bits 64

%include "defines.inc"

section .text
	global ft_calloc
	; rdi = nitems, rsi = size
	ft_calloc:
		; Check if one of arguments are 0 or negative
		cmp rdi, 0
		je malloc_0
		jl end_null
		cmp rsi, 0
		je malloc_0
		jl end_null

		; save rbx
		push rbx
		mov rbx, rdi

		; multiplication and security for overflow
		xor rdi, rdi
		mul rbx, rsi
		cmovno rdi, rbx; Move if not overflow
		cmp rdi, 0
		je end_null_pop

		; malloc and security if malloc failed
		call malloc wrt ..plt 
		cmp rax, 0
		je end_null_pop

		; set everything to 0
		bzero:
			dec rbx
			mov [rax + rbx], 0

			cmp rbx, 0
			jg bzero

		pop rbx
		ret

		end_null_pop:
			pop rbx
		end_null:
			xor rax, rax
			ret

		malloc_0:
			mov rdi, 0
			call malloc wrt ..plt
			ret