diff options
Diffstat (limited to 'sysdeps/x86_64/strcat.S')
| -rw-r--r-- | sysdeps/x86_64/strcat.S | 258 |
1 files changed, 0 insertions, 258 deletions
diff --git a/sysdeps/x86_64/strcat.S b/sysdeps/x86_64/strcat.S deleted file mode 100644 index 44e6512339..0000000000 --- a/sysdeps/x86_64/strcat.S +++ /dev/null @@ -1,258 +0,0 @@ -/* strcat(dest, src) -- Append SRC on the end of DEST. - Optimized for x86-64. - Copyright (C) 2002-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Andreas Jaeger <aj@suse.de>, 2002. - - 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" - -/* Will be removed when new strcpy implementation gets merged. */ - - .text -ENTRY (strcat) - movq %rdi, %rcx /* Dest. register. */ - andl $7, %ecx /* mask alignment bits */ - movq %rdi, %rax /* Duplicate destination pointer. */ - movq $0xfefefefefefefeff,%r8 - - /* First step: Find end of destination. */ - jz 4f /* aligned => start loop */ - - neg %ecx /* We need to align to 8 bytes. */ - addl $8,%ecx - /* Search the first bytes directly. */ -0: cmpb $0x0,(%rax) /* is byte NUL? */ - je 2f /* yes => start copy */ - incq %rax /* increment pointer */ - decl %ecx - jnz 0b - - - - /* Now the source is aligned. Scan for NUL byte. */ - .p2align 4 -4: - /* First unroll. */ - movq (%rax), %rcx /* get double word (= 8 bytes) in question */ - addq $8,%rax /* adjust pointer for next word */ - movq %r8, %rdx /* magic value */ - addq %rcx, %rdx /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 3f /* highest byte is NUL => return pointer */ - xorq %rcx, %rdx /* (word+magic)^word */ - orq %r8, %rdx /* set all non-carry bits */ - incq %rdx /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jnz 3f /* found NUL => return pointer */ - - /* Second unroll. */ - movq (%rax), %rcx /* get double word (= 8 bytes) in question */ - addq $8,%rax /* adjust pointer for next word */ - movq %r8, %rdx /* magic value */ - addq %rcx, %rdx /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 3f /* highest byte is NUL => return pointer */ - xorq %rcx, %rdx /* (word+magic)^word */ - orq %r8, %rdx /* set all non-carry bits */ - incq %rdx /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jnz 3f /* found NUL => return pointer */ - - /* Third unroll. */ - movq (%rax), %rcx /* get double word (= 8 bytes) in question */ - addq $8,%rax /* adjust pointer for next word */ - movq %r8, %rdx /* magic value */ - addq %rcx, %rdx /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 3f /* highest byte is NUL => return pointer */ - xorq %rcx, %rdx /* (word+magic)^word */ - orq %r8, %rdx /* set all non-carry bits */ - incq %rdx /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jnz 3f /* found NUL => return pointer */ - - /* Fourth unroll. */ - movq (%rax), %rcx /* get double word (= 8 bytes) in question */ - addq $8,%rax /* adjust pointer for next word */ - movq %r8, %rdx /* magic value */ - addq %rcx, %rdx /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 3f /* highest byte is NUL => return pointer */ - xorq %rcx, %rdx /* (word+magic)^word */ - orq %r8, %rdx /* set all non-carry bits */ - incq %rdx /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - jz 4b /* no NUL found => continue loop */ - - .p2align 4 /* Align, it's a jump target. */ -3: subq $8,%rax /* correct pointer increment. */ - - testb %cl, %cl /* is first byte NUL? */ - jz 2f /* yes => return */ - incq %rax /* increment pointer */ - - testb %ch, %ch /* is second byte NUL? */ - jz 2f /* yes => return */ - incq %rax /* increment pointer */ - - testl $0x00ff0000, %ecx /* is third byte NUL? */ - jz 2f /* yes => return pointer */ - incq %rax /* increment pointer */ - - testl $0xff000000, %ecx /* is fourth byte NUL? */ - jz 2f /* yes => return pointer */ - incq %rax /* increment pointer */ - - shrq $32, %rcx /* look at other half. */ - - testb %cl, %cl /* is first byte NUL? */ - jz 2f /* yes => return */ - incq %rax /* increment pointer */ - - testb %ch, %ch /* is second byte NUL? */ - jz 2f /* yes => return */ - incq %rax /* increment pointer */ - - testl $0xff0000, %ecx /* is third byte NUL? */ - jz 2f /* yes => return pointer */ - incq %rax /* increment pointer */ - -2: - /* Second step: Copy source to destination. */ - - movq %rsi, %rcx /* duplicate */ - andl $7,%ecx /* mask alignment bits */ - movq %rax, %rdx /* move around */ - jz 22f /* aligned => start loop */ - - neg %ecx /* align to 8 bytes. */ - addl $8, %ecx - /* Align the source pointer. */ -21: - movb (%rsi), %al /* Fetch a byte */ - testb %al, %al /* Is it NUL? */ - movb %al, (%rdx) /* Store it */ - jz 24f /* If it was NUL, done! */ - incq %rsi - incq %rdx - decl %ecx - jnz 21b - - /* Now the sources is aligned. Unfortunatly we cannot force - to have both source and destination aligned, so ignore the - alignment of the destination. */ - .p2align 4 -22: - /* 1st unroll. */ - movq (%rsi), %rax /* Read double word (8 bytes). */ - addq $8, %rsi /* Adjust pointer for next word. */ - movq %rax, %r9 /* Save a copy for NUL finding. */ - addq %r8, %r9 /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 23f /* highest byte is NUL => return pointer */ - xorq %rax, %r9 /* (word+magic)^word */ - orq %r8, %r9 /* set all non-carry bits */ - incq %r9 /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - - jnz 23f /* found NUL => return pointer */ - - movq %rax, (%rdx) /* Write value to destination. */ - addq $8, %rdx /* Adjust pointer. */ - - /* 2nd unroll. */ - movq (%rsi), %rax /* Read double word (8 bytes). */ - addq $8, %rsi /* Adjust pointer for next word. */ - movq %rax, %r9 /* Save a copy for NUL finding. */ - addq %r8, %r9 /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 23f /* highest byte is NUL => return pointer */ - xorq %rax, %r9 /* (word+magic)^word */ - orq %r8, %r9 /* set all non-carry bits */ - incq %r9 /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - - jnz 23f /* found NUL => return pointer */ - - movq %rax, (%rdx) /* Write value to destination. */ - addq $8, %rdx /* Adjust pointer. */ - - /* 3rd unroll. */ - movq (%rsi), %rax /* Read double word (8 bytes). */ - addq $8, %rsi /* Adjust pointer for next word. */ - movq %rax, %r9 /* Save a copy for NUL finding. */ - addq %r8, %r9 /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 23f /* highest byte is NUL => return pointer */ - xorq %rax, %r9 /* (word+magic)^word */ - orq %r8, %r9 /* set all non-carry bits */ - incq %r9 /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - - jnz 23f /* found NUL => return pointer */ - - movq %rax, (%rdx) /* Write value to destination. */ - addq $8, %rdx /* Adjust pointer. */ - - /* 4th unroll. */ - movq (%rsi), %rax /* Read double word (8 bytes). */ - addq $8, %rsi /* Adjust pointer for next word. */ - movq %rax, %r9 /* Save a copy for NUL finding. */ - addq %r8, %r9 /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 23f /* highest byte is NUL => return pointer */ - xorq %rax, %r9 /* (word+magic)^word */ - orq %r8, %r9 /* set all non-carry bits */ - incq %r9 /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - - jnz 23f /* found NUL => return pointer */ - - movq %rax, (%rdx) /* Write value to destination. */ - addq $8, %rdx /* Adjust pointer. */ - jmp 22b /* Next iteration. */ - - /* Do the last few bytes. %rax contains the value to write. - The loop is unrolled twice. */ - .p2align 4 -23: - movb %al, (%rdx) /* 1st byte. */ - testb %al, %al /* Is it NUL. */ - jz 24f /* yes, finish. */ - incq %rdx /* Increment destination. */ - movb %ah, (%rdx) /* 2nd byte. */ - testb %ah, %ah /* Is it NUL?. */ - jz 24f /* yes, finish. */ - incq %rdx /* Increment destination. */ - shrq $16, %rax /* Shift... */ - jmp 23b /* and look at next two bytes in %rax. */ - - -24: - movq %rdi, %rax /* Source is return value. */ - retq -END (strcat) -libc_hidden_builtin_def (strcat) |