128bit bignum multiplying in Assembly

gistfile1.s

.data
 .align 4
x: .long 0x00124011,0x3130FFFF
y: .long 0x07001245,0x12f01348
ans: .long 0,0,0,0
.text
.globl main

main:

	#; initialize
	mov $0,%ecx
	mov $0,%ebp

	#; 1. multiply mp L.O * mc L.O.
	#; eax: mp; multiplier   L.O.
	#; edi: mc; multiplicand L.O.
	#; ecx: this.answer H.O.
	#; ans[0]: this.answer L.O.
	mov $0,%esi
	mov x(,%esi,4),%eax
	mov y(,%esi,4),%edi

	mul %edi
	mov %eax,ans(,%esi,4)
	mov %edx,%ecx

	#; 2. multiply mp H.O. * mc L.O
	#; eax: mp; multiplier   H.O.
	#; edi: mc; multiplicand L.O.
	#; ecx: (1).answer + this.answer L.O.
	#; ebp: this.answer H.O.
	mov $1,%esi
	mov x(,%esi,4),%eax
	mov $0,%esi
	mov y(,%esi,4),%edi
	
	mul %edi
	add %eax,%ecx
	adc $0,%ebp
	mov %edx,%ebp

	#; 3. multiply mp L.O. * mc H.O.
	#; eax: mp; multiplier   L.O.
	#; edi: mc; multiplicand H.O.
	#; ecx: (1).answer + (2.answer) + this.answer L.O.
	#; ebp: (2).answer + this.answer H.O.
	mov $0,%esi
	mov x(,%esi,4),%eax
	mov $1,%esi
	mov y(,%esi,4),%edi

	mul %edi
	add %eax,%ecx
	adc $0,%ebp
	add %edx,%ebp

	#; 4. multiply mp H.O. * mc H.O.
	#; eax: mp; multiplier   H.O.
	#; edi: mc; multiplicand H.O.
	#; edx: this.answer. H.O
	#; ebp: (2).answer + (3).answer + this.answer L.O.
	mov $1,%esi
	mov x(,%esi,4),%eax
	mov y(,%esi,4),%edi

	mul %edi
	add %eax,%ebp
	adc $0,%edx
	mov %edx,ans(,%esi,4)

	#; answer
	mov $0,%esi
	mov ans(,%esi,4),%eax

	mov %ecx,%ebx
	
	mov %ebp,%ecx

	mov $1,%esi
	mov ans(,%esi,4),%edx

call stop