From e6f3fe362f1aab78b1448d69ecdbd9e3872636d3 Mon Sep 17 00:00:00 2001 From: Wilco Dijkstra Date: Wed, 26 Oct 2022 14:16:50 +0100 Subject: [PATCH] aarch64: Use memcpy_simd as the default memcpy Since __memcpy_simd is the fastest memcpy on almost all cores, replace the generic memcpy with it. If SVE is available, a SVE memcpy will be used by default (including for Neoverse N2). --- sysdeps/aarch64/memcpy.S | 192 +++++++-------- sysdeps/aarch64/multiarch/Makefile | 1 - sysdeps/aarch64/multiarch/ifunc-impl-list.c | 2 - sysdeps/aarch64/multiarch/memcpy.c | 4 - sysdeps/aarch64/multiarch/memcpy_advsimd.S | 248 -------------------- sysdeps/aarch64/multiarch/memmove.c | 4 - 6 files changed, 81 insertions(+), 370 deletions(-) delete mode 100644 sysdeps/aarch64/multiarch/memcpy_advsimd.S diff --git a/sysdeps/aarch64/memcpy.S b/sysdeps/aarch64/memcpy.S index 98d4e2c0e2..7b396b202f 100644 --- a/sysdeps/aarch64/memcpy.S +++ b/sysdeps/aarch64/memcpy.S @@ -1,4 +1,5 @@ -/* Copyright (C) 2012-2022 Free Software Foundation, Inc. +/* Generic optimized memcpy using SIMD. + Copyright (C) 2012-2022 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -20,7 +21,7 @@ /* Assumptions: * - * ARMv8-a, AArch64, unaligned accesses. + * ARMv8-a, AArch64, Advanced SIMD, unaligned accesses. * */ @@ -36,21 +37,18 @@ #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 -#define E_l x14 -#define E_h x15 -#define F_l x16 -#define F_h x17 -#define G_l count -#define G_h dst -#define H_l src -#define H_h srcend #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 + #ifndef MEMMOVE # define MEMMOVE memmove #endif @@ -69,10 +67,9 @@ 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. -*/ + from the end. */ -ENTRY_ALIGN (MEMCPY, 6) +ENTRY (MEMCPY) PTR_ARG (0) PTR_ARG (1) SIZE_ARG (2) @@ -87,10 +84,10 @@ ENTRY_ALIGN (MEMCPY, 6) /* 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] + ldr A_q, [src] + ldr B_q, [srcend, -16] + str A_q, [dstin] + str B_q, [dstend, -16] ret /* Copy 8-15 bytes. */ @@ -102,7 +99,6 @@ L(copy16): str A_h, [dstend, -8] ret - .p2align 3 /* Copy 4-7 bytes. */ L(copy8): tbz count, 2, L(copy4) @@ -128,87 +124,69 @@ L(copy0): .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] + ldp A_q, B_q, [src] + ldp C_q, D_q, [srcend, -32] 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] + stp A_q, B_q, [dstin] + stp C_q, D_q, [dstend, -32] ret .p2align 4 /* Copy 65..128 bytes. */ L(copy128): - ldp E_l, E_h, [src, 32] - ldp F_l, F_h, [src, 48] + ldp E_q, F_q, [src, 32] 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] + ldp G_q, H_q, [srcend, -64] + stp G_q, H_q, [dstend, -64] 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 C_l, C_h, [dstend, -32] - stp D_l, D_h, [dstend, -16] + stp A_q, B_q, [dstin] + stp E_q, F_q, [dstin, 32] + stp C_q, D_q, [dstend, -32] ret - .p2align 4 + /* Align loop64 below to 16 bytes. */ + nop + /* 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 - sub src, src, tmp1 + /* 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_l, A_h, [src, 16] - stp D_l, D_h, [dstin] - ldp B_l, B_h, [src, 32] - ldp C_l, C_h, [src, 48] - ldp D_l, D_h, [src, 64]! + 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_l, A_h, [dst, 16] - ldp A_l, A_h, [src, 16] - stp B_l, B_h, [dst, 32] - ldp B_l, B_h, [src, 32] - stp C_l, C_h, [dst, 48] - ldp C_l, C_h, [src, 48] - stp D_l, D_h, [dst, 64]! - ldp D_l, D_h, [src, 64]! + 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_l, E_h, [srcend, -64] - stp A_l, A_h, [dst, 16] - ldp A_l, A_h, [srcend, -48] - stp B_l, B_h, [dst, 32] - ldp B_l, B_h, [srcend, -32] - stp C_l, C_h, [dst, 48] - ldp C_l, C_h, [srcend, -16] - stp D_l, D_h, [dst, 64] - stp E_l, E_h, [dstend, -64] - stp A_l, A_h, [dstend, -48] - stp B_l, B_h, [dstend, -32] - stp C_l, C_h, [dstend, -16] + 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) libc_hidden_builtin_def (MEMCPY) -ENTRY_ALIGN (MEMMOVE, 4) + +ENTRY (MEMMOVE) PTR_ARG (0) PTR_ARG (1) SIZE_ARG (2) @@ -220,64 +198,56 @@ ENTRY_ALIGN (MEMMOVE, 4) cmp count, 32 b.hi L(copy32_128) - /* Small copies: 0..32 bytes. */ + /* Small moves: 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] + ldr A_q, [src] + ldr B_q, [srcend, -16] + str A_q, [dstin] + str B_q, [dstend, -16] ret - .p2align 4 L(move_long): /* Only use backward copy if there is an overlap. */ sub tmp1, dstin, src - cbz tmp1, L(copy0) + cbz tmp1, L(move0) 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 + 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_l, A_h, [srcend, -16] - stp D_l, D_h, [dstend, -16] - ldp B_l, B_h, [srcend, -32] - ldp C_l, C_h, [srcend, -48] - ldp D_l, D_h, [srcend, -64]! + 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_l, A_h, [dstend, -16] - ldp A_l, A_h, [srcend, -16] - stp B_l, B_h, [dstend, -32] - ldp B_l, B_h, [srcend, -32] - stp C_l, C_h, [dstend, -48] - ldp C_l, C_h, [srcend, -48] - stp D_l, D_h, [dstend, -64]! - ldp D_l, D_h, [srcend, -64]! + 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 G_l, G_h, [src, 48] - stp A_l, A_h, [dstend, -16] - ldp A_l, A_h, [src, 32] - stp B_l, B_h, [dstend, -32] - ldp B_l, B_h, [src, 16] - stp C_l, C_h, [dstend, -48] - ldp C_l, C_h, [src] - stp D_l, D_h, [dstend, -64] - stp G_l, G_h, [dstin, 48] - stp A_l, A_h, [dstin, 32] - stp B_l, B_h, [dstin, 16] - stp C_l, C_h, [dstin] + 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) diff --git a/sysdeps/aarch64/multiarch/Makefile b/sysdeps/aarch64/multiarch/Makefile index 16297192ee..223777d94e 100644 --- a/sysdeps/aarch64/multiarch/Makefile +++ b/sysdeps/aarch64/multiarch/Makefile @@ -3,7 +3,6 @@ sysdep_routines += \ memchr_generic \ memchr_nosimd \ memcpy_a64fx \ - memcpy_advsimd \ memcpy_falkor \ memcpy_generic \ memcpy_sve \ diff --git a/sysdeps/aarch64/multiarch/ifunc-impl-list.c b/sysdeps/aarch64/multiarch/ifunc-impl-list.c index c6fe149a7c..ac8980288e 100644 --- a/sysdeps/aarch64/multiarch/ifunc-impl-list.c +++ b/sysdeps/aarch64/multiarch/ifunc-impl-list.c @@ -37,7 +37,6 @@ __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, !bti, __memcpy_thunderx2) IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_falkor) - IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_simd) #if HAVE_AARCH64_SVE_ASM IFUNC_IMPL_ADD (array, i, memcpy, sve, __memcpy_a64fx) IFUNC_IMPL_ADD (array, i, memcpy, sve, __memcpy_sve) @@ -47,7 +46,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, 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) - IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_simd) #if HAVE_AARCH64_SVE_ASM IFUNC_IMPL_ADD (array, i, memmove, sve, __memmove_a64fx) IFUNC_IMPL_ADD (array, i, memmove, sve, __memmove_sve) diff --git a/sysdeps/aarch64/multiarch/memcpy.c b/sysdeps/aarch64/multiarch/memcpy.c index 0486213f08..21d954e7f3 100644 --- a/sysdeps/aarch64/multiarch/memcpy.c +++ b/sysdeps/aarch64/multiarch/memcpy.c @@ -29,7 +29,6 @@ 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; @@ -41,9 +40,6 @@ select_memcpy_ifunc (void) { INIT_ARCH (); - if (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr)) - return __memcpy_simd; - if (sve && HAVE_AARCH64_SVE_ASM) { if (IS_A64FX (midr)) diff --git a/sysdeps/aarch64/multiarch/memcpy_advsimd.S b/sysdeps/aarch64/multiarch/memcpy_advsimd.S deleted file mode 100644 index fe9beaf5ea..0000000000 --- a/sysdeps/aarch64/multiarch/memcpy_advsimd.S +++ /dev/null @@ -1,248 +0,0 @@ -/* Generic optimized memcpy using SIMD. - Copyright (C) 2020-2022 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 - . */ - -#include - -/* 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) - PTR_ARG (0) - PTR_ARG (1) - SIZE_ARG (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) - PTR_ARG (0) - PTR_ARG (1) - SIZE_ARG (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 261996ecc4..70e8eaef7c 100644 --- a/sysdeps/aarch64/multiarch/memmove.c +++ b/sysdeps/aarch64/multiarch/memmove.c @@ -29,7 +29,6 @@ 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; @@ -41,9 +40,6 @@ select_memmove_ifunc (void) { INIT_ARCH (); - if (IS_NEOVERSE_N1 (midr) || IS_NEOVERSE_N2 (midr)) - return __memmove_simd; - if (sve && HAVE_AARCH64_SVE_ASM) { if (IS_A64FX (midr)) -- 2.34.1