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43 lines
1.1 KiB
ArmAsm
43 lines
1.1 KiB
ArmAsm
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/*
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* Based on arch/arm/lib/strchr.S
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*
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* Copyright (C) 1995-2000 Russell King
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* Copyright (C) 2013 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program 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
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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/*
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* Find the first occurrence of a character in a string.
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*
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* Parameters:
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* x0 - str
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* x1 - c
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* Returns:
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* x0 - address of first occurrence of 'c' or 0
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*/
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ENTRY(strchr)
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and w1, w1, #0xff
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1: ldrb w2, [x0], #1
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cmp w2, w1
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ccmp w2, wzr, #4, ne
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b.ne 1b
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sub x0, x0, #1
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cmp w2, w1
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csel x0, x0, xzr, eq
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ret
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ENDPROC(strchr)
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