| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Copyright (C) 1996-2016 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | Contributed by Richard Henderson <rth@tamu.edu>, 1996. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library. If not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | /* Append a null-terminated string from SRC to DST. */ |
| 20 | |
| 21 | #include <sysdep.h> |
| 22 | |
| 23 | .text |
| 24 | |
| 25 | ENTRY(strcat) |
| 26 | ldgp gp, 0(pv) |
| 27 | #ifdef PROF |
| 28 | .set noat |
| 29 | lda AT, _mcount |
| 30 | jsr AT, (AT), _mcount |
| 31 | .set at |
| 32 | #endif |
| 33 | .prologue 1 |
| 34 | |
| 35 | mov a0, v0 # set up return value |
| 36 | |
| 37 | /* Find the end of the string. */ |
| 38 | |
| 39 | ldq_u t0, 0(a0) # load first quadword (a0 may be misaligned) |
| 40 | lda t1, -1(zero) |
| 41 | insqh t1, a0, t1 |
| 42 | andnot a0, 7, a0 |
| 43 | or t1, t0, t0 |
| 44 | cmpbge zero, t0, t1 # t1 <- bitmask: bit i == 1 <==> i-th byte == 0 |
| 45 | bne t1, $found |
| 46 | |
| 47 | $loop: ldq t0, 8(a0) |
| 48 | addq a0, 8, a0 # addr += 8 |
| 49 | cmpbge zero, t0, t1 |
| 50 | beq t1, $loop |
| 51 | |
| 52 | $found: negq t1, t2 # clear all but least set bit |
| 53 | and t1, t2, t1 |
| 54 | |
| 55 | and t1, 0xf0, t2 # binary search for that set bit |
| 56 | and t1, 0xcc, t3 |
| 57 | and t1, 0xaa, t4 |
| 58 | cmovne t2, 4, t2 |
| 59 | cmovne t3, 2, t3 |
| 60 | cmovne t4, 1, t4 |
| 61 | addq t2, t3, t2 |
| 62 | addq a0, t4, a0 |
| 63 | addq a0, t2, a0 |
| 64 | |
| 65 | /* Now do the append. */ |
| 66 | |
| 67 | mov ra, t9 |
| 68 | jmp $31, __stxcpy |
| 69 | |
| 70 | END(strcat) |
| 71 | libc_hidden_builtin_def (strcat) |