ISA.md

Instruction Set/Architecture

Sol, unlike lua, is purely stack based instead of register based. I will try to keep this instruction set small so that it is easy to comprehend.

file header is 16 bytes file starts with "\x1bSOL" version is next 4 bytes vm id is next 8

Working data piece (wdp) Operating data piece (odp)

• stk op[8bit] stk[8bit] {arg[8bit]}

  • op:
    • get[0x00] gets from top of stack and puts it into (wdp)
      arg:
      • 0x00: takes it from stack
      • 0x01: copies pointer
      • 0x02: copies
    • put[0x01] puts (wdp) on top of the stack
      arg:
      • 0x00: put it on to stack
      • 0x01: puts pointer on to stack
      • 0x02: copies onto stack
    • sink[0x2] makes the value on top of the stack sink arg places or if the MSB of arg is on then it takes it to the place relative to the bottom
    • float[0x3] makes the value at arg from the top (or bottom if MSB on) float to the top of the stack
      if multiple with same label makes them all float in their current order
    • lbl[0x4]
      labels the top stack item with (wdp)
    • gl[0x5]
      puts pointer of the label from top of stack to (wdp)
  • stk:
    • w[0x00]
      the current working stack
    • sw[0x01]
      the secondairy working stack, only accessible from its own scope, does not pass to parent or child
    • e[0x02]
      the stack that is exported by return or calling a function
    • i[0x03]
      the recived e stack
    • st[0x04]
      substack tree
      can only have pointers
      can only get and put, can only hold one thing
    • cs[0x05]
      current substack (from st)
    • ps[0x06]
      all accessible things from parent w stacks (used for closures)
    • pis[0x07]
      ps but i stacks
    • pls[0x08]
      platform stack, aka all builtin functions/whatever

• mdp op[8bit]

  • op:
    • delete[0x00]
      deletes the current reference, if it is the last one then object is deleted
    • deleteall [0x01]
      deletes all references and object
    • swap[0x02]
      swaps wdp and odp
    • unlink[0x03]
      detatches object from all other references (essentially copy but whatever)
    • setall[0x04]
      sets all references of the value/pointer in wdp to the value/pointer from odp

• ujmp loc[exp(24bit)]

  
  Jumps to instruction

• dsub len[exp(24bit)]

  
  defines a subroutine (function) len instructions long and places it on the stack, as well as removing the instructions that make up the function from the code, so watch out using jumps

• return

  returns the e stack and jumps back to after call

• call

  takes the function in wdp, puts it in sw stack, then calls it

• sop op[8bit]

  does: wdp op odp. or if its unary it just does it on wdp puts result on top of wstack

  • op:
    • add[0x00]
    • sub[0x01]
    • mult[0x02]
    • div[0x03]
    • modulo[0x04]
    • unary negation[0x05]
    • bitwise and[0x07]
    • unary bitwise not[0x08]
    • bitwise or[0x09]
    • bitwise nand[0x0a]
    • bitwise nor[0x0b]
    • bitwise xor[0x0c]
    • bitwise xnor[0x0d]
    • equivelent [0x0e]
    • strict equals [0x0f]
    • is (are they both pointer to same object) [0x10]
    • gte [0x11]
    • lte [0x12]
    • gee [0x13]
    • lee [0x14]
    • gt [0x15]
    • lt [0x16]
    • ge [0x17]
    • le [0x18]
    • ne [0x19]
    • nee [0x1a]

• const typ[8bit] len[exp(16bit)]

  reads len bytes after the instruction and puts it on w stack, then goes past any 0x00 s untill it gets to the next instruction

  • typ:
    • int[0x00] top bit is sign
    • float[0x01] probably platform specific
    • str[0x02] simple
    • bool[0x03] first bit?
    • null/nil/none/void/whatever[0x04]

• exp bytes[exp(8bit)]

  adds to the the size of the exp() field in the next instruction bytes bytes long, this is a marker, not a actual instruction. this is not counted in the instruction list for jmps and whatever