph can obtained by
calling getCallGraph() on the analysis pass.
I'll move the few other passes that use the call graph over soon and
then rip out the old call graph.
No diffs in the stdlib.
Swift SVN r21565
With this change we generate the SCCs in the call graph (for the kinds
of calls we currently recognize) in bottom-up, which we can then
iterate over directly or in reverse for invocation- and
reverse-invocation-order traversal of the call graph.
(This still isn't hooked up - but will be after some dumping routines
and verification of the output).
Swift SVN r21552
This enables us to both check if any instructions may use or decrement a value
in an instruction range and if we find such an instruction know the furthest
where we can move the retain or release.
Swift SVN r21522
