1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* 2 /*
3 * arch/alpha/lib/strcat.S 3 * arch/alpha/lib/strcat.S
4 * Contributed by Richard Henderson (rth@tamu. 4 * Contributed by Richard Henderson (rth@tamu.edu)
5 * 5 *
6 * Append a null-terminated string from SRC to 6 * Append a null-terminated string from SRC to DST.
7 */ 7 */
8 #include <linux/export.h> 8 #include <linux/export.h>
9 9
10 .text 10 .text
11 11
12 .align 3 12 .align 3
13 .globl strcat 13 .globl strcat
14 .ent strcat 14 .ent strcat
15 strcat: 15 strcat:
16 .frame $30, 0, $26 16 .frame $30, 0, $26
17 .prologue 0 17 .prologue 0
18 18
19 mov $16, $0 # set up retur 19 mov $16, $0 # set up return value
20 20
21 /* Find the end of the string. */ 21 /* Find the end of the string. */
22 22
23 ldq_u $1, 0($16) # load first q 23 ldq_u $1, 0($16) # load first quadword (a0 may be misaligned)
24 lda $2, -1 24 lda $2, -1
25 insqh $2, $16, $2 25 insqh $2, $16, $2
26 andnot $16, 7, $16 26 andnot $16, 7, $16
27 or $2, $1, $1 27 or $2, $1, $1
28 cmpbge $31, $1, $2 # bits set iff 28 cmpbge $31, $1, $2 # bits set iff byte == 0
29 bne $2, $found 29 bne $2, $found
30 30
31 $loop: ldq $1, 8($16) 31 $loop: ldq $1, 8($16)
32 addq $16, 8, $16 32 addq $16, 8, $16
33 cmpbge $31, $1, $2 33 cmpbge $31, $1, $2
34 beq $2, $loop 34 beq $2, $loop
35 35
36 $found: negq $2, $3 # clear all bu 36 $found: negq $2, $3 # clear all but least set bit
37 and $2, $3, $2 37 and $2, $3, $2
38 38
39 and $2, 0xf0, $3 # binary searc 39 and $2, 0xf0, $3 # binary search for that set bit
40 and $2, 0xcc, $4 40 and $2, 0xcc, $4
41 and $2, 0xaa, $5 41 and $2, 0xaa, $5
42 cmovne $3, 4, $3 42 cmovne $3, 4, $3
43 cmovne $4, 2, $4 43 cmovne $4, 2, $4
44 cmovne $5, 1, $5 44 cmovne $5, 1, $5
45 addq $3, $4, $3 45 addq $3, $4, $3
46 addq $16, $5, $16 46 addq $16, $5, $16
47 addq $16, $3, $16 47 addq $16, $3, $16
48 48
49 /* Now do the append. */ 49 /* Now do the append. */
50 50
51 mov $26, $23 51 mov $26, $23
52 br __stxcpy 52 br __stxcpy
53 53
54 .end strcat 54 .end strcat
55 EXPORT_SYMBOL(strcat); 55 EXPORT_SYMBOL(strcat);
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