projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| d5efd131 MF |
1 | /* Optimized version of the standard strncmp() function. |
| 2 | This file is part of the GNU C Library. | |
| 04277e02 | 3 | Copyright (C) 2000-2019 Free Software Foundation, Inc. |
| d5efd131 MF |
4 | Contributed by Dan Pop <Dan.Pop@cern.ch>. |
| 5 | ||
| 6 | The GNU C Library is free software; you can redistribute it and/or | |
| 7 | modify it under the terms of the GNU Lesser General Public | |
| 8 | License as published by the Free Software Foundation; either | |
| 9 | version 2.1 of the License, or (at your option) any later version. | |
| 10 | ||
| 11 | The GNU C Library is distributed in the hope that it will be useful, | |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 14 | Lesser General Public License for more details. | |
| 15 | ||
| 16 | You should have received a copy of the GNU Lesser General Public | |
| 75efb018 | 17 | License along with the GNU C Library; if not, see |
| 5a82c748 | 18 | <https://www.gnu.org/licenses/>. */ |
| d5efd131 MF |
19 | |
| 20 | /* Return: the result of the comparison | |
| 21 | ||
| 22 | Inputs: | |
| 23 | in0: s1 | |
| 24 | in1: s2 | |
| c70a4b1d | 25 | in2: n |
| d5efd131 MF |
26 | |
| 27 | Unlike memcmp(), this function is optimized for mismatches within the | |
| 28 | first few characters. */ | |
| 29 | ||
| 30 | #include <sysdep.h> | |
| 31 | #undef ret | |
| 32 | ||
| 33 | #define s1 in0 | |
| 34 | #define s2 in1 | |
| 35 | #define n in2 | |
| 36 | ||
| 37 | #define val1 r15 | |
| 38 | #define val2 r16 | |
| 39 | ||
| 40 | ||
| 41 | ENTRY(strncmp) | |
| 42 | alloc r2 = ar.pfs, 3, 0, 0, 0 | |
| 43 | mov ret0 = r0 | |
| 44 | cmp.eq p6, p0 = r0, r0 // set p6 | |
| 45 | cmp.eq p7, p0 = n, r0 // return immediately if n == 0 | |
| 46 | (p7) br.cond.spnt .restore_and_exit ;; | |
| 47 | .loop: | |
| 48 | ld1 val1 = [s1], 1 | |
| 49 | ld1 val2 = [s2], 1 | |
| 50 | adds n = -1, n // n-- | |
| 51 | ;; | |
| 52 | cmp.ne.and p6, p0 = val1, r0 | |
| 53 | cmp.ne.and p6, p0 = val2, r0 | |
| 54 | cmp.ne.and p6, p0 = n, r0 | |
| 55 | cmp.eq.and p6, p0 = val1, val2 | |
| 56 | (p6) br.cond.sptk .loop | |
| 57 | sub ret0 = val1, val2 | |
| 58 | .restore_and_exit: | |
| 59 | br.ret.sptk.many b0 | |
| 0347518d | 60 | END(strncmp) |
| d5efd131 | 61 | libc_hidden_builtin_def (strncmp) |