From ee4435bcd6f94b7463cbd7e960e84ddf03965272 Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Thu, 20 Nov 2003 15:23:03 +0000 Subject: Add an initial set of arm optimized string functions. These do seem to make noticable speed improvement... -Erik --- libc/string/arm/memset.S | 72 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 libc/string/arm/memset.S (limited to 'libc/string/arm/memset.S') diff --git a/libc/string/arm/memset.S b/libc/string/arm/memset.S new file mode 100644 index 000000000..07d3913f9 --- /dev/null +++ b/libc/string/arm/memset.S @@ -0,0 +1,72 @@ +/* Copyright (C) 1998 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Philip Blundell + + 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. */ + +#include + + .text + .global memset; + .type memset,%function + .align 4; \ + +memset: + mov a4, a1 + cmp a3, $8 @ at least 8 bytes to do? + blt 2f + orr a2, a2, a2, lsl $8 + orr a2, a2, a2, lsl $16 +1: + tst a4, $3 @ aligned yet? + strneb a2, [a4], $1 + subne a3, a3, $1 + bne 1b + mov ip, a2 +1: + cmp a3, $8 @ 8 bytes still to do? + blt 2f + stmia a4!, {a2, ip} + sub a3, a3, $8 + cmp a3, $8 @ 8 bytes still to do? + blt 2f + stmia a4!, {a2, ip} + sub a3, a3, $8 + cmp a3, $8 @ 8 bytes still to do? + blt 2f + stmia a4!, {a2, ip} + sub a3, a3, $8 + cmp a3, $8 @ 8 bytes still to do? + stmgeia a4!, {a2, ip} + subge a3, a3, $8 + bge 1b +2: + movs a3, a3 @ anything left? + moveq pc, lr @ nope + rsb a3, a3, $7 + add pc, pc, a3, lsl $2 + mov r0, r0 + strb a2, [a4], $1 + strb a2, [a4], $1 + strb a2, [a4], $1 + strb a2, [a4], $1 + strb a2, [a4], $1 + strb a2, [a4], $1 + strb a2, [a4], $1 + mov pc, lr + +.size memset,.-memset; + -- cgit v1.2.3