diff options
Diffstat (limited to 'kernel/arch/alpha/lib/strcat.S')
| -rw-r--r-- | kernel/arch/alpha/lib/strcat.S | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/kernel/arch/alpha/lib/strcat.S b/kernel/arch/alpha/lib/strcat.S new file mode 100644 index 000000000..393f50384 --- /dev/null +++ b/kernel/arch/alpha/lib/strcat.S @@ -0,0 +1,52 @@ +/* + * arch/alpha/lib/strcat.S + * Contributed by Richard Henderson (rth@tamu.edu) + * + * Append a null-terminated string from SRC to DST. + */ + + .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 |