Documentation

Codegen-generated Id infos, to be passed to downstream via interfaces.

This stuff is for optimization purposes only, they're not compulsory.

• When CafInfo of an imported Id is not known it's safe to treat it as CAFFY.
• When LambdaFormInfo of an imported Id is not known it's safe to treat it as `LFUnknown True` (which just says "it could be anything" and we do slow entry).

See also Note [Conveying CAF-info and LFInfo between modules] above.

Information about an identifier, from the code generator's point of view. Every identifier is bound to a LambdaFormInfo in the environment, which gives the code generator enough info to be able to tail call or return that identifier.

Maps names in the current module to their LambdaFormInfos

We represent liveness bitmaps as a Bitmap (whose internal representation really is a bitmap). These are pinned onto case return vectors to indicate the state of the stack for the garbage collector.

In the compiled program, liveness bitmaps that fit inside a single word (StgWord) are stored as a single word, while larger bitmaps are stored as a pointer to an array of words.

An ArgDescr describes the argument pattern of a function

StandardFormInfo tells whether this thunk has one of a small number of standard forms

Word offset, or word count