The old analysis pass doesn't take into account profile data, nor does
it consider post-dominance. It primarily dealt with _fastPath/_slowPath.
A block that is dominated by a cold block is itself cold. That's true
whether it's forwards or backwards dominance.
We can also consider a call to any `Never` returning function as a
cold-exit, though the block(s) leading up to that call may be executed
frequently because of concurrency. For now, I'm ignoring the concurrency
case and assuming it's cold. To make use of this "no return" prediction,
use the `-enable-noreturn-prediction` flag, which is currently off by
default.
SILFunction::shouldBePreservedForDebugger checks if some optimizations
are enabled to decide whether a function should be preserved so its
accessible form the debugger or not. Some of these settings used to live
only in IRGenOptions making SILFunction depend on IRGenOptions.
* Add a new flag -experimental-package-cmo that requires -experimental-allow-non-resilient-access.
* Support serializing package decls for CMO in package if enabled.
* Only applies to default mode CMO.
* Unlike the existing CMO, package CMO can be built with -enable-library-evolution as package
modules are required to be built together in the same project.
* Create hasPublicOrPackageVisibility to opt in for package decls; needed for CMO, SILVerifier,
and other call sites that verify or determine codegen.
Resolves rdar://121976014
It's not thread safe and can cause false alarms in case multiple modules exist in different threads. E.g. when building swiftmodules from interfaces.
The leaking check is not important anymore because the builder APIs enforce that instructions are not leaking.
I.e. it's not possible to create an instruction without inserting it into a basic block. Also, it's not possible to remove an instruction from a block without deleting it.
rdar://122169263
Rename -experimental-serialize-external-decls only to
-experimental-skip-non-exportable-decls in preparation for the flag being used
to influence more than just serialization.
Resolves rdar://116771543
For chains of async functions where suspensions can be statically
proven to never be required, this pass removes all suspensions and
turns the functions into synchronous functions.
For example, this function does not actually require any suspensions,
once the correct executor is acquired upon initial entry:
```
func fib(_ n: Int) async -> Int {
if n <= 1 { return n }
return await fib(n-1) + fib(n-2)
}
```
So we can turn the above into this for better performance:
```
func fib() async -> Int {
return fib_sync()
}
func fib_sync(_ n: Int) -> Int {
if n <= 1 { return n }
return fib(n-1) + fib(n-2)
}
```
while rewriting callers of `fib` to use the `sync` entry-point
when we can prove that it will be invoked on a compatible executor.
This pass is currently experimental and under development. Thus, it
is disabled by default and you must use
`-enable-experimental-async-demotion` to try it.
Introduces a concept of a dependency scanning action context hash, which is used to select an instance of a global dependency scanning cache which gets re-used across dependency scanning actions.
The pass to decide which functions should get stack protection was added in https://github.com/apple/swift/pull/60933, but was disabled by default.
This PR enables stack protection by default, but not the possibility to move arguments into temporaries - to keep the risk low.
Moving to temporaries can be enabled with the new frontend option `-enable-move-inout-stack-protector`.
rdar://93677524
So far, the swift-frontend decided by itself if CMO can be enabled. This caused problems when used with an old driver, which doesn't consider CMO.
Now, the driver decides when to use default CMO by passing this flag to swift-frontend.
If we are emitting a TBD file, the TBD file only contains public symbols of this module.
But not public symbols of imported modules which are statically linked to the current binary.
This prevents referencing public symbols from other modules which could (potentially) linked statically.
Unfortunately there is no way to find out if another module is linked statically or dynamically, so we have to be conservative.
Fixes an unresolved-symbol linker error.
rdar://89364148
The reason why I am doing this is that we are going to be enabling lexical
lifetimes early in the pipeline so that I can use it for the move operator's
diagnostics.
To make it easy for passes to know whether or not they should support lexical
lifetimes, I included a query on SILOptions called
supportsLexicalLifetimes. This will return true if the pass (given the passed in
option) should insert the lexical lifetime flag. This ensures that passes that
run in both pipelines (e.x.: AllocBoxToStack) know whether or not to set the
lexical lifetime flag without having to locally reason about it.
This is just chopping off layers of a larger patch I am upstreaming.
NOTE: This is technically NFC since it leaves the default alone of not inserting
lexical lifetimes at all.
Leaks checking is not thread safe and e.g. lldb creates multiple SILModules in multiple threads, which would result in false alarms.
Ideally we would make it thread safe, e.g. by putting the instruction counters in the SILModule, but this would be a big effort and it's not worth doing it. Leaks checking in the frontend's and SILOpt's SILModule (not including SILModules created for module interface building) is a good enough test.
rdar://84688015
