1#!/usr/local/bin/perl
2# alpha assember
3
4sub bn_sub_words
5	{
6	local($name)=@_;
7	local($cc,$a,$b,$r);
8
9	&init_pool(4);
10	($cc)=GR("r0");
11
12	$rp=&wparam(0);
13	$ap=&wparam(1);
14	$bp=&wparam(2);
15	$count=&wparam(3);
16
17	&function_begin($name,"");
18
19	&comment("");
20	&sub($count,4,$count);
21	&mov("zero",$cc);
22	&blt($count,&label("finish"));
23
24	($a0,$b0)=&NR(2);
25	&ld($a0,&QWPw(0,$ap));
26	&ld($b0,&QWPw(0,$bp));
27
28##########################################################
29	&set_label("loop");
30
31	($a1,$tmp,$b1,$a2,$b2,$a3,$b3,$o0)=&NR(8);
32	&ld($a1,&QWPw(1,$ap));
33	 &cmpult($a0,$b0,$tmp);	# will we borrow?
34	&ld($b1,&QWPw(1,$bp));
35	 &sub($a0,$b0,$a0);		# do the subtract
36	&ld($a2,&QWPw(2,$ap));
37	 &cmpult($a0,$cc,$b0);	# will we borrow?
38	&ld($b2,&QWPw(2,$bp));
39	 &sub($a0,$cc,$o0);	# will we borrow?
40	&ld($a3,&QWPw(3,$ap));
41	 &add($b0,$tmp,$cc); ($t1,$o1)=&NR(2); &FR($tmp);
42
43	&cmpult($a1,$b1,$t1);	# will we borrow?
44	 &sub($a1,$b1,$a1);	# do the subtract
45	&ld($b3,&QWPw(3,$bp));
46	 &cmpult($a1,$cc,$b1);	# will we borrow?
47	&sub($a1,$cc,$o1);	# will we borrow?
48	 &add($b1,$t1,$cc); ($tmp,$o2)=&NR(2); &FR($t1,$a1,$b1);
49
50	&cmpult($a2,$b2,$tmp);	# will we borrow?
51	 &sub($a2,$b2,$a2);		# do the subtract
52	&st($o0,&QWPw(0,$rp));	&FR($o0); # save
53	 &cmpult($a2,$cc,$b2);	# will we borrow?
54	&sub($a2,$cc,$o2);	# will we borrow?
55	 &add($b2,$tmp,$cc); ($t3,$o3)=&NR(2); &FR($tmp,$a2,$b2);
56
57	&cmpult($a3,$b3,$t3);	# will we borrow?
58	 &sub($a3,$b3,$a3);	# do the subtract
59	&st($o1,&QWPw(1,$rp)); &FR($o1);
60	 &cmpult($a3,$cc,$b3);	# will we borrow?
61	&sub($a3,$cc,$o3);	# will we borrow?
62	 &add($b3,$t3,$cc); &FR($t3,$a3,$b3);
63
64	&st($o2,&QWPw(2,$rp));	&FR($o2);
65	 &sub($count,4,$count);	# count-=4
66	&st($o3,&QWPw(3,$rp));	&FR($o3);
67	 &add($ap,4*$QWS,$ap);	# count+=4
68	&add($bp,4*$QWS,$bp);	# count+=4
69	 &add($rp,4*$QWS,$rp);	# count+=4
70
71	&blt($count,&label("finish"));
72	&ld($a0,&QWPw(0,$ap));
73	 &ld($b0,&QWPw(0,$bp));
74	&br(&label("loop"));
75##################################################
76	# Do the last 0..3 words
77
78	&set_label("last_loop");
79
80	&ld($a0,&QWPw(0,$ap));	# get a
81	 &ld($b0,&QWPw(0,$bp));	# get b
82	&cmpult($a0,$b0,$tmp);	# will we borrow?
83	&sub($a0,$b0,$a0);	# do the subtract
84	&cmpult($a0,$cc,$b0);	# will we borrow?
85	&sub($a0,$cc,$a0);	# will we borrow?
86	&st($a0,&QWPw(0,$rp));	# save
87	&add($b0,$tmp,$cc);	# add the borrows
88
89	&add($ap,$QWS,$ap);
90	&add($bp,$QWS,$bp);
91	&add($rp,$QWS,$rp);
92	&sub($count,1,$count);
93	&bgt($count,&label("last_loop"));
94	&function_end_A($name);
95
96######################################################
97	&set_label("finish");
98	&add($count,4,$count);
99	&bgt($count,&label("last_loop"));
100
101	&FR($a0,$b0);
102	&set_label("end");
103	&function_end($name);
104
105	&fin_pool;
106	}
107
1081;
109