##########
# mov.s for use in CSE351 Lec 9 on Condition Codes
#
# Intended for use with a gdb demo:
# gcc -o mov mov.s
##########

	.text
	.globl	main
	.type	main, @function
main:
	
	movq	$0x1020304050607080, %rax	# put non-zero junk in bytes of %rax,
	movq	%rax, %rbx			#   %rbx,
	movq	%rax, %rcx			#   and %rcx

	movzbw	%al, %bx			# pull lowest byte into %bx (16 bits) and zero-extend
						#   --> %rbx = 0x1020304050600080

	movzbq	%al, %rbx			# pull lowest byte into %rbx and zero-extend
						#   --> %rbx = 0x80 even though MSB=1

	leaq	g, %rax				# get address of global variable data
	movsbl	4(%rax), %ecx			# pull byte 0x80 into %ecx and sign-extend
						#   --> %rcx = 0xFFFFFF80 because 32-bit values
						#       placed in a x86-64 register zero out
						#       upper 32 bits
	ret
	.size	main, .-main
	.globl	g
	.data
	.align 8
	.type	g, @object
	.size	g, 8
g:	
	.quad	0x7778798081828384