/* Optimized version of the standard strchr() 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 address of the first occurence of chr in str or NULL Inputs: in0: str in1: chr A modified version of memchr.S, the search ends when the character is found or the terminating null character is encountered. This implementation assumes little endian mode. For big endian mode, the instruction czx1.r should be replaced by czx1.l. */ #include "sysdep.h" #undef ret #define saved_lc r18 #define poschr r19 #define pos0 r20 #define val1 r21 #define val2 r22 #define tmp r24 #define chrx8 r25 #define loopcnt r30 #define str in0 #define chr in1 ENTRY(strchr) .prologue alloc r2 = ar.pfs, 2, 0, 0, 0 .save ar.lc, saved_lc mov saved_lc = ar.lc // save the loop counter .body mov ret0 = str and tmp = 7, str // tmp = str % 8 mux1 chrx8 = chr, @brcst extr.u chr = chr, 0, 8 // retain only the last byte cmp.ne p8, p0 = r0, r0 // clear p8 ;; sub loopcnt = 8, tmp // loopcnt = 8 - tmp cmp.eq p6, p0 = tmp, r0 (p6) br.cond.sptk .str_aligned;; adds loopcnt = -1, loopcnt;; mov ar.lc = loopcnt .l1: ld1 val2 = [ret0], 1 ;; cmp.eq p6, p0 = val2, chr cmp.eq p7, p0 = val2, r0 (p6) br.cond.spnt .restore_and_exit (p7) br.cond.spnt .notfound br.cloop.sptk .l1 .str_aligned: ld8 val1 = [ret0], 8;; nop.b 0 nop.b 0 .l2: ld8.s val2 = [ret0], 8 // don't bomb out here czx1.r pos0 = val1 xor tmp = val1, chrx8 // if val1 contains chr, tmp will ;; // contain a zero in its position czx1.r poschr = tmp cmp.ne p6, p0 = 8, pos0 ;; cmp.ne p7, p0 = 8, poschr (p7) br.cond.spnt .foundit (p6) br.cond.spnt .notfound chk.s val2, .recovery .back: mov val1 = val2 br.cond.dptk .l2 .foundit: (p6) cmp.lt p8, p0 = pos0, poschr // we found chr and null in the word (p8) br.cond.spnt .notfound // null was found before chr add ret0 = ret0, poschr ;; adds ret0 = -15, ret0 ;; // should be -16, but we decrement .restore_and_exit: // ret0 in the next instruction adds ret0 = -1, ret0 // ret0 was pointing 1 char too far mov ar.lc = saved_lc // restore the loop counter br.ret.sptk.many b0 .notfound: mov ret0 = r0 // return NULL if null was found mov ar.lc = saved_lc br.ret.sptk.many b0 .recovery: adds ret0 = -8, ret0;; ld8 val2 = [ret0], 8 // bomb out here br.cond.sptk .back END(strchr) weak_alias (strchr, index) libc_hidden_def (strchr)