The groundwork is done

That's the warmup behind you. You can read a line of MIPS, you know where a function's arguments and return value live, and — as of the last chapter — you can recover a signature from nothing but the target in front of you.

Now the real work starts. This tier, Core idioms, is a tour of every shape C compiles into, and we begin where the machine is friendliest: integer arithmetic. Over the next handful of lessons you'll learn to read:

• add, subtract, multiply, and divide between registers,
• the fingerprints IDO leaves behind — constant multiplies that dissolve into shift-and-add chains, real div instructions babysat by hazard nops, and a modulo the hardware computes as a by-product,
• and how operator precedence decides the order the instructions come out in.

Same rules as the last chapter: the editor starts empty, the name is in the header, and the signature is yours to work out. Let's go add two numbers.