| /* Copyright (C) 1996-2016 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Richard Henderson <rth@tamu.edu>, 1996. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* Append no more than COUNT characters from the null-terminated string SRC |
| to the null-terminated string DST. Always null-terminate the new DST. */ |
| |
| #include <sysdep.h> |
| |
| .text |
| |
| ENTRY(strncat) |
| ldgp gp, 0(pv) |
| #ifdef PROF |
| .set noat |
| lda AT, _mcount |
| jsr AT, (AT), _mcount |
| .set at |
| #endif |
| .prologue 1 |
| |
| mov a0, v0 # set up return value |
| beq a2, $zerocount |
| |
| /* Find the end of the string. */ |
| |
| ldq_u t0, 0(a0) # load first quadword (a0 may be misaligned) |
| lda t1, -1(zero) |
| insqh t1, a0, t1 |
| andnot a0, 7, a0 |
| or t1, t0, t0 |
| cmpbge zero, t0, t1 # t1 <- bitmask: bit i == 1 <==> i-th byte == 0 |
| bne t1, $found |
| |
| $loop: ldq t0, 8(a0) |
| addq a0, 8, a0 # addr += 8 |
| cmpbge zero, t0, t1 |
| beq t1, $loop |
| |
| $found: negq t1, t2 # clear all but least set bit |
| and t1, t2, t1 |
| |
| and t1, 0xf0, t2 # binary search for that set bit |
| and t1, 0xcc, t3 |
| and t1, 0xaa, t4 |
| cmovne t2, 4, t2 |
| cmovne t3, 2, t3 |
| cmovne t4, 1, t4 |
| addq t2, t3, t2 |
| addq a0, t4, a0 |
| addq a0, t2, a0 |
| |
| /* Now do the append. */ |
| |
| jsr t9, __stxncpy |
| |
| /* Worry about the null termination. */ |
| |
| zapnot t0, t8, t1 # was last byte a null? |
| bne t1, 0f |
| ret |
| |
| 0: and t10, 0x80, t1 |
| bne t1, 1f |
| |
| /* Here there are bytes left in the current word. Clear one. */ |
| addq t10, t10, t10 # end-of-count bit <<= 1 |
| zap t0, t10, t0 |
| stq_u t0, 0(a0) |
| ret |
| |
| 1: /* Here we must read the next DST word and clear the first byte. */ |
| ldq_u t0, 8(a0) |
| zap t0, 1, t0 |
| stq_u t0, 8(a0) |
| |
| $zerocount: |
| ret |
| |
| END(strncat) |