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/Kconfig | 4 +++
arch/arc/lib/Makefile | 5 +++-
arch/arc/lib/memcpy-archs-unaligned.S | 46 +++++++++++++++++++++++++++++++++++
3 files changed, 54 insertions(+), 1 deletion(-)
create mode 100644 arch/arc/lib/memcpy-archs-unaligned.S
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index a1d976c612a6..88f1a3205b8f 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -396,6 +396,10 @@ config ARC_USE_UNALIGNED_MEM_ACCESS
which is disabled by default. Enable unaligned access in
hardware and use it in software.
+#dummy symbol for using in makefile
+config ARC_NO_UNALIGNED_MEM_ACCESS
+ def_bool !ARC_USE_UNALIGNED_MEM_ACCESS
+
config ARC_HAS_LL64
bool "Insn: 64bit LDD/STD"
help
diff --git a/arch/arc/lib/Makefile b/arch/arc/lib/Makefile
index b1656d156097..59cc8b61342e 100644
--- a/arch/arc/lib/Makefile
+++ b/arch/arc/lib/Makefile
@@ -8,4 +8,7 @@
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-$(CONFIG_ISA_ARCV2) += memset-archs.o strcmp-archs.o
+
+lib-$(CONFIG_ARC_NO_UNALIGNED_MEM_ACCESS) += memcpy-archs.o
+lib-$(CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS) += memcpy-archs-unaligned.o
diff --git a/arch/arc/lib/memcpy-archs-unaligned.S
b/arch/arc/lib/memcpy-archs-unaligned.S
new file mode 100644
index 000000000000..e09b51d4de70
--- /dev/null
+++ b/arch/arc/lib/memcpy-archs-unaligned.S
@@ -0,0 +1,46 @@
+/* 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
