PageRenderTime 25ms CodeModel.GetById 14ms app.highlight 7ms RepoModel.GetById 1ms app.codeStats 0ms

/arch/alpha/lib/csum_ipv6_magic.S

http://github.com/mirrors/linux
Assembly | 118 lines | 97 code | 21 blank | 0 comment | 1 complexity | 59c86484aa6699ec712eb3d68ed42f94 MD5 | raw file
  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * arch/alpha/lib/csum_ipv6_magic.S
  4 * Contributed by Richard Henderson <rth@tamu.edu>
  5 *
  6 * unsigned short csum_ipv6_magic(struct in6_addr *saddr,
  7 *                                struct in6_addr *daddr,
  8 *                                __u32 len,
  9 *                                unsigned short proto,
 10 *                                unsigned int csum);
 11 *
 12 * Misalignment handling (which costs 16 instructions / 8 cycles)
 13 * added by Ivan Kokshaysky <ink@jurassic.park.msu.ru>
 14 */
 15
 16#include <asm/export.h>
 17	.globl csum_ipv6_magic
 18	.align 4
 19	.ent csum_ipv6_magic
 20	.frame $30,0,$26,0
 21csum_ipv6_magic:
 22	.prologue 0
 23
 24	ldq_u	$0,0($16)	# e0    : load src & dst addr words
 25	zapnot	$20,15,$20	# .. e1 : zero extend incoming csum
 26	extqh	$18,1,$4	# e0    : byte swap len & proto while we wait
 27	ldq_u	$21,7($16)	# .. e1 : handle misalignment
 28
 29	extbl	$18,1,$5	# e0	:
 30	ldq_u	$1,8($16)	# .. e1 :
 31	extbl	$18,2,$6	# e0 	:
 32	ldq_u	$22,15($16)	# .. e1 :
 33
 34	extbl	$18,3,$18	# e0	:
 35	ldq_u	$2,0($17)	# .. e1 :
 36	sra	$4,32,$4	# e0	:
 37	ldq_u	$23,7($17)	# .. e1 :
 38
 39	extql	$0,$16,$0	# e0	:
 40	ldq_u	$3,8($17)	# .. e1 :
 41	extqh	$21,$16,$21	# e0	:
 42	ldq_u	$24,15($17)	# .. e1 :
 43
 44	sll	$5,16,$5	# e0	:
 45	or	$0,$21,$0	# .. e1 : 1st src word complete
 46	extql	$1,$16,$1	# e0	:
 47	addq	$20,$0,$20	# .. e1 : begin summing the words
 48
 49	extqh	$22,$16,$22	# e0	:
 50	cmpult	$20,$0,$0	# .. e1 :
 51	sll	$6,8,$6		# e0	:
 52	or	$1,$22,$1	# .. e1 : 2nd src word complete
 53
 54	extql	$2,$17,$2	# e0	:
 55	or	$4,$18,$18	# .. e1 :
 56	extqh	$23,$17,$23	# e0	:
 57	or	$5,$6,$5	# .. e1 :
 58
 59	extql	$3,$17,$3	# e0	:
 60	or	$2,$23,$2	# .. e1 : 1st dst word complete
 61	extqh	$24,$17,$24	# e0	:
 62	or	$18,$5,$18	# .. e1 : len complete
 63
 64	extwh	$19,7,$7	# e0    :
 65	or	$3,$24,$3	# .. e1 : 2nd dst word complete
 66	extbl	$19,1,$19	# e0    :
 67	addq	$20,$1,$20	# .. e1 :
 68
 69	or	$19,$7,$19	# e0    :
 70	cmpult	$20,$1,$1	# .. e1 :
 71	sll	$19,48,$19	# e0    :
 72	nop			# .. e0 :
 73
 74	sra	$19,32,$19	# e0    : proto complete
 75	addq	$20,$2,$20	# .. e1 :
 76	cmpult	$20,$2,$2	# e0    :
 77	addq	$20,$3,$20	# .. e1 :
 78
 79	cmpult	$20,$3,$3	# e0    :
 80	addq	$20,$18,$20	# .. e1 :
 81	cmpult	$20,$18,$18	# e0    :
 82	addq	$20,$19,$20	# .. e1 :
 83
 84	cmpult	$20,$19,$19	# e0    :
 85	addq	$0,$1,$0	# .. e1 : merge the carries back into the csum
 86	addq	$2,$3,$2	# e0    :
 87	addq	$18,$19,$18	# .. e1 :
 88
 89	addq	$0,$2,$0	# e0    :
 90	addq	$20,$18,$20	# .. e1 :
 91	addq	$0,$20,$0	# e0    :
 92	unop			#       :
 93
 94	extwl	$0,2,$2		# e0    : begin folding the 64-bit value
 95	zapnot	$0,3,$3		# .. e1 :
 96	extwl	$0,4,$1		# e0    :
 97	addq	$2,$3,$3	# .. e1 :
 98
 99	extwl	$0,6,$0		# e0    :
100	addq	$3,$1,$3	# .. e1 :
101	addq	$0,$3,$0	# e0    :
102	unop			#       :
103
104	extwl	$0,2,$1		# e0    : fold 18-bit value
105	zapnot	$0,3,$0		# .. e1 :
106	addq	$0,$1,$0	# e0    :
107	unop			#       :
108
109	extwl	$0,2,$1		# e0    : fold 17-bit value
110	zapnot	$0,3,$0		# .. e1 :
111	addq	$0,$1,$0	# e0    :
112	not	$0,$0		# .. e1 : and complement.
113
114	zapnot	$0,3,$0		# e0    :
115	ret			# .. e1 :
116
117	.end csum_ipv6_magic
118	EXPORT_SYMBOL(csum_ipv6_magic)