Study Questions $($Chapter $03$ Part E$)$

$1.$ Question $3\mathrm{.}15$ on page $224$: Write an ARM assembly language routine to count the number of $1$s in a $32$bit

word in r$0$ and return the result in r$1.$

$2.$ Question $3\mathrm{.}16$ on page $224$: A word consists of the bytes b$4,$ b$3,$ b$2,$ b$1.$ Write an ARM assembly language

function to re$$order $($transpose$)$ these bytes in the order b$1,$ b$3,$ b$2,$ b$4.$

$3.$ Question $3\mathrm{.}22$ on page $224$: Write ARM code to implement the following C operation.

int s $=0$;

for $($ i $=0$; i $<10$; i$++)\{$

s $=$ s $+$ i$*$i;$)$

$4.$ Question $3\mathrm{.}39$ on page $225$: Write an ARM assembly language program that scans a string terminated by

the null byte $0$x$00$ and copies the string from a source location pointed at by r$0$ to a destination pointed at

by r$1.$

$5.$ Write an ARM assembly language program to count the number of characters in a null$$terminated string

$($STRING$1)$ and store the result in memory at the location identified by label $$length$.$

You may want to define the data of the program as follow:

STRING$1$ DCB "This is a test string$1"$ ;String$1$

EoS$1$ DCB $0$x$00$ ;end of string$1$

length DCD $0$x$00$ ;to store the calculated string length

$6.$ Write an ARM assembly language program to concatenate two null$$terminated strings $($STRING$1$ and STRING$2)$

and store the result in another null$$terminated STRING$3.$ Assume that the length of STRING$1+$ the length of

STRING$2<=255.$

You may want to define the strings as follow:

STRING$1$ DCB "This is a test string$1"$ ;String$1$

EoS$1$ DCB $0$x$00$ ;end of string$1$

STRING$2$ DCB "This is a test string$2"$ ;String

EoS$2$ DCB $0$x$00$ ;end of string$2$

STRING$3$ space $0$xFF