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73 lines
1.8 KiB
ArmAsm
73 lines
1.8 KiB
ArmAsm
/* memcpy/mempcpy/memmove implement with rep movsb
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Copyright (C) 2022-2023 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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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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<https://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#if defined USE_MULTIARCH && IS_IN (libc)
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.text
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ENTRY (__mempcpy_chk_erms)
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cmp %RDX_LP, %RCX_LP
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jb HIDDEN_JUMPTARGET (__chk_fail)
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END (__mempcpy_chk_erms)
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/* Only used to measure performance of REP MOVSB. */
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ENTRY (__mempcpy_erms)
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mov %RDI_LP, %RAX_LP
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/* Skip zero length. */
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test %RDX_LP, %RDX_LP
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jz 2f
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add %RDX_LP, %RAX_LP
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jmp L(start_movsb)
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END (__mempcpy_erms)
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ENTRY (__memmove_chk_erms)
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cmp %RDX_LP, %RCX_LP
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jb HIDDEN_JUMPTARGET (__chk_fail)
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END (__memmove_chk_erms)
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ENTRY (__memmove_erms)
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movq %rdi, %rax
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/* Skip zero length. */
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test %RDX_LP, %RDX_LP
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jz 2f
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L(start_movsb):
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mov %RDX_LP, %RCX_LP
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cmp %RSI_LP, %RDI_LP
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jb 1f
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/* Source == destination is less common. */
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je 2f
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lea (%rsi,%rcx), %RDX_LP
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cmp %RDX_LP, %RDI_LP
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jb L(movsb_backward)
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1:
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rep movsb
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2:
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ret
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L(movsb_backward):
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leaq -1(%rdi,%rcx), %rdi
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leaq -1(%rsi,%rcx), %rsi
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std
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rep movsb
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cld
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ret
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END (__memmove_erms)
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strong_alias (__memmove_erms, __memcpy_erms)
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strong_alias (__memmove_chk_erms, __memcpy_chk_erms)
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#endif
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