Given below is a very simple C code and it$$s RISCV instruction sequence $($written

manually$).$

int x$,$y$,$m$,$c;

m $=3$;

x $=-7$;

c $=10$;

y $=$ mx $+$ c;

Assembly for rars

$.$data

m:

$.$word $3$

x:

$.$word $-7$

c:

$.$word $10$

y:

$.$word $-1$ # random initial value

$.$text

# Initialize m $,$ x$,$ c and y

# m in t$1,$ x in t$2,$ c in t$3,$ y in t$4$

#addi t$1,$ x$0,3$

lui t$0,\%$hi$($m$)$

addi t$0,$ t$0,\%$lo$($m$)$

lw t$1,0($t$0)$

#addi t$2,$ x$0,-7$

lui t$0,\%$hi$($x$)$

addi t$0,$ t$0,\%$lo$($x$)$

lw t$2,0($t$0)$

#addi t$3,$ x$0,10$

lui t$0,\%$hi$($c$)$

addi t$0,$ t$0,\%$lo$($c$)$

lw t$3,0($t$0)$

add t$4,$ x$0,$ x$0$

# Multiply without mul instruction

mul$\_$m$\_$x:

beq t$1,$ x$0,$ done

add t$4,$ t$4,$ t$2$

addi t$1,$ t$1,-1$

jal x$0,$ mul$\_$m$\_$x

done :

add t$4,$ t$4,$ t$3$

lui t$0,\%$hi$($y$)$

addi t$0,$ t$0,\%$lo$($y$)$

sw t$4,0($t$0)$

Question:

a$.$

The code given for Q$1$ assumes t$1=$ m is always $>=0.$

We do not handle the case when t$1=$ m is less than $0$

Please correct the given assembly code to handle positive and negative values for all m$,$ x and c$.$

The test it with $-$

m $=-3,$ x $=2,$ c $=5$

m $=-3,$ x $=-2,$ c $=-5$

m $=3,$ x $=2,$ c $=-5$

m $=-3,$ x $=0,$ c $=5$

m $=0,$ x $=4,$ c $=-5$

For each case, please feel free to use registers as you need $($within the ABI rules$)$ but store the

final result in t$4$

b$.$

Please write the above code using a function. Pass m$,$ x and c to the function and the function

must calculate the results and return, then the main assembly code puts the result in t$4($if not

already there$)$ and exits.

Please test it with $-$

m $=-3,$ x $=2,$ c $=5$

m $=-3,$ x $=-2,$ c $=-5$

m $=3,$ x $=2,$ c $=-5$

m $=-3,$ x $=0,$ c $=5$

m $=0,$ x $=4,$ c $=-5$