Write 80387 ALP to find the roots of the quadratic equation. All the possible cases must be considered in calculating the roots.

                                            Savitribai Phule Pune University
                            Second Year of Computer Engineering (2015 Course)
                                                     210257: Microprocessor Lab
                                                                Assignment No.07

Problem Statement:Write 80387 ALP to find the roots of the quadratic equation. All the possible cases must be considered in calculating the roots.

section .data
msg1 db "Complex Root",10
msglen1 equ $-msg1
msg2 db "Root1: "
msglen2 equ $-msg2
msg3 db "Root2: "
msglen3 equ $-msg3
a dd 1.00
b dd 8.00
c dd 15.00
four dd 4.00
two dd 2.00

hdec dq 100
point db "."
       
section .bss
   
    root1 resd 1
    root2 resd 1
    resbuff rest 1
    temp resb 2
    disc resd 1

%macro write 2            ;macro for display
    mov rax,1
    mov rdi,1
    mov rsi,%1
    mov rdx,%2
    syscall
%endmacro

%macro read 2            ;macro for input
    mov rax,0
    mov rdi,0
    mov rsi,%1
    mov rdx,%2
    syscall
%endmacro

%macro exit 0            ;macro for exit
    mov rax,60
    xor rdi,rdi
    syscall
%endmacro

section .text
  global _start
  _start:
 
  finit                ; initialise 80387 co-processor
  fld dword[b]            ; stack: b

   
    
  fmul dword[b]             ; stack: b*b

  fld dword[a]            ; stack: a, b*b

  fmul dword[c]             ; stack: a*c, b*b

  fmul dword[four]        ; stack: 4*a*c,b*b
 
  fsub                 ; stack: b*b - 4*a*c

  ftst                 ; compares ST0 and 0
  
  
  fstsw ax                ;Stores the coprocessor status word ;into either a word in memory or the AX register
  sahf        ;Stores the AH register into the FLAGS register.
  jb no_real_solutions         ; if disc < 0, no real solutions
  fsqrt             ; stack: sqrt(b*b - 4*a*c)

  fst dword[disc]     ; store disc= sqrt(b*b - 4*a*c)

  fsub dword[b]                 ; stack: disc-b

  fdiv dword[a]             ; stack: disc-b/2*a or (-b+disc)/2a


  fdiv dword[two]

  write msg2,msglen2 
 call disp_proc
  fldz                ;stack:0
  fsub dword[disc]        ;stack:-disc
  fsub dword[b]             ; stack: -disc - b
  fdiv dword[a]        ; stack: (-b - disc)/(2*a)
  fdiv dword[two]
 
  write msg3,msglen3
  call disp_proc
  jmp exi

no_real_solutions:
write msg1,msglen1
exi :

mov rax,60
mov rdi,1
syscall
     

disp_proc:
    FIMUL dword[hdec]
    FBSTP tword[resbuff]
    mov rsi,resbuff+9
    mov rcx,09
  next1:
     
      push rcx
      push rsi
     
      mov bl,[rsi]
      call disp
     
      pop rsi
      pop rcx
     
       dec rsi
      loop next1
    push rsi
      write point,1
    pop rsi
      mov bl,[rsi]
      call disp
    ret
 

disp:
        mov edi,temp                ;mov dnum address into edi
        mov ecx,02                    ;initialize ecx with 2
        dispup1:
            rol bl,4                ;rotate bl by 4 bits
            mov dl,bl                ;move bl into dl
            and dl,0fh            ;and of dl with 0fh
            add dl,30h            ;add 30h into dl
            cmp dl,39h            ;compare dl with 39h
            jbe dispskip1            ;jump if below and equal to dispskip1
            add dl,07h            ;add 7h into dl
            dispskip1:
                mov [edi],dl        ;mov dl into dnum
                inc edi            ;increament edi by a byte
            loop dispup1        ;loop dispup1 while ecx not zero
            write temp,2            ;Display dnum by calling macro
          ret                    ;return from procedure