a369150213
This PR makes two changes, both suggested by @fitzgen in #36: 1. It updates the top-level description of the analysis to more simply and accurately describe the analysis lattice. 2. It modifies both the `CheckerValue` and `CheckerState` types to be enums with separate arms for the top/universe value, and adds helpers as appropriate to update the values. There should be no functional change; this update just makes the meet-functions and updates more clear, and makes a bad state ("top" but with values) unrepresentable. Closes #36.
regalloc2: another register allocator
This is a register allocator that started life as, and is about 50% still, a port of IonMonkey's backtracking register allocator to Rust. In many regards, it has been generalized, optimized, and improved since the initial port, and now supports both SSA and non-SSA use-cases.
In addition, it contains substantial amounts of testing infrastructure (fuzzing harnesses and checkers) that does not exist in the original IonMonkey allocator.
See the design overview for (much!) more detail on how the allocator works.
License
This crate is licensed under the Apache 2.0 License with LLVM
Exception. This license text can be found in the file LICENSE.
Parts of the code are derived from regalloc.rs: in particular,
src/checker.rs and src/domtree.rs. This crate has the same license
as regalloc.rs, so the license on these files does not differ.