xref: /onnv-gate/usr/src/uts/sparc/ml/ip_ocsum.s (revision 0:68f95e015346)
1*0Sstevel@tonic-gate/*
2*0Sstevel@tonic-gate * CDDL HEADER START
3*0Sstevel@tonic-gate *
4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate * with the License.
8*0Sstevel@tonic-gate *
9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate * and limitations under the License.
13*0Sstevel@tonic-gate *
14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate *
20*0Sstevel@tonic-gate * CDDL HEADER END
21*0Sstevel@tonic-gate */
22*0Sstevel@tonic-gate/*
23*0Sstevel@tonic-gate * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate * Use is subject to license terms.
25*0Sstevel@tonic-gate */
26*0Sstevel@tonic-gate
27*0Sstevel@tonic-gate#ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate
29*0Sstevel@tonic-gate#include <sys/asm_linkage.h>
30*0Sstevel@tonic-gate
31*0Sstevel@tonic-gate#if defined(lint)
32*0Sstevel@tonic-gate#include <sys/types.h>
33*0Sstevel@tonic-gate#endif	/* lint */
34*0Sstevel@tonic-gate
35*0Sstevel@tonic-gate/*
36*0Sstevel@tonic-gate * ip_ocsum(address, halfword_count, sum)
37*0Sstevel@tonic-gate * Do a 16 bit one's complement sum of a given number of (16-bit)
38*0Sstevel@tonic-gate * halfwords. The halfword pointer must not be odd.
39*0Sstevel@tonic-gate *	%o0 address; %o1 count; %o2 sum accumulator; %o4 temp
40*0Sstevel@tonic-gate * 	%g2 and %g3 used in main loop
41*0Sstevel@tonic-gate *
42*0Sstevel@tonic-gate * (from @(#)ocsum.s 1.3 89/02/24 SMI)
43*0Sstevel@tonic-gate *
44*0Sstevel@tonic-gate */
45*0Sstevel@tonic-gate
46*0Sstevel@tonic-gate#if defined(lint)
47*0Sstevel@tonic-gate
48*0Sstevel@tonic-gate/* ARGSUSED */
49*0Sstevel@tonic-gateunsigned int
50*0Sstevel@tonic-gateip_ocsum(u_short *address, int halfword_count, unsigned int sum)
51*0Sstevel@tonic-gate{ return (0); }
52*0Sstevel@tonic-gate
53*0Sstevel@tonic-gate#else	/* lint */
54*0Sstevel@tonic-gate
55*0Sstevel@tonic-gate	ENTRY(ip_ocsum)
56*0Sstevel@tonic-gate	cmp	%o1, 31		! less than 62 bytes?
57*0Sstevel@tonic-gate	bl,a	.dohw		!   just do halfwords
58*0Sstevel@tonic-gate	tst	%o1		! delay slot, test count
59*0Sstevel@tonic-gate
60*0Sstevel@tonic-gate	btst	31, %o0		! (delay slot)
61*0Sstevel@tonic-gate	bz	2f		! if 32 byte aligned, skip
62*0Sstevel@tonic-gate	nop
63*0Sstevel@tonic-gate
64*0Sstevel@tonic-gate	!
65*0Sstevel@tonic-gate	! Do first halfwords until 32-byte aligned
66*0Sstevel@tonic-gate	!
67*0Sstevel@tonic-gate1:
68*0Sstevel@tonic-gate	lduh	[%o0], %g2	! read data
69*0Sstevel@tonic-gate	add	%o0, 2, %o0	! increment address
70*0Sstevel@tonic-gate	add	%o2, %g2, %o2	! add to accumulator, don't need carry yet
71*0Sstevel@tonic-gate	btst	31, %o0		! 32 byte aligned?
72*0Sstevel@tonic-gate	bnz	1b
73*0Sstevel@tonic-gate	sub	%o1, 1, %o1	! decrement count
74*0Sstevel@tonic-gate	!
75*0Sstevel@tonic-gate	! loop to add in 32 byte chunks
76*0Sstevel@tonic-gate	! The loads and adds are staggered to help avoid load/use
77*0Sstevel@tonic-gate	! interlocks on highly pipelined implementations, and double
78*0Sstevel@tonic-gate	! loads are used for 64-bit wide memory systems.
79*0Sstevel@tonic-gate	!
80*0Sstevel@tonic-gate2:
81*0Sstevel@tonic-gate	sub	%o1, 16, %o1	! decrement count to aid testing
82*0Sstevel@tonic-gate4:
83*0Sstevel@tonic-gate	ldd	[%o0], %g2	! read data
84*0Sstevel@tonic-gate	ldd	[%o0+8], %o4	! read more data
85*0Sstevel@tonic-gate	addcc	%o2, %g2, %o2	! add to accumulator
86*0Sstevel@tonic-gate	addxcc	%o2, %g3, %o2	! add to accumulator with carry
87*0Sstevel@tonic-gate	ldd	[%o0+16], %g2	! read more data
88*0Sstevel@tonic-gate	addxcc	%o2, %o4, %o2	! add to accumulator with carry
89*0Sstevel@tonic-gate	addxcc	%o2, %o5, %o2	! add to accumulator with carry
90*0Sstevel@tonic-gate	ldd	[%o0+24], %o4	! read more data
91*0Sstevel@tonic-gate	addxcc	%o2, %g2, %o2	! add to accumulator with carry
92*0Sstevel@tonic-gate	addxcc	%o2, %g3, %o2	! add to accumulator with carry
93*0Sstevel@tonic-gate	addxcc	%o2, %o4, %o2	! add to accumulator
94*0Sstevel@tonic-gate	addxcc	%o2, %o5, %o2	! add to accumulator with carry
95*0Sstevel@tonic-gate	addxcc	%o2, 0, %o2	! if final carry, add it in
96*0Sstevel@tonic-gate	subcc	%o1, 16, %o1	! decrement count (in halfwords)
97*0Sstevel@tonic-gate	bge	4b
98*0Sstevel@tonic-gate	add	%o0, 32, %o0	! delay slot, increment address
99*0Sstevel@tonic-gate
100*0Sstevel@tonic-gate	add	%o1, 16, %o1	! add back in
101*0Sstevel@tonic-gate	!
102*0Sstevel@tonic-gate	! Do any remaining halfwords
103*0Sstevel@tonic-gate	!
104*0Sstevel@tonic-gate	b	.dohw
105*0Sstevel@tonic-gate	tst	%o1		! delay slot, for more to do
106*0Sstevel@tonic-gate
107*0Sstevel@tonic-gate3:
108*0Sstevel@tonic-gate	add	%o0, 2, %o0	! increment address
109*0Sstevel@tonic-gate	addcc	%o2, %g2, %o2	! add to accumulator
110*0Sstevel@tonic-gate	addxcc	%o2, 0, %o2	! if carry, add it in
111*0Sstevel@tonic-gate	subcc	%o1, 1, %o1	! decrement count
112*0Sstevel@tonic-gate.dohw:
113*0Sstevel@tonic-gate	bg,a	3b		! more to do?
114*0Sstevel@tonic-gate	lduh	[%o0], %g2	! read data
115*0Sstevel@tonic-gate
116*0Sstevel@tonic-gate	!
117*0Sstevel@tonic-gate	! at this point the 32-bit accumulator
118*0Sstevel@tonic-gate	! has the result that needs to be returned in 16-bits
119*0Sstevel@tonic-gate	!
120*0Sstevel@tonic-gate	sll	%o2, 16, %o4	! put low halfword in high halfword %o4
121*0Sstevel@tonic-gate	addcc	%o4, %o2, %o2	! add the 2 halfwords in high %o2, set carry
122*0Sstevel@tonic-gate	srl	%o2, 16, %o2	! shift to low halfword
123*0Sstevel@tonic-gate	retl			! return
124*0Sstevel@tonic-gate	addxcc	%o2, 0, %o0	! add in carry if any. result in %o0
125*0Sstevel@tonic-gate	SET_SIZE(ip_ocsum)
126*0Sstevel@tonic-gate
127*0Sstevel@tonic-gate#endif 	/* lint */
128