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Diffstat (limited to 'sysdeps/i386/i686/strtok.S')
| -rw-r--r-- | sysdeps/i386/i686/strtok.S | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/sysdeps/i386/i686/strtok.S b/sysdeps/i386/i686/strtok.S new file mode 100644 index 0000000000..62d54c4e1a --- /dev/null +++ b/sysdeps/i386/i686/strtok.S @@ -0,0 +1,240 @@ +/* strtok (str, delim) -- Return next DELIM separated token from STR. + For Intel 80686. + Copyright (C) 1998 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <sysdep.h> +#include "asm-syntax.h" + +/* This file can be used for three variants of the strtok function: + + strtok: + INPUT PARAMETER: + str (sp + 4) + delim (sp + 8) + + strtok_r: + INPUT PARAMETER: + str (sp + 4) + delim (sp + 8) + save_ptr (sp + 12) + + We do a common implementation here. */ + +#ifndef USE_AS_STRTOK_R + .bss + .local save_ptr + ASM_TYPE_DIRECTIVE (save_ptr, @object) + .size save_ptr, 4 +save_ptr: + .space 4 + +#define FUNCTION strtok +#endif + + .text + +#if !defined USE_AS_STRTOK_R && defined PIC +0: movl (%esp), %ebx + ret +#endif + +ENTRY (FUNCTION) + +#if !defined USE_AS_STRTOK_R && defined PIC + pushl %ebx /* Save PIC register. */ + call 0b + addl $_GLOBAL_OFFSET_TABLE_, %ebx +#endif + + /* First we create a table with flags for all possible characters. + For the ASCII (7bit/8bit) or ISO-8859-X character sets which are + supported by the C string functions we have 256 characters. + Before inserting marks for the stop characters we clear the whole + table. */ + movl %edi, %edx + subl $256, %esp + movl $64, %ecx + movl %esp, %edi + xorl %eax, %eax + rep + stosl + + /* Note: %ecx = 0 !!! */ + movl %edx, %edi + +#if !defined USE_AS_STRTOK_R && defined PIC + movl 264(%esp), %edx /* Get start of string. */ +#else + movl 260(%esp), %edx /* Get start of string. */ +#endif + +#ifdef USE_AS_STRTOK_R + /* The value is stored in the third argument. */ + movl 268(%esp), %eax + movl (%eax), %eax +#else + /* The value is in the local variable defined above. But + we have to take care for PIC code. */ +# ifndef PIC + movl save_ptr, %eax +# else + movl save_ptr@GOTOFF(%ebx), %eax +# endif +#endif + + /* If the pointer is NULL we have to use the stored value of + the last run. */ + cmpl $0, %edx + cmove %eax, %edx + +#if !defined USE_AS_STRTOK_R && defined PIC + movl 268(%esp), %eax /* Get start of delimiter set. */ +#else + movl 264(%esp), %eax /* Get start of delimiter set. */ +#endif + +/* For understanding the following code remember that %ecx == 0 now. + Although all the following instruction only modify %cl we always + have a correct zero-extended 32-bit value in %ecx. */ + +L(2): movb (%eax), %cl /* get byte from stopset */ + testb %cl, %cl /* is NUL char? */ + jz L(1) /* yes => start compare loop */ + movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ + + movb 1(%eax), %cl /* get byte from stopset */ + testb $0xff, %cl /* is NUL char? */ + jz L(1) /* yes => start compare loop */ + movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ + + movb 2(%eax), %cl /* get byte from stopset */ + testb $0xff, %cl /* is NUL char? */ + jz L(1) /* yes => start compare loop */ + movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ + + movb 3(%eax), %cl /* get byte from stopset */ + addl $4, %eax /* increment stopset pointer */ + movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ + testb $0xff, %cl /* is NUL char? */ + jnz L(2) /* no => process next dword from stopset */ + +L(1): leal -4(%edx), %eax /* prepare loop */ + + /* We use a neat trick for the following loop. Normally we would + have to test for two termination conditions + 1. a character in the stopset was found + and + 2. the end of the string was found + As a sign that the character is in the stopset we store its + value in the table. The value of NUL is NUL so the loop + terminates for NUL in every case. */ + +L(3): addl $4, %eax /* adjust pointer for full loop round */ + + movb (%eax), %cl /* get byte from string */ + testb %cl, (%esp,%ecx) /* is it contained in stopset? */ + jz L(4) /* no => start of token */ + + movb 1(%eax), %cl /* get byte from string */ + testb %cl, (%esp,%ecx) /* is it contained in stopset? */ + jz L(5) /* no => start of token */ + + movb 2(%eax), %cl /* get byte from string */ + testb %cl, (%esp,%ecx) /* is it contained in stopset? */ + jz L(6) /* no => start of token */ + + movb 3(%eax), %cl /* get byte from string */ + testb %cl, (%esp,%ecx) /* is it contained in stopset? */ + jnz L(3) /* yes => start of loop */ + + incl %eax /* adjust pointer */ +L(6): incl %eax +L(5): incl %eax + + /* Now we have to terminate the string. */ + +L(4): leal -4(%eax), %edx /* We use %EDX for the next run. */ + +L(7): addl $4, %edx /* adjust pointer for full loop round */ + + movb (%edx), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */ + je L(8) /* yes => return */ + + movb 1(%edx), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */ + je L(9) /* yes => return */ + + movb 2(%edx), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */ + je L(10) /* yes => return */ + + movb 3(%edx), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */ + jne L(7) /* no => start loop again */ + + incl %edx /* adjust pointer */ +L(10): incl %edx +L(9): incl %edx + +L(8): /* Remove the stopset table. */ + addl $256, %esp + + cmpl %eax, %edx + je L(returnNULL) /* There was no token anymore. */ + + movb $0, (%edx) /* Terminate string. */ + + /* Are we at end of string? */ + cmpb $0, %cl + leal 1(%edx), %ecx + cmovne %ecx, %edx + + /* Store the pointer to the next character. */ +#ifdef USE_AS_STRTOK_R + movl 12(%esp), %ecx + movl %edx, (%ecx) +#else +# ifndef PIC + movl %edx, save_ptr +# else + movl %edx, save_ptr@GOTOFF(%ebx) + popl %ebx +# endif +#endif + ret + +L(returnNULL): + xorl %eax, %eax + + /* Store current pointer for next round. */ +#ifdef USE_AS_STRTOK_R + movl 12(%esp), %ecx + movl %edx, (%ecx) +#else +# ifndef PIC + movl %edx, save_ptr +# else + movl %edx, save_ptr@GOTOFF(%ebx) + popl %ebx +# endif +#endif + ret +END (FUNCTION) |