From 525de033a9d19bc79ce353745d14927a793dd4e8 Mon Sep 17 00:00:00 2001 From: Xuelei Zhang Date: Thu, 19 Dec 2019 15:26:33 +0000 Subject: aarch64: Optimized memset for Kunpeng processor. Due to the branch prediction issue of Kunpeng processor, we found memset_generic has poor performance on middle sizes setting, and so we reconstructed the logic, expanded the loop by 4 times in set_long to solve the problem, even when setting below 1K sizes have benefit. Another change is that DZ_ZVA seems no work when setting zero, so we discarded it and used set_long to set zero instead. Fewer branches and predictions also make the zero case have slightly improvement. Checked on aarch64-linux-gnu. Reviewed-by: Wilco Dijkstra --- sysdeps/aarch64/multiarch/Makefile | 2 +- sysdeps/aarch64/multiarch/ifunc-impl-list.c | 1 + sysdeps/aarch64/multiarch/memset.c | 5 +- sysdeps/aarch64/multiarch/memset_kunpeng.S | 113 ++++++++++++++++++++++++++++ 4 files changed, 119 insertions(+), 2 deletions(-) create mode 100644 sysdeps/aarch64/multiarch/memset_kunpeng.S (limited to 'sysdeps/aarch64') diff --git a/sysdeps/aarch64/multiarch/Makefile b/sysdeps/aarch64/multiarch/Makefile index 4150b89a90..8378107c78 100644 --- a/sysdeps/aarch64/multiarch/Makefile +++ b/sysdeps/aarch64/multiarch/Makefile @@ -1,7 +1,7 @@ ifeq ($(subdir),string) sysdep_routines += memcpy_generic memcpy_thunderx memcpy_thunderx2 \ memcpy_falkor memmove_falkor \ - memset_generic memset_falkor memset_emag \ + memset_generic memset_falkor memset_emag memset_kunpeng \ memchr_generic memchr_nosimd \ strlen_generic strlen_asimd endif diff --git a/sysdeps/aarch64/multiarch/ifunc-impl-list.c b/sysdeps/aarch64/multiarch/ifunc-impl-list.c index be13b916e5..bcbd90d0c4 100644 --- a/sysdeps/aarch64/multiarch/ifunc-impl-list.c +++ b/sysdeps/aarch64/multiarch/ifunc-impl-list.c @@ -53,6 +53,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, can do a comparative analysis with __memset_generic. */ IFUNC_IMPL_ADD (array, i, memset, (zva_size == 64), __memset_falkor) IFUNC_IMPL_ADD (array, i, memset, (zva_size == 64), __memset_emag) + IFUNC_IMPL_ADD (array, i, memset, 1, __memset_kunpeng) IFUNC_IMPL_ADD (array, i, memset, 1, __memset_generic)) IFUNC_IMPL (i, name, memchr, IFUNC_IMPL_ADD (array, i, memchr, 1, __memchr_nosimd) diff --git a/sysdeps/aarch64/multiarch/memset.c b/sysdeps/aarch64/multiarch/memset.c index e9cdd385f2..4cc34b9b99 100644 --- a/sysdeps/aarch64/multiarch/memset.c +++ b/sysdeps/aarch64/multiarch/memset.c @@ -30,10 +30,13 @@ extern __typeof (__redirect_memset) __libc_memset; extern __typeof (__redirect_memset) __memset_falkor attribute_hidden; extern __typeof (__redirect_memset) __memset_emag attribute_hidden; +extern __typeof (__redirect_memset) __memset_kunpeng attribute_hidden; extern __typeof (__redirect_memset) __memset_generic attribute_hidden; libc_ifunc (__libc_memset, - ((IS_FALKOR (midr) || IS_PHECDA (midr)) && zva_size == 64 + IS_KUNPENG (midr) + ?__memset_kunpeng + : ((IS_FALKOR (midr) || IS_PHECDA (midr)) && zva_size == 64 ? __memset_falkor : (IS_EMAG (midr) && zva_size == 64 ? __memset_emag diff --git a/sysdeps/aarch64/multiarch/memset_kunpeng.S b/sysdeps/aarch64/multiarch/memset_kunpeng.S new file mode 100644 index 0000000000..a03441ae72 --- /dev/null +++ b/sysdeps/aarch64/multiarch/memset_kunpeng.S @@ -0,0 +1,113 @@ +/* Optimized memset for Huawei Kunpeng processor. + Copyright (C) 2012-2019 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 +#include + +#if IS_IN (libc) +# define MEMSET __memset_kunpeng + +/* Assumptions: + * + * ARMv8-a, AArch64, unaligned accesses + * + */ + +ENTRY_ALIGN (MEMSET, 6) + + DELOUSE (0) + DELOUSE (2) + + dup v0.16B, valw + add dstend, dstin, count + + cmp count, 128 + b.hs L(set_long) + + cmp count, 16 + b.lo L(less16) + + /* Set 16..127 bytes. */ + str q0, [dstin] + tbnz count, 6, L(set127) + str q0, [dstend, -16] + tbz count, 5, 1f + str q0, [dstin, 16] + str q0, [dstend, -32] +1: ret + + .p2align 4 + /* Set 64..127 bytes. Write 64 bytes from the start and + 64 bytes from the end. */ +L(set127): + stp q0, q0, [dstin, 16] + str q0, [dstin, 48] + stp q0, q0, [dstend, -64] + stp q0, q0, [dstend, -32] + ret + + .p2align 4 + /* Set 0..15 bytes. */ +L(less16): + tbz count, 3, L(less8) + str d0, [dstin] + str d0, [dstend, -8] + ret +L(less8): + tbz count, 2, 2f + str s0, [dstin] + str s0, [dstend, -4] + ret +2: cbz count, 3f + str b0, [dstin] + tbz count, 1, 3f + str h0, [dstend, -2] +3: ret + + .p2align 4 +L(set_long): + bic dst, dstin, 15 + str q0, [dstin] + sub count, dstend, dst /* Count is 16 too large. */ + sub dst, dst, 16 /* Dst is biased by -32. */ + sub count, count, 64 + 16 + 1 /* Adjust count and bias for loop. */ +1: stp q0, q0, [dst, 32] + stp q0, q0, [dst, 64]! + subs count, count, 64 + b.lo 1f + stp q0, q0, [dst, 32] + stp q0, q0, [dst, 64]! + subs count, count, 64 + b.lo 1f + stp q0, q0, [dst, 32] + stp q0, q0, [dst, 64]! + subs count, count, 64 + b.lo 1f + stp q0, q0, [dst, 32] + stp q0, q0, [dst, 64]! + subs count, count, 64 + b.hs 1b + +1: stp q0, q0, [dstend, -64] + stp q0, q0, [dstend, -32] + ret + +END (MEMSET) +libc_hidden_builtin_def (MEMSET) +#endif -- cgit 1.4.1