59 lines
1.5 KiB
ArmAsm
59 lines
1.5 KiB
ArmAsm
/* Copyright (C) 2000-2022 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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/* Finds length of a 0-terminated string. */
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#include <sysdep.h>
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.arch ev6
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.set noreorder
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.set noat
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ENTRY(strlen)
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#ifdef PROF
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ldgp gp, 0(pv)
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lda AT, _mcount
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jsr AT, (AT), _mcount
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.prologue 1
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#else
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.prologue 0
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#endif
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ldq_u $1, 0($16) # L : load first quadword ($16 may be misaligned)
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lda $2, -1($31) # E :
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insqh $2, $16, $2 # U :
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andnot $16, 7, $0 # E :
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or $2, $1, $1 # E :
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cmpbge $31, $1, $2 # E : $2 <- bitmask: bit i == 1 <==> i-th byte == 0
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nop # E :
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bne $2, $found # U :
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$loop: ldq $1, 8($0) # L :
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addq $0, 8, $0 # E : addr += 8
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cmpbge $31, $1, $2 # E :
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beq $2, $loop # U :
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$found:
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cttz $2, $3 # U0 :
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addq $0, $3, $0 # E :
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subq $0, $16, $0 # E :
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ret $31, ($26) # L0 :
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END(strlen)
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libc_hidden_builtin_def (strlen)
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