Add the memory tier: compiled loads/stores call `extern "C"` trampolines that
dispatch through the `MemoryAccess` trait, so MMIO dispatch, mem-watch,
page_version, and mmio_access_count stay bit-identical to the interpreter.
Validated bit-exact via the in-process differential harness on a full
boot+movie run (movie plays, clean exit):
checked 148.2M blocks, 38.78% native (57.5M, up from 22.02%), MISMATCHES=0
Mechanism:
* 8 trampolines: xj_read8/16/32/64(env, addr) and
xj_write8/16/32/64(ctx, env, addr, val). Registered with the JITBuilder via
symbol(), declared Linkage::Import in Jit::new (FuncIds in TrampIds), and
re-referenced into each compiled function via declare_func_in_func.
* emit_op now takes an EmitCtx { ctxp, memenv, trampoline FuncRefs }.
* Store trampolines replicate the interpreter's pre-store reservation
invalidation (store_reservation_kick) — an ordinary store to a reserved
line must be observed by stwcx peers. They receive the PpcContext pointer so
they can read ctx.reservation_table; the diff clone clears it (None), so
speculation never touches shared reservation state.
Coverage added (all mirroring execute() exactly):
* loads (zero-extended, non-update): lbz/lbzx, lhz/lhzx, lwz/lwzx, ld/ldx.
* stores (non-update): stb/stbx, sth/sthx, stw/stwx, std/stdx.
EA via ea_d (D-form disp) / ea_x (X-form indexed): ra==0 => 0 base, then
truncate to 32 bits. Update (u) forms and algebraic sign-extending loads
(lha/lwa) are not lowered yet.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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