.text
.type capitalize, @function
.global capitalize

#%rdi - string

capitalize:
	MOV %rdi, %rax
	XOR %r8, %r8
	MOV $0, %r8
loop:
	CMP $0, (%rdi)
	JE afterLoop
	CMP $1, %r8
	JE tryToSwap
	JMP checkIfDot
afterSwap:
	INC %rdi
	JMP loop
afterLoop:
	RET

tryToSwap:
	CMPB $'a', (%rdi)
	JL afterSwap
	CMPB $'z', (%rdi)
	JG afterSwap
	SUBB $32, (%rdi)
	MOV $0, %r8
	JMP afterSwap

checkIfDot:
	CMPB $'.', (%rdi)
	JNE afterSwap
	CMPB $'?', (%rdi)
	JNE afterSwap
	CMPB $'!', (%rdi)
	JNE afterSwap
	MOV $1, %r8
	JMP afterSwap