#
# File: switch1_mod.s
# Author: William T Krieger, Oct 2003
#
# My modification of the switch1 test case demonstrating a 
# simple switch statement.

	.text
	.align 32

LC0:	.ascii "Enter 1. Add, 2. Sub, 3. Mul, 4. Div: \0"
LC1:	.ascii "%d\0"
FMT_ADD:	.ascii "Add!\12\0"
FMT_SUB:	.ascii "Sub!\12\0"
FMT_MUL:	.ascii "Mul\12\0"
FMT_DIV:	.ascii "Div\12\0"
FMT_BAD:	.ascii "Bad choice\12\0"
FMT_DONE:	.ascii "Done.\12\0"

	.align 4
	.globl _main
_main:
	pushl %ebp		# enter main()
	movl %esp,%ebp

	pushl $LC0		# call printf( fmt)
	call _printf
	addl $4,%esp

	addl $-4,%esp		# adjust stack for 1 local var: int x;

	leal -4(%ebp),%eax	# call scanf( fmt, &x)
	pushl %eax
	pushl $LC1
	call _scanf

	movl -4(%ebp),%eax	# eax = x

	cmpl $1,%eax		# if x == 1, then jmp CASE_ADD
	je CASE_ADD
	cmpl $2,%eax		# if x == 2, then jmp CASE_SUB
	je CASE_SUB
	cmpl $3,%eax		# if x == 3, then jmp CASE_MUL
	je CASE_MUL
	cmpl $4,%eax		# if x == 4, then jmp CASE_DIV
	je CASE_DIV

	###
	# For each case label below, the appropriate format string is pushed
	# onto the stack so that printf can be called at the CASE_WRAPUP label
	###

	pushl $FMT_BAD		# default case, pushes an error message
	jmp CASE_WRAPUP

CASE_ADD:
	pushl $FMT_ADD
	jmp CASE_WRAPUP

CASE_SUB:
	pushl $FMT_SUB
	jmp CASE_WRAPUP

CASE_MUL:
	pushl $FMT_MUL
	jmp CASE_WRAPUP

CASE_DIV:
	pushl $FMT_DIV
	jmp CASE_WRAPUP

CASE_WRAPUP:
	call _printf		# calls printf, using one of the format strings
						# pushed in a case label above
	addl $4,%esp

DONE:
	pushl $FMT_DONE		# call printf( fmt)
	call _printf
	addl $4,%esp

	movl %ebp,%esp		# exit main()
	popl %ebp
	ret