linux/arch/arc/lib/memcpy-archs-unaligned.S
Eugeniy Paltsev 4d1e7918aa 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: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2019-02-25 08:52:16 -08:00

48 lines
1009 B
ArmAsm

/* 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)