832666c45e
* Manually rename BasicBlock to BlockPredecessor BasicBlock is a pair of (Ebb, Inst) that is used to represent the basic block subcomponent of an Ebb that is a predecessor to an Ebb. Eventually we will be able to remove this struct, but for now it makes sense to give it a non-conflicting name so that we can start to transition Ebb to represent a basic block. I have not updated any comments that refer to BasicBlock, as eventually we will remove BlockPredecessor and replace with Block, which is a basic block, so the comments will become correct. * Manually rename SSABuilder block types to avoid conflict SSABuilder has its own Block and BlockData types. These along with associated identifier will cause conflicts in a later commit, so they are renamed to be more verbose here. * Automatically rename 'Ebb' to 'Block' in *.rs * Automatically rename 'EBB' to 'block' in *.rs * Automatically rename 'ebb' to 'block' in *.rs * Automatically rename 'extended basic block' to 'basic block' in *.rs * Automatically rename 'an basic block' to 'a basic block' in *.rs * Manually update comment for `Block` `Block`'s wikipedia article required an update. * Automatically rename 'an `Block`' to 'a `Block`' in *.rs * Automatically rename 'extended_basic_block' to 'basic_block' in *.rs * Automatically rename 'ebb' to 'block' in *.clif * Manually rename clif constant that contains 'ebb' as substring to avoid conflict * Automatically rename filecheck uses of 'EBB' to 'BB' 'regex: EBB' -> 'regex: BB' '$EBB' -> '$BB' * Automatically rename 'EBB' 'Ebb' to 'block' in *.clif * Automatically rename 'an block' to 'a block' in *.clif * Fix broken testcase when function name length increases Test function names are limited to 16 characters. This causes the new longer name to be truncated and fail a filecheck test. An outdated comment was also fixed.
This crate contains array-based data structures used by the core Cranelift code generator which use densely numbered entity references as mapping keys.
One major difference between this crate and crates like slotmap, slab, and generational-arena is that this crate currently provides no way to delete entities. This limits its use to situations where deleting isn't important, however this also makes it more efficient, because it doesn't need extra bookkeeping state to reuse the storage for deleted objects, or to ensure that new objects always have unique keys (eg. slotmap's and generational-arena's versioning).
Another major difference is that this crate protects against using a key from
one map to access an element in another. Where SlotMap, Slab, and Arena
have a value type parameter, PrimaryMap has a key type parameter and a value
type parameter. The crate also provides the entity_impl macro which makes it
easy to declare new unique types for use as keys. Any attempt to use a key in
a map it's not intended for is diagnosed with a type error.
Another is that this crate has two core map types, PrimaryMap and
SecondaryMap, which serve complementary purposes. A PrimaryMap creates its
own keys when elements are inserted, while an SecondaryMap reuses the keys
values of a PrimaryMap, conceptually storing additional data in the same
index space. SecondaryMap's values must implement Default and all elements
in an SecondaryMap initially have the value of default().
A common way to implement Default is to wrap a type in Option, however
this crate also provides the PackedOption utility which can use less memory
in some cases.
Additional utilities provided by this crate include:
EntityList, for allocating many small arrays (such as instruction operand lists in a compiler code generator).SparseMap: an alternative toSecondaryMapwhich can use less memory in some situations.EntitySet: a specialized form ofSecondaryMapusing a bitvector to record which entities are members of the set.