[PATCH v5 05/18] riscv: Add RVV memcpy for multiarch and non-multiarch
Yao Zihong
zihong.plct@isrc.iscas.ac.cn
Tue Feb 3 15:05:29 GMT 2026
Co-authored-by: Hau Hsu <hau.hsu@sifive.com>
Co-authored-by: Jerry Shih <jerry.shih@sifive.com>
Signed-off-by: Yao Zihong <zihong.plct@isrc.iscas.ac.cn>
---
.../riscv/multiarch/dl-symbol-redir-ifunc.h | 1 +
sysdeps/riscv/multiarch/memcpy-vector.S | 24 +++++++++
sysdeps/riscv/rvv/memcpy.S | 54 +++++++++++++++++++
.../unix/sysv/linux/riscv/multiarch/Makefile | 1 +
.../linux/riscv/multiarch/ifunc-impl-list.c | 2 +
.../unix/sysv/linux/riscv/multiarch/memcpy.c | 5 ++
6 files changed, 87 insertions(+)
create mode 100644 sysdeps/riscv/multiarch/memcpy-vector.S
create mode 100644 sysdeps/riscv/rvv/memcpy.S
diff --git a/sysdeps/riscv/multiarch/dl-symbol-redir-ifunc.h b/sysdeps/riscv/multiarch/dl-symbol-redir-ifunc.h
index 24b78711e3..230623a068 100644
--- a/sysdeps/riscv/multiarch/dl-symbol-redir-ifunc.h
+++ b/sysdeps/riscv/multiarch/dl-symbol-redir-ifunc.h
@@ -20,6 +20,7 @@
#define _DL_IFUNC_GENERIC_H
#ifndef SHARED
+asm ("memcpy = __memcpy_generic");
asm ("memset = __memset_generic");
#endif
diff --git a/sysdeps/riscv/multiarch/memcpy-vector.S b/sysdeps/riscv/multiarch/memcpy-vector.S
new file mode 100644
index 0000000000..97b80b8069
--- /dev/null
+++ b/sysdeps/riscv/multiarch/memcpy-vector.S
@@ -0,0 +1,24 @@
+/* Re-include the RISC-V RVV based memcpy implementation.
+ Copyright (C) 2026 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/>. */
+
+#if IS_IN(libc)
+# define MEMCPY __memcpy_vector
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(name)
+# include <sysdeps/riscv/rvv/memcpy.S>
+#endif
diff --git a/sysdeps/riscv/rvv/memcpy.S b/sysdeps/riscv/rvv/memcpy.S
new file mode 100644
index 0000000000..b4d600c59d
--- /dev/null
+++ b/sysdeps/riscv/rvv/memcpy.S
@@ -0,0 +1,54 @@
+/* RISC-V RVV based memcpy.
+ Copyright (C) 2026 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>
+#include <sys/asm.h>
+
+#ifndef MEMCPY
+# define MEMCPY memcpy
+#endif
+
+#define dst a0
+#define src a1
+#define num a2
+
+#define ivl a3
+#define dst_ptr a4
+
+#define ELEM_LMUL_SETTING m8
+#define vdata v0
+
+ENTRY (MEMCPY)
+.option push
+.option arch, +v
+ mv dst_ptr, dst
+L(loop):
+ vsetvli ivl, num, e8, ELEM_LMUL_SETTING, ta, ma
+
+ vle8.v vdata, (src)
+ sub num, num, ivl
+ add src, src, ivl
+ vse8.v vdata, (dst_ptr)
+ add dst_ptr, dst_ptr, ivl
+
+ bnez num, L(loop)
+
+ ret
+.option pop
+END (MEMCPY)
+libc_hidden_builtin_def (memcpy)
diff --git a/sysdeps/unix/sysv/linux/riscv/multiarch/Makefile b/sysdeps/unix/sysv/linux/riscv/multiarch/Makefile
index 7cfb4f04dc..0bf7c8e37d 100644
--- a/sysdeps/unix/sysv/linux/riscv/multiarch/Makefile
+++ b/sysdeps/unix/sysv/linux/riscv/multiarch/Makefile
@@ -14,6 +14,7 @@ sysdep_routines += \
memcmpeq-vector \
memcpy \
memcpy-generic \
+ memcpy-vector \
memcpy_noalignment \
memset \
memset-generic \
diff --git a/sysdeps/unix/sysv/linux/riscv/multiarch/ifunc-impl-list.c b/sysdeps/unix/sysv/linux/riscv/multiarch/ifunc-impl-list.c
index 6285a3cf0f..27a7817308 100644
--- a/sysdeps/unix/sysv/linux/riscv/multiarch/ifunc-impl-list.c
+++ b/sysdeps/unix/sysv/linux/riscv/multiarch/ifunc-impl-list.c
@@ -44,6 +44,8 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
}
IFUNC_IMPL (i, name, memcpy,
+ IFUNC_IMPL_ADD (array, i, memcpy, rvv_enabled,
+ __memcpy_vector)
IFUNC_IMPL_ADD (array, i, memcpy, fast_unaligned,
__memcpy_noalignment)
IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_generic))
diff --git a/sysdeps/unix/sysv/linux/riscv/multiarch/memcpy.c b/sysdeps/unix/sysv/linux/riscv/multiarch/memcpy.c
index f096693431..11919d815a 100644
--- a/sysdeps/unix/sysv/linux/riscv/multiarch/memcpy.c
+++ b/sysdeps/unix/sysv/linux/riscv/multiarch/memcpy.c
@@ -32,11 +32,16 @@ extern __typeof (__redirect_memcpy) __libc_memcpy;
extern __typeof (__redirect_memcpy) __memcpy_generic attribute_hidden;
extern __typeof (__redirect_memcpy) __memcpy_noalignment attribute_hidden;
+extern __typeof (__redirect_memcpy) __memcpy_vector attribute_hidden;
static inline __typeof (__redirect_memcpy) *
select_memcpy_ifunc (uint64_t dl_hwcap, __riscv_hwprobe_t hwprobe_func)
{
unsigned long long int v;
+ if (__riscv_hwprobe_one (hwprobe_func, RISCV_HWPROBE_KEY_IMA_EXT_0, &v) == 0
+ && (v & RISCV_HWPROBE_IMA_V) == RISCV_HWPROBE_IMA_V)
+ return __memcpy_vector;
+
if (__riscv_hwprobe_one (hwprobe_func, RISCV_HWPROBE_KEY_CPUPERF_0, &v) == 0
&& (v & RISCV_HWPROBE_MISALIGNED_MASK) == RISCV_HWPROBE_MISALIGNED_FAST)
return __memcpy_noalignment;
--
2.47.3
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