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).
Signed-off-by: Eugeniy Paltsev <eugeniy.palt...@synopsys.com> --- arch/arc/lib/Makefile | 8 +++++- arch/arc/lib/memcpy-archs-unaligned.S | 47 +++++++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+), 1 deletion(-) create mode 100644 arch/arc/lib/memcpy-archs-unaligned.S diff --git a/arch/arc/lib/Makefile b/arch/arc/lib/Makefile index b1656d156097..f7537b466b23 100644 --- a/arch/arc/lib/Makefile +++ b/arch/arc/lib/Makefile @@ -8,4 +8,10 @@ lib-y := strchr-700.o strcpy-700.o strlen.o memcmp.o lib-$(CONFIG_ISA_ARCOMPACT) += memcpy-700.o memset.o strcmp.o -lib-$(CONFIG_ISA_ARCV2) += memcpy-archs.o memset-archs.o strcmp-archs.o +lib-$(CONFIG_ISA_ARCV2) += memset-archs.o strcmp-archs.o + +ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS +lib-$(CONFIG_ISA_ARCV2) +=memcpy-archs-unaligned.o +else +lib-$(CONFIG_ISA_ARCV2) +=memcpy-archs.o +endif diff --git a/arch/arc/lib/memcpy-archs-unaligned.S b/arch/arc/lib/memcpy-archs-unaligned.S new file mode 100644 index 000000000000..28993a73fdde --- /dev/null +++ b/arch/arc/lib/memcpy-archs-unaligned.S @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * ARCv2 memcpy implementation optimized for unaligned memory access using. + * + * Copyright (C) 2019 Synopsys + * Author: Eugeniy Paltsev <eugeniy.palt...@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) -- 2.14.5 _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
