KOS_OP_FAST_ATTR_INPLACE

  • Style: EXTRA (OPCOUNT, FASTVAR, CONST, NOARG). Row a0 = operator selector and count, a1 = the object’s fast slot, a2 = the attribute name.

  • Stack: [..., v0 .. v_{n-1}] → [...]. Read the object from its slot, reduce obj.attr in place with the count values left to right, store it back; pushes nothing. Hot: prologue only, tail-calling the body the elector slot holds, which guards through the field slot and reads, computes, and stores through its location; an empty elector slot or an ungated site takes the electing function, and the generic path runs kos_attr_inplace_cached through the field slot.

  • Compiler form: The lowered form of VAR_ATTR_INPLACE.

  • Implementation: koskari/lib/opcode/FAST_ATTR_INPLACE.c