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author | Andreas Jaeger <aj@suse.de> | 2002-08-31 17:45:33 +0000 |
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committer | Andreas Jaeger <aj@suse.de> | 2002-08-31 17:45:33 +0000 |
commit | 78df0fcb80247ca7573a8ed07cc992b7031674c1 (patch) | |
tree | 339b581727c7ae5782f5118bf98567acda987553 /sysdeps/x86_64/strcat.S | |
parent | 7c9466bc7688e084cfbf9311eb91bdbaed1ea888 (diff) | |
download | glibc-78df0fcb80247ca7573a8ed07cc992b7031674c1.tar.gz glibc-78df0fcb80247ca7573a8ed07cc992b7031674c1.tar.xz glibc-78df0fcb80247ca7573a8ed07cc992b7031674c1.zip |
Update.
* sysdeps/x86_64/dl-machine.h (elf_machine_runtime_setup): Declare external functions with hidden attribute. (elf_machine_rela): Optimize. * sysdeps/x86_64/memset.S: New file. * sysdeps/x86_64/bzero.S: New file. * sysdeps/x86_64/stpcpy.S: New file. * sysdeps/x86_64/strcat.S: New file. * sysdeps/x86_64/strchr.S: New file. * sysdeps/x86_64/strcpy.S: New file. * sysdeps/x86_64/strcspn.S: New file. * sysdeps/x86_64/strlen.S: New file. * sysdeps/x86_64/strpbrk.S: New file. * sysdeps/x86_64/strspn.S: New file. * sysdeps/x86_64/strcmp.S: New file. * sysdeps/x86_64/strtok_r.S: New file. * sysdeps/x86_64/strtok.S: New file. * sysdeps/x86_64/memcpy.S: New file. * sysdeps/x86_64/mempcpy.S: New file.
Diffstat (limited to 'sysdeps/x86_64/strcat.S')
-rw-r--r-- | sysdeps/x86_64/strcat.S | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/sysdeps/x86_64/strcat.S b/sysdeps/x86_64/strcat.S new file mode 100644 index 0000000000..549fd21b4a --- /dev/null +++ b/sysdeps/x86_64/strcat.S @@ -0,0 +1,257 @@ +/* strcat(dest, src) -- Append SRC on the end of DEST. + Optimized for x86-64. + Copyright (C) 2002 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, 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" + + + .text +ENTRY (BP_SYM (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 %rax, %rcx /* duplicate */ + andl $7,%ecx /* mask alignment bits */ + movq %rax, %rdx /* move around */ + jz 22f /* aligned => start loop */ + + /* 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 (BP_SYM (strcat)) |