This PR changes `IRType.boxed` to map `erased` to `tobject` rather than
`object`, since `erased` has a representation of a boxed scalar 0 when
we are forced to represent it at runtime. This case does not occur at
all in the Lean codebase.
This PR adds support for compilation of `casesOn` for subsingletons. We
rely on the elaborator's type checking to restrict this to inductives in
`Prop` that can actually eliminate into `Type n`. This does not yet
cover other recursors of these types (or of inductives not in `Prop` for
that matter).
This is mostly a refactoring that replaces other analyses with type
information, but due to the introduction of `tagged` it also has the
side effect of eliminating ref counting ops entirely for types that
always have a tagged scalar representation, e.g. `Unit`.
This PR correctly populates the `xType` field of the `IR.FnBody.case`
constructor. It turns out that there is no obvious consequence for this
being incorrect, because it is conservatively recomputed by the `Boxing`
pass.
This PR changes the implementation of `trace.Compiler.result` to use the
decls as they are provided rather than looking them up in the LCNF mono
environment extension, which was seemingly done to save the trouble of
re-normalizing fvar IDs before printing the decl. This means that the
`._closed` decls created by the `extractClosed` pass will now be
included in the output, which was definitely confusing before if you
didn't know what was happening.
This currently relies on the encoding pun of Nat.zero as the first
tagged constructor of Nat. Since Nat.succ is lowered to addition, it
makes sense to also lower Nat.zero to a zero literal. This might also
expose more optimization opportunities in the future.
This PR fixes IR constructor argument lowering to correctly handle an
irrelevant argument being passed for a relevant parameter in all cases.
This happened because constructor argument lowering (incompletely)
reimplemented general LCNF-to-IR argument lowering, and the fix is to
just adopt the generic helper functions. This is probably due to an
incomplete refactoring when the new compiler was still on a branch.
This PR moves the implementation of `lean_add_extern`/`addExtern` from
C++ into Lean. I believe is the last C++ helper function from the
library/compiler directory being relied upon by the new compiler. I put
it into its own file and duplicated some code because this function
needs to execute in CoreM, whereas the other IR functions live in their
own monad stack. After the C++ compiler is removed, we can move the IR
functions into CoreM.
This PR adds support for `.mdata` in LCNF mono types (and then drops it
at the IR type level instead). This better matches the behavior of
extern decls in the C++ code of the old compiler, which is still being
used to create extern decls at the moment and will soon be replaced.
This is covered by existing tests.
