This instructions marks the point where all let-fields of a class are initialized.
This is important to ensure the correctness of ``ref_element_addr [immutable]`` for let-fields,
because in the initializer of a class, its let-fields are not immutable, yet.
Codegen is the same, but `begin_dealloc_ref` consumes the operand and produces a new SSA value.
This cleanly splits the liferange to the region before and within the destructor of a class.
I was originally hoping to reuse mark_must_check for multiple types of checkers.
In practice, this is not what happened... so giving it a name specifically to do
with non copyable types makes more sense and makes the code clearer.
Just a pure rename.
For example:
```
var p = Point(x: 10, y: 20)
let o = UnsafePointer(&p)
```
Also support outlined arrays with pointers to other globals. For example:
```
var g1 = 1
var g2 = 2
func f() -> [UnsafePointer<Int>] {
return [UnsafePointer(&g1), UnsafePointer(&g2)]
}
```
* add `GlobalVariable.staticInitializerInstructions` to access all initializer instructions of a global
* implement `GlobalVariable.staticInitValue` with `GlobalVariable.staticInitializerInstructions`
* this requires that `InstructionList.reversed()` works without accessing the parent block of the iterator instruction
* allow `Context.erase(instruction:)` to delete instructions from a global's initializer list, which means to handle the case where a deleted instruction has no parent function.
For a redundant pair of pointer-address conversions, e.g.
%2 = address_to_pointer %1
%3 = pointer_to_address %2 [strict]
replace all uses of %3 with %1.
A begin_apply can yield multiple addresses. We need to store the result of the apply in order to distinguish between two AccessBases with different results from the same begin_apply.
`ownership` is a bad name in `LoadInst`, because it hides `Value.ownership`.
Therefore rename it to `loadOwnership`.
Do the same for ownership in StoreInst to be consistent.
Before this change, if a global variable is required to be statically initialized (e.g. due to @_section attribute), we don't allow its type to be a struct, only a scalar type works. This change improves on that by teaching MandatoryPerformanceOptimizations pass to inline struct initializer calls into initializer of globals, as long as they are simple enough so that we can be sure that we don't trigger recursive/infinite inlining.
add field types:
`x`: existential address projection, like `open_existential_addr`
`i<n>`: indexed element with constant index, like `index_addr` with an integer literal as index
`i*`: indexed element with an unknown index
The `bare` attribute indicates that the object header is not used throughout the lifetime of the value.
This means, no reference counting operations are performed on the object and its metadata is not used.
The header of bare objects doesn't need to be initialized.
The `bare` attribute indicates that the object header is not used throughout the lifetime of the object.
This means, no reference counting operations are performed on the object and its metadata is not used.
The header of bare objects doesn't need to be initialized.
Look through `upcast` and `init_existential_ref` instructions and replace the operand of this cast instruction with the original value.
For example:
```
%2 = upcast %1 : $Derived to $Base
%3 = init_existential_ref %2 : $Base : $Base, $AnyObject
checked_cast_br %3 : $AnyObject to Derived, bb1, bb2
```
This makes it more likely that the cast can be constant folded because the source operand's type is more accurate.
In the example above, the cast reduces to
```
checked_cast_br %1 : $Derived to Derived, bb1, bb2
```
which can be trivially folded to always-succeeds.
Found while looking at `_SwiftDeferredNSDictionary.bridgeValues()`
* add `UnownedRetainInst` and `UnownedReleaseInst`
* add `var value` to `RetainValueInst` and `ReleaseValueInst`
* make the protocol `UnaryInstruction` be an `Instruction`
* add `var Type.isValueTypeWithDeinit`
* add `var Type.isUnownedStorageType`
* add `var OperandArray.values`
The main change here is in IRGen which needs to be able to emit constant enum values.
Use `emitValueInjection` to create the enum constant.
Usually this method creates code in the current function.
But if all arguments to the enum are constant, the builder never has to emit an instruction.
Instead it can constant fold everything and just returns the final constant.
Also, create statically initialized let-globals as constant global (`constant` instead of `global`).
This comes up in the code for constructing an empty string literal.
With this optimization it's possible to statically initialize empty string global variables.
* add the StaticInitCloner utility
* remove bridging of `copyStaticInitializer` and `createStaticInitializer`
* add `Context.mangleOutlinedVariable` and `Context.createGlobalVariable`
* add new create-functions for instructions
* allow the Builder to build static initializer instructions for global variables
* some refactoring to simplify the implementation
* Check if the address in question is even visible from outside the function
* Return the memory effects of the called function
Also, add a new API `Instruction.memoryEffects`, which is internally used by `mayReadFromMemory` et al.
