SIMD-0128: Migrate Address Lookup Table Program to Core BPF (#128)

* migrate address lookup table

* update based on SIMD 0140

* use present-tense

* add link to reimplemented program

Author: buffalojoec

proposals/0128-migrate-address-lookup-table-to-core-bpf.md

@@ -0,0 +1,75 @@
+---
+simd: '0128'
+title: Migrate Address Lookup Table to Core BPF
+authors:
+  - Joe Caulfield - Anza Technology
+category: Standard
+type: Core
+status: Draft
+created: 2024-03-13
+feature: (fill in with feature tracking issues once accepted)
+---
+
+## Summary
+
+Migrate the Address Lookup Table program to Core BPF.
+
+## Motivation
+
+BPF programs offer less complexity than native programs for other clients, such
+as Firedancer, since developers will no longer have to keep up with program
+changes in their runtime implementations. Instead, the program can just be
+updated once.
+
+In this spirit, Address Lookup Table should be migrated to Core BPF.
+
+## Alternatives Considered
+
+The Address Lookup Table program could instead remain a builtin program. This
+would mean each validator client implementation would have to build and maintain
+this program alongside their runtime, including any future changes.
+
+## New Terminology
+
+N/A.
+
+## Detailed Design
+
+The Address Lookup Table program is reimplemented in order to be compiled
+to BPF and executed by the BPF loader.
+
+The reimplemented program's ABI exactly matches that of the original.
+
+The reimplemented program's functionality exactly matches that of the
+original, differing only in compute usage. Instead it has dynamic compute
+usage based on the VM's compute unit meter.
+
+The reimplemented program can be found here:
+https://github.com/solana-program/address-lookup-table.
+
+The program shall be migrated to Core BPF using the procedure outlined in
+[SIMD 0088](./0088-enable-core-bpf-programs.md).
+
+The program has no upgrade authority. If changes are required, for
+essential network operations, the program will be updated using feature-gates.
+
+## Impact
+
+Validator client teams are no longer required to implement and maintain the
+Address Lookup Table program within their runtime.
+
+All validator client teams can work to maintain the single Address Lookup Table
+program together.
+
+## Security Considerations
+
+The program's reimplementation poses no new security considerations compared to
+the original builtin version.
+
+The greatest security concern is a mistake in the reimplementation.
+
+## Backwards Compatibility
+
+The Core BPF implementation is 100% backwards compatible with the original
+builtin implementation.
+