lib/strconv: f64tos Ryū shortest float→string (#106 fold-5a)

Graduate f64tos from the lossy fixed-point placeholder to Ryū shortest-
round-trippable (ftos.ha:432 + ftos_ryu.ha). f64tos(n:f64) str, G-format
(void/NONE) — the faithful documented subset (full parametric fftosf is
dead code for G/void/NONE → deferred #64). Ryū core decomposed: struct-
RETURN + scalar params (Hare's r128 idiom; avoids tuple-ABI #163-166).
f64 powers tables [15][2]/[13][2]u64 (2D #156). Zero float literals.
Both E+F encode paths reachable+tested, no dead code.

Graduation (lib-note "don't keep both"): old lossy f64tos deleted; fmt
fprintf_f64_huge "huge"→"9.5e18" (improvement). 5 value-faithful filed-
bug dodges (byte-id, documented): #167/#169/#170/#43/#144. Test 908.
Make test 186/186 incl 990-997 byte-id + combined_ww_fresh.

Drew's strconv 5-fold plan — primary completion (f64tos). f32tos coda
#67 (behind #143); parametric ftosf #64.
This commit is contained in:
2026-05-27 15:39:03 +09:00
parent 81796cd533
commit 0e66073e32
11 changed files with 3219 additions and 762 deletions

File diff suppressed because it is too large Load Diff

File diff suppressed because it is too large Load Diff