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decomp: promote _printf, select_world_object_resource_tables and _sceFs_Rcv_Intr (3100 B) - #177
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mateuszklysz merged 3 commits intoOct 14, 2026
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check-unit reports Object matches (promotable). The C body's format switch emits its jump table in .rodata, so pin it at retail's jtbl_001527B0 (0x1527B0, file 0x53730) in RODATA_OVERLAYS, right after printfloat's literals; without the pin the linker discards it. ./verify-baseline.sh: PASS: reconstructed boot ELF matches retail
The two hoisted %hi registers (resident_class_slot_by_id, moby_class_resources) came out in s0/s4 swapped. Global alloc ranks them by refs/live length and then by pseudo number, which PRE assigns in GCSE hash order of the symbol string. Reading class_slot before taking the table base equalises the live lengths, and naming the table D_001B3200 without the asm-label prefix puts its %hi first in the hash order, which gives retail's allocation. ./verify-baseline.sh: PASS: reconstructed boot ELF matches retail
The semaphore release loop compared ret against the slot (bne operands reversed) and, with the slots read through a volatile table, the reversed compare kept a separate sign-extension pseudo that took v0 from the semaphore. Reading the table plainly lets combine fold the extension, and releasing the slot through a volatile store keeps it ahead of the branch, out of the delay slot, as in retail. ./verify-baseline.sh: PASS: reconstructed boot ELF matches retail
Decompilation progress
3 newly matched functions (3,100 B)
Compared with main (34fd269). C_FUZZY uses main's last measurement. |
Report for SCUS_971.99 (34fd269 - 3c502e6)📈 Matched code: 87.79% (+0.09%, +3100 bytes) ✅ 3 new matches
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2 of 3 tasks
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Before
_printf,select_world_object_resource_tablesand_sceFs_Rcv_Intrwere assembly-backed units built from theirINCLUDE_ASMoracles. Their C bodies under#elsewere close but not exact.After
Three units promoted to exact C (3100 B):
sdk/debug/printf_impl(_printf, 1516 B): the C body already matched incheck-unit, but its formatswitchtable was discarded at link time. Pinned at retail'sjtbl_001527B0(0x1527B0, file 0x53730) inRODATA_OVERLAYS, right afterprintfloat's literals.textbin/world/data/select_world_object_resource_tables(684 B): the two hoisted%hiregisters came out in s0/s4 swapped. Global alloc ranks them by refs/live length, then by pseudo number, which PRE assigns in GCSE hash order of the symbol string. Readingclass_slotbefore taking the table base equalises the live lengths, and naming the tableD_001B3200without the asm-label prefix puts its%hifirst in the hash order.sdk/library/_sceFs_Rcv_Intr(900 B): the semaphore release loop compares the slot againstret(retailbneoperand order). The slot table is read plainly so combine folds the sign extension, and the slot is released through a volatile store, which keeps it ahead of the branch instead of in its delay slot.Verification
make elfends withPASS: reconstructed boot ELF matches retailmake overlaysends withPASS(overlay changes): n/a, no overlay changesmake checkpasses (92 tests OK)