diff options
Diffstat (limited to 'REORG.TODO/sysdeps/i386/strcspn.S')
| -rw-r--r-- | REORG.TODO/sysdeps/i386/strcspn.S | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/i386/strcspn.S b/REORG.TODO/sysdeps/i386/strcspn.S new file mode 100644 index 0000000000..c852a3b1e5 --- /dev/null +++ b/REORG.TODO/sysdeps/i386/strcspn.S @@ -0,0 +1,240 @@ +/* strcspn (str, ss) -- Return the length of the initial segment of STR + which contains no characters from SS. + For Intel 80x86, x>=3. + Copyright (C) 1994-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu> + Bug fixes by Alan Modra <Alan@SPRI.Levels.UniSA.Edu.Au> + + 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 + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include "asm-syntax.h" + +#define PARMS 4 /* no space for saved regs */ +#define STR PARMS +#define STOP STR+4 + + .text +ENTRY (strcspn) + + movl STR(%esp), %edx + movl STOP(%esp), %eax + + /* 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. */ + +/* Don't change the "testb $0xff,%%cl" to "testb %%cl,%%cl". We want + longer instructions so that the next loop aligns without adding nops. */ + +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 + But as a sign that the character 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. */ + +L(3): addl $4, %eax /* adjust pointer for full loop round */ + + movb (%eax), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */ + je L(4) /* yes => return */ + + movb 1(%eax), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */ + je L(5) /* yes => return */ + + movb 2(%eax), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */ + je L(6) /* yes => return */ + + movb 3(%eax), %cl /* get byte from string */ + cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */ + jne L(3) /* yes => return */ + + incl %eax /* adjust pointer */ +L(6): incl %eax +L(5): incl %eax + +L(4): addl $256, %esp /* remove stopset */ + cfi_adjust_cfa_offset (-256) + subl %edx, %eax /* we have to return the number of valid + characters, so compute distance to first + non-valid character */ + ret +END (strcspn) +libc_hidden_builtin_def (strcspn) |