I also added some basic tests of its functionality. I am doing this in
preparation for making some more invasive changes to getTrackableValue and I
want to be able to test it out very specifically in SIL.
* `sitofp` signed integer to floating point
* `rint` round floating point to integral
* `bitcast` between integer and floating point
Constant folding `bitcast`s also made it necessary to rewrite constant folding for Nan and inf values, because the old code explicitly checked for `bitcast` intrinsics.
Relying on constant folded `bitcast`s makes the new version much simpler.
It is important to constant fold these intrinsics already in SIL because it enables other optimizations.
Due to compile time issues, I added a cache into
getUnderlyingTrackedValue(). This caused an iterator invalidation issue when we
recursed in the case when we had an underlying object since we would recurse
into getUnderlyingTrackedValue() instead of getUnderlyingTrackedValueHelper()
potentially causing us to cache another value and thus causing the underlying
DenseMap to expand. Now we instead just call getUnderlyingTrackedValueHelper()
so that we avoid the invalidation issue. This may cause us to use slightly more
compile time but we are still only ever going to compute the underlying value
once for any specific value.
Specifically,
1. UseDefChainVisitor::actorIsolation is dead. I removed it to prevent any
confusion/thoughts that it actually found isolation. I also removed it from
UnderlyingTrackedValue since that was the only place where we were using it. I
left UnderlyingTrackedValue there in case I need to add additional state there
in the future.
2. Now that UseDefChainVisitor is only used to find the base of a value (while
not looking through Sendable addresses), I renamed it to
AddressBaseComputingVisitor.
3. I renamed UseDefChainVisitor::isMerge to isProjectedFromAggregate. That is
actually what we use it for. I also added a comment explaining what it is used
for.
This is a narrow fix, we are going to work on fixing this properly
and allowing both devirtualization and specialization for distributed
requirement witnesses.
Anything that uses an ad-hoc serialization requirement scheme cannot
be devirtualized because that would result in loss of ad-hoc conformance
in new substitution map.
Resolves: https://github.com/swiftlang/swift/issues/79318
Resolves: rdar://146101172
When performing a dynamic cast to an existential type that satisfies
(Metatype)Sendable, it is unsafe to allow isolated conformances of any
kind to satisfy protocol requirements for the existential. Identify
these cases and mark the corresponding cast instructions with a new flag,
`[prohibit_isolated_conformances]` that will be used to indicate to the
runtime that isolated conformances need to be rejected.
Fixes a false alarm in case of recursive calls with different type parameters.
For example:
```
protocol P {
associatedtype E: P
}
func noRecursionMismatchingTypeArgs1<T: P>(_ t: T.Type) {
if T.self == Int.self {
return
}
noRecursionMismatchingTypeArgs1(T.E.self)
}
```
The body of a function has to be re-analyzed for every call
site of the function, which is very expensive and if the
body is not changed would produce the same result.
This takes about ~10% from swift-syntax overall build time
in release configuration.
Run the swift-frontend in a mode that will generate LLVM IR adding the
option `-print-cond-fail-messages` will dump all cond_fail message strings
encountered in the SIL.
```
% swift-frontend -Xllvm -print-cond-fail-messages -emit-ir/-c ...
cond_fail message encountered: Can't take a prefix of negative length from a collection
cond_fail message encountered: Range out of bounds
cond_fail message encountered: Array index is out of range
```
We need to consider that archetypes (generic types) can be existentials if they conform to self-conforming protocols.
Fixes a miscompile
rdar://147269904
