# A demo of accessing fields of structs in MIPS.

# Offsets for fields in `struct student`
STUDENT_OFFSET_ZID = 0
STUDENT_OFFSET_FIRST = 4
STUDENT_OFFSET_LAST = 20 + STUDENT_OFFSET_FIRST
STUDENT_OFFSET_PROGRAM = 20 + STUDENT_OFFSET_LAST
STUDENT_OFFSET_ALIAS = 4 + STUDENT_OFFSET_PROGRAM

# sizeof the struct - note that there are 2 padding
# bytes at the end of the struct.
SIZEOF_STRUCT_STUDENT = 10 + STUDENT_OFFSET_ALIAS + 2

	.text
main:
	# Locals:
	#  - $t0: struct student *selection

	la	$t0, xavier

	li	$v0, 4				# syscall 4: print_string
	la	$a0, zid_msg			# 
	syscall					# printf("zID: z");

	li	$v0, 1				# syscall 1: print_int
	lw	$a0, STUDENT_OFFSET_ZID($t0)	#
	syscall					# printf("%d", selection->zid);

	li	$v0, 11				# syscall 11: print_char
	li	$a0, '\n'			#
	syscall					# putchar('\n');

	li	$v0, 4				# syscall 4: print_string
	la	$a0, first_name_msg		# 
	syscall					# printf("First name: ");

	li	$v0, 4				# syscall 4: print_string
	la	$a0, STUDENT_OFFSET_FIRST($t0)	#
	syscall					# printf("%s", selection->first);

	li	$v0, 11				# syscall 11: print_char
	li	$a0, '\n'			#
	syscall					# putchar('\n');

	li	$v0, 4				# syscall 4: print_string
	la	$a0, last_name_msg		# 
	syscall					# printf("Last name: ");

	li	$v0, 4				# syscall 4: print_string
	la	$a0, STUDENT_OFFSET_LAST($t0)	#
	syscall					# printf("%s", selection->last);

	li	$v0, 11				# syscall 11: print_char
	li	$a0, '\n'			#
	syscall					# putchar('\n');

	li	$v0, 4				# syscall 4: print_string
	la	$a0, program_msg		# 
	syscall					# printf("Program: ");

	li	$v0, 1				# syscall 1: print_int
	lw	$a0, STUDENT_OFFSET_PROGRAM($t0)#
	syscall					# printf("%d", selection->program);

	li	$v0, 11				# syscall 11: print_char
	li	$a0, '\n'			#
	syscall					# putchar('\n');

	li	$v0, 4				# syscall 4: print_string
	la	$a0, alias_msg			#
	syscall					# printf("Alias: ");

	li	$v0, 4				# syscall 4: print_string
	la 	$a0, STUDENT_OFFSET_ALIAS($t0)	#
	syscall					# printf("%s", selection->alias);

	li	$v0, 11				# syscall 11: print_char
	li	$a0, '\n'			#
	syscall					# putchar('\n');


	li	$v0, 0				#
	jr	$ra				# return 0;
	.data
abiram:						# struct student abiram {
	.word	5308310				#  int zid;
	.asciiz	"Abiram"			#  char first[20];
	.space	20 - 7
	.asciiz "Nadarajah"			#  char last[20];
	.space	20 - 10
	.word	3778				#  int program;
	.asciiz	"abiramn"			#  char alias[10];
	.space	10 - 8
	.align	2
						# }

xavier:						# struct student xavier {
	.word	5417087				#  int zid;
	.asciiz	"Xavier"			#  char first[20];
	.space	20 - 7
	.asciiz "Cooney"			#  char last[20];
	.space	20 - 7
	.word	3778				#  int program;
	.asciiz	"xavc"				#  char alias[10];
	.space	10 - 5
						# }

zid_msg:
	.asciiz "zID: z"

first_name_msg:
	.asciiz "First name: "

last_name_msg:
	.asciiz "Last name: "

program_msg:
	.asciiz "Program: "

alias_msg:
	.asciiz	"Alias: "