fuelvm-instructions.md

Reserved Registers

index	register	description
0x00	zero	always zero
0x01	one	always one
0x02	of	contains overflow of arithmetic
0x03	pc	memory address of the current instruction
0x04	ssp	memory address of the stack start
0x05	sp	memory address of the current stack index
0x06	fp	memory address of the current call frame
0x07	hp	memory address of the end of the heap
0x08	err	error codes
0x09	ggas	gas avaiable globally
0x0a	cgas	gas available in the context
0x0b	bal	received balance for the context
0x0c	is	start of the currently-executing code
0x0d	ret	return value or pointer
0x0e	retl	return value length,in bytes
0x0f	flag	flags register

Arithmetic

syntax	behavior	notes
add c,a,b	c = a + b
addi c,a,imm	c = a + imm
sub c,a,b	c = a - b
subi c,a,imm	c = a - imm
mul c,a,b	c = a * b
muli c,a,imm	c = a * imm
div c,a,b	c = a / b
divi c,a,imm	c = a / imm
mod c,a,b	c = a % b
modi c,a,imm	c = a % imm
exp c,a,b	c = a ** b
exp c,a,imm	c = a ** imm
mroo c,a,b	c = math.floor(math.root(a,b))
mlog c,a,b	c = math.floor(math.log(a,b))
move a,b	a = b
movi a,imm	a = imm

Bitwise

syntax	behavior	notes
eq c,a,b	c = a == b
gt c,a,b	c = a > b
lt c,a,b	c = a < b
and c,a,b	c = a & b
andi c,a,imm	c = a & imm
noop		no operation
not b,a	b = ~a
or c,a,b	c = a | b
ori c,a,imm	c = a | imm
sll c,a,b	c = a << b
slli c,a,imm	c = a << imm
srl c,a,b	c = a >> b
srli c,a,imm	c = a >> imm
xor c,a,b	c = a ^ b
xori c,a,imm	c = a ^ imm

Control Flow

syntax	behavior	notes
jmp a	pc = is+a	jumps to a
ji imm	pc = is+imm*4	jumps to constant
jne a b c	pc = a != b ? is+c*4 : pc+4	jump to c if a != b
jnei a b imm	pc = a != b ? is+imm*4 : pc+4	jump to imm if a != b
jnzi a imm	pc = a != 0 ? is+imm*4 : pc+4	jump to imm if a != 0
ret a	return a	return from context with a

Memory

syntax	behavior	notes
alloc a	hp -= a	allocate a bytes from heap
cfei imm	sp += imm	extend call frame by imm
cfsi imm	sp -= imm	shrink call frame by imm
lb a,b,imm	a = mem[b+imm,1]	load byte from memory at b + imm
lw a,b,imm	a = mem[b+(imm*8),8]	load word from memory at b + imm
mcl a,b	mem[a,b] = 0	clears b bytes of memory at offset a
mcli a,imm	mem[a,imm] = 0	clear imm bytes of memory at offset a
mcp a,b,c	mem[a,c] = mem[b,c]	copy c bytes of memory from b to a
mcpi a,b,imm	mem[a,imm] = mem[b,imm]	copy imm bytes of memory from b to a
meq a,b,c,d	a = mem[b,d] == mem[c,d]	true if d bytes of memory at b and c match
sb a,b,imm	mem[a+imm,1] = b[7,1]	stores rightmost byte of b at a + imm
sw a,b,imm	mem[a+(imm*8),8] = b	stores word, b, at a + imm

Contract

syntax	behavior	notes
bal a,b,c	a = bal(mem[b,32],mem[c,32])	get balance of account c given asset id b
bhei a	a = blockheight	get fuel block height
bhsh a b	mem[a,32] = blockhash(b)	store in memory at a the hash of block b
burn a	burn(a)	burn a amount of the contract's asset ID
call a,b,c,d	call(a,b,c,d)	call w data at a, b amount of c asset and d gas
cb a	mem[a,32] = coinbase	store coinbase account in memory at a
cpp a,b,c,d	mem[a,d] = code(b,c,d)	copy d bytes of contract b at c to a
croo a,b	mem[a,32] = coderoot(mem[b,32])	copy code merkle root of contract at b
csiz a,b	a = codesize(mem[b,32])	get code size of contract at b
ldc a,b,c	mem[ssp,c] = code(a,b,c)	copy c bytes from contract b at a to execute
log a,b,c,d	log(a,b,c,d)	log event with topics a, b, c, and d
logd a,b,c,d	logd(a,b,c,d)	log event with topics a and b with d bytes at c
mint a	mint(a)	mint a amount of the contract's asset ID
retd	returndata(a,b)	return b bytes from a to the context's caller
rvrt a	revert(a)	halt execution, revert state changes, return a
smo a,b,c,d	msg(mem[fp,32],mem[a,32],mem[a+32,b],d,c)	send msg to recipient address
scwq a,b,c	state[mem[a,32],32*c] = None	clear c slots of storage from a
srw a,b,c	a = state[mem[c,32]][0,8]	read from state at c into a
srwq a,b,c,d	mem[a,32*d] = state[mem[c,32*d]]	read d slots of state into a
sww a,b,c	state[mem[a,32]] = (rc,0)	write c to slot at a
swwq a,b,c,d	state[mem[a,32],32*d] = mem[c,32*d]	write d slots from c to a
time a,b	a = time(b)	get timestamp of block b
tr a,b,c	transfer(mem[a,32],b,mem[c,32])	transfer b amount of asset c to a
tro a,b,c,d	transferout(mem[a,32],b,c,mem[d,32])	transfer c amount of d to address a w output b

Cryptography

syntax	behavior	notes
ecr a,b,c	mem[a,32] = ecrecover(mem[b,64],mem[c,32])	ec recover from b, b+1, c
k256 a,b,c	mem[a,32] = keccak256(mem[b,c])	hash c bytes from b into a
s256 a,b,c	mem[a,32] = sha256(mem[b,c])	hash c bytes from b into a

Misc

syntax	behavior	notes
flag a	flag = a	set flag
gm a,imm		get metadata from memory
gtf a,b,imm		get fields from the transaction

Storage

├── contract_a
│   ├── key : value
│   ├── key : value
│   └── key : value
│
└── contract_b
    ├── key : value
    └── key : value