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#include "SDL_interface.S"
#define SCREEN_WIDTH 800
#define SCREEN_HEIGHT 600
// integer-params: RDI, RSI, RDX, RCX, R8, R9
// caller-saved: RAX, RCX, RDX, RSI, RDI, R8-R11
// callee-saved: RBX, RSP, RBP, R12-R15
.section .rodata
failed_to_create_window: .string "Window could not be created\nSDL_error: %s\n"
failed_to_initialize_sdl: .string "SDL could not be initialized\nSDL_error: %s\n"
greeting: .string "Hello, SDL!\n"
window_title: .string "snake.s"
.section .text
.global main
// void _print_sdl_error(char const * format)
.type _print_sdl_error, @function
_print_sdl_error:
push %rbp
mov %rsp, %rbp
push %rdi
sub $8, %rsp
call SDL_GetError@PLT
mov %rax, %rsi
add $8, %rsp
pop %rdi
call printf@PLT
jmp .Lexit
leave
ret
.type main, @function
main:
push %rbp
mov %rsp, %rbp
// initialize SDL
mov $SDL_INIT_VIDEO, %rdi
call SDL_Init@PLT
// check if initialization was successful
cmp $0, %rax
jae 1f
lea failed_to_initialize_sdl(%rip), %rdi
call _print_sdl_error@PLT
mov $1, %rax
jmp .Lexit
1:
// create a window
lea window_title(%rip), %rdi
mov $SDL_WINDOWPOS_UNDEFINED, %rsi
mov $SDL_WINDOWPOS_UNDEFINED, %rdx
mov $SCREEN_WIDTH, %rcx
mov $SCREEN_HEIGHT, %r8
mov $SDL_WINDOW_SHOWN, %r9
call SDL_CreateWindow@PLT
cmp $0, %rax
jne 1f
lea failed_to_create_window(%rip), %rdi
call _print_sdl_error@PLT
mov $1, %rax
jmp .Lexit
1:
mov %rax, %rdi
call SDL_DestroyWindow@PLT
call SDL_Quit@PLT
.Lsuccess:
lea greeting(%rip), %rdi
xor %rax, %rax
call printf@PLT
xor %rax, %rax
.Lexit:
leave
ret
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