* [2.31 COMMITTED] AArch64: Backport memcpy improvements
@ 2020-10-14 15:36 Wilco Dijkstra
0 siblings, 0 replies; only message in thread
From: Wilco Dijkstra @ 2020-10-14 15:36 UTC (permalink / raw)
To: libc-stable; +Cc: nd
commit 4bc9918c998085800ecf5bbb3c863e66ea6252a0
Author: Wilco Dijkstra <wdijkstr@arm.com>
Date: Wed Oct 14 13:56:21 2020 +0100
AArch64: Use __memcpy_simd on Neoverse N2/V1
Add CPU detection of Neoverse N2 and Neoverse V1, and select __memcpy_simd as
the memcpy/memmove ifunc.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit e11ed9d2b4558eeacff81557dc9557001af42a6b)
commit 4722d1fb9d605e084dd0d9030a1643386c26cfdf
Author: Wilco Dijkstra <wdijkstr@arm.com>
Date: Wed Mar 11 17:15:25 2020 +0000
[AArch64] Improve integer memcpy
Further optimize integer memcpy. Small cases now include copies up
to 32 bytes. 64-128 byte copies are split into two cases to improve
performance of 64-96 byte copies. Comments have been rewritten.
(cherry picked from commit 700065132744e0dfa6d4d9142d63f6e3a1934726)
commit bea507a3f55604064e2305fdf71e80ee4f43c2d3
Author: Wilco Dijkstra <wdijkstr@arm.com>
Date: Wed Jul 15 16:58:07 2020 +0100
AArch64: Rename IS_ARES to IS_NEOVERSE_N1
Rename IS_ARES to IS_NEOVERSE_N1 since that is a bit clearer.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 0f6278a8793a5d04ea31878119eccf99f469a02d)
commit d0a5b769027b17a7000ebc58e240ddd98ae0d719
Author: Wilco Dijkstra <wdijkstr@arm.com>
Date: Fri Aug 28 17:51:40 2020 +0100
AArch64: Improve backwards memmove performance
On some microarchitectures performance of the backwards memmove improves if
the stores use STR with decreasing addresses. So change the memmove loop
in memcpy_advsimd.S to use 2x STR rather than STP.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit bd394d131c10c9ec22c6424197b79410042eed99)
commit 24a30c595958a1b23b620bc3dea62b0ab9d8f480
Author: Wilco Dijkstra <wdijkstr@arm.com>
Date: Wed Jul 15 16:55:07 2020 +0100
AArch64: Add optimized Q-register memcpy
Add a new memcpy using 128-bit Q registers - this is faster on modern
cores and reduces codesize. Similar to the generic memcpy, small cases
include copies up to 32 bytes. 64-128 byte copies are split into two
cases to improve performance of 64-96 byte copies. Large copies align
the source rather than the destination.
bench-memcpy-random is ~9% faster than memcpy_falkor on Neoverse N1,
so make this memcpy the default on N1 (on Centriq it is 15% faster than
memcpy_falkor).
Passes GLIBC regression tests.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
(cherry picked from commit 4a733bf375238a6a595033b5785cea7f27d61307)
commit 88db98fa6e427c05d202af8b3d0f1402df20c44d
Author: Wilco Dijkstra <wdijkstr@arm.com>
Date: Wed Jul 15 16:50:02 2020 +0100
AArch64: Align ENTRY to a cacheline
Given almost all uses of ENTRY are for string/memory functions,
align ENTRY to a cacheline to simplify things.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 34f0d01d5e43c7dedd002ab47f6266dfb5b79c22)
diff --git a/sysdeps/aarch64/memcpy.S b/sysdeps/aarch64/memcpy.S
index d0d47e9..e0b4c45 100644
--- a/sysdeps/aarch64/memcpy.S
+++ b/sysdeps/aarch64/memcpy.S
@@ -33,11 +33,11 @@
#define A_l x6
#define A_lw w6
#define A_h x7
-#define A_hw w7
#define B_l x8
#define B_lw w8
#define B_h x9
#define C_l x10
+#define C_lw w10
#define C_h x11
#define D_l x12
#define D_h x13
@@ -51,16 +51,6 @@
#define H_h srcend
#define tmp1 x14
-/* Copies are split into 3 main cases: small copies of up to 32 bytes,
- medium copies of 33..128 bytes which are fully unrolled. Large copies
- of more than 128 bytes align the destination and use an unrolled loop
- processing 64 bytes per iteration.
- In order to share code with memmove, small and medium copies read all
- data before writing, allowing any kind of overlap. So small, medium
- and large backwards memmoves are handled by falling through into memcpy.
- Overlapping large forward memmoves use a loop that copies backwards.
-*/
-
#ifndef MEMMOVE
# define MEMMOVE memmove
#endif
@@ -68,118 +58,115 @@
# define MEMCPY memcpy
#endif
-ENTRY_ALIGN (MEMMOVE, 6)
+/* This implementation supports both memcpy and memmove and shares most code.
+ It uses unaligned accesses and branchless sequences to keep the code small,
+ simple and improve performance.
- DELOUSE (0)
- DELOUSE (1)
- DELOUSE (2)
+ Copies are split into 3 main cases: small copies of up to 32 bytes, medium
+ copies of up to 128 bytes, and large copies. The overhead of the overlap
+ check in memmove is negligible since it is only required for large copies.
- sub tmp1, dstin, src
- cmp count, 128
- ccmp tmp1, count, 2, hi
- b.lo L(move_long)
-
- /* Common case falls through into memcpy. */
-END (MEMMOVE)
-libc_hidden_builtin_def (MEMMOVE)
-ENTRY (MEMCPY)
+ Large copies use a software pipelined loop processing 64 bytes per
+ iteration. The destination pointer is 16-byte aligned to minimize
+ unaligned accesses. The loop tail is handled by always copying 64 bytes
+ from the end.
+*/
+ENTRY_ALIGN (MEMCPY, 6)
DELOUSE (0)
DELOUSE (1)
DELOUSE (2)
- prfm PLDL1KEEP, [src]
add srcend, src, count
add dstend, dstin, count
- cmp count, 32
- b.ls L(copy32)
cmp count, 128
b.hi L(copy_long)
+ cmp count, 32
+ b.hi L(copy32_128)
- /* Medium copies: 33..128 bytes. */
+ /* Small copies: 0..32 bytes. */
+ cmp count, 16
+ b.lo L(copy16)
ldp A_l, A_h, [src]
- ldp B_l, B_h, [src, 16]
- ldp C_l, C_h, [srcend, -32]
ldp D_l, D_h, [srcend, -16]
- cmp count, 64
- b.hi L(copy128)
stp A_l, A_h, [dstin]
- stp B_l, B_h, [dstin, 16]
- stp C_l, C_h, [dstend, -32]
stp D_l, D_h, [dstend, -16]
ret
- .p2align 4
- /* Small copies: 0..32 bytes. */
-L(copy32):
- /* 16-32 bytes. */
- cmp count, 16
- b.lo 1f
- ldp A_l, A_h, [src]
- ldp B_l, B_h, [srcend, -16]
- stp A_l, A_h, [dstin]
- stp B_l, B_h, [dstend, -16]
- ret
- .p2align 4
-1:
- /* 8-15 bytes. */
- tbz count, 3, 1f
+ /* Copy 8-15 bytes. */
+L(copy16):
+ tbz count, 3, L(copy8)
ldr A_l, [src]
ldr A_h, [srcend, -8]
str A_l, [dstin]
str A_h, [dstend, -8]
ret
- .p2align 4
-1:
- /* 4-7 bytes. */
- tbz count, 2, 1f
+
+ .p2align 3
+ /* Copy 4-7 bytes. */
+L(copy8):
+ tbz count, 2, L(copy4)
ldr A_lw, [src]
- ldr A_hw, [srcend, -4]
+ ldr B_lw, [srcend, -4]
str A_lw, [dstin]
- str A_hw, [dstend, -4]
+ str B_lw, [dstend, -4]
ret
- /* Copy 0..3 bytes. Use a branchless sequence that copies the same
- byte 3 times if count==1, or the 2nd byte twice if count==2. */
-1:
- cbz count, 2f
+ /* Copy 0..3 bytes using a branchless sequence. */
+L(copy4):
+ cbz count, L(copy0)
lsr tmp1, count, 1
ldrb A_lw, [src]
- ldrb A_hw, [srcend, -1]
+ ldrb C_lw, [srcend, -1]
ldrb B_lw, [src, tmp1]
strb A_lw, [dstin]
strb B_lw, [dstin, tmp1]
- strb A_hw, [dstend, -1]
-2: ret
+ strb C_lw, [dstend, -1]
+L(copy0):
+ ret
+
+ .p2align 4
+ /* Medium copies: 33..128 bytes. */
+L(copy32_128):
+ ldp A_l, A_h, [src]
+ ldp B_l, B_h, [src, 16]
+ ldp C_l, C_h, [srcend, -32]
+ ldp D_l, D_h, [srcend, -16]
+ cmp count, 64
+ b.hi L(copy128)
+ stp A_l, A_h, [dstin]
+ stp B_l, B_h, [dstin, 16]
+ stp C_l, C_h, [dstend, -32]
+ stp D_l, D_h, [dstend, -16]
+ ret
.p2align 4
- /* Copy 65..128 bytes. Copy 64 bytes from the start and
- 64 bytes from the end. */
+ /* Copy 65..128 bytes. */
L(copy128):
ldp E_l, E_h, [src, 32]
ldp F_l, F_h, [src, 48]
+ cmp count, 96
+ b.ls L(copy96)
ldp G_l, G_h, [srcend, -64]
ldp H_l, H_h, [srcend, -48]
+ stp G_l, G_h, [dstend, -64]
+ stp H_l, H_h, [dstend, -48]
+L(copy96):
stp A_l, A_h, [dstin]
stp B_l, B_h, [dstin, 16]
stp E_l, E_h, [dstin, 32]
stp F_l, F_h, [dstin, 48]
- stp G_l, G_h, [dstend, -64]
- stp H_l, H_h, [dstend, -48]
stp C_l, C_h, [dstend, -32]
stp D_l, D_h, [dstend, -16]
ret
- /* Align DST to 16 byte alignment so that we don't cross cache line
- boundaries on both loads and stores. There are at least 128 bytes
- to copy, so copy 16 bytes unaligned and then align. The loop
- copies 64 bytes per iteration and prefetches one iteration ahead. */
-
.p2align 4
+ /* Copy more than 128 bytes. */
L(copy_long):
+ /* Copy 16 bytes and then align dst to 16-byte alignment. */
+ ldp D_l, D_h, [src]
and tmp1, dstin, 15
bic dst, dstin, 15
- ldp D_l, D_h, [src]
sub src, src, tmp1
add count, count, tmp1 /* Count is now 16 too large. */
ldp A_l, A_h, [src, 16]
@@ -188,7 +175,8 @@ L(copy_long):
ldp C_l, C_h, [src, 48]
ldp D_l, D_h, [src, 64]!
subs count, count, 128 + 16 /* Test and readjust count. */
- b.ls L(last64)
+ b.ls L(copy64_from_end)
+
L(loop64):
stp A_l, A_h, [dst, 16]
ldp A_l, A_h, [src, 16]
@@ -201,10 +189,8 @@ L(loop64):
subs count, count, 64
b.hi L(loop64)
- /* Write the last full set of 64 bytes. The remainder is at most 64
- bytes, so it is safe to always copy 64 bytes from the end even if
- there is just 1 byte left. */
-L(last64):
+ /* Write the last iteration and copy 64 bytes from the end. */
+L(copy64_from_end):
ldp E_l, E_h, [srcend, -64]
stp A_l, A_h, [dst, 16]
ldp A_l, A_h, [srcend, -48]
@@ -219,20 +205,42 @@ L(last64):
stp C_l, C_h, [dstend, -16]
ret
- .p2align 4
-L(move_long):
- cbz tmp1, 3f
+END (MEMCPY)
+libc_hidden_builtin_def (MEMCPY)
+
+ENTRY_ALIGN (MEMMOVE, 4)
+ DELOUSE (0)
+ DELOUSE (1)
+ DELOUSE (2)
add srcend, src, count
add dstend, dstin, count
+ cmp count, 128
+ b.hi L(move_long)
+ cmp count, 32
+ b.hi L(copy32_128)
- /* Align dstend to 16 byte alignment so that we don't cross cache line
- boundaries on both loads and stores. There are at least 128 bytes
- to copy, so copy 16 bytes unaligned and then align. The loop
- copies 64 bytes per iteration and prefetches one iteration ahead. */
+ /* Small copies: 0..32 bytes. */
+ cmp count, 16
+ b.lo L(copy16)
+ ldp A_l, A_h, [src]
+ ldp D_l, D_h, [srcend, -16]
+ stp A_l, A_h, [dstin]
+ stp D_l, D_h, [dstend, -16]
+ ret
- and tmp1, dstend, 15
+ .p2align 4
+L(move_long):
+ /* Only use backward copy if there is an overlap. */
+ sub tmp1, dstin, src
+ cbz tmp1, L(copy0)
+ cmp tmp1, count
+ b.hs L(copy_long)
+
+ /* Large backwards copy for overlapping copies.
+ Copy 16 bytes and then align dst to 16-byte alignment. */
ldp D_l, D_h, [srcend, -16]
+ and tmp1, dstend, 15
sub srcend, srcend, tmp1
sub count, count, tmp1
ldp A_l, A_h, [srcend, -16]
@@ -242,10 +250,9 @@ L(move_long):
ldp D_l, D_h, [srcend, -64]!
sub dstend, dstend, tmp1
subs count, count, 128
- b.ls 2f
+ b.ls L(copy64_from_start)
- nop
-1:
+L(loop64_backwards):
stp A_l, A_h, [dstend, -16]
ldp A_l, A_h, [srcend, -16]
stp B_l, B_h, [dstend, -32]
@@ -255,12 +262,10 @@ L(move_long):
stp D_l, D_h, [dstend, -64]!
ldp D_l, D_h, [srcend, -64]!
subs count, count, 64
- b.hi 1b
+ b.hi L(loop64_backwards)
- /* Write the last full set of 64 bytes. The remainder is at most 64
- bytes, so it is safe to always copy 64 bytes from the start even if
- there is just 1 byte left. */
-2:
+ /* Write the last iteration and copy 64 bytes from the start. */
+L(copy64_from_start):
ldp G_l, G_h, [src, 48]
stp A_l, A_h, [dstend, -16]
ldp A_l, A_h, [src, 32]
@@ -273,7 +278,7 @@ L(move_long):
stp A_l, A_h, [dstin, 32]
stp B_l, B_h, [dstin, 16]
stp C_l, C_h, [dstin]
-3: ret
+ ret
-END (MEMCPY)
-libc_hidden_builtin_def (MEMCPY)
+END (MEMMOVE)
+libc_hidden_builtin_def (MEMMOVE)
diff --git a/sysdeps/aarch64/multiarch/Makefile b/sysdeps/aarch64/multiarch/Makefile
index 8378107..3c5292d 100644
--- a/sysdeps/aarch64/multiarch/Makefile
+++ b/sysdeps/aarch64/multiarch/Makefile
@@ -1,5 +1,5 @@
ifeq ($(subdir),string)
-sysdep_routines += memcpy_generic memcpy_thunderx memcpy_thunderx2 \
+sysdep_routines += memcpy_generic memcpy_advsimd memcpy_thunderx memcpy_thunderx2 \
memcpy_falkor memmove_falkor \
memset_generic memset_falkor memset_emag memset_kunpeng \
memchr_generic memchr_nosimd \
diff --git a/sysdeps/aarch64/multiarch/ifunc-impl-list.c b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
index b7da62c..4b004ac 100644
--- a/sysdeps/aarch64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/aarch64/multiarch/ifunc-impl-list.c
@@ -42,11 +42,13 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_thunderx)
IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_thunderx2)
IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_falkor)
+ IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_simd)
IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_generic))
IFUNC_IMPL (i, name, memmove,
IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_thunderx)
IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_thunderx2)
IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_falkor)
+ IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_simd)
IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_generic))
IFUNC_IMPL (i, name, memset,
/* Enable this on non-falkor processors too so that other cores
diff --git a/sysdeps/aarch64/multiarch/memcpy.c b/sysdeps/aarch64/multiarch/memcpy.c
index 2fafefd..799d60c 100644
--- a/sysdeps/aarch64/multiarch/memcpy.c
+++ b/sysdeps/aarch64/multiarch/memcpy.c
@@ -29,6 +29,7 @@
extern __typeof (__redirect_memcpy) __libc_memcpy;
extern __typeof (__redirect_memcpy) __memcpy_generic attribute_hidden;
+extern __typeof (__redirect_memcpy) __memcpy_simd attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_thunderx attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_thunderx2 attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_falkor attribute_hidden;
@@ -36,11 +37,14 @@ extern __typeof (__redirect_memcpy) __memcpy_falkor attribute_hidden;
libc_ifunc (__libc_memcpy,
(IS_THUNDERX (midr)
? __memcpy_thunderx
- : (IS_FALKOR (midr) || IS_PHECDA (midr) || IS_ARES (midr) || IS_KUNPENG920 (midr)
+ : (IS_FALKOR (midr) || IS_PHECDA (midr) || IS_KUNPENG920 (midr)
? __memcpy_falkor
: (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr)
? __memcpy_thunderx2
- : __memcpy_generic))));
+ : (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr)
+ || IS_NEOVERSE_V1 (midr)
+ ? __memcpy_simd
+ : __memcpy_generic)))));
# undef memcpy
strong_alias (__libc_memcpy, memcpy);
diff --git a/sysdeps/aarch64/multiarch/memcpy_advsimd.S b/sysdeps/aarch64/multiarch/memcpy_advsimd.S
new file mode 100644
index 0000000..48bb6d7
--- /dev/null
+++ b/sysdeps/aarch64/multiarch/memcpy_advsimd.S
@@ -0,0 +1,248 @@
+/* Generic optimized memcpy using SIMD.
+ Copyright (C) 2020 Free Software Foundation, Inc.
+
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+/* Assumptions:
+ *
+ * ARMv8-a, AArch64, Advanced SIMD, unaligned accesses.
+ *
+ */
+
+#define dstin x0
+#define src x1
+#define count x2
+#define dst x3
+#define srcend x4
+#define dstend x5
+#define A_l x6
+#define A_lw w6
+#define A_h x7
+#define B_l x8
+#define B_lw w8
+#define B_h x9
+#define C_lw w10
+#define tmp1 x14
+
+#define A_q q0
+#define B_q q1
+#define C_q q2
+#define D_q q3
+#define E_q q4
+#define F_q q5
+#define G_q q6
+#define H_q q7
+
+
+/* This implementation supports both memcpy and memmove and shares most code.
+ It uses unaligned accesses and branchless sequences to keep the code small,
+ simple and improve performance.
+
+ Copies are split into 3 main cases: small copies of up to 32 bytes, medium
+ copies of up to 128 bytes, and large copies. The overhead of the overlap
+ check in memmove is negligible since it is only required for large copies.
+
+ Large copies use a software pipelined loop processing 64 bytes per
+ iteration. The destination pointer is 16-byte aligned to minimize
+ unaligned accesses. The loop tail is handled by always copying 64 bytes
+ from the end. */
+
+ENTRY (__memcpy_simd)
+ DELOUSE (0)
+ DELOUSE (1)
+ DELOUSE (2)
+
+ add srcend, src, count
+ add dstend, dstin, count
+ cmp count, 128
+ b.hi L(copy_long)
+ cmp count, 32
+ b.hi L(copy32_128)
+
+ /* Small copies: 0..32 bytes. */
+ cmp count, 16
+ b.lo L(copy16)
+ ldr A_q, [src]
+ ldr B_q, [srcend, -16]
+ str A_q, [dstin]
+ str B_q, [dstend, -16]
+ ret
+
+ /* Copy 8-15 bytes. */
+L(copy16):
+ tbz count, 3, L(copy8)
+ ldr A_l, [src]
+ ldr A_h, [srcend, -8]
+ str A_l, [dstin]
+ str A_h, [dstend, -8]
+ ret
+
+ /* Copy 4-7 bytes. */
+L(copy8):
+ tbz count, 2, L(copy4)
+ ldr A_lw, [src]
+ ldr B_lw, [srcend, -4]
+ str A_lw, [dstin]
+ str B_lw, [dstend, -4]
+ ret
+
+ /* Copy 0..3 bytes using a branchless sequence. */
+L(copy4):
+ cbz count, L(copy0)
+ lsr tmp1, count, 1
+ ldrb A_lw, [src]
+ ldrb C_lw, [srcend, -1]
+ ldrb B_lw, [src, tmp1]
+ strb A_lw, [dstin]
+ strb B_lw, [dstin, tmp1]
+ strb C_lw, [dstend, -1]
+L(copy0):
+ ret
+
+ .p2align 4
+ /* Medium copies: 33..128 bytes. */
+L(copy32_128):
+ ldp A_q, B_q, [src]
+ ldp C_q, D_q, [srcend, -32]
+ cmp count, 64
+ b.hi L(copy128)
+ stp A_q, B_q, [dstin]
+ stp C_q, D_q, [dstend, -32]
+ ret
+
+ .p2align 4
+ /* Copy 65..128 bytes. */
+L(copy128):
+ ldp E_q, F_q, [src, 32]
+ cmp count, 96
+ b.ls L(copy96)
+ ldp G_q, H_q, [srcend, -64]
+ stp G_q, H_q, [dstend, -64]
+L(copy96):
+ stp A_q, B_q, [dstin]
+ stp E_q, F_q, [dstin, 32]
+ stp C_q, D_q, [dstend, -32]
+ ret
+
+ /* Align loop64 below to 16 bytes. */
+ nop
+
+ /* Copy more than 128 bytes. */
+L(copy_long):
+ /* Copy 16 bytes and then align src to 16-byte alignment. */
+ ldr D_q, [src]
+ and tmp1, src, 15
+ bic src, src, 15
+ sub dst, dstin, tmp1
+ add count, count, tmp1 /* Count is now 16 too large. */
+ ldp A_q, B_q, [src, 16]
+ str D_q, [dstin]
+ ldp C_q, D_q, [src, 48]
+ subs count, count, 128 + 16 /* Test and readjust count. */
+ b.ls L(copy64_from_end)
+L(loop64):
+ stp A_q, B_q, [dst, 16]
+ ldp A_q, B_q, [src, 80]
+ stp C_q, D_q, [dst, 48]
+ ldp C_q, D_q, [src, 112]
+ add src, src, 64
+ add dst, dst, 64
+ subs count, count, 64
+ b.hi L(loop64)
+
+ /* Write the last iteration and copy 64 bytes from the end. */
+L(copy64_from_end):
+ ldp E_q, F_q, [srcend, -64]
+ stp A_q, B_q, [dst, 16]
+ ldp A_q, B_q, [srcend, -32]
+ stp C_q, D_q, [dst, 48]
+ stp E_q, F_q, [dstend, -64]
+ stp A_q, B_q, [dstend, -32]
+ ret
+
+END (__memcpy_simd)
+libc_hidden_builtin_def (__memcpy_simd)
+
+
+ENTRY (__memmove_simd)
+ DELOUSE (0)
+ DELOUSE (1)
+ DELOUSE (2)
+
+ add srcend, src, count
+ add dstend, dstin, count
+ cmp count, 128
+ b.hi L(move_long)
+ cmp count, 32
+ b.hi L(copy32_128)
+
+ /* Small moves: 0..32 bytes. */
+ cmp count, 16
+ b.lo L(copy16)
+ ldr A_q, [src]
+ ldr B_q, [srcend, -16]
+ str A_q, [dstin]
+ str B_q, [dstend, -16]
+ ret
+
+L(move_long):
+ /* Only use backward copy if there is an overlap. */
+ sub tmp1, dstin, src
+ cbz tmp1, L(move0)
+ cmp tmp1, count
+ b.hs L(copy_long)
+
+ /* Large backwards copy for overlapping copies.
+ Copy 16 bytes and then align srcend to 16-byte alignment. */
+L(copy_long_backwards):
+ ldr D_q, [srcend, -16]
+ and tmp1, srcend, 15
+ bic srcend, srcend, 15
+ sub count, count, tmp1
+ ldp A_q, B_q, [srcend, -32]
+ str D_q, [dstend, -16]
+ ldp C_q, D_q, [srcend, -64]
+ sub dstend, dstend, tmp1
+ subs count, count, 128
+ b.ls L(copy64_from_start)
+
+L(loop64_backwards):
+ str B_q, [dstend, -16]
+ str A_q, [dstend, -32]
+ ldp A_q, B_q, [srcend, -96]
+ str D_q, [dstend, -48]
+ str C_q, [dstend, -64]!
+ ldp C_q, D_q, [srcend, -128]
+ sub srcend, srcend, 64
+ subs count, count, 64
+ b.hi L(loop64_backwards)
+
+ /* Write the last iteration and copy 64 bytes from the start. */
+L(copy64_from_start):
+ ldp E_q, F_q, [src, 32]
+ stp A_q, B_q, [dstend, -32]
+ ldp A_q, B_q, [src]
+ stp C_q, D_q, [dstend, -64]
+ stp E_q, F_q, [dstin, 32]
+ stp A_q, B_q, [dstin]
+L(move0):
+ ret
+
+END (__memmove_simd)
+libc_hidden_builtin_def (__memmove_simd)
diff --git a/sysdeps/aarch64/multiarch/memmove.c b/sysdeps/aarch64/multiarch/memmove.c
index ed5a47f..46a4cb3 100644
--- a/sysdeps/aarch64/multiarch/memmove.c
+++ b/sysdeps/aarch64/multiarch/memmove.c
@@ -29,6 +29,7 @@
extern __typeof (__redirect_memmove) __libc_memmove;
extern __typeof (__redirect_memmove) __memmove_generic attribute_hidden;
+extern __typeof (__redirect_memmove) __memmove_simd attribute_hidden;
extern __typeof (__redirect_memmove) __memmove_thunderx attribute_hidden;
extern __typeof (__redirect_memmove) __memmove_thunderx2 attribute_hidden;
extern __typeof (__redirect_memmove) __memmove_falkor attribute_hidden;
@@ -40,7 +41,10 @@ libc_ifunc (__libc_memmove,
? __memmove_falkor
: (IS_THUNDERX2 (midr) || IS_THUNDERX2PA (midr)
? __memmove_thunderx2
- : __memmove_generic))));
+ : (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr)
+ || IS_NEOVERSE_V1 (midr)
+ ? __memmove_simd
+ : __memmove_generic)))));
# undef memmove
strong_alias (__libc_memmove, memmove);
diff --git a/sysdeps/aarch64/sysdep.h b/sysdeps/aarch64/sysdep.h
index 604c489..f1feb19 100644
--- a/sysdeps/aarch64/sysdep.h
+++ b/sysdeps/aarch64/sysdep.h
@@ -45,7 +45,7 @@
#define ENTRY(name) \
.globl C_SYMBOL_NAME(name); \
.type C_SYMBOL_NAME(name),%function; \
- .align 4; \
+ .p2align 6; \
C_LABEL(name) \
cfi_startproc; \
CALL_MCOUNT
diff --git a/sysdeps/unix/sysv/linux/aarch64/cpu-features.h b/sysdeps/unix/sysv/linux/aarch64/cpu-features.h
index 1389cea..346d045 100644
--- a/sysdeps/unix/sysv/linux/aarch64/cpu-features.h
+++ b/sysdeps/unix/sysv/linux/aarch64/cpu-features.h
@@ -51,8 +51,12 @@
#define IS_PHECDA(midr) (MIDR_IMPLEMENTOR(midr) == 'h' \
&& MIDR_PARTNUM(midr) == 0x000)
-#define IS_ARES(midr) (MIDR_IMPLEMENTOR(midr) == 'A' \
- && MIDR_PARTNUM(midr) == 0xd0c)
+#define IS_NEOVERSE_N1(midr) (MIDR_IMPLEMENTOR(midr) == 'A' \
+ && MIDR_PARTNUM(midr) == 0xd0c)
+#define IS_NEOVERSE_N2(midr) (MIDR_IMPLEMENTOR(midr) == 'A' \
+ && MIDR_PARTNUM(midr) == 0xd49)
+#define IS_NEOVERSE_V1(midr) (MIDR_IMPLEMENTOR(midr) == 'A' \
+ && MIDR_PARTNUM(midr) == 0xd40)
#define IS_EMAG(midr) (MIDR_IMPLEMENTOR(midr) == 'P' \
&& MIDR_PARTNUM(midr) == 0x000)
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2020-10-14 15:36 [2.31 COMMITTED] AArch64: Backport memcpy improvements Wilco Dijkstra
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