Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /* SPDX-License-Identifier: GPL-2.0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * arch/alpha/lib/strncat.S
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  * Contributed by Richard Henderson (rth@tamu.edu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  * Append no more than COUNT characters from the null-terminated string SRC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * to the null-terminated string DST.  Always null-terminate the new DST.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  * This differs slightly from the semantics in libc in that we never write
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  * past count, whereas libc may write to count+1.  This follows the generic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  * implementation in lib/string.c and is, IMHO, more sensible.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <asm/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 	.text
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 	.align 3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	.globl strncat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	.ent strncat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) strncat:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	.frame $30, 0, $26
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	.prologue 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	mov	$16, $0		# set up return value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	beq	$18, $zerocount
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	/* Find the end of the string.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	ldq_u   $1, 0($16)	# load first quadword ($16 may be misaligned)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	lda     $2, -1($31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	insqh   $2, $16, $2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	andnot  $16, 7, $16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	or      $2, $1, $1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	cmpbge  $31, $1, $2	# bits set iff byte == 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	bne     $2, $found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) $loop:	ldq     $1, 8($16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	addq    $16, 8, $16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	cmpbge  $31, $1, $2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	beq     $2, $loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) $found:	negq    $2, $3		# clear all but least set bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	and     $2, $3, $2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	and     $2, 0xf0, $3	# binary search for that set bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	and	$2, 0xcc, $4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	and	$2, 0xaa, $5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	cmovne	$3, 4, $3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	cmovne	$4, 2, $4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	cmovne	$5, 1, $5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 	addq	$3, $4, $3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	addq	$16, $5, $16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 	addq	$16, $3, $16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	/* Now do the append.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	bsr	$23, __stxncpy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 	/* Worry about the null termination.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 	zapnot	$1, $27, $2	# was last byte a null?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 	bne	$2, 0f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 0:	cmplt	$27, $24, $2	# did we fill the buffer completely?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 	or	$2, $18, $2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 	bne	$2, 2f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 	and	$24, 0x80, $2	# no zero next byte
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 	bne	$2, 1f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 	/* Here there are bytes left in the current word.  Clear one.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 	addq	$24, $24, $24	# end-of-count bit <<= 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 2:	zap	$1, $24, $1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 	stq_u	$1, 0($16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) 1:	/* Here we must read the next DST word and clear the first byte.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) 	ldq_u	$1, 8($16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) 	zap	$1, 1, $1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) 	stq_u	$1, 8($16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) $zerocount:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) 	.end strncat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) 	EXPORT_SYMBOL(strncat)