Welcome to the proving ground
Everything in this chapter shipped on a cartridge. These are real functions from a shipped N64 game — no more teaching examples built to demonstrate one idea. From here on you get what the original programmers wrote: their struct layouts, their habits, their occasional weirdness. Your job is unchanged — read the assembly, write the C, match — but nobody arranged the target to be tidy for you.
The opener is from the engine's generic queue, a ring buffer that game systems use to hand work to each other. This function answers one question: is the queue full? The struct is in the context below; its fields are s16s, so expect halfword loads.
One shape to re-arm before you go in. Here's timerDone, which checks whether a timer two ticks from now hits its limit:
lh t7, 0(a0) # t->ticks
lh t6, 2(a0) # t->limit
addiu t8, t7, 2 # ticks + 2
xor v0, t6, t8 # zero exactly when the two sides agree
sltiu v0, v0, 1 # "unsigned < 1" → 1 when the xor gave 0
jr ra
nop
That xor/sltiu pair is how this compiler spells == when the result is returned rather than branched on — you met it in tier 2. The addiu in the middle means one side of the comparison isn't a bare field: some constant is added before comparing. Recover which field gets the constant, which field sits alone, and what the constant is, and the C writes itself.
The target has the same skeleton with its own offsets and its own immediate. Read it against the GenericQueue layout in the context.
Your task
Write func_801cbe88 to reproduce the target assembly.