projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| dff8da6b | 1 | /* Copyright (C) 1996-2024 Free Software Foundation, Inc. |
| 3c7b2587 | 2 | This file is part of the GNU C Library. |
| cf182b58 | 3 | |
| 3c7b2587 | 4 | The GNU C Library is free software; you can redistribute it and/or |
| 3214b89b AJ |
5 | modify it under the terms of the GNU Lesser General Public |
| 6 | License as published by the Free Software Foundation; either | |
| 7 | version 2.1 of the License, or (at your option) any later version. | |
| cf182b58 | 8 | |
| 3c7b2587 UD |
9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 3214b89b | 12 | Lesser General Public License for more details. |
| cf182b58 | 13 | |
| 3214b89b | 14 | You should have received a copy of the GNU Lesser General Public |
| ab84e3ff | 15 | License along with the GNU C Library. If not, see |
| 5a82c748 | 16 | <https://www.gnu.org/licenses/>. */ |
| cf182b58 UD |
17 | |
| 18 | /* Append no more than COUNT characters from the null-terminated string SRC | |
| 19 | to the null-terminated string DST. Always null-terminate the new DST. */ | |
| 20 | ||
| 21 | #include <sysdep.h> | |
| 22 | ||
| 23 | .text | |
| 24 | ||
| 25 | ENTRY(strncat) | |
| 26 | ldgp gp, 0(pv) | |
| 60c74cf0 | 27 | #ifdef PROF |
| 3c7b2587 | 28 | .set noat |
| 60c74cf0 UD |
29 | lda AT, _mcount |
| 30 | jsr AT, (AT), _mcount | |
| 3c7b2587 | 31 | .set at |
| 60c74cf0 | 32 | #endif |
| cf182b58 UD |
33 | .prologue 1 |
| 34 | ||
| 35 | mov a0, v0 # set up return value | |
| 36 | beq a2, $zerocount | |
| 37 | ||
| 38 | /* Find the end of the string. */ | |
| 39 | ||
| 40 | ldq_u t0, 0(a0) # load first quadword (a0 may be misaligned) | |
| 41 | lda t1, -1(zero) | |
| 42 | insqh t1, a0, t1 | |
| 43 | andnot a0, 7, a0 | |
| 44 | or t1, t0, t0 | |
| 45 | cmpbge zero, t0, t1 # t1 <- bitmask: bit i == 1 <==> i-th byte == 0 | |
| 46 | bne t1, $found | |
| 47 | ||
| 48 | $loop: ldq t0, 8(a0) | |
| 49 | addq a0, 8, a0 # addr += 8 | |
| 50 | cmpbge zero, t0, t1 | |
| 51 | beq t1, $loop | |
| 52 | ||
| 53 | $found: negq t1, t2 # clear all but least set bit | |
| 54 | and t1, t2, t1 | |
| 55 | ||
| 56 | and t1, 0xf0, t2 # binary search for that set bit | |
| 57 | and t1, 0xcc, t3 | |
| 58 | and t1, 0xaa, t4 | |
| 59 | cmovne t2, 4, t2 | |
| 60 | cmovne t3, 2, t3 | |
| 61 | cmovne t4, 1, t4 | |
| 62 | addq t2, t3, t2 | |
| 63 | addq a0, t4, a0 | |
| 64 | addq a0, t2, a0 | |
| 65 | ||
| 66 | /* Now do the append. */ | |
| 67 | ||
| 68 | jsr t9, __stxncpy | |
| 69 | ||
| 70 | /* Worry about the null termination. */ | |
| 71 | ||
| 72 | zapnot t0, t8, t1 # was last byte a null? | |
| 73 | bne t1, 0f | |
| 74 | ret | |
| 75 | ||
| 76 | 0: and t10, 0x80, t1 | |
| 77 | bne t1, 1f | |
| 78 | ||
| 79 | /* Here there are bytes left in the current word. Clear one. */ | |
| 80 | addq t10, t10, t10 # end-of-count bit <<= 1 | |
| 81 | zap t0, t10, t0 | |
| 82 | stq_u t0, 0(a0) | |
| 83 | ret | |
| 84 | ||
| 85 | 1: /* Here we must read the next DST word and clear the first byte. */ | |
| 86 | ldq_u t0, 8(a0) | |
| 87 | zap t0, 1, t0 | |
| 88 | stq_u t0, 8(a0) | |
| 89 | ||
| 90 | $zerocount: | |
| 91 | ret | |
| 92 | ||
| 93 | END(strncat) |