From 7dd438230613f3a29babf22543ee9ed89b8828d1 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sat, 20 Dec 2008 14:34:19 +0000 Subject: libc/string/i386/rawmemchr.c: i386 version, adapted from strlen() libc/string/i386/strlen.c: small optimization, same code size) text data bss dec hex filename - 240449 1759 11960 254168 3e0d8 lib/libuClibc-0.9.30-svn.so + 240339 1759 11960 254058 3e06a lib/libuClibc-0.9.30-svn.so --- libc/string/i386/rawmemchr.c | 24 ++++++++++++++++++++++++ libc/string/i386/strlen.c | 18 +++++++++--------- 2 files changed, 33 insertions(+), 9 deletions(-) create mode 100644 libc/string/i386/rawmemchr.c (limited to 'libc/string/i386') diff --git a/libc/string/i386/rawmemchr.c b/libc/string/i386/rawmemchr.c new file mode 100644 index 000000000..be0b142c3 --- /dev/null +++ b/libc/string/i386/rawmemchr.c @@ -0,0 +1,24 @@ +/* + * Adapted from strlen.c code + * + * Copyright (C) 2008 Denys Vlasenko + * + * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball. + */ + +#include + +#undef rawmemchr +void *rawmemchr(const void *s, int c) +{ + void *eax; + int ecx, edi; + __asm__ __volatile__( + " repne; scasb\n" + " leal -1(%%edi), %%eax\n" + : "=&c" (ecx), "=&D" (edi), "=&a" (eax) + : "0" (0xffffffff), "1" (s), "2" (c) + ); + return eax; +} +libc_hidden_def(rawmemchr) diff --git a/libc/string/i386/strlen.c b/libc/string/i386/strlen.c index 761d27aae..ff2baeb38 100644 --- a/libc/string/i386/strlen.c +++ b/libc/string/i386/strlen.c @@ -35,14 +35,14 @@ #undef strlen size_t strlen(const char *s) { - int d0; - register int __res; - __asm__ __volatile__( - "repne\n\t" - "scasb\n\t" - "notl %0\n\t" - "decl %0" - :"=c" (__res), "=&D" (d0) :"1" (s),"a" (0), "0" (0xffffffff)); - return __res; + int eax, ecx, edi; + __asm__ __volatile__( + " repne; scasb\n" + " notl %%ecx\n" + " leal -1(%%ecx), %%eax\n" + : "=&c" (ecx), "=&D" (edi), "=&a" (eax) + : "0" (0xffffffff), "1" (s), "2" (0) + ); + return eax; } libc_hidden_def(strlen) -- cgit v1.2.3