| /* strtok (str, delim) -- Return next DELIM separated token from STR. |
| For AMD x86-64. |
| Copyright (C) 1998,2000-2003,2005,2006 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Based on i686 version 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 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, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| #include <sysdep.h> |
| #include "asm-syntax.h" |
| #include "bp-sym.h" |
| #include "bp-asm.h" |
| |
| /* This file can be used for the strtok and strtok_r functions: |
| |
| strtok: |
| INPUT PARAMETER: |
| str %rdi |
| delim %rsi |
| |
| strtok_r: |
| INPUT PARAMETER: |
| str %rdi |
| delim %rsi |
| save_ptr %rdx |
| |
| We do a common implementation here. */ |
| |
| #ifdef USE_AS_STRTOK_R |
| # define SAVE_PTR (%r9) |
| #else |
| .bss |
| .local save_ptr |
| ASM_TYPE_DIRECTIVE (save_ptr, @object) |
| .size save_ptr, 8 |
| save_ptr: |
| .space 8 |
| |
| # ifdef PIC |
| # define SAVE_PTR save_ptr(%rip) |
| # else |
| # define SAVE_PTR save_ptr |
| # endif |
| |
| # define FUNCTION strtok |
| #endif |
| |
| .text |
| ENTRY (BP_SYM (FUNCTION)) |
| /* 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. */ |
| movq %rdi, %r8 /* Save value. */ |
| subq $256, %rsp /* Make space for 256 bytes. */ |
| cfi_adjust_cfa_offset(256) |
| movl $32, %ecx /* 32*8 bytes = 256 bytes. */ |
| movq %rsp, %rdi |
| xorl %eax, %eax /* We store 0s. */ |
| cld |
| rep |
| stosq |
| |
| /* Note: %rcx = 0 !!! */ |
| |
| #ifdef USE_AS_STRTOK_R |
| /* The value is stored in the third argument. */ |
| movq %rdx, %rax |
| movq %rdx, %r9 /* Save value - see def. of SAVE_PTR. */ |
| movq (%rax), %rax |
| #else |
| /* The value is in the local variable defined above. But |
| we have to take care for PIC code. */ |
| movq SAVE_PTR, %rax |
| #endif |
| movq %r8, %rdx /* Get start of string. */ |
| |
| /* If the pointer is NULL we have to use the stored value of |
| the last run. */ |
| cmpq $0, %rdx |
| cmove %rax, %rdx |
| testq %rdx, %rdx |
| jz L(returnNULL) |
| movq %rsi, %rax /* Get start of delimiter set. */ |
| |
| /* For understanding the following code remember that %rcx == 0 now. |
| Although all the following instruction only modify %cl we always |
| have a correct zero-extended 64-bit value in %rcx. */ |
| |
| L(2): movb (%rax), %cl /* get byte from stopset */ |
| testb %cl, %cl /* is NUL char? */ |
| jz L(1) /* yes => start compare loop */ |
| movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */ |
| |
| movb 1(%rax), %cl /* get byte from stopset */ |
| testb $0xff, %cl /* is NUL char? */ |
| jz L(1) /* yes => start compare loop */ |
| movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */ |
| |
| movb 2(%rax), %cl /* get byte from stopset */ |
| testb $0xff, %cl /* is NUL char? */ |
| jz L(1) /* yes => start compare loop */ |
| movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */ |
| |
| movb 3(%rax), %cl /* get byte from stopset */ |
| addq $4, %rax /* increment stopset pointer */ |
| movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */ |
| testb $0xff, %cl /* is NUL char? */ |
| jnz L(2) /* no => process next dword from stopset */ |
| |
| L(1): |
| |
| leaq -4(%rdx), %rax /* 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): addq $4, %rax /* adjust pointer for full loop round */ |
| |
| movb (%rax), %cl /* get byte from string */ |
| testb %cl, (%rsp,%rcx) /* is it contained in stopset? */ |
| jz L(4) /* no => start of token */ |
| |
| movb 1(%rax), %cl /* get byte from string */ |
| testb %cl, (%rsp,%rcx) /* is it contained in stopset? */ |
| jz L(5) /* no => start of token */ |
| |
| movb 2(%rax), %cl /* get byte from string */ |
| testb %cl, (%rsp,%rcx) /* is it contained in stopset? */ |
| jz L(6) /* no => start of token */ |
| |
| movb 3(%rax), %cl /* get byte from string */ |
| testb %cl, (%rsp,%rcx) /* is it contained in stopset? */ |
| jnz L(3) /* yes => start of loop */ |
| |
| incq %rax /* adjust pointer */ |
| L(6): incq %rax |
| L(5): incq %rax |
| |
| /* Now we have to terminate the string. */ |
| |
| L(4): leaq -4(%rax), %rdx /* We use %rDX for the next run. */ |
| |
| L(7): addq $4, %rdx /* adjust pointer for full loop round */ |
| |
| movb (%rdx), %cl /* get byte from string */ |
| cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */ |
| je L(8) /* yes => return */ |
| |
| movb 1(%rdx), %cl /* get byte from string */ |
| cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */ |
| je L(9) /* yes => return */ |
| |
| movb 2(%rdx), %cl /* get byte from string */ |
| cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */ |
| je L(10) /* yes => return */ |
| |
| movb 3(%rdx), %cl /* get byte from string */ |
| cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */ |
| jne L(7) /* no => start loop again */ |
| |
| incq %rdx /* adjust pointer */ |
| L(10): incq %rdx |
| L(9): incq %rdx |
| |
| L(8): cmpq %rax, %rdx |
| je L(returnNULL) /* There was no token anymore. */ |
| |
| movb $0, (%rdx) /* Terminate string. */ |
| |
| /* Are we at end of string? */ |
| cmpb $0, %cl |
| leaq 1(%rdx), %rcx |
| cmovne %rcx, %rdx |
| |
| /* Store the pointer to the next character. */ |
| movq %rdx, SAVE_PTR |
| |
| L(epilogue): |
| /* Remove the stopset table. */ |
| addq $256, %rsp |
| cfi_adjust_cfa_offset(-256) |
| retq |
| |
| L(returnNULL): |
| xorl %eax, %eax |
| /* Store the pointer to the next character. */ |
| movq %rdx, SAVE_PTR |
| jmp L(epilogue) |
| |
| END (BP_SYM (FUNCTION)) |
