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%include "unistd.asm"
%include "utils.asm"
stdout equ 1
global _start
section .rodata
JMP_TABLE: dq _start.lose, _start.draw, _start.win
section .text
_start:
mov rcx, [rsp] ; Get number of arguments
mov rdi, [rsp + rcx * 8] ; Get last argument
mov rax, SYS_access ; Check if file exists and is readable
mov esi, R_OK
syscall
test rax, rax
jnz .exit_err
mov rax, SYS_open
xor esi, esi
xor edx, edx
syscall
mov r8d, eax ; Move fd into r8
mov rax, SYS_mmap
xor edi, edi ; Let the kernel choose the address
mov rsi, 12288
mov rdx, PROT_READ
mov r10d, MAP_PRIVATE
xor r9d, r9d
syscall
cmp rax, -1 ; Exit on error
je .exit_err
xor r8d, r8d ; score
.loop:
cmp byte [rax], 0
je .exit
mov ecx, [rax]
add rax, 4
mov edx, ecx
and ecx, 0xff
shr edx, 2 * 8
and edx, 0xff
sub ecx, 'A' - 1
lea rdi, [JMP_TABLE]
jmp [rdi + rdx * 8 - 'X' * 8]
.lose:
%rep 2
inc ecx
mov edi, ecx
shr edi, 2
or ecx, edi
and ecx, 0b11
%endrep
add r8d, ecx
jmp .loop
.win:
inc ecx
mov edi, ecx
shr edi, 2
or ecx, edi
and ecx, 0b11
add r8d, 6
add r8d, ecx
jmp .loop
.draw:
add r8d, ecx
add r8d, 3
jmp .loop
.exit:
mov edi, stdout
mov esi, r8d
call write_ulong
mov rax, SYS_exit
xor edi, edi
syscall
.exit_err:
mov rax, SYS_exit
mov edi, 1
syscall
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