define(fd_r, w19)
    define(nread_r, x20)
    define(buf_base_r, x21)

    buf_size = 8
    alloc = -(16 + buf_size) & -16
    dealloc = -alloc
    buf_s = 16
    AT_FDCWD = -100

pn: .string "input.bin"                                     // Name of file
fmt1:   .string "|       Input           |       e^x             |       e^-x            |"     // header
fmt2:   .string "|     %13.10f \t|     %13.10f \t|     %13.10f \t|\n"               // Values
fmt3:   .string "Error opening file %s \n Aborting \n"
fmt4:   .string "\n_________________________________________________________________________\n"     //divider
value:  .double 0r1.0e-10

    .balign 4
    .global main

    counter     .req d19    // +1
    accum       .req d20    // Accumulator
    factorial   .req d21    // Factorial
    power       .req d22    // power
    quotient    .req d23    // Quotient
    numerator   .req d24    // Numerator



main:   stp x29, x30, [sp, alloc]!
    mov x29, sp


    // Printing formatted header
    adrp    x0, fmt1            // Header
    add x0, x0, :lo12:fmt1      // print header
    bl  printf
    adrp    x0, fmt4
    add x0, x0, :lo12:fmt4
    bl  printf


    // Open file
    mov w0, AT_FDCWD            // arg1 (cwd)
    adrp    x1, pn              // arg2 (pathname)
    add x1, x1, :lo12:pn
    mov w2, 0               // arg3 (read only)
    mov w3, 0               // arg4 (not used)
    mov x8, 56              // openat I/O
    svc 0               // Call sys func
    mov fd_r, w0            // Record file descriptor


    // Error check for openat
    cmp fd_r, 0
    b.ge    openok

    adrp    x0, fmt3            // Error
    add x0, x0, :lo12:fmt3
    bl  printf              // print
    mov w0, -1
    b   done


openok: add buf_base_r, x29, buf_size   // calculate buf base

top:    // read ints from binary file
    mov w0, fd_r            // 1st arg (fd)
    mov x1, buf_base_r          // 2nd arg (buf)
    mov w2, buf_size            // 3rd arg (n)
    mov x8, 63              // Read I/O
    svc 0               // Call sys func
    mov nread_r, x0         // # of bytes

    // Error check
    cmp nread_r, buf_size       // nread != 8
    b.ne    end             // read failed - exit loop

    bl  exp

    // e^x / e^-x
exp:    ldr d0, [buf_base_r]        // d is x
    bl  calc                // go to calculations
    fmov    d1, d0              // Mov arg1
    ldr d0, [buf_base_r]        // d is x
    fneg    d0, d0              // d is -x
    bl  calc
    fmov    d2, d0              // moves to arg2

    // Print
    adrp    x0, fmt2            // Printing the values %13.10f
    add x0, x0, :lo12:fmt2      // print
    ldr d0, [buf_base_r]        // arg
    bl  printf

    b   top
calc:   stp     x29, x30, [sp, -16]!        // Allocate
    mov     x29, sp

    fmov    counter, 1.0            // It's a counter
    fmov    power, 1.0
    fmov    accum, 1.0          // Accumulator is 1

        fmov    numerator, d0               // Num = x
        fmov    factorial, power
        fdiv    quotient, numerator, factorial  // x / factorial
        fadd    accum, accum, quotient      // accum + quotient

loop:   adrp    x27, value
    add x27, x27, :lo12:value
    ldr d3, [x27]           // d3 = 0r1.0e-10

    fmul    numerator, numerator, d0    // d0 * num
    fadd    power, power, counter       // power++
    fmul    factorial, factorial, power // factor * power
    fdiv    quotient, numerator, factorial  // quotient = num / fact
    fadd    accum, accum, quotient      // accum += quotient

    fabs    quotient, quotient
    fcmp    quotient, d3            // Compare
    b.ge    loop                // If quotient >= d3

    fmov    d0, accum
    ldp x29, x30, [sp], 16
    ret

end:    mov w0, fd_r            // 1st arg (fd)
    mov x8, 57              // closing I/O
    svc 0               // call sys func
    mov w0, 0               // ret

done:   ldp x29, x30, [sp], dealloc

    ret