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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/riscv/kernel/copy-unaligned.S
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/* SPDX-License-Identifier: GPL-2.0 */

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/* Copyright (C) 2023 Rivos Inc. */

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#include <linux/linkage.h>

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#include <asm/asm.h>

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	.text

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/* void __riscv_copy_words_unaligned(void *, const void *, size_t) */

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/* Performs a memcpy without aligning buffers, using word loads and stores. */

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/* Note: The size is truncated to a multiple of 8 * SZREG */

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SYM_FUNC_START(__riscv_copy_words_unaligned)

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	andi  a4, a2, ~((8*SZREG)-1)

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	beqz  a4, 2f

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	add   a3, a1, a4

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1:

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	REG_L a4,       0(a1)

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	REG_L a5,   SZREG(a1)

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	REG_L a6, 2*SZREG(a1)

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	REG_L a7, 3*SZREG(a1)

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	REG_L t0, 4*SZREG(a1)

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	REG_L t1, 5*SZREG(a1)

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	REG_L t2, 6*SZREG(a1)

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	REG_L t3, 7*SZREG(a1)

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	REG_S a4,       0(a0)

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	REG_S a5,   SZREG(a0)

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	REG_S a6, 2*SZREG(a0)

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	REG_S a7, 3*SZREG(a0)

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	REG_S t0, 4*SZREG(a0)

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	REG_S t1, 5*SZREG(a0)

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	REG_S t2, 6*SZREG(a0)

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	REG_S t3, 7*SZREG(a0)

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	addi  a0, a0, 8*SZREG

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	addi  a1, a1, 8*SZREG

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	bltu  a1, a3, 1b

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2:

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	ret

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SYM_FUNC_END(__riscv_copy_words_unaligned)

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/* void __riscv_copy_bytes_unaligned(void *, const void *, size_t) */

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/* Performs a memcpy without aligning buffers, using only byte accesses. */

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/* Note: The size is truncated to a multiple of 8 */

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SYM_FUNC_START(__riscv_copy_bytes_unaligned)

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	andi a4, a2, ~(8-1)

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	beqz a4, 2f

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	add  a3, a1, a4

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1:

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	lb   a4, 0(a1)

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	lb   a5, 1(a1)

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	lb   a6, 2(a1)

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	lb   a7, 3(a1)

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	lb   t0, 4(a1)

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	lb   t1, 5(a1)

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	lb   t2, 6(a1)

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	lb   t3, 7(a1)

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	sb   a4, 0(a0)

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	sb   a5, 1(a0)

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	sb   a6, 2(a0)

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	sb   a7, 3(a0)

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	sb   t0, 4(a0)

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	sb   t1, 5(a0)

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	sb   t2, 6(a0)

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	sb   t3, 7(a0)

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	addi a0, a0, 8

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	addi a1, a1, 8

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	bltu a1, a3, 1b

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2:

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	ret

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SYM_FUNC_END(__riscv_copy_bytes_unaligned)

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