/* SPDX-License-Identifier: GPL-2.0 */
/*
 * arch/alpha/lib/strcat.S
 * Contributed by Richard Henderson (rth@tamu.edu)
 *
 * Append a null-terminated string from SRC to DST.
 */
#include <linux/export.h>

        .text

        .align 3
        .globl strcat
        .ent strcat
strcat:
        .frame $30, 0, $26
        .prologue 0

        mov     $16, $0         # set up return value

        /* Find the end of the string.  */

        ldq_u   $1, 0($16)      # load first quadword (a0 may be misaligned)
        lda     $2, -1
        insqh   $2, $16, $2
        andnot  $16, 7, $16
        or      $2, $1, $1
        cmpbge  $31, $1, $2     # bits set iff byte == 0
        bne     $2, $found

$loop:  ldq     $1, 8($16)
        addq    $16, 8, $16
        cmpbge  $31, $1, $2
        beq     $2, $loop

$found: negq    $2, $3          # clear all but least set bit
        and     $2, $3, $2

        and     $2, 0xf0, $3    # binary search for that set bit
        and     $2, 0xcc, $4
        and     $2, 0xaa, $5
        cmovne  $3, 4, $3
        cmovne  $4, 2, $4
        cmovne  $5, 1, $5
        addq    $3, $4, $3
        addq    $16, $5, $16
        addq    $16, $3, $16

        /* Now do the append.  */

        mov     $26, $23
        br      __stxcpy

        .end strcat
EXPORT_SYMBOL(strcat);