48 lines
892 B
ArmAsm
48 lines
892 B
ArmAsm
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/*
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* Copyright (C) 2004-2006 Atmel Corporation
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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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/*
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* unsigned int csum_partial(const unsigned char *buff,
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* int len, unsigned int sum)
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*/
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.text
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.global csum_partial
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.type csum_partial,"function"
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.align 1
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csum_partial:
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/* checksum complete words, aligned or not */
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3: sub r11, 4
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brlt 5f
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4: ld.w r9, r12++
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add r10, r9
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acr r10
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sub r11, 4
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brge 4b
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/* return if we had a whole number of words */
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5: sub r11, -4
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reteq r10
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/* checksum any remaining bytes at the end */
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mov r9, 0
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mov r8, 0
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cp r11, 2
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brlt 6f
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ld.uh r9, r12++
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sub r11, 2
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breq 7f
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lsl r9, 16
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6: ld.ub r8, r12++
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lsl r8, 8
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7: or r9, r8
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add r10, r9
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acr r10
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retal r10
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.size csum_partial, . - csum_partial
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