2a9aa5368d
- Resolver-only reads across BBs; remove vmap fallbacks - Create PHIs at block start; insert casts in preds before terminators - Re-materialize int in preds to satisfy dominance (add/zext/trunc) - Use constant GEP for method strings to avoid order dependency - Order non-PHI lowering to preserve producer→consumer dominance - Update docs: RESOLVER_API.md, LLVM_HARNESS.md - compare_harness_on_off: ON/OFF exits match; linking green
2.2 KiB
2.2 KiB
Resolver API (Minimal i64 Prototype)
Goals
- Centralize "ValueId → current-block value" resolution.
- Guarantee dominance by localizing values at the start of the block (before non-PHI).
- De-duplicate per (block, value) to avoid redundant PHIs/casts.
Design
- Resolver-only reads: lowerers must fetch cross-block values via
Resolver(ban directvmap.getfor reads across BBs). Resolverkeeps small per-function caches keyed by(BasicBlockId, ValueId).resolve_i64(...)returns ani64-typed value, inserting a PHI at the beginning of the current block and wiring incoming from predecessor end-snapshots (sealed SSA). Any required casts are inserted in predecessor blocks just before their terminators to preserve dominance.resolve_ptr(...)returns ani8*value localized to the current block; integer handles are bridged viainttoptr.resolve_f64(...)returns anf64value localized to the current block; ints bridged viasitofp.- Internally uses sealed snapshots (
block_end_values) to avoid referencing values that do not dominate the use.
Usage (planned wiring)
- Create
let mut resolver = instructions::Resolver::new();at function lowering start. - Replace all integer value fetches in lowerers with
resolver.resolve_i64(...). - Keep builder insertion discipline via
BuilderCursor.
Ban: Direct vmap.get(..) for cross-BB reads
- Direct reads from
vmapare allowed only for values defined in the same block (after they are created). - For any value that may come from a predecessor, always go through
Resolver. - CI guard: keep
rg "vmap\.get\(" src/backend/llvmat zero for instruction paths (Resolver-only).
Next
- Migrate remaining
localize_to_i64call sites to the resolver. - Enforce vmap direct access ban in lowerers (Resolver-only for reads).
Tracing
NYASH_LLVM_TRACE_PHI=1: log PHI creation/wiring in the Rust/inkwell path.NYASH_LLVM_TRACE_FINAL=1: in the Python/llvmlite harness, trace selected final calls (e.g.,Main.node_json/3,Main.esc_json/1) to correlate ON/OFF outputs during parity checks.
Acceptance tie-in
- Combined with LoopForm: dispatch-only PHI + resolver-based value access → dominance violations drop to zero (A2.5).