If some functions are explicitly annotated by developers as @inline(__always) or @_transparent, they should always be a subject for the inlining of generics, even if this kind of inlining is not enabled currently for all functions.
A function is pure if it has no side-effects.
If there is a call of a pure function with constant arguments, it always makes sense to inline it, because we know that the whole computation will be constant folded.
Replace `NameOfType foo = dyn_cast<NameOfType>(bar)` with DRY version `auto foo = dyn_cast<NameOfType>(bar)`.
The DRY auto version is by far the dominant form already used in the repo, so this PR merely brings the exceptional cases (redundant repetition form) in line with the dominant form (auto form).
See the [C++ Core Guidelines](https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#es11-use-auto-to-avoid-redundant-repetition-of-type-names) for a general discussion on why to use `auto` to avoid redundant repetition of type names.
This was already done for getSuccessorBlocks() to distinguish getting successor
blocks from getting the full list of SILSuccessors via getSuccessors(). This
commit just makes all of the successor/predecessor code follow that naming
convention.
Some examples:
getSingleSuccessor() => getSingleSuccessorBlock().
isSuccessor() => isSuccessorBlock().
getPreds() => getPredecessorBlocks().
Really, IMO, we should consider renaming SILSuccessor to a more verbose name so
that it is clear that it is more of an internal detail of SILBasicBlock's
implementation rather than something that one should consider as apart of one's
mental model of the IR when one really wants to be thinking about predecessor
and successor blocks. But that is not what this commit is trying to change, it
is just trying to eliminate a bit of technical debt by making the naming
conventions here consistent.
- Move the common performance inliner functionality into PerformanceInlinerUtils.cpp.
- Move the functionality specific to non-generic inlining into NonGenericPerformanceInliner.cpp
- Temporarily disable the inlining of generics. It will be enabled in the subsequent commit.
