Assignment 6

define(fd_r, w19)
define(nread, x20)
define(buf_base, x21)


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

increment = 1

power           .req    d19
numerator       .req    d20
factor          .req    d21
term            .req    d22
accumulator     .req    d23
incr            .req    d24
counter         .req    d25
curNumb         .req    d26

someFloat:      .double 0r1.0e-10


error:  .string "Error opening file: %s\nAborting.\n"
file:   .string "input.bin"
header: .string "x                       e^x                     e^-x:\n"
values: .string "%13.10f                %13.10f         %13.10f\n"


        .balign 4
        .global main
main:   stp x29, x30, [sp, alloc]!
        mov x29, sp

        adrp x0, header
        add x0, x0, :lo12:header
        bl printf


        mov w0, AT_FDCWD
        adrp x1, file
        add x1, x1, :lo12:file
        mov w2, 0
        mov w3, 0
        mov x8, 56
        svc 0
        mov fd_r, w0

        cmp fd_r, 0
        b.ge fileOpen

        adrp x0, error
        add x0, x0, :lo12:error
        adrp x1, file
        add x1, x1, :lo12:file
        bl printf
        mov w0, -1
        b exit


fileOpen:
        add buf_base, x29, buf_s

top:    mov w0, fd_r
        mov x1, buf_base
        mov w2, buf_size
        mov x8, 63
        svc 0
        mov nread, x0

        cmp nread, buf_size
        b.ne end



        ldr d1, [buf_base]
        bl calc
        fmov d2, d1

        ldr d1, [buf_base]
        fneg d1, d1
        bl calc
        fmov d3, d1


        adrp x0, values
        add x0, x0, :lo12:values
        ldr d1, [buf_base]
        bl printf

        b       top


end:    mov w0, fd_r
        mov x8, 57
        svc 0

        mov w0, 0

exit:   ldp x29, x30, [sp], dealloc
        ret


        .balign 4
        .global calc


calc:   stp x29, x30, [sp, -16]!
        mov x29, sp

        // someFloat
        adrp x22, someFloat
        add x22, x22, :lo12:someFloat
        ldr d4, [x22]



        fmov power, 1.0
        fmov incr, 1.0
        fmov accumulator, 1.0
        fmov counter, 1.0


loop:   fmov numerator, d1
        fcmp power, incr
        b.gt calcNum

        fmov factor, power
        fmov curNumb, factor
        fsub curNumb, curNumb, incr
        fcmp power, curNumb
        b.gt calcFact

        fdiv term, numerator, factor
        fadd accumulator, accumulator, term

        fadd power, power, incr

        fabs term, term
        fcmp term, d4
        b.ge loop

        fmov d1, accumulator
        ldp x29, x30, [sp], 16
        ret


calcNum:
        fmul numerator, numerator, d1
        fadd counter, counter, incr

        fcmp power, counter
        b.gt calcNum

        ret

calcFact:
        fmul factor, factor, curNumb
        fsub curNumb, curNumb, incr

        fcmp curNumb, incr
        b.gt calcFact

        ret