/* strtok (str, delim) -- Return next DELIM separated token from STR. For Intel 80x86, x>=3. Copyright (C) 1996-2017 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 1996. 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 #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. */ #ifdef USE_AS_STRTOK_R # define SAVE_PTR 0(%ecx) #else .bss .local save_ptr .type save_ptr, @object .size save_ptr, 4 save_ptr: .space 4 # ifdef PIC # define SAVE_PTR save_ptr@GOTOFF(%ebx) # else # define SAVE_PTR save_ptr # endif # define FUNCTION strtok #endif #define PARMS 4 /* no space for saved regs */ #define RTN PARMS #define STR RTN #define DELIM STR+4 #define SAVE DELIM+4 .text ENTRY (FUNCTION) movl STR(%esp), %edx movl DELIM(%esp), %eax #if !defined USE_AS_STRTOK_R && defined PIC pushl %ebx /* Save PIC register. */ cfi_adjust_cfa_offset (4) call L(here) cfi_adjust_cfa_offset (4) cfi_rel_offset (ebx, 0) L(here): popl %ebx cfi_adjust_cfa_offset (-4) addl $_GLOBAL_OFFSET_TABLE_+[.-L(here)], %ebx #endif /* If the pointer is NULL we have to use the stored value of the last run. */ cmpl $0, %edx jne L(1) #ifdef USE_AS_STRTOK_R /* The value is stored in the third argument. */ movl SAVE(%esp), %edx movl (%edx), %edx #else /* The value is in the local variable defined above. But we have to take care for PIC code. */ movl SAVE_PTR, %edx #endif testl %edx, %edx jz L(returnNULL) L(1): /* 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 */ cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl %ecx cfi_adjust_cfa_offset (4) pushl $0 /* These immediate values make the label 2 */ cfi_adjust_cfa_offset (4) pushl $0 /* to be aligned on a 16 byte boundary to */ cfi_adjust_cfa_offset (4) pushl $0 /* get a better performance of the loop. */ cfi_adjust_cfa_offset (4) pushl $0 cfi_adjust_cfa_offset (4) pushl $0 cfi_adjust_cfa_offset (4) pushl $0 cfi_adjust_cfa_offset (4) /* 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_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_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_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_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 cfi_adjust_cfa_offset (-256) 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 je L(11) incl %edx L(11): /* Store the pointer to the next character. */ #ifdef USE_AS_STRTOK_R movl SAVE(%esp), %ecx #endif movl %edx, SAVE_PTR L(epilogue): #if !defined USE_AS_STRTOK_R && defined PIC popl %ebx cfi_adjust_cfa_offset (-4) cfi_restore (ebx) #endif ret L(returnNULL): xorl %eax, %eax #ifdef USE_AS_STRTOK_R movl SAVE(%esp), %ecx #endif movl %edx, SAVE_PTR jmp L(epilogue) END (FUNCTION)