Fourth failure (0x80012CFC, 54 bytes — worst residual of the cycle) against
two successes in one family confirms C's scheduler-bound diagnosis. Family
is a toolchain limit, not a source problem: 0x80012A10/0x80012AE0 (earlier
excluded) plus now 0x80012CFC/0x80012B20. Extensive arithmetic checks
(5 stack args fix a 9-parameter signature; lui immediates 0x08000000 and
0x38000000 are high halves) confirm the model without the bytes.
Christopher Williams
7a0a8b7cb5