lib/strconv: stof.ha port — Eisel-Lemire string→float (#106 fold-4)

stof64/stof32 (f64|f32 | invalid | overflow) via Eisel-Lemire fast-path
(powers_of_ten[596][2]u64 + eisel_lemire 128-bit multiply) + decimal
slow-path fallback (decimal.ww, fold-3). 16 fns + faithful powers_of_ten
(byte-identical to Hare). u128 via pure-u64 64×64→128 (ftos_ryu.ha).
Consumes &math.f64info (γ-cleanup), tagged-float-return (PREREQ-2 #157),
2D double-index (PREREQ-1 #156).

13 documented spelling-divergences (rule-9, each cites stof.ha): #155
(po10 double-index + per-field struct-copy), #161 (compound-assign explicit
form), #144 (-0.0 via 1u64<<63), #158, #138, test-only #143/parsef64.
Test 909 (DEC+hex+NaN/Inf/invalid/overflow, bit-exact, cstage ww run).
Make test 185/185 incl 990-997 byte-id + combined_ww_fresh. Makefile:
stof.ww added to w6c_ww/wwdump_ww deps (freshness, fold-3 precedent).

Drew's strconv 5-fold plan 4/5. Followup #162 (wwstage lexer parsef64
1-ULP — could adopt stof64).
This commit is contained in:
2026-05-27 13:55:56 +09:00
parent 4a91bdc8db
commit 81796cd533
8 changed files with 6977 additions and 606 deletions

File diff suppressed because it is too large Load Diff

File diff suppressed because it is too large Load Diff

File diff suppressed because it is too large Load Diff