#x86 machine code, 39 bytes

00000000: 9150 6800 0000 00e8 fcff ffff 5958 a901 .Ph.........YX..
00000010: 0000 0074 04d1 e8eb 066a 035a f7e2 4009 ...t.....j.Z..@.
00000020: c075 dec3 2564 20 .u..%d 

Assembly (NASM syntax):

section .text
	global func
	extern printf
func:					;the function uses fastcall conventions
	xchg eax, ecx			;load function arg into eax
	loop:
		push eax
		push fmt
		call printf	;print eax
		pop ecx
		pop eax
		test eax, 1	;if even zf=1
		jz even		;if eax is even jmp to even
		odd:		;eax=eax/2
			shr eax, 1
			jmp skip
		even:		;eax=eax*3+1
			push 3
			pop edx
			mul edx
			inc eax
		skip:
		or eax, eax
		jne loop	;if eax!=0, keep looping
	ret			;return eax
section .data
	fmt db '%d '

Try it online!

x86 machine code, 39 bytes

00000000: 9150 6800 0000 00e8 fcff ffff 5958 a901 .Ph.........YX..
00000010: 0000 0074 04d1 e8eb 066a 035a f7e2 4009 ...t.....j.Z..@.
00000020: c075 dec3 2564 20 .u..%d 

Assembly (NASM syntax):

section .text
	global func
	extern printf
func:					;the function uses fastcall conventions
	xchg eax, ecx			;load function arg into eax
	loop:
		push eax
		push fmt
		call printf	;print eax
		pop ecx
		pop eax
		test eax, 1	;if even zf=1
		jz even		;if eax is even jmp to even
		odd:		;eax=eax/2
			shr eax, 1
			jmp skip
		even:		;eax=eax*3+1
			push 3
			pop edx
			mul edx
			inc eax
		skip:
		or eax, eax
		jne loop	;if eax!=0, keep looping
	ret			;return eax
section .data
	fmt db '%d '

Try it online!

#x86 machine code, 39 bytes

00000000: 9150 6800 0000 00e8 fcff ffff 5958 a901 .Ph.........YX..
00000010: 0000 0074 04d1 e8eb 066a 035a f7e2 4009 ...t.....j.Z..@.
00000020: c075 dec3 2564 20 .u..%d 

Assembly:

section .text
	global func
	extern printf
func:					;the function uses fastcall conventions
	xchg eax, ecx			;load function arg into eax
	loop:
		push eax
		push fmt
		call printf	;print eax
		pop ecx
		pop eax
		test eax, 1	;if even zf=1
		jz even		;if eax is even jmp to even
		odd:		;eax=eax/2
			shr eax, 1
			jmp skip
		even:		;eax=eax*3+1
			push 3
			pop edx
			mul edx
			inc eax
		skip:
		or eax, eax
		jne loop	;if eax!=0, keep looping
	ret			;return eax
section .data
	fmt db '%d '

Try it online!

#x86 machine code, 39 bytes

00000000: 9150 6800 0000 00e8 fcff ffff 5958 a901 .Ph.........YX..
00000010: 0000 0074 04d1 e8eb 066a 035a f7e2 4009 ...t.....j.Z..@.
00000020: c075 dec3 2564 20 .u..%d 

Assembly (NASM syntax):

section .text
	global func
	extern printf
func:					;the function uses fastcall conventions
	xchg eax, ecx			;load function arg into eax
	loop:
		push eax
		push fmt
		call printf	;print eax
		pop ecx
		pop eax
		test eax, 1	;if even zf=1
		jz even		;if eax is even jmp to even
		odd:		;eax=eax/2
			shr eax, 1
			jmp skip
		even:		;eax=eax*3+1
			push 3
			pop edx
			mul edx
			inc eax
		skip:
		or eax, eax
		jne loop	;if eax!=0, keep looping
	ret			;return eax
section .data
	fmt db '%d '

Try it online!