fe021ad6d4
Simplify pinned-vreg API: don't require slice of all pinned vregs. Previously, we kept a bool flag `is_pinned` in the `VRegData`, and we required a `&[VReg]` of all pinned vregs to be provided by `Function::pinned_vregs()`. This was (I think) done for convenience, but it turns out not to really be necessary, as we can just query `is_pinned_vreg` where needed (and in the likely implementation, e.g. in Cranelift, this will be a `< NUM_PINNED_VREGS` check that can be inlined). This adds convenience for the embedder (the main benefit), and also reduces complexity, removes some state, and avoids some work initializing the regalloc state for a run.
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.