1 /* SPDX-License-Identifier: GPL-2.0 */ 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 */ 8 #include <linux/export.h> 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 55 EXPORT_SYMBOL(strcat); 56