The Swift Simplification pass can do more than the old MandatoryCombine pass: simplification of more instruction types and dead code elimination.
The result is a better -Onone performance while still keeping debug info consistent.
Currently following code patterns are simplified:
* `struct` -> `struct_extract`
* `enum` -> `unchecked_enum_data`
* `partial_apply` -> `apply`
* `br` to a 1:1 related block
* `cond_br` with a constant condition
* `isConcrete` and `is_same_metadata` builtins
More simplifications can be added in the future.
rdar://96708429
rdar://104562580
* Fix the mid-level pass pipeline.
Module passes need to be in a separate pipeline, otherwise the
pipeline restart mechanism will be broken.
This makes GlobalOpt and serialization run earlier in the
pipeline. There's no explicit reason for them to be run later, in the
middle of a function pass pipeline.
Also, pipeline boundaries, like serialization and module passes should
be explicit at the the top level function that creates the pass
pipelines.
* SILOptimizer: Add enforcement of function-pass pipelines.
Don't allow module passes to be inserted within a function pass
pipeline. This silently breaks the function pipeline both interfering
with analysis and the normal pipeline restart mechanism.
* Add misssing pass in addFunctionPasses
Co-authored-by: Andrew Trick <atrick@apple.com>
