Remove the _ReadWriteBarrier declaration, the #pragma intrinsic and the
barrier call that UEF-8 introduced, and recover January's schedule from
ordinary C89.
The barrier did exactly one thing: it stopped VC7's list scheduler from
hoisting the output-pointer formation above tag_get. Two source controls
replace it.
First, index the arrays instead of walking hand-written pointers. The
sibling object_export_function_values in source/objects/objects.c is
strict-exact and indexes; January's object shows VC7 strength-reducing
that into the same walking pointers and homed down-counter, with the
cdecl cleanup immediately after the call and both bases formed by lea
and no copy. Writing the unit exporter the same way makes the whole
preamble byte-exact and takes the residual from 30 bytes to 9. The
walking pointers in the target are compiler output, not source, which is
why every pointer-form experiment in the UEF matrix plateaued.
Second, bind animation->private_loop_frame_index to a named local used
twice, in the predicate and in the division. The last nine bytes were a
load-order swap; source operand order does not control it, but a two-use
local does. UEF-12 had tested named locals and seen them eliminated, but
it bound both operands with a single use each, and a single-use copy is
propagated away.
_unit_export_function_values is 384/384 bytes, 18/18 relocations, and its
normalized SHA-256 equals the target's 4149e4cd...b20c35;
section_infos_equal is True. The emitted section is raw byte-for-byte
identical to the previously accepted barrier build.
Verified: clean forced rebuild reproduces; compare_object_exact_sets
reports 189 exact both ways with lost_exact empty; verdicts diff over all
8246 functions gains 0 and regresses 0; halobetacache_build,
libcmt_build, semantic_progress and progress pass; object-admission,
semantic-match and parked audits pass; pytest tools 203 passed;
git diff --check clean.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Jonas Volman