| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Optimized version of the standard strncmp() function. |
| 2 | This file is part of the GNU C Library. |
| 3 | Copyright (C) 2000-2016 Free Software Foundation, Inc. |
| 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 |
| 17 | License along with the GNU C Library; if not, see |
| 18 | <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | /* Return: the result of the comparison |
| 21 | |
| 22 | Inputs: |
| 23 | in0: s1 |
| 24 | in1: s2 |
| 25 | in2: n |
| 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 |
| 60 | END(strncmp) |
| 61 | libc_hidden_builtin_def (strncmp) |