add RVV support and optmized uncompress speed

snappy-internal.h

@@ -46,7 +46,13 @@
 #include <arm_neon.h>
 #endif
 
-#if SNAPPY_HAVE_SSSE3 || SNAPPY_HAVE_NEON
+#if SNAPPY_RVV_1 || SNAPPY_RVV_0_7
+#define SNAPPY_HAVE_RVV 1
+#include <riscv_vector.h>
+#endif
+
+
+#if SNAPPY_HAVE_SSSE3 || SNAPPY_HAVE_NEON || SNAPPY_HAVE_RVV
 #define SNAPPY_HAVE_VECTOR_BYTE_SHUFFLE 1
 #else
 #define SNAPPY_HAVE_VECTOR_BYTE_SHUFFLE 0
@@ -60,8 +66,23 @@ namespace internal {
 using V128 = __m128i;
 #elif SNAPPY_HAVE_NEON
 using V128 = uint8x16_t;
+#elif SNAPPY_HAVE_RVV
+using V128 = vuint8m1_t;
 #endif
 
+#ifdef SNAPPY_RVV_1
+#define VSETVL_E8M1 __riscv_vsetvl_e8m1
+#define VLE8_V_U8M1 __riscv_vle8_v_u8m1
+#define VSE8_V_U8M1 __riscv_vse8_v_u8m1
+#define VRGATHER_VV_U8M1 __riscv_vrgather_vv_u8m1
+#define VMV_V_X_U8M1 __riscv_vmv_v_x_u8m1
+#elif SNAPPY_RVV_0_7
+#define VSETVL_E8M1 vsetvl_e8m1
+#define VLE8_V_U8M1 vle8_v_u8m1
+#define VSE8_V_U8M1 vse8_v_u8m1
+#define VRGATHER_VV_U8M1 vrgather_vv_u8m1
+#define VMV_V_X_U8M1 vmv_v_x_u8m1
+#endif
 // Load 128 bits of integer data. `src` must be 16-byte aligned.
 inline V128 V128_Load(const V128* src);
 
@@ -110,6 +131,32 @@ inline V128 V128_Shuffle(V128 input, V128 shuffle_mask) {
 }
 
 inline V128 V128_DupChar(char c) { return vdupq_n_u8(c); }
+
+#elif SNAPPY_HAVE_RVV
+inline V128 V128_Load(const V128* src) {
+  size_t vl = VSETVL_E8M1(16); 
+  return VLE8_V_U8M1(reinterpret_cast<const uint8_t*>(src), vl);
+}
+
+inline V128 V128_LoadU(const V128* src) {
+  size_t vl = VSETVL_E8M1(16); 
+  return VLE8_V_U8M1(reinterpret_cast<const uint8_t*>(src), vl);
+}
+
+inline void V128_StoreU(V128* dst, V128 val) {
+  size_t vl = VSETVL_E8M1(16);
+  VSE8_V_U8M1(reinterpret_cast<uint8_t*>(dst), val, vl);
+}
+
+inline V128 V128_Shuffle(V128 input, V128 shuffle_mask) {
+  size_t vl = VSETVL_E8M1(16);
+  return VRGATHER_VV_U8M1(input, shuffle_mask, vl);
+}
+
+inline V128 V128_DupChar(char c) {
+  size_t vl = VSETVL_E8M1(16);
+  return VMV_V_X_U8M1(static_cast<uint8_t>(c), vl);
+}
 #endif
 #endif  // SNAPPY_HAVE_VECTOR_BYTE_SHUFFLE