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Drew T
fc7d8c4019
- a22: func_8017B238 closed by giving the if-arm's pointer and the else arm's first table address one function-scope
local. Three decisions turn on that edit, all dump-proven: make_regs_eqv's head rule (cse.c:840-857), set_preference
stripping one RTX level so an arithmetic set inherits its operand's register (global.c:1535), and combine_regs with
birthing_insn_p's reg_n_sets == 1 (local-alloc.c:1765-1788, sched.c:2469) — which is why the merge must be with the
else arm's non-call-crossing temp. 26,714 -> 26,462 sites.
- a14 reaches score 0 on func_80139BE0 but only by an INVENTED identically-zero term whose sole purpose is to keep a
value live. NOT BANKED: an invented no-op expression is a compiler-forcing construct in C clothing, and worse than the
marked launder it replaces because the launder is counted and this would be silent. The phase's own rule is ban the
silence, not the lever. Parked for the structs/types phase with its reading; the tree comment above it ('no pure-C
spelling survives that fold') is refuted.
- a6 corrects cookbook 455: cse1 (cse.c:7439-7502) rewrites the producer's destination to the copy's whenever the
producer is the immediately preceding insn; combine only finishes the job once that adjacency is broken. It enumerated
the three lever-free blockers can_combine_p admits and showed the body can pay for none, then scanned all 4,284 built
objects for the shape — 101 hits, every lever-free precedent paying with a genuine second use, a narrow local with two
consumers, or a join label.
- a24's residual was one absent load: cse forwards a just-stored halfword so no lh is emitted, and seven branch
displacement mismatches were downstream of it. Its method gap is the instrument to fix next — three agents have now
asked for local-alloc's quantity table in the pack, and alloc_table.py prints an empty or one-row table because it
keys on dump lines that are often absent.
- Drew's struct question answered on the record: structs are not in the binary (types are erased; no metadata in a
retail build), what is there is base + offset + width + stride, so a struct is an inference across every function
touching a base — which makes per-function struct invention the wrong unit and is the failure P35 already recorded.
Recommendation: keep pins as the main lane, build a zero-token struct evidence census beside it, park stuck pins with
their evidence, and fix call signatures first because they are the bigger and cheaper blocker (471 narrow call sites
in 323 pinned bodies). Measured: 372,224 raw cast dereferences against 92,624 struct member accesses.
