xtensa/lib/strnlen_user.S

50 	addi	a4, a2, -4	# because we overincrement at the end;
51 				# we compensate with load offsets of 4
52 	movi	a5, MASK0	# mask for byte 0
53 	movi	a6, MASK1	# mask for byte 1
54 	movi	a7, MASK2	# mask for byte 2
55 	movi	a8, MASK3	# mask for byte 3
56 	bbsi.l	a2, 0, .L1mod2	# if only  8-bit aligned
57 	bbsi.l	a2, 1, .L2mod4	# if only 16-bit aligned
60  * String is word-aligned.
63 	srli	a10, a3, 2	# number of loop iterations with 4B per loop
69 	add	a10, a10, a4	# a10 = end of last 4B chunk
72 EX(10f)	l32i	a9, a4, 4		# get next word of string
73 	addi	a4, a4, 4		# advance string pointer
74 	bnone	a9, a5, .Lz0		# if byte 0 is zero
75 	bnone	a9, a6, .Lz1		# if byte 1 is zero
76 	bnone	a9, a7, .Lz2		# if byte 2 is zero
77 	bnone	a9, a8, .Lz3		# if byte 3 is zero
83 EX(10f)	l32i	a9, a4, 4	# load 4 bytes for remaining checks
88 	bnone	a9, a5, .Lz0	# if byte 0 is zero
89 	bnone	a9, a6, .Lz1	# if byte 1 is zero
92 	# check one more byte (byte 2 of word)
101 # NOTE that in several places below, we point to the byte just after
102 # the zero byte in order to include the NULL terminator in the count.
104 .Lz3:	# byte 3 is zero
105 	addi	a4, a4, 3	# point to zero byte
106 .Lz0:	# byte 0 is zero
107 	addi	a4, a4, 1	# point just beyond zero byte
110 .Lz1:	# byte 1 is zero
111 	addi	a4, a4, 1+1	# point just beyond zero byte
114 .Lz2:	# byte 2 is zero
115 	addi	a4, a4, 2+1	# point just beyond zero byte
120 EX(10f)	l8ui	a9, a4, 4		# get byte 0
122 	beqz	a9, .Lz3		# if byte 0 is zero
123 	bbci.l	a4, 1, .Laligned	# if string pointer is now word-aligned
125 .L2mod4:	# address is 2 mod 4
128 	bnone	a9, a7, .Lz2	# if byte 2 (of word, not string) is zero
129 	bany	a9, a8, .Laligned # if byte 3 (of word, not string) is nonzero
130 	# byte 3 is zero
131 	addi	a4, a4, 3+1	# point just beyond zero byte
139 	.align	4