Commit 4d1e7918 authored by Eugeniy Paltsev's avatar Eugeniy Paltsev Committed by Vineet Gupta
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ARCv2: lib: introduce memcpy optimized for unaligned access 



Optimise code to use efficient unaligned memory access which is
available on ARCv2. This allows us to really simplify memcpy code
and speed up the code one and a half times (in case of unaligned
source or destination).

Don't wire it up yet !

Signed-off-by: default avatarEugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 5d4ab8d0

arch/arc/lib/memcpy-archs-unaligned.S

0 → 100644
+47 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0+ */

/*

 * ARCv2 memcpy implementation optimized for unaligned memory access using.

 *

 * Copyright (C) 2019 Synopsys

 * Author: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>

 */



#include <linux/linkage.h>



#ifdef CONFIG_ARC_HAS_LL64

# define LOADX(DST,RX)		ldd.ab	DST, [RX, 8]

# define STOREX(SRC,RX)		std.ab	SRC, [RX, 8]

# define ZOLSHFT		5

# define ZOLAND			0x1F

#else

# define LOADX(DST,RX)		ld.ab	DST, [RX, 4]

# define STOREX(SRC,RX)		st.ab	SRC, [RX, 4]

# define ZOLSHFT		4

# define ZOLAND			0xF

#endif



ENTRY_CFI(memcpy)

	mov	r3, r0		; don;t clobber ret val



	lsr.f	lp_count, r2, ZOLSHFT

	lpnz	@.Lcopy32_64bytes

	;; LOOP START

	LOADX	(r6, r1)

	LOADX	(r8, r1)

	LOADX	(r10, r1)

	LOADX	(r4, r1)

	STOREX	(r6, r3)

	STOREX	(r8, r3)

	STOREX	(r10, r3)

	STOREX	(r4, r3)

.Lcopy32_64bytes:



	and.f	lp_count, r2, ZOLAND ;Last remaining 31 bytes

	lpnz	@.Lcopyremainingbytes

	;; LOOP START

	ldb.ab	r5, [r1, 1]

	stb.ab	r5, [r3, 1]

.Lcopyremainingbytes:



	j	[blink]

END_CFI(memcpy)

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