This is an automated email from the ASF dual-hosted git repository.
chenBright pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/brpc.git
The following commit(s) were added to refs/heads/master by this push:
new 72f7f297 iobuf: add RISC-V Vector (RVV) optimized memcpy for cp()
(#3375)
72f7f297 is described below
commit 72f7f297eb4c90d0472c627845973cf787eb3fe2
Author: Felix-Gong <[email protected]>
AuthorDate: Sun Jul 12 22:43:41 2026 +0800
iobuf: add RISC-V Vector (RVV) optimized memcpy for cp() (#3375)
Add a RVV-accelerated cp() path for RISC-V 64-bit systems with
the Vector (RVV) extension. Uses VL-agnostic intrinsics with
LMUL=8 (e8m8) for maximum vector width.
Key design:
- Falls back to memcpy for < 64 bytes (RVV overhead threshold)
- VL-agnostic: works with any VLEN (128/256/512/1024+)
- Uses __has_include for compiler compatibility
- Guarded by __riscv && __riscv_vector && header availability
On SG2044 (rv64gcv, VLEN=128): vectorized copy processes 128
bytes per iteration with e8m8 LMUL.
Other platforms and compilers without riscv_vector.h fall back
to the existing memcpy path.
Signed-off-by: Xiaofei Gong <[email protected]>
Signed-off-by: YuanSheng <[email protected]>
---
src/butil/iobuf.cpp | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/src/butil/iobuf.cpp b/src/butil/iobuf.cpp
index 01469e22..a743f792 100644
--- a/src/butil/iobuf.cpp
+++ b/src/butil/iobuf.cpp
@@ -179,9 +179,40 @@ inline iov_function get_pwritev_func() {
#endif // ARCH_CPU_X86_64
+#if defined(__riscv) && defined(__riscv_vector) &&
__has_include(<riscv_vector.h>)
+#include <riscv_vector.h>
+
+// RVV-optimized memory copy using VL-agnostic intrinsics.
+// Uses largest available LMUL (e8m8) for maximum vector width.
+// Falls back to memcpy for small copies (< 64 bytes).
+static inline void* cp_rvv(void* __restrict dest, const void* __restrict src,
+ size_t n) {
+ if (n < 64) {
+ return memcpy(dest, src, n);
+ }
+ char* d = static_cast<char*>(dest);
+ const char* s = static_cast<const char*>(src);
+ size_t vl;
+ for (size_t i = 0; i < n; i += vl) {
+ vl = __riscv_vsetvl_e8m8(n - i);
+ vuint8m8_t data =
+ __riscv_vle8_v_u8m8(
+ reinterpret_cast<const uint8_t*>(s + i), vl);
+ __riscv_vse8_v_u8m8(
+ reinterpret_cast<uint8_t*>(d + i), data, vl);
+ }
+ return dest;
+}
+#define HAS_RVV_CP
+#endif
+
void* cp(void *__restrict dest, const void *__restrict src, size_t n) {
+#if defined(HAS_RVV_CP)
+ return cp_rvv(dest, src, n);
+#else
// memcpy in gcc 4.8 seems to be faster enough.
return memcpy(dest, src, n);
+#endif
}
// Function pointers to allocate or deallocate memory for a IOBuf::Block
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
