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Manual.md

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Registers

Name Description
r0, r1, ..., r11 Generic registers
in Input
out Output
aor Always-one register
azr Always-zero register
fss Function stack start
Arithmetic carry bit
Jump target address

For input and output, just cp from/to in/out.

Instruction Categories

  • All srcs and dsts can be either immediate or registers.
  • halt must be called after a program finishes.

Arithmetic Operations

Mnemonic Format Description
add add src1 src2 dst Addition
sub sub src1 src2 dst Subtraction
and and src1 src2 dst Bitwise AND
or or src1 src2 dst Bitwise OR
not not src dst Bitwise NOT
xor xor src1 src2 dst Bitwise XOR
div div src1 src2 dst Division
mod mod src1 src2 dst Modulo
cadd cadd src1 src2 dst Carry addition
anc anc src1 src2 dst Add with no carry bit set
snc snc src1 src2 dst Subtract with no carry bit set
  • By default, add and cadd will set the carry bit on overflow, whereas anc won't.

Shift Operations

Mnemonic Format Description
shl shl src1 src2 dst (Logical) shift left
shr shr src1 src2 dst (Logical) shift right
wshl wshl src1 src2 dst Wrapping shift left
wshr wshr src1 src2 dst Wrapping shift right

Control Flow

Mnemonic Format Description
jp jp Unconditional jump
jpeq jpeq src1 src2 Jump if equal
jpne jpne src1 src2 Jump if not equal
jplt jplt src1 src2 Jump if less than
jple jple src1 src2 Jump if less or equal
jpgt jpgt src1 src2 Jump if greater than
jpge jpge src1 src2 Jump if greater or equal
jamv jamv label Jump address move

  • Before any jump, the jump target address should be set via jamv. See example below.

    infinite_loop:
cp azr out
jamv infinite_loop
jp

Memory Operations

Mnemonic Format Description
ld ld addr dst Load from memory
st st addr src Store to memory
  • addr can be either immediate or a register.

Stack Operations

Mnemonic Format Description
push push src Push to stack
pop pop dst Pop from stack

Function Calls

Mnemonic Format Description
call call label Call function
ret ret Return from function
fpush fpush src Function push, used for parameters and return-value
fpop fpop dst Function pop, used for parameters and return-value

Examples

; compute 5%3
; `fpush` has an reversed order
fpush 3
fpush 5
call f_mod
fpop r0 ; now r0 is 2

f_mod:
  fpop r0
  fpop r1
  mod r0 r1 r0
  fpush r0
  ret

Miscellaneous

Mnemonic Format Description
halt halt Halt execution
cp cp src, dst Copy value
mvc mvc dst Move carry to register
nop nop No operation

Assembly Format

.data 0          ; Data section (starts at address 0) (should not indent)
; These data are stored in memory directly.
my_array [1, 2, 3] array_len  ; Define an array
message 'Hello' msg_len       ; Define a string

.consts               ; Constants section (should not indent)
MAX_VALUE 100     ; Define a constant

.entry main           ; Program entry point

.code                 ; Code section
; Code goes here
main:
  nop
  halt                ; must present