Entry 333

"CheckOperate run against the game: 600 random cases"

2026-10-01scripttest

Filestools/test_event_vm.pycrates/piney-event/tests/vm.rscrates/piney-event/tests/vm_fixture.txtdocs/engine/field-game.md

90 noted that ccEvent::CheckOperate(9), the talk rule, had only been checked in pieces. The target test was the interpreter's, but the function as a whole had not been run against the game.

CheckOperate(num, flag) (INF SLUS_202.67:0x001b32f0, 224 bytes) is a leaf:

• num < 0 answers 1;
• with flag 0 and operateSet (+0x778, s16) below 0, it stores num there;
• the answer is 0 when operate (+0x770, 64 bits) is not 0 and has the bit 1 << num. The shift is a 32-bit sllv and sign-extends, so num 31 tests bits 31-63 and num 32 tests bit 0;
• for num 9 with cmndTarget set, it stores operateTarget (+0x780) and answers 0 when one of target[16] (+0x40, s16 type and code) has 1 << type (again 32-bit) among cmndTarget->base +8's type flags and its code equal to base +0xc. Empty targets (-1, -1) test bit 31 and code -1.

tools/test_event_vm.py now writes 600 operate lines (seed 9). Each starts from ccEvent::Init with random registers:

• operate (0 in 30% of cases);
• operateSet (-1 in half);
• sixteen targets (60% empty);
• cmndTarget either NULL or a character whose type flags are random, given one live target's bit and code in 40% of cases;
• num from -1, 9, 9 and 0-63, with flag 0 or 1.

Each line records the game's answer, operateSet after, and whether operateTarget was set. They were appended to vm_fixture.txt; the rest of the fixture is unchanged by the harness edit.

check_operate_matches_the_game (piney-event, tests/vm.rs) replays them with Vm::check_operate on an OperateHost and needs no disc. All 600 match. Moving the type bit by one in the port fails it.