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73 lines
1.2 KiB
ArmAsm
73 lines
1.2 KiB
ArmAsm
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/*
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* Copyright (C) 2004-2006 Atmel Corporation
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*
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* Based on linux/arch/arm/lib/memset.S
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* Copyright (C) 1995-2000 Russell King
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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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* ASM optimised string functions
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*/
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#include <asm/asm.h>
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/*
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* r12: void *b
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* r11: int c
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* r10: size_t len
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*
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* Returns b in r12
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*/
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.text
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.global memset
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.type memset, @function
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.align 5
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memset:
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mov r9, r12
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mov r8, r12
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or r11, r11, r11 << 8
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andl r9, 3, COH
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brne 1f
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2: or r11, r11, r11 << 16
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sub r10, 4
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brlt 5f
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/* Let's do some real work */
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4: st.w r8++, r11
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sub r10, 4
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brge 4b
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/*
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* When we get here, we've got less than 4 bytes to set. r10
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* might be negative.
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*/
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5: sub r10, -4
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reteq r12
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/* Fastpath ends here, exactly 32 bytes from memset */
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/* Handle unaligned count or pointer */
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bld r10, 1
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brcc 6f
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st.b r8++, r11
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st.b r8++, r11
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bld r10, 0
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retcc r12
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6: st.b r8++, r11
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retal r12
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/* Handle unaligned pointer */
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1: sub r10, 4
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brlt 5b
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add r10, r9
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lsl r9, 1
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add pc, r9
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st.b r8++, r11
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st.b r8++, r11
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st.b r8++, r11
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rjmp 2b
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.size memset, . - memset
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