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70fe2eb794
Implement strcspn/strpbrk/strspn IFUNC selectors in C All internal calls within libc.so can use IFUNC on x86-64 since unlike x86, x86-64 supports PC-relative addressing to access the GOT entry so that it can call via PLT without using an extra register. For libc.a, we can't use IFUNC for functions which are called before IFUNC has been initialized. Use IFUNC internally reduces the icache footprint since libc.so and other codes in the process use the same implementations. This patch uses IFUNC for strcspn/strpbrk/strspn functions within libc. * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add strcspn-sse2, strpbrk-sse2 and strspn-sse2. * sysdeps/x86_64/strcspn.S (STRPBRK_P): Removed. Check USE_AS_STRPBRK instead of STRPBRK_P. * sysdeps/x86_64/strpbrk.S (USE_AS_STRPBRK): New. * sysdeps/x86_64/multiarch/ifunc-sse4_2.h: New file. * sysdeps/x86_64/multiarch/strcspn-sse2.S: Likewise. * sysdeps/x86_64/multiarch/strcspn.c: Likewise. * sysdeps/x86_64/multiarch/strpbrk-sse2.S: Likewise. * sysdeps/x86_64/multiarch/strpbrk.c: Likewise. * sysdeps/x86_64/multiarch/strspn-sse2.S: Likewise. * sysdeps/x86_64/multiarch/strspn.c: Likewise. * sysdeps/x86_64/multiarch/strcspn.S: Removed. * sysdeps/x86_64/multiarch/strpbrk.S: Likewise. * sysdeps/x86_64/multiarch/strspn.S: Likewise. * sysdeps/x86_64/multiarch/strpbrk-c.c: Remove "#ifdef SHARED" and "#endif".
123 lines
4.2 KiB
ArmAsm
123 lines
4.2 KiB
ArmAsm
/* strcspn (str, ss) -- Return the length of the initial segment of STR
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which contains no characters from SS.
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For AMD x86-64.
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Copyright (C) 1994-2017 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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#include "asm-syntax.h"
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.text
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ENTRY (strcspn)
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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 skipset. */
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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 skipset */
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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 skipset table */
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movb 1(%rax), %cl /* get byte from skipset */
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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 skipset table */
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movb 2(%rax), %cl /* get byte from skipset */
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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 skipset table */
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movb 3(%rax), %cl /* get byte from skipset */
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addq $4, %rax /* increment skipset pointer */
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movb %cl, (%rsp,%rcx) /* set corresponding byte in skipset table */
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testb $0xff, %cl /* is NUL char? */
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jnz L(2) /* no => process next dword from skipset */
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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 skipset 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 skipset 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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cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */
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je L(4) /* yes => return */
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movb 1(%rax), %cl /* get byte from string */
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cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */
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je L(5) /* yes => return */
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movb 2(%rax), %cl /* get byte from string */
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cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */
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jz L(6) /* yes => return */
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movb 3(%rax), %cl /* get byte from string */
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cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */
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jne L(3) /* no => 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 skipset */
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cfi_adjust_cfa_offset(-256)
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#ifdef USE_AS_STRPBRK
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xorl %edx,%edx
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orb %cl, %cl /* was last character NUL? */
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cmovzq %rdx, %rax /* Yes: return NULL */
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#else
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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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#endif
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ret
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END (strcspn)
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libc_hidden_builtin_def (strcspn)
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