alpha/lib/ev6-csum_ipv6_magic.S

17  *	E	- either cluster
39  * Finally, original 'folding' approach is to split the long into 4 unsigned shorts
40  * add 4 ushorts, resulting in ushort/carry
58 	.align 4
65 	inslh	$18,7,$4	# U : 0000000000AABBCC
69 	and	$16,7,$6	# E : src misalignment
79 	cmoveq	$6,$31,$22	# E : src aligned?
82 	addl	$19,$7,$19	# E : U L U L : <sign bits>bbaabb00
84 	or	$0,$22,$0	# E : 1st src word complete
86 	or	$18,$4,$18	# E : 000000CCDDAABBCC
89 	and	$17,7,$6	# E : dst misalignment
91 	or	$1,$5,$1	# E : 2nd src word complete
94 	cmoveq	$6,$31,$22	# E : dst aligned?
96 	addq	$20,$0,$20	# E : begin summing the words
99 	srl	$18,16,$4	# U : 0000000000CCDDAA
100 	or	$2,$22,$2	# E : 1st dst word complete
102 	or	$3,$23,$3	# E : U L U L : 2nd dst word complete
104 	cmpult	$20,$0,$0	# E :
105 	addq	$20,$1,$20	# E :
107 	zap	$4,0xa,$4	# U : U U L L : 0000000000CC00AA
109 	or	$18,$4,$18	# E : 00000000DDCCBBAA
110 	nop			# E :
111 	cmpult	$20,$1,$1	# E :
112 	addq	$20,$2,$20	# E : U L U L
114 	cmpult	$20,$2,$2	# E :
115 	addq	$20,$3,$20	# E :
116 	cmpult	$20,$3,$3	# E : (1 cycle stall on $20)
117 	addq	$20,$18,$20	# E : U L U L (1 cycle stall on $20)
119 	cmpult	$20,$18,$18	# E :
120 	addq	$20,$19,$20	# E : (1 cycle stall on $20)
121 	addq	$0,$1,$0	# E : merge the carries back into the csum
122 	addq	$2,$3,$2	# E :
124 	cmpult	$20,$19,$19	# E :
125 	addq	$18,$19,$18	# E : (1 cycle stall on $19)
126 	addq	$0,$2,$0	# E :
127 	addq	$20,$18,$20	# E : U L U L :
130 	addq	$0,$20,$0	# E :
132 	nop			# E :
135 	addq	$1,$0,$1	# E : Finished generating ulong
138 	extwl	$1,4,$1		# U : ushort[2] (1 cycle stall on $1)
140 	addq	$0,$2,$0	# E
141 	addq	$0,$1,$3	# E : Finished generating uint
144 	nop			# E : L U L U
146 	addq	$1,$3,$0	# E : Final carry
147 	not	$0,$4		# E : complement (1 cycle stall on $0)
148 	zapnot	$4,3,$0		# U : clear upper garbage bits
149 		/* (1 cycle stall on $4) */