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Diffstat (limited to 'sysdeps/i386/strtok.S')
| -rw-r--r-- | sysdeps/i386/strtok.S | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/sysdeps/i386/strtok.S b/sysdeps/i386/strtok.S new file mode 100644 index 0000000000..28845e08cf --- /dev/null +++ b/sysdeps/i386/strtok.S @@ -0,0 +1,329 @@ +/* strtok (str, delim) -- Return next DELIM separated token from STR. +For Intel 80x86, x>=3. +Copyright (C) 1996 Free Software Foundation, Inc. +This file is part of the GNU C Library. +Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. + +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 <errnos.h> +#include <sysdep.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) + + strsep: + INPUT PARAMETERS + str_ptr (sp + 4) + delim (sp + 8) + + We do a common implementation here. */ + +#if !defined (USE_AS_STRTOK_R) && !defined (USE_AS_STRSEP) + .bss + .local save_ptr + ASM_TYPE_DIRECTIVE (save_ptr, @object) + .size save_ptr, 4 +save_ptr: + .space 4 + +#define FUNCTION strtok +#endif + + /* We use the possibility to do some more initialization + for the strtok implementation. */ + .text +Lillegal_argument: +#ifndef PIC + movl $EINVAL, C_SYMBOL_NAME(errno) + xorl %eax, %eax +#else +# if defined (USE_AS_STRTOK_R) || defined (USE_AS_STRSEP) + pushl %ebx /* Save PIC register. */ + call Lhere2 +Lhere2: popl %ebx + addl $_GLOBAL_OFFSET_TABLE_+[.-Lhere2], %ebx +# endif + movl errno@GOT(%ebx), %ebx + movl $EINVAL, (%ebx) + xorl %eax, %eax + popl %ebx +#endif + ret + + +ENTRY (FUNCTION) + + movl 4(%esp), %edx /* Get start of string. */ + movl 8(%esp), %eax /* Get start of delimiter set. */ + +#ifdef USE_AS_STRSEP + /* %EDX does not yet contain the string starting point. Only + a pointer to the location where it is stored. */ + movl (%edx), %edx +#else +# if !defined (USE_AS_STRTOK_R) && defined (PIC) + pushl %ebx /* Save PIC register. */ + call Lhere +Lhere: popl %ebx + addl $_GLOBAL_OFFSET_TABLE_+[.-Lhere], %ebx +# endif + + /* If the pointer is NULL we have to use the stored value of + the last run. */ + cmpl $0, %edx + jne L0 + +# ifdef USE_AS_STRTOK_R + /* The value is stored in the third argument. */ + movl 12(%esp), %edx + movl (%edx), %edx +# else + /* The value is in the local variable defined above. But + we have to take care for PIC code. */ +# ifndef PIC + movl save_ptr, %edx +# else + movl save_ptr@GOTOFF(%ebx), %edx +# endif +# endif +#endif + + /* Compare whether pointer is NULL. We are tolerant here + because the C function do the same. */ + cmpl $0, %edx + je Lillegal_argument + +#ifndef USE_AS_STRSEP +L0: +#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. The unrolled form is much faster than a loop. */ + xorl %ecx, %ecx /* %ecx = 0 !!! */ + + pushl %ecx /* make a 256 bytes long block filled with 0 */ + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl %ecx + pushl $0 /* These immediate values make the label 2 */ + pushl $0 /* to be aligned on a 16 byte boundary to */ + pushl $0 /* get a better performance of the loop. */ + pushl $0 + pushl $0 + pushl $0 + +/* 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. */ + +L2: movb (%eax), %cl /* get byte from stopset */ + testb %cl, %cl /* is NUL char? */ + jz L1 /* 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 L1 /* 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 L1 /* 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 L2 /* no => process next dword from stopset */ + +L1: 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 + But as a sign that the chracter is in the stopset we store its + value in the table. But the value of NUL is NUL so the loop + terminates for NUL in every case. */ + +L3: 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 L4 /* no => start of token */ + + movb 1(%eax), %cl /* get byte from string */ + testb %cl, (%esp,%ecx) /* is it contained in stopset? */ + jz L5 /* no => start of token */ + + movb 2(%eax), %cl /* get byte from string */ + testb %cl, (%esp,%ecx) /* is it contained in stopset? */ + jz L6 /* no => start of token */ + + movb 3(%eax), %cl /* get byte from string */ + testb %cl, (%esp,%ecx) /* is it contained in stopset? */ + jnz L3 /* yes => start of loop */ + + incl %eax /* adjust pointer */ +L6: incl %eax +L5: incl %eax + + /* Now we have to terminate the string. */ + +L4: leal -4(%eax), %edx /* We use %EDX for the next run. */ + +L7: 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 L8 /* yes => return */ + + movb 1(%edx), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */ + je L9 /* yes => return */ + + movb 2(%edx), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */ + je L10 /* yes => return */ + + movb 3(%edx), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */ + jne L7 /* no => start loop again */ + + incl %edx /* adjust pointer */ +L10: incl %edx +L9: incl %edx + +L8: /* Remove the stopset table. */ + addl $256, %esp + + cmpl %eax, %edx + je LreturnNULL /* There was no token anymore. */ + + movb $0, (%edx) /* Terminate string. */ + + /* Are we at end of string? */ + cmpb $0, %cl + je L11 + + incl %edx +L11: + + /* Store the pointer to the next character. */ +#ifdef USE_AS_STRTOK_R + movl 12(%esp), %ecx + movl %edx, (%ecx) +#elif USE_AS_STRSEP + movl 4(%esp), %ecx + movl %edx, (%ecx) +#else +# ifndef PIC + movl %edx, save_ptr +# else + movl %edx, save_ptr@GOTOFF(%ebx) + popl %ebx +# endif +#endif + ret + +LreturnNULL: + xorl %eax, %eax + + /* Store NULL as pointer to the next character. */ +#ifdef USE_AS_STRTOK_R + movl 12(%esp), %ecx + movl %eax, (%ecx) +#elif USE_AS_STRSEP + movl 4(%esp), %ecx + movl %eax, (%ecx) +#else +# ifndef PIC + movl %eax, save_ptr +# else + movl %eax, save_ptr@GOTOFF(%ebx) + popl %ebx +# endif +#endif + ret |