projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 1da177e4 LT |
2 | /* |
| 3 | * arch/alpha/lib/strcat.S | |
| 4 | * Contributed by Richard Henderson (rth@tamu.edu) | |
| 5 | * | |
| 6 | * Append a null-terminated string from SRC to DST. | |
| 7 | */ | |
| 00fc0e0d | 8 | #include <asm/export.h> |
| 1da177e4 LT |
9 | |
| 10 | .text | |
| 11 | ||
| 12 | .align 3 | |
| 13 | .globl strcat | |
| 14 | .ent strcat | |
| 15 | strcat: | |
| 16 | .frame $30, 0, $26 | |
| 17 | .prologue 0 | |
| 18 | ||
| 19 | mov $16, $0 # set up return value | |
| 20 | ||
| 21 | /* Find the end of the string. */ | |
| 22 | ||
| 23 | ldq_u $1, 0($16) # load first quadword (a0 may be misaligned) | |
| 24 | lda $2, -1 | |
| 25 | insqh $2, $16, $2 | |
| 26 | andnot $16, 7, $16 | |
| 27 | or $2, $1, $1 | |
| 28 | cmpbge $31, $1, $2 # bits set iff byte == 0 | |
| 29 | bne $2, $found | |
| 30 | ||
| 31 | $loop: ldq $1, 8($16) | |
| 32 | addq $16, 8, $16 | |
| 33 | cmpbge $31, $1, $2 | |
| 34 | beq $2, $loop | |
| 35 | ||
| 36 | $found: negq $2, $3 # clear all but least set bit | |
| 37 | and $2, $3, $2 | |
| 38 | ||
| 39 | and $2, 0xf0, $3 # binary search for that set bit | |
| 40 | and $2, 0xcc, $4 | |
| 41 | and $2, 0xaa, $5 | |
| 42 | cmovne $3, 4, $3 | |
| 43 | cmovne $4, 2, $4 | |
| 44 | cmovne $5, 1, $5 | |
| 45 | addq $3, $4, $3 | |
| 46 | addq $16, $5, $16 | |
| 47 | addq $16, $3, $16 | |
| 48 | ||
| 49 | /* Now do the append. */ | |
| 50 | ||
| 51 | mov $26, $23 | |
| 52 | br __stxcpy | |
| 53 | ||
| 54 | .end strcat | |
| 00fc0e0d | 55 | EXPORT_SYMBOL(strcat); |