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/ev67-strcat.S
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  * 21264 version contributed by Rick Gorton <rick.gorton@alpha-processor.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  * Append a null-terminated string from SRC to DST.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * Much of the information about 21264 scheduling/coding comes from:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  *	Compiler Writer's Guide for the Alpha 21264
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  *	abbreviated as 'CWG' in other comments here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  *	ftp.digital.com/pub/Digital/info/semiconductor/literature/dsc-library.html
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  * Scheduling notation:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  *	E	- either cluster
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  *	U	- upper subcluster; U0 - subcluster U0; U1 - subcluster U1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  *	L	- lower subcluster; L0 - subcluster L0; L1 - subcluster L1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  * Try not to change the actual algorithm if possible for consistency.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)  * Commentary: It seems bogus to walk the input string twice - once
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)  * to determine the length, and then again while doing the copy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)  * A significant (future) enhancement would be to only read the input
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)  * string once.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <asm/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	.text
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	.align 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	.globl strcat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	.ent strcat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) strcat:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	.frame $30, 0, $26
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	.prologue 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	mov	$16, $0		# E : set up return value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	/* Find the end of the string.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	ldq_u   $1, 0($16)	# L : load first quadword (a0 may be misaligned)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	lda     $2, -1		# E :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	insqh   $2, $16, $2	# U :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	andnot  $16, 7, $16	# E :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	or      $2, $1, $1	# E :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	cmpbge  $31, $1, $2	# E : bits set iff byte == 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	bne     $2, $found	# U :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) $loop:	ldq     $1, 8($16)	# L :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	addq    $16, 8, $16	# E :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	cmpbge  $31, $1, $2	# E :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	beq     $2, $loop	# U :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) $found:	cttz	$2, $3		# U0 :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 	addq	$16, $3, $16	# E :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	/* Now do the append.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 	mov	$26, $23	# E :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 	br	__stxcpy	# L0 :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 	.end strcat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	EXPORT_SYMBOL(strcat)