From 2b8cac814cd5a0a305d62dcd1d589faccb705a4d Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 21 Mar 2013 16:23:43 +0000 Subject: arm64: klib: Optimised string functions This patch introduces AArch64-specific string functions (strchr, strrchr). Signed-off-by: Catalin Marinas --- arch/arm64/lib/strchr.S | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 arch/arm64/lib/strchr.S (limited to 'arch/arm64/lib/strchr.S') diff --git a/arch/arm64/lib/strchr.S b/arch/arm64/lib/strchr.S new file mode 100644 index 00000000000..dae0cf5591f --- /dev/null +++ b/arch/arm64/lib/strchr.S @@ -0,0 +1,42 @@ +/* + * 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 . + */ + +#include +#include + +/* + * 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) -- cgit v1.2.3