86 lines
2.2 KiB
ArmAsm
86 lines
2.2 KiB
ArmAsm
/*-
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* Copyright (c) 2005 Olivier Houchard
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <machine/asm.h>
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__FBSDID("$FreeBSD$");
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.syntax unified
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ENTRY(strlen)
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mov r1, #0
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/* Check that the pointer is aligned on 32 bits. */
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ands r3, r0, #3
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beq .Loop
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sub r0, r0, r3
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ldr r2, [r0]
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add r0, r0, #4
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cmp r3, #2
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blt .Ldo_3
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bgt .Ldo_1
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/* So that the N bit is set. */
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cmp r3, #0
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b .Ldo_2
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.Loop:
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ldr r2, [r0]
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add r0, r0, #4
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#ifndef __ARMEB__
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ands r3, r2, #0x000000ff
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#else
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ands r3, r2, #0xff000000
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#endif
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it ne
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addne r1, r1, #1
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.Ldo_3:
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itt ne
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#ifndef __ARMEB__
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andsne r3, r2, #0x0000ff00
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#else
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andsne r3, r2, #0x00ff0000
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#endif
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addne r1, r1, #1
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.Ldo_2:
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itt ne
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#ifndef __ARMEB__
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andsne r3, r2, #0x00ff0000
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#else
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andsne r3, r2, #0x0000ff00
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#endif
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addne r1, r1, #1
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.Ldo_1:
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ittt ne
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#ifndef __ARMEB__
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andsne r3, r2, #0xff000000
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#else
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andsne r3, r2, #0x000000ff
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#endif
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addne r1, r1, #1
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bne .Loop
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.Lexit:
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mov r0, r1
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RET
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END(strlen)
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