From the S76 func_8002FF0C agent (166 ins -> MATCH, verified in-TU with a
spliced src/800_b.c compiling rc=0 and all 63 relocs matching).
__asm__ __volatile__("" ::: "memory") is a CSE MEMORY-TABLE invalidator, not
only a scheduling fence, and the colon-less __asm__("") does NOT substitute:
it forces D_800A46D2 to be re-read rather than folded to sign_extend(r), and
without it the function is exactly two instructions short. Pairs with §464
lever 4 — same two spellings, register half there, memory half here.
Write (b*3)<<3, not b*24: expand_mult never honours its target, so b*24
leaves a move copy that survives into the join block and costs a sixth
callee-saved register plus a 0x30 frame. A top-level LSHIFT_EXPR expands into
the variable's own pseudo. General for any constant multiply factoring as
odd<<n.
Independently confirms §470's 'two distinct locals for the same b*24' on a
different function via a different agent — treat as established.
And the house array spelling can be the defect: D_800A46D2 must be scalar at
block scope; extern s16 D_800A46D2[] forces la for both accesses and costs 12
mismatches. A fleet-consensus declaration is a prior, not a law.
Drew T
3db8b2b117