Question

You are tasked to calculate a specific algebraic expansion, i.e. compute the value of f and g for the expression:

( I have just to use loop add and sub no other functions)

f = AC – 3C+ BD - 4AB

without using any intrinsic multiplication instructions. More formally, write MIPS assembly code that accepts four positive integers a, b, c, and d as input parameters. The code shall execute in MARS to prompt the user to enter four positive integers represented in decimal, each separated by the Enter key. The program shall calculate f=(AC3-3C2+BD2-4B) and g=(A2C+B2D2) using your own self-written multiplication routine. The program will then output f in decimal and binary, using syscall routines for each output. Hint: MARS supports output in binary format using the appropriate parameters with syscall. For the Clanguage prototype, there are many approaches to print a value in binary in C. Here is my favorite singleline-in-a-loop solution that you can use with any C-compiler to print x in binary, shown with x=9 as an example:

main() { int i,x=9; for (i=31;i>=0;i--) { /*

put char with ASCII code for either 0 or 1 by adding 1 for the ith bit to ASCII of '0'

*/ put char('0' + ((x>>i) & 1)); } return(0); } Y

ou can use the above in your C-code prototype or write your own binary output routine in C if you want.

Sample output for Part A is:

Enter 4 integers for A,B,C,D respectively

15

9

12

3

f_ten = 25533

f_two = 00000000000000000110001110111101

g_ten = 3429

g_two = 00000000000000000000110101100101

Answer 1

.file "dtob.c"
.text
.globl f
.type f, @function
f:
.LFB0:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
movl %edi, -4(%rbp)
movl %esi, -8(%rbp)
movl %edx, -12(%rbp)
movl %ecx, -16(%rbp)
movl -12(%rbp), %eax
imull -12(%rbp), %eax
imull -12(%rbp), %eax
imull -4(%rbp), %eax
movl %eax, %ecx
movl -12(%rbp), %eax
imull -12(%rbp), %eax
movl %eax, %edx
movl %edx, %eax
addl %eax, %eax
addl %edx, %eax
negl %eax
leal (%rcx,%rax), %edx
movl -16(%rbp), %eax
imull -16(%rbp), %eax
imull -8(%rbp), %eax
leal (%rdx,%rax), %ecx
movl -8(%rbp), %edx
movl $0, %eax
subl %edx, %eax
sall $2, %eax
addl %ecx, %eax
cltq
popq %rbp
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE0:
.size f, .-f
.globl g
.type g, @function
g:
.LFB1:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
movl %edi, -4(%rbp)
movl %esi, -8(%rbp)
movl %edx, -12(%rbp)
movl %ecx, -16(%rbp)
movl -4(%rbp), %eax
imull -4(%rbp), %eax
imull -12(%rbp), %eax
movl %eax, %edx
movl -8(%rbp), %eax
imull -8(%rbp), %eax
movl %eax, %ecx
movl -16(%rbp), %eax
imull -16(%rbp), %eax
imull %ecx, %eax
addl %edx, %eax
cltq
popq %rbp
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE1:
.size g, .-g
.globl dec_to_bin
.type dec_to_bin, @function
dec_to_bin:
.LFB2:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
subq $32, %rsp
movq %rdi, -24(%rbp)
movl $31, -4(%rbp)
jmp .L6
.L7:
movl -4(%rbp), %eax
movq -24(%rbp), %rdx
movl %eax, %ecx
sarq %cl, %rdx
movq %rdx, %rax
andl $1, %eax
addl $48, %eax
movl %eax, %edi
call putchar
subl $1, -4(%rbp)
.L6:
cmpl $0, -4(%rbp)
jns .L7
movl $10, %edi
call putchar
leave
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE2:
.size dec_to_bin, .-dec_to_bin
.section .rodata
.LC0:
.string "Enter a,b,c and d vlaues : "
.LC1:
.string "%d%d%d%d"
.LC2:
.string "f_ten = %ld\n"
.LC3:
.string "f_two = "
.LC4:
.string "g_ten = %ld\n"
.LC5:
.string "g_two = "
.text
.globl main
.type main, @function
main:
.LFB3:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
subq $32, %rsp
movl $.LC0, %edi
call puts
leaq -20(%rbp), %rsi
leaq -24(%rbp), %rcx
leaq -28(%rbp), %rdx
leaq -32(%rbp), %rax
movq %rsi, %r8
movq %rax, %rsi
movl $.LC1, %edi
movl $0, %eax
call __isoc99_scanf
movl -20(%rbp), %ecx
movl -24(%rbp), %edx
movl -28(%rbp), %esi
movl -32(%rbp), %eax
movl %eax, %edi
call f
movq %rax, -16(%rbp)
movl -20(%rbp), %ecx
movl -24(%rbp), %edx
movl -28(%rbp), %esi
movl -32(%rbp), %eax
movl %eax, %edi
call g
movq %rax, -8(%rbp)
movq -16(%rbp), %rax
movq %rax, %rsi
movl $.LC2, %edi
movl $0, %eax
call printf
movl $.LC3, %edi
movl $0, %eax
call printf
movq -16(%rbp), %rax
movq %rax, %rdi
call dec_to_bin
movq -8(%rbp), %rax
movq %rax, %rsi
movl $.LC4, %edi
movl $0, %eax
call printf
movl $.LC5, %edi
movl $0, %eax
call printf
movq -8(%rbp), %rax
movq %rax, %rdi
call dec_to_bin
leave
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE3:
.size main, .-main
.ident "GCC: (Ubuntu 4.8.4-2ubuntu1~14.04.3) 4.8.4"
.section .note.GNU-stack,"",@progbits