Lines Matching +full:non +full:- +full:zero

1 /* SPDX-License-Identifier: GPL-2.0-only */
3  * Copyright (c) 2013-2021, Arm Limited.
6  * https://github.com/ARM-software/optimized-routines/blob/e823e3abf5f89ecb/string/aarch64/strncmp.S
14  * ARMv8-a, AArch64
55 	/* Calculate the number of full and partial words -1.  */
59 	/* NUL detection works on the principle that (X - 1) & (~X) & 0x80
60 	   (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and
70 	eor	diff, data1, data2	/* Non-zero if differences found.  */
72 	bics	has_nul, tmp1, tmp2	/* Non-zero if NUL terminator.  */
84 	lsl	limit, limit, #3	/* Bits -> bytes.  */
103 	/* The MS-non-zero bit of the syndrome marks either the first bit
104 	   that is different, or the top bit of the first zero byte.
111 	/* But we need to zero-extend (char is unsigned) the value and then
112 	   perform a signed 32-bit subtraction.  */
117 	/* For big-endian we cannot use the trick with the syndrome value
118 	   as carry-propagation can corrupt the upper bits if the trailing
129 	/* Re-compute the NUL-byte detection, using a byte-reversed value.  */
137 	/* The MS-non-zero bit of the syndrome marks either the first bit
138 	   that is different, or the top bit of the first zero byte.
143 	/* But we need to zero-extend (char is unsigned) the value and then
144 	   perform a signed 32-bit subtraction.  */
159 	neg	tmp3, count, lsl #3	/* 64 - bits(bytes beyond align). */
164 	/* Big-endian.  Early bytes are at MSB.  */
167 	/* Little-endian.  Early bytes are at LSB.  */
233 	eor	diff, data1, data2	/* Non-zero if differences found.  */
234 	bics	has_nul, tmp1, tmp2	/* Non-zero if NUL terminator.  */
251 	eor	diff, data1, data2	/* Non-zero if differences found.  */
252 	bics	has_nul, tmp1, tmp2	/* Non-zero if NUL terminator.  */