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

libs/libcmt/time.obj exact-match ledger

This atomic lane independently revalidates an older completed result on a fresh worktree based on campaign commit 63501296. The historical branch was used only to identify the candidate; target provenance and every admission measurement below were repeated in this lane.

Plain-English behavior

time asks Windows for the current system clock as a 64-bit count of 100-nanosecond ticks since 1601. It subtracts the difference between the Windows and Unix epochs, divides by the number of ticks in one second, optionally stores that Unix timestamp through the caller's pointer, and returns the same value.

Primary provenance and target inventory

The locally archived XDK 3911 libcmt.lib has SHA-256 60aa4c87c97eeb6662b31d9d37cf3caba1afabaec72c47b090e7a0ce8b632f55. Its member obj\i386\time.obj records both ..\time.c and the full original path d:\xbox-finalfre\private\sdktools\crt\crtw32\time\time.c, plus compiler id 0x001c2426. The member's _time COMDAT is already strict-equal to the January split target:

• code size 56/56 bytes;
• two IMAGE_REL_I386_REL32 relocations, at +0x0a to _GetSystemTimeAsFileTime@4 and +0x29 to __aulldiv, both addend zero;
• identical normalized SHA-256 f481c71336d955df61673ad2844701121e93e39d9392cce86c4c261bfd870d7f;
• no target-owned .data, .bss, or .rdata.

This proves the target is Microsoft's readable CRT C translation unit rather than a vendored-assembly object, and gives a primary reference object for the function, relocation destinations, ownership, compiler identity, and size.

Recovered representation and experiments

The retained source overlays the two 32-bit FILETIME halves with an unsigned 64-bit tick value in a named union. That is the ordinary VC7/XDK representation for this Windows structure and lets the compiler perform the epoch subtraction directly on the two halves before calling its unsigned 64-bit divide helper. The constants are typed 64-bit values: 116444736000000000ui64 ticks between the epochs and 10000000ui64 ticks per second.

ID	Source shape	Size T/B	Relocs T/B	Result
E01	Named union with parts and ticks views	56/56	2/2	retained; strict exact
E02	Build the 64-bit value explicitly with shift and OR	65/56	2/2	rejected; redundant zero/OR work and an extra saved register

No raw offsets, pointer-cast punning, packing, assembly, volatile, forced inlining, undefined behavior, object-byte patch, comparator exception, or compiler-flag override is used.

Strict production verification

The production object was rebuilt with XDK 3911 CL 13.00.9254.1 under the configured libcmt flags /O1 /Gy /I"xbox/include". The fresh result is strict exact:

symbol	target	candidate	relocs	normalized SHA-256
_time	56 B	56 B	2 / 2	f481c71336d955df61673ad2844701121e93e39d9392cce86c4c261bfd870d7f

Both relocations match in address, type, destination, and addend: +0x0a targets _GetSystemTimeAsFileTime@4 + 0, and +0x29 targets __aulldiv + 0. tools.coff_compare.section_infos_equal returned true. Both objects contain one 56-byte .text COMDAT with identical flags, externally owned by function symbol _time at offset zero; neither owns runtime data. The candidate's other sections are ordinary compiler directives and debug metadata.

The complete halobetacache_build and libcmt_build succeeded. A forced clean rebuild again emitted the configured /O1 /Gy command and reproduced strict equality, ruling out stale-object credit. The regenerated semantic audit scanned 405 implemented units with zero unit errors and 3,381 accepted exact functions. Progress reported 295/833 exact objects overall and 28/212 libcmt objects; libcmt had 1,981/55,015 exact code bytes and 196/8,637 exact data bytes at this lane's snapshot. The full tooling suite passed 179/179 tests.

After the atomic commit, the fail-closed per-unit regression manifest was snapshotted and checked successfully with no failures, warnings, regressions, ownership changes, or unexpected new matches. git diff --check and the final scope/policy audit were also clean.

House/Berth audit

The implementation is ordinary readable C with its sole parameter on its own line and one explicit final return. It uses named typed members rather than raw structure offsets. No tag, datum, or object access is involved. No original January bug was found, so no bug-preservation comment is needed.