Math co-processor 8087 program to obtain Mean, Variance and Standard Deviation in NASM[x86/64]

Problem Statement: Write 8087 ALP to obtain:
i) Mean ii) Variance iii) Standard Deviation
For a given set of data elements defined in data segment. Also display result.



section .data

numbers db "The numbers are:102.59,198.21,100.67,230.78,67.93",10
len equ $-numbers
meanmsg db 10,"CALCULATED MEAN IS:-"
meanmsg_len equ $-meanmsg
sdmsg db 10,"CALCULATED STANDARD DEVIATION IS:-"
sdmsg_len equ $-sdmsg
varmsg db 10,"CALCULATED VARIANCE IS:-"
varmsg_len equ $-varmsg
array dd 102.56,198.21,100.67,230.78,67.93
arraycnt dw 05
dpoint db '.'
hdec dq 100

section .bss
dispbuff resb 1
resbuff rest 1

mean resd 1
variance resd 1

%macro linuxsyscall 4
mov rax,%1
mov rdi,%2
mov rsi,%3
mov rdx,%4
syscall
%endmacro   


section .text
global _start
_start:
linuxsyscall 01,01,numbers,len
finit
fldz
mov rbx,array
mov rsi,00
xor rcx,rcx
mov cx,[arraycnt]

up:
fadd dword[RBX+RSI*4]
inc rsi
loop up

fidiv word[arraycnt]
fst dword[mean]
linuxsyscall 01,01,meanmsg,meanmsg_len
call dispres

mov rcx,00
mov cx,[arraycnt]
mov rbx,array
mov rsi,00
FLDZ

up1:
FLDZ
FLD dword[RBX+RSI*4]
FSUB dword[mean]
FST ST1
FMUL
FADD
inc rsi
loop up1

FIDIV word[arraycnt]
FST dword[variance]
FSQRT
linuxsyscall 01,01,sdmsg,sdmsg_len
CALL dispres

FLD dword[variance]
linuxsyscall 01,01,varmsg,varmsg_len
CALL dispres

exit: 
mov rax,60
mov rdi,0
syscall


disp8_proc:
mov rdi,dispbuff
mov rcx,02

back:
rol bl,04
mov dl,bl
and dl,0FH
cmp dl,09
jbe next1
add dl,07H

next1:  
add dl,30H
mov [rdi],dl
inc rdi
loop back
ret

dispres:
fimul dword[hdec]
fbstp tword[resbuff]
xor rcx,rcx
mov rcx,09H
mov rsi,resbuff+9

up2:
push rcx
push rsi
mov bl,[rsi]
call disp8_proc

linuxsyscall 01,01,dispbuff,2
pop rsi
dec rsi
pop rcx
loop up2

linuxsyscall 01,01,dpoint,1
mov bl,[resbuff]
call disp8_proc
linuxsyscall 01,01,dispbuff,2
ret

Output

amodi@ubuntu:~/MIL/Assign7$ nasm -f elf64 -l asgn7.lst asgn7.asm
amodi@ubuntu:~/MIL/Assign7$ ld -o asgn7 asgn7.o
amodi@ubuntu:~/MIL/Assign7$ ./asgn7
The numbers are: 102.59,198.21,100.67,230.78,67.93

CALCULATED MEAN IS:-000000000000000140.30
CALCULATED STANDARD DEVIATION IS:-000000000000000062.32
CALCULATED VARIANCE IS:-000000000000003954.34