Two Sum - Assembly

solution.c

__attribute__((naked))
int* twoSum(int* nums, int numsSize, int target, int* returnSize) {
    // Leetcode doesn't have assembly, so I will be using the 
    // inline assembly from C (following intel syntax). This is
    // the brute force approach, O(n^2).
    __asm__(".intel_syntax noprefix;                                \
                                                                    \
        /*Create a stack and load incoming parameters into it*/;    \
        push rbx;                                                   \
        sub rsp, 0x40;                                              \
        mov qword ptr [rsp+0x10], rdi;                              \
        mov dword ptr [rsp+0x18], esi;                              \
        mov dword ptr [rsp+0x20], edx;                              \
        mov qword ptr [rsp+0x28], rcx;                              \
                                                                    \       
        /*malloc memory for answer*/;                               \
        mov rdi, 8;                                                 \
        call malloc;                                                \
        mov qword ptr [rsp+0x30], rax;                              \
                                                                    \
        /*Outer loop*/;                                             \
        xor r8, r8;                                                 \
        oloop%=:                                                    \
        mov r9, r8;                                                 \
        add r9, 1;                                                  \
        iloop%=:                                                    \
        mov rbx, qword ptr [rsp+0x10];                              \
        xor rax, rax;                                               \
        lea rbx, [rbx+r8*4];                                        \
        add eax, dword ptr [rbx];                                   \
        mov rbx, qword ptr [rsp+0x10];                              \
        lea rbx, [rbx+r9*4];                                        \
        add eax, dword ptr [rbx];                                   \
        mov ebx, dword ptr [rsp+0x20];                              \
                                                                    \
        /*If sum equals target, store and leave*/;                  \
        cmp ebx, eax;                                               \
        jne continue%=;                                             \
        mov rax, qword ptr [rsp+0x30];                              \
        mov dword ptr [rax], r8d;                                   \
        lea rax, [rax+4];                                           \
        mov dword ptr [rax], r9d;                                   \
        mov rax,  qword ptr [rsp+0x28];                             \
        mov dword ptr [rax], 0x2;                                   \
        jmp leave%=;                                                \
                                                                    \
        continue%=:                                                 \
        inc r9;                                                     \
        cmp r9d, dword ptr [rsp+0x18];                              \
        jle iloop%=;                                                \
        inc r8;                                                     \
        cmp r8d, dword ptr [rsp+0x18];                              \
        jle oloop%=;                                                \
                                                                    \
        leave%=:                                                    \
        mov rax, qword ptr [rsp+0x30];                              \
        add rsp, 0x40;                                              \
        pop rbx;                                                    \
        ret;                                                        \
        .att_syntax;                                                \
    " : :);
}