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