IFUNC_IMPL (i, name, memcpy,
IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_thunderx)
IFUNC_IMPL_ADD (array, i, memcpy, !bti, __memcpy_thunderx2)
- IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_falkor)
#if HAVE_AARCH64_SVE_ASM
IFUNC_IMPL_ADD (array, i, memcpy, sve, __memcpy_a64fx)
IFUNC_IMPL_ADD (array, i, memcpy, sve, __memcpy_sve)
IFUNC_IMPL (i, name, memmove,
IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_thunderx)
IFUNC_IMPL_ADD (array, i, memmove, !bti, __memmove_thunderx2)
- IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_falkor)
#if HAVE_AARCH64_SVE_ASM
IFUNC_IMPL_ADD (array, i, memmove, sve, __memmove_a64fx)
IFUNC_IMPL_ADD (array, i, memmove, sve, __memmove_sve)
+++ /dev/null
-/* Optimized memcpy for Qualcomm Falkor processor.
- Copyright (C) 2017-2022 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, falkor, unaligned accesses. */
-
-#define dstin x0
-#define src x1
-#define count x2
-#define dst x3
-#define srcend x4
-#define dstend x5
-#define tmp1 x14
-#define A_x x6
-#define B_x x7
-#define A_w w6
-#define B_w w7
-
-#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
-#define Q_q q6
-#define S_q q22
-
-/* Copies are split into 3 main cases:
-
- 1. Small copies of up to 32 bytes
- 2. Medium copies of 33..128 bytes which are fully unrolled
- 3. Large copies of more than 128 bytes.
-
- Large copies align the source to a quad word and use an unrolled loop
- processing 64 bytes per iteration.
-
- FALKOR-SPECIFIC DESIGN:
-
- The smallest copies (32 bytes or less) focus on optimal pipeline usage,
- which is why the redundant copies of 0-3 bytes have been replaced with
- conditionals, since the former would unnecessarily break across multiple
- issue groups. The medium copy group has been enlarged to 128 bytes since
- bumping up the small copies up to 32 bytes allows us to do that without
- cost and also allows us to reduce the size of the prep code before loop64.
-
- The copy loop uses only one register q0. This is to ensure that all loads
- hit a single hardware prefetcher which can get correctly trained to prefetch
- a single stream.
-
- The non-temporal stores help optimize cache utilization. */
-
-#if IS_IN (libc)
-ENTRY (__memcpy_falkor)
-
- PTR_ARG (0)
- PTR_ARG (1)
- SIZE_ARG (2)
-
- cmp count, 32
- add srcend, src, count
- add dstend, dstin, count
- b.ls L(copy32)
- cmp count, 128
- b.hi L(copy_long)
-
- /* Medium copies: 33..128 bytes. */
-L(copy128):
- sub tmp1, count, 1
- ldr A_q, [src]
- ldr B_q, [src, 16]
- ldr C_q, [srcend, -32]
- ldr D_q, [srcend, -16]
- tbz tmp1, 6, 1f
- ldr E_q, [src, 32]
- ldr F_q, [src, 48]
- ldr G_q, [srcend, -64]
- ldr H_q, [srcend, -48]
- str G_q, [dstend, -64]
- str H_q, [dstend, -48]
- str E_q, [dstin, 32]
- str F_q, [dstin, 48]
-1:
- str A_q, [dstin]
- str B_q, [dstin, 16]
- str C_q, [dstend, -32]
- str D_q, [dstend, -16]
- ret
-
- .p2align 4
- /* Small copies: 0..32 bytes. */
-L(copy32):
- /* 16-32 */
- cmp count, 16
- b.lo 1f
- ldr A_q, [src]
- ldr B_q, [srcend, -16]
- str A_q, [dstin]
- str B_q, [dstend, -16]
- ret
- .p2align 4
-1:
- /* 8-15 */
- tbz count, 3, 1f
- ldr A_x, [src]
- ldr B_x, [srcend, -8]
- str A_x, [dstin]
- str B_x, [dstend, -8]
- ret
- .p2align 4
-1:
- /* 4-7 */
- tbz count, 2, 1f
- ldr A_w, [src]
- ldr B_w, [srcend, -4]
- str A_w, [dstin]
- str B_w, [dstend, -4]
- ret
- .p2align 4
-1:
- /* 2-3 */
- tbz count, 1, 1f
- ldrh A_w, [src]
- ldrh B_w, [srcend, -2]
- strh A_w, [dstin]
- strh B_w, [dstend, -2]
- ret
- .p2align 4
-1:
- /* 0-1 */
- tbz count, 0, 1f
- ldrb A_w, [src]
- strb A_w, [dstin]
-1:
- ret
-
- /* Align SRC to 16 bytes and copy; that way at least one of the
- accesses is aligned throughout the copy sequence.
-
- The count is off by 0 to 15 bytes, but this is OK because we trim
- off the last 64 bytes to copy off from the end. Due to this the
- loop never runs out of bounds. */
-
- .p2align 4
- nop /* Align loop64 below. */
-L(copy_long):
- ldr A_q, [src]
- sub count, count, 64 + 16
- and tmp1, src, 15
- str A_q, [dstin]
- bic src, src, 15
- sub dst, dstin, tmp1
- add count, count, tmp1
-
-L(loop64):
- ldr A_q, [src, 16]!
- str A_q, [dst, 16]
- ldr A_q, [src, 16]!
- subs count, count, 64
- str A_q, [dst, 32]
- ldr A_q, [src, 16]!
- str A_q, [dst, 48]
- ldr A_q, [src, 16]!
- str A_q, [dst, 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. */
- ldr E_q, [srcend, -64]
- str E_q, [dstend, -64]
- ldr D_q, [srcend, -48]
- str D_q, [dstend, -48]
- ldr C_q, [srcend, -32]
- str C_q, [dstend, -32]
- ldr B_q, [srcend, -16]
- str B_q, [dstend, -16]
- ret
-
-END (__memcpy_falkor)
-
-
-/* RATIONALE:
-
- The move has 4 distinct parts:
- * Small moves of 32 bytes and under.
- * Medium sized moves of 33-128 bytes (fully unrolled).
- * Large moves where the source address is higher than the destination
- (forward copies)
- * Large moves where the destination address is higher than the source
- (copy backward, or move).
-
- We use only two registers q6 and q22 for the moves and move 32 bytes at a
- time to correctly train the hardware prefetcher for better throughput.
-
- For small and medium cases memcpy is used. */
-
-ENTRY (__memmove_falkor)
-
- PTR_ARG (0)
- PTR_ARG (1)
- SIZE_ARG (2)
-
- cmp count, 32
- add srcend, src, count
- add dstend, dstin, count
- b.ls L(copy32)
- cmp count, 128
- b.ls L(copy128)
- sub tmp1, dstin, src
- ccmp tmp1, count, 2, hi
- b.lo L(move_long)
-
- /* CASE: Copy Forwards
-
- Align src 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 32 bytes per iteration and prefetches one iteration ahead. */
-
- ldr S_q, [src]
- and tmp1, src, 15
- bic src, src, 15
- sub dst, dstin, tmp1
- add count, count, tmp1 /* Count is now 16 too large. */
- ldr Q_q, [src, 16]!
- str S_q, [dstin]
- ldr S_q, [src, 16]!
- sub count, count, 32 + 32 + 16 /* Test and readjust count. */
-
- .p2align 4
-1:
- subs count, count, 32
- str Q_q, [dst, 16]
- ldr Q_q, [src, 16]!
- str S_q, [dst, 32]!
- ldr S_q, [src, 16]!
- b.hi 1b
-
- /* Copy 32 bytes from the end before writing the data prefetched in the
- last loop iteration. */
-2:
- ldr B_q, [srcend, -32]
- ldr C_q, [srcend, -16]
- str Q_q, [dst, 16]
- str S_q, [dst, 32]
- str B_q, [dstend, -32]
- str C_q, [dstend, -16]
- ret
-
- /* CASE: Copy Backwards
-
- Align srcend 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 32 bytes per iteration and prefetches one iteration ahead. */
-
- .p2align 4
- nop
- nop
-L(move_long):
- cbz tmp1, 3f /* Return early if src == dstin */
- ldr S_q, [srcend, -16]
- and tmp1, srcend, 15
- sub srcend, srcend, tmp1
- ldr Q_q, [srcend, -16]!
- str S_q, [dstend, -16]
- sub count, count, tmp1
- ldr S_q, [srcend, -16]!
- sub dstend, dstend, tmp1
- sub count, count, 32 + 32
-
-1:
- subs count, count, 32
- str Q_q, [dstend, -16]
- ldr Q_q, [srcend, -16]!
- str S_q, [dstend, -32]!
- ldr S_q, [srcend, -16]!
- b.hi 1b
-
- /* Copy 32 bytes from the start before writing the data prefetched in the
- last loop iteration. */
-
- ldr B_q, [src, 16]
- ldr C_q, [src]
- str Q_q, [dstend, -16]
- str S_q, [dstend, -32]
- str B_q, [dstin, 16]
- str C_q, [dstin]
-3: ret
-
-END (__memmove_falkor)
-#endif
projects / thirdparty / glibc.git / commitdiff
