We will reimplement the VM to use 8bit instruction code. By bytecode, we mean real byte code. The whole purpose is reducing the memory consumption of mruby VM.
Instructions are bytes. There can be 256 instructions. Currently, we have 106 instructions. Instructions can take 0 to 3 operands.
The size of operands can be either 8bits, 16bits or 24bits. In the table.1 below, the third field describes the size of operands.
- B: 8bit
- S: 16bit
- W: 24bit
If the first and second operands are of type B (8bits), they may be
extended to 16bits by the operand extension instruction immediately
preceding them.
See also OP_EXT1, OP_EXT2 and OP_EXT3.
| No. | Instruction Name | Operand type | Semantics |
|---|---|---|---|
| 0 | OP_NOP |
- |
no operation |
| 1 | OP_MOVE |
BB |
R(a) = R(b) |
| 2 | OP_LOADL |
BB |
R(a) = Pool(b) |
| 3 | OP_LOADI |
BB |
R(a) = mrb_int(b) |
| 4 | OP_LOADINEG |
BB |
R(a) = mrb_int(-b) |
| 5 | OP_LOADI__1 |
B |
R(a) = mrb_int(-1) |
| 6 | OP_LOADI_0 |
B |
R(a) = mrb_int(0) |
| 7 | OP_LOADI_1 |
B |
R(a) = mrb_int(1) |
| 8 | OP_LOADI_2 |
B |
R(a) = mrb_int(2) |
| 9 | OP_LOADI_3 |
B |
R(a) = mrb_int(3) |
| 10 | OP_LOADI_4 |
B |
R(a) = mrb_int(4) |
| 11 | OP_LOADI_5 |
B |
R(a) = mrb_int(5) |
| 12 | OP_LOADI_6 |
B |
R(a) = mrb_int(6) |
| 13 | OP_LOADI_7 |
B |
R(a) = mrb_int(7) |
| 14 | OP_LOADI16 |
BS |
R(a) = mrb_int(b) |
| 15 | OP_LOADI32 |
BSS |
R(a) = mrb_int((b<<16)+c) |
| 16 | OP_LOADSYM |
BB |
R(a) = Syms(b) |
| 17 | OP_LOADNIL |
B |
R(a) = nil |
| 18 | OP_LOADSELF |
B |
R(a) = self |
| 19 | OP_LOADT |
B |
R(a) = true |
| 20 | OP_LOADF |
B |
R(a) = false |
| 21 | OP_GETGV |
BB |
R(a) = getglobal(Syms(b)) |
| 22 | OP_SETGV |
BB |
setglobal(Syms(b), R(a)) |
| 23 | OP_GETSV |
BB |
R(a) = Special[Syms(b)] |
| 24 | OP_SETSV |
BB |
Special[Syms(b)] = R(a) |
| 25 | OP_GETIV |
BB |
R(a) = ivget(Syms(b)) |
| 26 | OP_SETIV |
BB |
ivset(Syms(b),R(a)) |
| 27 | OP_GETCV |
BB |
R(a) = cvget(Syms(b)) |
| 28 | OP_SETCV |
BB |
cvset(Syms(b),R(a)) |
| 29 | OP_GETCONST |
BB |
R(a) = constget(Syms(b)) |
| 30 | OP_SETCONST |
BB |
constset(Syms(b),R(a)) |
| 31 | OP_GETMCNST |
BB |
R(a) = R(a)::Syms(b) |
| 32 | OP_SETMCNST |
BB |
R(a+1)::Syms(b) = R(a) |
| 33 | OP_GETUPVAR |
BBB |
R(a) = uvget(b,c) |
| 34 | OP_SETUPVAR |
BBB |
uvset(b,c,R(a)) |
| 35 | OP_GETIDX |
B |
R(a) = R(a)[R(a+1)] |
| 36 | OP_SETIDX |
B |
R(a)[R(a+1)] = R(a+2) |
| 37 | OP_JMP |
S |
pc+=a |
| 38 | OP_JMPIF |
BS |
if R(a) pc+=b |
| 39 | OP_JMPNOT |
BS |
if !R(a) pc+=b |
| 40 | OP_JMPNIL |
BS |
if R(a)==nil pc+=b |
| 41 | OP_JMPUW |
S |
unwind_and_jump_to(a) |
| 42 | OP_EXCEPT |
B |
R(a) = exc |
| 43 | OP_RESCUE |
BB |
R(b) = R(a).isa?(R(b)) |
| 44 | OP_RAISEIF |
B |
raise(R(a)) if R(a) |
| 45 | OP_SSEND |
BBB |
R(a) = self.send(Syms(b),R(a+1)..,R(a+n+1):R(a+n+2)..) (c=n|k<<4) |
| 46 | OP_SSENDB |
BBB |
R(a) = self.send(Syms(b),R(a+1)..,R(a+n+1):R(a+n+2)..,&R(a+n+2k+1)) |
| 47 | OP_SEND |
BBB |
R(a) = R(a).send(Syms(b),R(a+1)..,R(a+n+1):R(a+n+2)..) (c=n|k<<4) |
| 48 | OP_SENDB |
BBB |
R(a) = R(a).send(Syms(b),R(a+1)..,R(a+n+1):R(a+n+2)..,&R(a+n+2k+1)) |
| 49 | OP_CALL |
- |
self.call(*, **, &) (But overlay the current call frame; tailcall) |
| 50 | OP_SUPER |
BB |
R(a) = super(R(a+1),... ,R(a+b+1)) |
| 51 | OP_ARGARY |
BS |
R(a) = argument array (16=m5:r1:m5:d1:lv4) |
| 52 | OP_ENTER |
W |
arg setup according to flags (23=m5:o5:r1:m5:k5:d1:b1) |
| 53 | OP_KEY_P |
BB |
R(a) = kdict.key?(Syms(b)) |
| 54 | OP_KEYEND |
- |
raise unless kdict.empty? |
| 55 | OP_KARG |
BB |
R(a) = kdict[Syms(b)]; kdict.delete(Syms(b)) |
| 56 | OP_RETURN |
B |
return R(a) (normal) |
| 57 | OP_RETURN_BLK |
B |
return R(a) (in-block return) |
| 58 | OP_BREAK |
B |
break R(a) |
| 59 | OP_BLKPUSH |
BS |
R(a) = block (16=m5:r1:m5:d1:lv4) |
| 60 | OP_ADD |
B |
R(a) = R(a)+R(a+1) |
| 61 | OP_ADDI |
BB |
R(a) = R(a)+mrb_int(b) |
| 62 | OP_SUB |
B |
R(a) = R(a)-R(a+1) |
| 63 | OP_SUBI |
BB |
R(a) = R(a)-mrb_int(b) |
| 64 | OP_MUL |
B |
R(a) = R(a)*R(a+1) |
| 65 | OP_DIV |
B |
R(a) = R(a)/R(a+1) |
| 66 | OP_EQ |
B |
R(a) = R(a)==R(a+1) |
| 67 | OP_LT |
B |
R(a) = R(a)<R(a+1) |
| 68 | OP_LE |
B |
R(a) = R(a)<=R(a+1) |
| 69 | OP_GT |
B |
R(a) = R(a)>R(a+1) |
| 70 | OP_GE |
B |
R(a) = R(a)>=R(a+1) |
| 71 | OP_ARRAY |
BB |
R(a) = ary_new(R(a),R(a+1)..R(a+b)) |
| 72 | OP_ARRAY2 |
BBB |
R(a) = ary_new(R(b),R(b+1)..R(b+c)) |
| 73 | OP_ARYCAT |
B |
ary_cat(R(a),R(a+1)) |
| 74 | OP_ARYPUSH |
BB |
ary_push(R(a),R(a+1)..R(a+b)) |
| 75 | OP_ARYSPLAT |
B |
R(a) = ary_splat(R(a)) |
| 76 | OP_AREF |
BBB |
R(a) = R(b)[c] |
| 77 | OP_ASET |
BBB |
R(b)[c] = R(a) |
| 78 | OP_APOST |
BBB |
*R(a),R(a+1)..R(a+c) = R(a)[b..] |
| 79 | OP_INTERN |
B |
R(a) = intern(R(a)) |
| 80 | OP_SYMBOL |
BB |
R(a) = intern(Pool(b)) |
| 81 | OP_STRING |
BB |
R(a) = str_dup(Pool(b)) |
| 82 | OP_STRCAT |
B |
str_cat(R(a),R(a+1)) |
| 83 | OP_HASH |
BB |
R(a) = hash_new(R(a),R(a+1)..R(a+b*2-1)) |
| 84 | OP_HASHADD |
BB |
hash_push(R(a),R(a+1)..R(a+b*2)) |
| 85 | OP_HASHCAT |
B |
R(a) = hash_cat(R(a),R(a+1)) |
| 86 | OP_LAMBDA |
BB |
R(a) = lambda(Irep(b),OP_L_LAMBDA) |
| 87 | OP_BLOCK |
BB |
R(a) = lambda(Irep(b),OP_L_BLOCK) |
| 88 | OP_METHOD |
BB |
R(a) = lambda(Irep(b),OP_L_METHOD) |
| 89 | OP_RANGE_INC |
B |
R(a) = range_new(R(a),R(a+1),FALSE) |
| 90 | OP_RANGE_EXC |
B |
R(a) = range_new(R(a),R(a+1),TRUE) |
| 91 | OP_OCLASS |
B |
R(a) = ::Object |
| 92 | OP_CLASS |
BB |
R(a) = newclass(R(a),Syms(b),R(a+1)) |
| 93 | OP_MODULE |
BB |
R(a) = newmodule(R(a),Syms(b)) |
| 94 | OP_EXEC |
BB |
R(a) = blockexec(R(a),Irep(b)) |
| 95 | OP_DEF |
BB |
R(a).newmethod(Syms(b),R(a+1)); R(a) = Syms(b) |
| 96 | OP_ALIAS |
BB |
alias_method(target_class,Syms(a),Syms(b)) |
| 97 | OP_UNDEF |
B |
undef_method(target_class,Syms(a)) |
| 98 | OP_SCLASS |
B |
R(a) = R(a).singleton_class |
| 99 | OP_TCLASS |
B |
R(a) = target_class |
| 100 | OP_DEBUG |
BBB |
print a,b,c |
| 101 | OP_ERR |
B |
raise(LocalJumpError, Pool(a)) |
| 102 | OP_EXT1 |
- |
make 1st operand (a) 16bit |
| 103 | OP_EXT2 |
- |
make 2nd operand (b) 16bit |
| 104 | OP_EXT3 |
- |
make 1st and 2nd operands 16bit |
| 105 | OP_STOP |
- |
stop VM |