Cesarus85--mjolnir-vr/docs/object_matching_logs/libcmt_cfout_obj.md

libs/libcmt/cfout.obj exact-match ledger

Plain-English scope

This runtime object converts the bit fields of a C double into Microsoft's internal ten-byte _LDOUBLE representation, then asks the CRT's decimal output engine to produce the sign, decimal exponent, and mantissa text used by formatted floating-point output.

The atomic admission unit owns two functions and no data.

Provenance and preflight

• Initial campaign base: b06c22eafa6cb574bd59bb522bf34a7ff62828b1.
• Final revalidation base: 08f86f9b84fd45804cb1177fabd07ddaa672b9b6.
• XDK 3911 CL 13.00.9254.1; unchanged libcmt /O1 /Gy flags.
• XDK libcmt.lib SHA-256: 60aa4c87c97eeb6662b31d9d37cf3caba1afabaec72c47b090e7a0ce8b632f55.
• CodeView source path: d:/xbox-finalfre/private/sdktools/crt/fpw32/conv/cfout.c.
• Authentic Microsoft source mirror: xerohour/xbox_leak_may_2020, commit fd00b4b3b2abb1ea6ef9ac64b755419741a3af00, blob c41631f9b54e45d183d5be1a7bec72face263858, path xbox trunk/xbox/private/sdktools/crt/fpw32/conv/cfout.c.

Before any production edit, the authentic archive member was compared with the January split object. Both owned sections were already strict-identical:

• __dtold: 186 bytes, zero relocations.
• _fltout2: 102 bytes, two relocations, to __dtold and $I10_OUTPUT.

Neither object owns .data, .bss, or .rdata.

Experiment ledger

ID	Readable source shape	Result	Disposition
P0	Authentic Microsoft control flow with public strcpy declaration	__dtold exact; _fltout2 92B/3 relocations because the public header emits a call while Microsoft's private CRT header inlined it	Rejected
P1	Same topology, spelling the terminating character-copy loop directly	EXACT: __dtold 186B/0 relocations and _fltout2 102B/2 relocations; normalized hashes equal	Accepted

Original-bug audit

No original defect is apparent. The zero, denormal, finite, infinity, and NaN bit patterns follow the CRT's intended internal conversion contract. Any behavioral modernization would be inappropriate in this exact-match layer.

House/Berth audit

• Readable typed C, descriptive locals, and named constant.
• No assembly, volatile, forced inline, pragmas, UB, byte forcing, or flag changes.
• January bytes and symbolic relocation identities remain authoritative.
• Matching credit is withheld until the complete object and all project gates pass after a final canonical rebase.

Current strict gates

• Forced build under unchanged /O1 /Gy: passed.
• __dtold: exact normalized SHA-256 6473f9dfd544aab6a4aab656bc5cdcfc6ba28dbc80e2fc7946b55f48853ea792.
• _fltout2: exact normalized SHA-256 bc242540fbc99b75a8efe9fdf769c47b74c63350ea8932071e443ef7fd284c4d.
• Complete section inventory: two code COMDATs and no owned non-code data, identical between January and candidate.
• Full Halo and libcmt builds: passed.
• Progress/semantic report after rebase: zero unit errors; this campaign checkpoint is 360/833 Matching overall and 93/212 in libcmt (including other objects integrated into canonical while this lane ran).
• Semantic audit: 461 units scanned, 3,587 functions evaluated, 3,503 accepted exact, zero unit errors.
• Admission audit: zero candidates and zero revocations; only the known pre-existing source/shell/shell_xbox contradiction remains.
• Tool tests: 179/179 passed.
• git diff --check and prohibited-construct scan: passed.
• Clean-tree regression snapshot/check: both functions still_exact; no failures, warnings, changed non-exact siblings, or ownership warnings.
• Every decisive gate above was repeated after rebasing to the final campaign base.