@aaronsgiles Here's an interesting pathological case that makes the MIPS3 DRC hard-lock MAME:
BFC05184: jr $ra
BFC05188: addiu $sp,$sp,$80
A0000F10: bgtzl $ra,$ra,$9fffd2d0
A0000F14: sb $0,$f10($0)
BFC00380: beq $fp,$0,$bfc00390
BFC00384: nop
It isn't a big deal because the instruction in question is garbage due to an unrelated bug. But as best I can tell, it isn't expecting a single-instruction block which is also an inter-block branch. If I could cajole you out of retirement to have a look, it'd be appreciated. :)