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Diffstat (limited to 'sysdeps/i386/strcat.S')
| -rw-r--r-- | sysdeps/i386/strcat.S | 265 |
1 files changed, 0 insertions, 265 deletions
diff --git a/sysdeps/i386/strcat.S b/sysdeps/i386/strcat.S deleted file mode 100644 index 4a26b3c528..0000000000 --- a/sysdeps/i386/strcat.S +++ /dev/null @@ -1,265 +0,0 @@ -/* strcat(dest, src) -- Append SRC on the end of DEST. - For Intel 80x86, x>=4. - Copyright (C) 1994-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Ulrich Drepper <drepper@ipd.info.uni-karlsruhe.de>. - Optimised a little 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+4 /* space for 1 saved reg */ -#define RTN PARMS -#define DEST RTN -#define SRC DEST+4 - - .text -ENTRY (strcat) - - pushl %edi /* Save callee-safe register. */ - cfi_adjust_cfa_offset (4) - - movl DEST(%esp), %edx - movl SRC(%esp), %ecx - - testb $0xff, (%ecx) /* Is source string empty? */ - jz L(8) /* yes => return */ - - /* Test the first bytes separately until destination is aligned. */ - testl $3, %edx /* destination pointer aligned? */ - jz L(1) /* yes => begin scan loop */ - testb $0xff, (%edx) /* is end of string? */ - jz L(2) /* yes => start appending */ - incl %edx /* increment source pointer */ - - testl $3, %edx /* destination pointer aligned? */ - jz L(1) /* yes => begin scan loop */ - testb $0xff, (%edx) /* is end of string? */ - jz L(2) /* yes => start appending */ - incl %edx /* increment source pointer */ - - testl $3, %edx /* destination pointer aligned? */ - jz L(1) /* yes => begin scan loop */ - testb $0xff, (%edx) /* is end of string? */ - jz L(2) /* yes => start appending */ - incl %edx /* increment source pointer */ - - /* Now we are aligned. Begin scan loop. */ - jmp L(1) - - cfi_rel_offset (edi, 0) - ALIGN(4) - -L(4): addl $16,%edx /* increment destination pointer for round */ - -L(1): movl (%edx), %eax /* get word (= 4 bytes) in question */ - movl $0xfefefeff, %edi /* magic value */ - - /* If you compare this with the algorithm in memchr.S you will - notice that here is an `xorl' statement missing. But you must - not forget that we are looking for C == 0 and `xorl $0, %eax' - is a no-op. */ - - addl %eax, %edi /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - - /* According to the algorithm we had to reverse the effect of the - XOR first and then test the overflow bits. But because the - following XOR would destroy the carry flag and it would (in a - representation with more than 32 bits) not alter then last - overflow, we can now test this condition. If no carry is signaled - no overflow must have occurred in the last byte => it was 0. */ - jnc L(3) - - /* We are only interested in carry bits that change due to the - previous add, so remove original bits */ - xorl %eax, %edi /* ((word^charmask)+magic)^(word^charmask) */ - - /* Now test for the other three overflow bits. */ - orl $0xfefefeff, %edi /* set all non-carry bits */ - incl %edi /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - - /* If at least one byte of the word is C we don't get 0 in %ecx. */ - jnz L(3) - - movl 4(%edx), %eax /* get word from source */ - movl $0xfefefeff, %edi /* magic value */ - addl %eax, %edi /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc L(5) /* highest byte is C => stop copying */ - xorl %eax, %edi /* ((word^charmask)+magic)^(word^charmask) */ - orl $0xfefefeff, %edi /* set all non-carry bits */ - incl %edi /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jnz L(5) /* one byte is NUL => stop copying */ - - movl 8(%edx), %eax /* get word from source */ - movl $0xfefefeff, %edi /* magic value */ - addl %eax, %edi /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc L(6) /* highest byte is C => stop copying */ - xorl %eax, %edi /* ((word^charmask)+magic)^(word^charmask) */ - orl $0xfefefeff, %edi /* set all non-carry bits */ - incl %edi /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jnz L(6) /* one byte is NUL => stop copying */ - - movl 12(%edx), %eax /* get word from source */ - movl $0xfefefeff, %edi /* magic value */ - addl %eax, %edi /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc L(7) /* highest byte is C => stop copying */ - xorl %eax, %edi /* ((word^charmask)+magic)^(word^charmask) */ - orl $0xfefefeff, %edi /* set all non-carry bits */ - incl %edi /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jz L(4) /* no byte is NUL => carry on copying */ - -L(7): addl $4, %edx /* adjust source pointer */ -L(6): addl $4, %edx -L(5): addl $4, %edx - -L(3): testb %al, %al /* is first byte NUL? */ - jz L(2) /* yes => start copying */ - incl %edx /* increment source pointer */ - - testb %ah, %ah /* is second byte NUL? */ - jz L(2) /* yes => start copying */ - incl %edx /* increment source pointer */ - - testl $0xff0000, %eax /* is third byte NUL? */ - jz L(2) /* yes => start copying */ - incl %edx /* increment source pointer */ - -L(2): subl %ecx, %edx /* reduce number of loop variants */ - - /* Now we have to align the source pointer. */ - testl $3, %ecx /* pointer correctly aligned? */ - jz L(29) /* yes => start copy loop */ - movb (%ecx), %al /* get first byte */ - movb %al, (%ecx,%edx) /* and store it */ - andb %al, %al /* is byte NUL? */ - jz L(8) /* yes => return */ - incl %ecx /* increment pointer */ - - testl $3, %ecx /* pointer correctly aligned? */ - jz L(29) /* yes => start copy loop */ - movb (%ecx), %al /* get first byte */ - movb %al, (%ecx,%edx) /* and store it */ - andb %al, %al /* is byte NUL? */ - jz L(8) /* yes => return */ - incl %ecx /* increment pointer */ - - testl $3, %ecx /* pointer correctly aligned? */ - jz L(29) /* yes => start copy loop */ - movb (%ecx), %al /* get first byte */ - movb %al, (%ecx,%edx) /* and store it */ - andb %al, %al /* is byte NUL? */ - jz L(8) /* yes => return */ - incl %ecx /* increment pointer */ - - /* Now we are aligned. */ - jmp L(29) /* start copy loop */ - - ALIGN(4) - -L(28): movl %eax, 12(%ecx,%edx)/* store word at destination */ - addl $16, %ecx /* adjust pointer for full round */ - -L(29): movl (%ecx), %eax /* get word from source */ - movl $0xfefefeff, %edi /* magic value */ - addl %eax, %edi /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc L(9) /* highest byte is C => stop copying */ - xorl %eax, %edi /* ((word^charmask)+magic)^(word^charmask) */ - orl $0xfefefeff, %edi /* set all non-carry bits */ - incl %edi /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jnz L(9) /* one byte is NUL => stop copying */ - movl %eax, (%ecx,%edx) /* store word to destination */ - - movl 4(%ecx), %eax /* get word from source */ - movl $0xfefefeff, %edi /* magic value */ - addl %eax, %edi /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc L(91) /* highest byte is C => stop copying */ - xorl %eax, %edi /* ((word^charmask)+magic)^(word^charmask) */ - orl $0xfefefeff, %edi /* set all non-carry bits */ - incl %edi /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jnz L(91) /* one byte is NUL => stop copying */ - movl %eax, 4(%ecx,%edx) /* store word to destination */ - - movl 8(%ecx), %eax /* get word from source */ - movl $0xfefefeff, %edi /* magic value */ - addl %eax, %edi /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc L(92) /* highest byte is C => stop copying */ - xorl %eax, %edi /* ((word^charmask)+magic)^(word^charmask) */ - orl $0xfefefeff, %edi /* set all non-carry bits */ - incl %edi /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jnz L(92) /* one byte is NUL => stop copying */ - movl %eax, 8(%ecx,%edx) /* store word to destination */ - - movl 12(%ecx), %eax /* get word from source */ - movl $0xfefefeff, %edi /* magic value */ - addl %eax, %edi /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc L(93) /* highest byte is C => stop copying */ - xorl %eax, %edi /* ((word^charmask)+magic)^(word^charmask) */ - orl $0xfefefeff, %edi /* set all non-carry bits */ - incl %edi /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jz L(28) /* no is NUL => carry on copying */ - -L(93): addl $4, %ecx /* adjust pointer */ -L(92): addl $4, %ecx -L(91): addl $4, %ecx - -L(9): movb %al, (%ecx,%edx) /* store first byte of last word */ - orb %al, %al /* is it NUL? */ - jz L(8) /* yes => return */ - - movb %ah, 1(%ecx,%edx) /* store second byte of last word */ - orb %ah, %ah /* is it NUL? */ - jz L(8) /* yes => return */ - - shrl $16, %eax /* make upper bytes accessible */ - movb %al, 2(%ecx,%edx) /* store third byte of last word */ - orb %al, %al /* is it NUL? */ - jz L(8) /* yes => return */ - - movb %ah, 3(%ecx,%edx) /* store fourth byte of last word */ - -L(8): movl DEST(%esp), %eax /* start address of destination is result */ - popl %edi /* restore saved register */ - cfi_adjust_cfa_offset (-4) - cfi_restore (edi) - - ret -END (strcat) -libc_hidden_builtin_def (strcat) |