perf: global dead code elimination (Issue #4 — Tasks A + B)#7
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…dr, and __ hooks Root cause: count_top_fn_callers and mark_live_top_fns checked for TOK_FN (=0) but `fn` is lexed as TOK_IDENT — so no function bodies were ever scanned and both reach/caller_cnt tables stayed all-zero, eliminating ~400 of 816 functions during self-compilation. Fixes applied: - Use streq "fn" fallback in DCE scans (mirrors main compilation loop pattern) - Add should_skip_compile_fn helper; protect expansion products (impl/generic/ trait methods have names appended to source buffer at offset >= g_orig_src_len) - Protect __ runtime hooks (e.g. __thread_done used via spawn return address) - Detect fn_addr(name) references in scan_top_fn_calls so fn_addr targets are marked live even without a direct call - Remove debug print statements committed with initial DCE implementation Result: 394/394 conformance tests pass, self-host converges at 1,990,912 bytes
jailalawat
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Summary
Closes #4 — implements global dead code elimination for top-level functions.
Task A: Call graph + unreachable function elimination
IDENT LPAREN),fn_addr(name)references, and DOT-method callsmainthrough the call graphmainwith no callers are skipped at compile timeTask B: Cross-block use counts via reaching-definitions framework
g_fn_caller_cnt_tbltracks raw call frequency across all function bodies (reaching-definitions style: counts how many call sites reference each function)g_fn_reach_tbl(transitive reachability frommain): both must be zero for a function to be eliminated — this is equivalent to "zero reaching definitions reach a live use"Bug fixes over initial implementation
count_top_fn_callers/mark_live_top_fnsusedTOK_FN == 0check, butfnlexes asTOK_IDENT— neither function ever ran. Fixed withstreqfallback matching the main compilation loop__runtime hooks (e.g.__thread_doneused as spawn return address) are exempt from DCEfn_addr(name)references now count as live uses of the referenced functionTest plan
dead_fn_unreachable_undeffail test: compile errors correctly on undefined dead function🤖 Generated with Claude Code