/* Optimized version of the standard strncmp() function. This file is part of the GNU C Library. Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc. Contributed by Dan Pop <Dan.Pop@cern.ch>. 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ /* Return: the result of the comparison Inputs: in0: s1 in1: s2 in2: n Unlike memcmp(), this function is optimized for mismatches within the first few characters. */ #include "sysdep.h" #undef ret #define s1 in0 #define s2 in1 #define n in2 #define val1 r15 #define val2 r16 ENTRY(strncmp) alloc r2 = ar.pfs, 3, 0, 0, 0 mov ret0 = r0 cmp.eq p6, p0 = r0, r0 // set p6 cmp.eq p7, p0 = n, r0 // return immediately if n == 0 (p7) br.cond.spnt .restore_and_exit ;; .loop: ld1 val1 = [s1], 1 ld1 val2 = [s2], 1 adds n = -1, n // n-- ;; cmp.ne.and p6, p0 = val1, r0 cmp.ne.and p6, p0 = val2, r0 cmp.ne.and p6, p0 = n, r0 cmp.eq.and p6, p0 = val1, val2 (p6) br.cond.sptk .loop sub ret0 = val1, val2 .restore_and_exit: br.ret.sptk.many b0 END(strncmp) libc_hidden_def (strncmp)