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_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
--- /dev/null
+/* 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):
+ stp A_q, B_q, [dstend, -32]
+ ldp A_q, B_q, [srcend, -96]
+ stp C_q, D_q, [dstend, -64]
+ ldp C_q, D_q, [srcend, -128]
+ sub srcend, srcend, 64
+ sub dstend, dstend, 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)
projects / thirdparty / glibc.git / commitdiff
