From 58ec4fb881719d0b69989f9a4955290fca531831 Mon Sep 17 00:00:00 2001 From: Wilco Dijkstra Date: Mon, 20 Jun 2016 17:48:20 +0100 Subject: Add a simple rawmemchr implementation. Use strlen for rawmemchr(s, '\0') as it is the fastest way to search for '\0'. Otherwise use memchr with an infinite size. This is 3x faster on benchtests for large sizes. Passes GLIBC tests. * sysdeps/aarch64/rawmemchr.S (__rawmemchr): New file. * sysdeps/aarch64/strlen.S (__strlen): Change to __strlen to avoid PLT. --- ChangeLog | 5 +++++ sysdeps/aarch64/rawmemchr.S | 42 ++++++++++++++++++++++++++++++++++++++++++ sysdeps/aarch64/strlen.S | 5 +++-- 3 files changed, 50 insertions(+), 2 deletions(-) create mode 100644 sysdeps/aarch64/rawmemchr.S diff --git a/ChangeLog b/ChangeLog index a9cedf0cb9..4ed597bd76 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2016-06-20 Wilco Dijkstra + + * sysdeps/aarch64/rawmemchr.S (__rawmemchr): New file. + * sysdeps/aarch64/strlen.S (__strlen): Change to __strlen to avoid PLT. + 2016-06-20 Wilco Dijkstra * sysdeps/aarch64/memcpy.S (memcpy): diff --git a/sysdeps/aarch64/rawmemchr.S b/sysdeps/aarch64/rawmemchr.S new file mode 100644 index 0000000000..ec958e8f54 --- /dev/null +++ b/sysdeps/aarch64/rawmemchr.S @@ -0,0 +1,42 @@ +/* rawmemchr - find a character in a memory zone + + Copyright (C) 2015 Free Software Foundation, Inc. + + This file is part of the GNU C Library. + + 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, see + . */ + +#include + +/* Special case rawmemchr (s, 0) as strlen, otherwise tailcall memchr. + Call strlen without setting up a full frame - it preserves x14/x15. +*/ + +ENTRY (__rawmemchr) + cbz w1, L(do_strlen) + mov x2, -1 + b __memchr + +L(do_strlen): + mov x15, x30 + cfi_return_column (x15) + mov x14, x0 + bl __strlen + add x0, x14, x0 + ret x15 + +END (__rawmemchr) +weak_alias (__rawmemchr, rawmemchr) +libc_hidden_builtin_def (__rawmemchr) diff --git a/sysdeps/aarch64/strlen.S b/sysdeps/aarch64/strlen.S index 9b4d1da60c..a07834bf96 100644 --- a/sysdeps/aarch64/strlen.S +++ b/sysdeps/aarch64/strlen.S @@ -84,7 +84,7 @@ whether the first fetch, which may be misaligned, crosses a page boundary. */ -ENTRY_ALIGN (strlen, 6) +ENTRY_ALIGN (__strlen, 6) and tmp1, srcin, MIN_PAGE_SIZE - 1 mov zeroones, REP8_01 cmp tmp1, MIN_PAGE_SIZE - 16 @@ -213,5 +213,6 @@ L(page_cross): csel data1, data1, tmp4, eq csel data2, data2, tmp2, eq b L(page_cross_entry) -END (strlen) +END (__strlen) +weak_alias (__strlen, strlen) libc_hidden_builtin_def (strlen) -- cgit 1.4.1