# EX$14-$mult$-$SP$2021$

# Objective: experiment with:

# multiply: mult

# Description:

# mult $s$2,$ $s$3$

# When $S$2(32-$bit$)$ x $S$3(32-$bit$)$ the result is $64$ bits

# MIPS processor places:

# $*$ the most significant $32$ bits in Register: Hi

# $*$ the least significant $32$ bits in Register: Lo

main:

# Case $1$: positive x positive $=$ positive:

addi $s$2,$ $zero,$2$ # $s$2=0+2=2$

addi $s$3,$ $zero,$3$ # $s$3=0+3=3$

mult $s$2,$ $s$3$ # $(2$ points$)$ verify with MARS: Hi $=0$x $00000000\_\_\_\_$ ; Lo $=0$x$00000006\_\_\_\_\_$

# Case $2$: positive x negative $=$ negative:

addi $s$2,$ $zero,$2$ # $s$2=2$

addi $s$3,$ $zero,$-3$ # $s$3=-3(=$ ffff fffd$)(2\text{'}$s complement$)$

mult $s$2,$ $s$3$ # $(2$ points$)$ verify with MARS: Hi $=0$x FFFFFFFF$\_\_\_\_$ ; Lo $=0$xFFFFFFFA

# Case $3$: negative x negative $=$ positive:

addi $s$2,$ $zero,$-2$ # $s$2=-2(=$ ffff fffe$)(2\text{'}$s complement$)$

addi $s$3,$ $zero,$-3$ # $s$3=-3(=$ ffff fffd$)(2\text{'}$s complement$)$

mult $s$2,$ $s$3$ # $(2$ points$)$ verify with MARS: Hi $=0$x $\_\_\_\_\_\_\_\_\_$ ; Lo $=0$x $\_\_\_\_\_\_\_\_\_\_\_$

wait: j wait # wait