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* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
116 lines
4.1 KiB
ArmAsm
116 lines
4.1 KiB
ArmAsm
/* strspn (str, ss) -- Return the length of the initial segment of STR
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which contains only characters from SS.
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For AMD x86-64.
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Copyright (C) 1994-2019 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>.
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Bug fixes by Alan Modra <Alan@SPRI.Levels.UniSA.Edu.Au>.
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Adopted for x86-64 by Andreas Jaeger <aj@suse.de>.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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.text
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ENTRY (strspn)
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movq %rdi, %rdx /* Save SRC. */
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/* First we create a table with flags for all possible characters.
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For the ASCII (7bit/8bit) or ISO-8859-X character sets which are
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supported by the C string functions we have 256 characters.
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Before inserting marks for the stop characters we clear the whole
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table. */
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movq %rdi, %r8 /* Save value. */
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subq $256, %rsp /* Make space for 256 bytes. */
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cfi_adjust_cfa_offset(256)
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movl $32, %ecx /* 32*8 bytes = 256 bytes. */
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movq %rsp, %rdi
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xorl %eax, %eax /* We store 0s. */
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cld
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rep
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stosq
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movq %rsi, %rax /* Setup stopset. */
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/* For understanding the following code remember that %rcx == 0 now.
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Although all the following instruction only modify %cl we always
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have a correct zero-extended 64-bit value in %rcx. */
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.p2align 4
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L(2): movb (%rax), %cl /* get byte from stopset */
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testb %cl, %cl /* is NUL char? */
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jz L(1) /* yes => start compare loop */
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movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */
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movb 1(%rax), %cl /* get byte from stopset */
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testb $0xff, %cl /* is NUL char? */
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jz L(1) /* yes => start compare loop */
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movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */
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movb 2(%rax), %cl /* get byte from stopset */
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testb $0xff, %cl /* is NUL char? */
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jz L(1) /* yes => start compare loop */
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movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */
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movb 3(%rax), %cl /* get byte from stopset */
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addq $4, %rax /* increment stopset pointer */
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movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */
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testb $0xff, %cl /* is NUL char? */
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jnz L(2) /* no => process next dword from stopset */
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L(1): leaq -4(%rdx), %rax /* prepare loop */
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/* We use a neat trick for the following loop. Normally we would
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have to test for two termination conditions
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1. a character in the stopset was found
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and
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2. the end of the string was found
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But as a sign that the character is in the stopset we store its
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value in the table. But the value of NUL is NUL so the loop
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terminates for NUL in every case. */
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.p2align 4
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L(3): addq $4, %rax /* adjust pointer for full loop round */
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movb (%rax), %cl /* get byte from string */
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testb %cl, (%rsp,%rcx) /* is it contained in skipset? */
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jz L(4) /* no => return */
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movb 1(%rax), %cl /* get byte from string */
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testb %cl, (%rsp,%rcx) /* is it contained in skipset? */
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jz L(5) /* no => return */
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movb 2(%rax), %cl /* get byte from string */
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testb %cl, (%rsp,%rcx) /* is it contained in skipset? */
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jz L(6) /* no => return */
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movb 3(%rax), %cl /* get byte from string */
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testb %cl, (%rsp,%rcx) /* is it contained in skipset? */
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jnz L(3) /* yes => start loop again */
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incq %rax /* adjust pointer */
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L(6): incq %rax
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L(5): incq %rax
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L(4): addq $256, %rsp /* remove stopset */
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cfi_adjust_cfa_offset(-256)
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subq %rdx, %rax /* we have to return the number of valid
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characters, so compute distance to first
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non-valid character */
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ret
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END (strspn)
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libc_hidden_builtin_def (strspn)
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