/* * Based on arch/arm/lib/strchr.S * * Copyright (C) 1995-2000 Russell King * Copyright (C) 2013 ARM Ltd. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <linux/linkage.h> #include <asm/assembler.h> /* * Find the first occurrence of a character in a string. * * Parameters: * x0 - str * x1 - c * Returns: * x0 - address of first occurrence of 'c' or 0 */ ENTRY(strchr) and w1, w1, #0xff 1: ldrb w2, [x0], #1 cmp w2, w1 ccmp w2, wzr, #4, ne b.ne 1b sub x0, x0, #1 cmp w2, w1 csel x0, x0, xzr, eq ret ENDPROC(strchr)