1 a32765e3 2005-08-10 devnull /*	mpvecadd(mpdigit *a, int alen, mpdigit *b, int blen, mpdigit *sum) */
 2 a32765e3 2005-08-10 devnull /*		sum[0:alen] = a[0:alen-1] + b[0:blen-1] */
 3 a32765e3 2005-08-10 devnull /*	prereq: alen >= blen, sum has room for alen+1 digits */
 4 a32765e3 2005-08-10 devnull /* (very old gnu assembler doesn't allow multiline comments) */
 5 ac0e2db6 2004-04-21 devnull 
 6 ac0e2db6 2004-04-21 devnull .text
 7 ac0e2db6 2004-04-21 devnull 
 8 ac0e2db6 2004-04-21 devnull .p2align 2,0x90
 9 ac0e2db6 2004-04-21 devnull .globl mpvecadd
10 ac0e2db6 2004-04-21 devnull 	.type mpvecadd, @function
11 ac0e2db6 2004-04-21 devnull mpvecadd:
12 ac0e2db6 2004-04-21 devnull 	/* Prelude */
13 ac0e2db6 2004-04-21 devnull 	pushl %ebp
14 ac0e2db6 2004-04-21 devnull 	movl %ebx, -4(%esp)		/* save on stack */
15 ac0e2db6 2004-04-21 devnull 	movl %esi, -8(%esp)
16 ac0e2db6 2004-04-21 devnull 	movl %edi, -12(%esp)
17 ac0e2db6 2004-04-21 devnull 
18 ac0e2db6 2004-04-21 devnull 	movl	12(%esp), %edx		/* alen */
19 ac0e2db6 2004-04-21 devnull 	movl	20(%esp), %ecx		/* blen */
20 ac0e2db6 2004-04-21 devnull 	movl	8(%esp), %esi		/* a */
21 ac0e2db6 2004-04-21 devnull 	movl	16(%esp), %ebx		/* b */
22 ac0e2db6 2004-04-21 devnull 	subl	%ecx, %edx
23 ac0e2db6 2004-04-21 devnull 	movl	24(%esp), %edi		/* sum */
24 ac0e2db6 2004-04-21 devnull 	xorl	%ebp, %ebp		/* this also sets carry to 0 */
25 ac0e2db6 2004-04-21 devnull 
26 ac0e2db6 2004-04-21 devnull 	/* skip addition if b is zero */
27 ac0e2db6 2004-04-21 devnull 	testl	%ecx,%ecx
28 ac0e2db6 2004-04-21 devnull 	je	_add1
29 ac0e2db6 2004-04-21 devnull 
30 ac0e2db6 2004-04-21 devnull 	/* sum[0:blen-1],carry = a[0:blen-1] + b[0:blen-1] */
31 ac0e2db6 2004-04-21 devnull _addloop1:
32 ac0e2db6 2004-04-21 devnull 	movl	(%esi, %ebp, 4), %eax
33 ac0e2db6 2004-04-21 devnull 	adcl	(%ebx, %ebp, 4), %eax
34 ac0e2db6 2004-04-21 devnull 	movl	%eax, (%edi, %ebp, 4)
35 ac0e2db6 2004-04-21 devnull 	incl	%ebp
36 ac0e2db6 2004-04-21 devnull 	loop	_addloop1
37 ac0e2db6 2004-04-21 devnull 
38 ac0e2db6 2004-04-21 devnull _add1:
39 ac0e2db6 2004-04-21 devnull 	/* jump if alen > blen */
40 ac0e2db6 2004-04-21 devnull 	incl	%edx
41 ac0e2db6 2004-04-21 devnull 	movl	%edx, %ecx
42 ac0e2db6 2004-04-21 devnull 	loop	_addloop2
43 ac0e2db6 2004-04-21 devnull 
44 ac0e2db6 2004-04-21 devnull 	/* sum[alen] = carry */
45 ac0e2db6 2004-04-21 devnull _addend:
46 ac0e2db6 2004-04-21 devnull 	jb	_addcarry
47 ac0e2db6 2004-04-21 devnull 	movl	$0, (%edi, %ebp, 4)
48 ac0e2db6 2004-04-21 devnull 	jmp done
49 ac0e2db6 2004-04-21 devnull 
50 ac0e2db6 2004-04-21 devnull _addcarry:
51 ac0e2db6 2004-04-21 devnull 	movl	$1, (%edi, %ebp, 4)
52 ac0e2db6 2004-04-21 devnull 	jmp done
53 ac0e2db6 2004-04-21 devnull 
54 ac0e2db6 2004-04-21 devnull 	/* sum[blen:alen-1],carry = a[blen:alen-1] + 0 */
55 ac0e2db6 2004-04-21 devnull _addloop2:
56 ac0e2db6 2004-04-21 devnull 	movl	(%esi, %ebp, 4),%eax
57 ac0e2db6 2004-04-21 devnull 	adcl	$0, %eax
58 ac0e2db6 2004-04-21 devnull 	movl	%eax, (%edi, %ebp, 4)
59 ac0e2db6 2004-04-21 devnull 	incl	%ebp
60 ac0e2db6 2004-04-21 devnull 	loop	_addloop2
61 ac0e2db6 2004-04-21 devnull 	jmp	_addend
62 ac0e2db6 2004-04-21 devnull 
63 ac0e2db6 2004-04-21 devnull done:
64 ac0e2db6 2004-04-21 devnull 	/* Postlude */
65 ac0e2db6 2004-04-21 devnull 	movl -4(%esp), %ebx		/* restore from stack */
66 ac0e2db6 2004-04-21 devnull 	movl -8(%esp), %esi
67 ac0e2db6 2004-04-21 devnull 	movl -12(%esp), %edi
68 ac0e2db6 2004-04-21 devnull 	movl %esp, %ebp
69 ac0e2db6 2004-04-21 devnull 	leave
70 ac0e2db6 2004-04-21 devnull 	ret